From 062b894a4b6202326b9ff6f0671890237b9d4a45 Mon Sep 17 00:00:00 2001 From: Sebastien Bourdeauducq Date: Sat, 29 May 2021 14:09:11 +0800 Subject: [PATCH] use updated upstream core_io --- Cargo.lock | 27 +- Cargo.toml | 4 - libcoreio/Cargo.toml | 14 - libcoreio/src/io/buffered.rs | 1674 --------------------- libcoreio/src/io/cursor.rs | 896 ------------ libcoreio/src/io/error.rs | 551 ------- libcoreio/src/io/impls.rs | 378 ----- libcoreio/src/io/mod.rs | 2664 ---------------------------------- libcoreio/src/io/prelude.rs | 13 - libcoreio/src/io/util.rs | 269 ---- libcoreio/src/lib.rs | 51 - 11 files changed, 19 insertions(+), 6522 deletions(-) delete mode 100644 libcoreio/Cargo.toml delete mode 100644 libcoreio/src/io/buffered.rs delete mode 100644 libcoreio/src/io/cursor.rs delete mode 100644 libcoreio/src/io/error.rs delete mode 100644 libcoreio/src/io/impls.rs delete mode 100644 libcoreio/src/io/mod.rs delete mode 100644 libcoreio/src/io/prelude.rs delete mode 100644 libcoreio/src/io/util.rs delete mode 100644 libcoreio/src/lib.rs diff --git a/Cargo.lock b/Cargo.lock index 1b96ce3..9fa798c 100644 --- a/Cargo.lock +++ b/Cargo.lock @@ -38,9 +38,11 @@ checksum = "3748f82c7d366a0b4950257d19db685d4958d2fa27c6d164a3f069fec42b748b" [[package]] name = "core_io" -version = "0.1.20200410" +version = "0.1.20210325" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "97f8932064288cc79feb4d343a399d353a6f6f001e586ece47fe518a9e8507df" dependencies = [ - "memchr", + "rustc_version", ] [[package]] @@ -167,12 +169,6 @@ version = "0.7.2" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "c75de51135344a4f8ed3cfe2720dc27736f7711989703a0b43aadf3753c55577" -[[package]] -name = "memchr" -version = "2.4.0" -source = "registry+https://github.com/rust-lang/crates.io-index" -checksum = "b16bd47d9e329435e309c58469fe0791c2d0d1ba96ec0954152a5ae2b04387dc" - [[package]] name = "nb" version = "0.1.3" @@ -200,6 +196,21 @@ version = "1.0.0" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "bd7a31eed1591dcbc95d92ad7161908e72f4677f8fabf2a32ca49b4237cbf211" +[[package]] +name = "rustc_version" +version = "0.1.7" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "c5f5376ea5e30ce23c03eb77cbe4962b988deead10910c372b226388b594c084" +dependencies = [ + "semver", +] + +[[package]] +name = "semver" +version = "0.1.20" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "d4f410fedcf71af0345d7607d246e7ad15faaadd49d240ee3b24e5dc21a820ac" + [[package]] name = "smoltcp" version = "0.7.3" diff --git a/Cargo.toml b/Cargo.toml index adaf875..c23f4aa 100644 --- a/Cargo.toml +++ b/Cargo.toml @@ -6,7 +6,6 @@ members = [ "libsupport_zynq", "libasync", "libconfig", - "libcoreio", "experiments", "szl", ] @@ -19,6 +18,3 @@ opt-level = 'z' lto = true debug-assertions = false overflow-checks = false - -[patch.crates-io] -core_io = { path = "./libcoreio" } diff --git a/libcoreio/Cargo.toml b/libcoreio/Cargo.toml deleted file mode 100644 index fa6bc56..0000000 --- a/libcoreio/Cargo.toml +++ /dev/null @@ -1,14 +0,0 @@ -[package] -authors = ["M-Labs"] -name = "core_io" -version = "0.1.20200410" - -[lib] -name = "core_io" - -[dependencies] -memchr = { version = "2", default-features = false, optional = true } - -[features] -alloc = [] -collections = ["alloc", "memchr"] diff --git a/libcoreio/src/io/buffered.rs b/libcoreio/src/io/buffered.rs deleted file mode 100644 index 63d0b0d..0000000 --- a/libcoreio/src/io/buffered.rs +++ /dev/null @@ -1,1674 +0,0 @@ -//! Buffering wrappers for I/O traits - -use core::prelude::v1::*; -use crate::io::prelude::*; -use collections::vec::Vec; -use alloc::boxed::Box; - -use core::cmp; -use core::fmt; -use crate::io::{ - self, Error, ErrorKind, Initializer, SeekFrom, DEFAULT_BUF_SIZE, -}; - -/// The `BufReader` struct adds buffering to any reader. -/// -/// It can be excessively inefficient to work directly with a [`Read`] instance. -/// For example, every call to [`read`][`TcpStream::read`] on [`TcpStream`] -/// results in a system call. A `BufReader` performs large, infrequent reads on -/// the underlying [`Read`] and maintains an in-memory buffer of the results. -/// -/// `BufReader` can improve the speed of programs that make *small* and -/// *repeated* read calls to the same file or network socket. It does not -/// help when reading very large amounts at once, or reading just one or a few -/// times. It also provides no advantage when reading from a source that is -/// already in memory, like a `Vec`. -/// -/// When the `BufReader` is dropped, the contents of its buffer will be -/// discarded. Creating multiple instances of a `BufReader` on the same -/// stream can cause data loss. Reading from the underlying reader after -/// unwrapping the `BufReader` with `BufReader::into_inner` can also cause -/// data loss. -/// -/// [`Read`]: ../../std/io/trait.Read.html -/// [`TcpStream::read`]: ../../std/net/struct.TcpStream.html#method.read -/// [`TcpStream`]: ../../std/net/struct.TcpStream.html -/// -/// # Examples -/// -/// ```no_run -/// use std::io::prelude::*; -/// use std::io::BufReader; -/// use std::fs::File; -/// -/// fn main() -> std::io::Result<()> { -/// let f = File::open("log.txt")?; -/// let mut reader = BufReader::new(f); -/// -/// let mut line = String::new(); -/// let len = reader.read_line(&mut line)?; -/// println!("First line is {} bytes long", len); -/// Ok(()) -/// } -/// ``` -pub struct BufReader { - inner: R, - buf: Box<[u8]>, - pos: usize, - cap: usize, -} - -impl BufReader { - /// Creates a new `BufReader` with a default buffer capacity. The default is currently 8 KB, - /// but may change in the future. - /// - /// # Examples - /// - /// ```no_run - /// use std::io::BufReader; - /// use std::fs::File; - /// - /// fn main() -> std::io::Result<()> { - /// let f = File::open("log.txt")?; - /// let reader = BufReader::new(f); - /// Ok(()) - /// } - /// ``` - pub fn new(inner: R) -> BufReader { - BufReader::with_capacity(DEFAULT_BUF_SIZE, inner) - } - - /// Creates a new `BufReader` with the specified buffer capacity. - /// - /// # Examples - /// - /// Creating a buffer with ten bytes of capacity: - /// - /// ```no_run - /// use std::io::BufReader; - /// use std::fs::File; - /// - /// fn main() -> std::io::Result<()> { - /// let f = File::open("log.txt")?; - /// let reader = BufReader::with_capacity(10, f); - /// Ok(()) - /// } - /// ``` - pub fn with_capacity(capacity: usize, inner: R) -> BufReader { - unsafe { - let mut buffer = Vec::with_capacity(capacity); - buffer.set_len(capacity); - inner.initializer().initialize(&mut buffer); - BufReader { inner, buf: buffer.into_boxed_slice(), pos: 0, cap: 0 } - } - } -} - -impl BufReader { - /// Gets a reference to the underlying reader. - /// - /// It is inadvisable to directly read from the underlying reader. - /// - /// # Examples - /// - /// ```no_run - /// use std::io::BufReader; - /// use std::fs::File; - /// - /// fn main() -> std::io::Result<()> { - /// let f1 = File::open("log.txt")?; - /// let reader = BufReader::new(f1); - /// - /// let f2 = reader.get_ref(); - /// Ok(()) - /// } - /// ``` - pub fn get_ref(&self) -> &R { - &self.inner - } - - /// Gets a mutable reference to the underlying reader. - /// - /// It is inadvisable to directly read from the underlying reader. - /// - /// # Examples - /// - /// ```no_run - /// use std::io::BufReader; - /// use std::fs::File; - /// - /// fn main() -> std::io::Result<()> { - /// let f1 = File::open("log.txt")?; - /// let mut reader = BufReader::new(f1); - /// - /// let f2 = reader.get_mut(); - /// Ok(()) - /// } - /// ``` - pub fn get_mut(&mut self) -> &mut R { - &mut self.inner - } - - /// Returns a reference to the internally buffered data. - /// - /// Unlike `fill_buf`, this will not attempt to fill the buffer if it is empty. - /// - /// # Examples - /// - /// ```no_run - /// use std::io::{BufReader, BufRead}; - /// use std::fs::File; - /// - /// fn main() -> std::io::Result<()> { - /// let f = File::open("log.txt")?; - /// let mut reader = BufReader::new(f); - /// assert!(reader.buffer().is_empty()); - /// - /// if reader.fill_buf()?.len() > 0 { - /// assert!(!reader.buffer().is_empty()); - /// } - /// Ok(()) - /// } - /// ``` - pub fn buffer(&self) -> &[u8] { - &self.buf[self.pos..self.cap] - } - - /// Returns the number of bytes the internal buffer can hold at once. - /// - /// # Examples - /// - /// ```no_run - /// #![feature(buffered_io_capacity)] - /// use std::io::{BufReader, BufRead}; - /// use std::fs::File; - /// - /// fn main() -> std::io::Result<()> { - /// let f = File::open("log.txt")?; - /// let mut reader = BufReader::new(f); - /// - /// let capacity = reader.capacity(); - /// let buffer = reader.fill_buf()?; - /// assert!(buffer.len() <= capacity); - /// Ok(()) - /// } - /// ``` - pub fn capacity(&self) -> usize { - self.buf.len() - } - - /// Unwraps this `BufReader`, returning the underlying reader. - /// - /// Note that any leftover data in the internal buffer is lost. Therefore, - /// a following read from the underlying reader may lead to data loss. - /// - /// # Examples - /// - /// ```no_run - /// use std::io::BufReader; - /// use std::fs::File; - /// - /// fn main() -> std::io::Result<()> { - /// let f1 = File::open("log.txt")?; - /// let reader = BufReader::new(f1); - /// - /// let f2 = reader.into_inner(); - /// Ok(()) - /// } - /// ``` - pub fn into_inner(self) -> R { - self.inner - } - - /// Invalidates all data in the internal buffer. - #[inline] - fn discard_buffer(&mut self) { - self.pos = 0; - self.cap = 0; - } -} - -impl BufReader { - /// Seeks relative to the current position. If the new position lies within the buffer, - /// the buffer will not be flushed, allowing for more efficient seeks. - /// This method does not return the location of the underlying reader, so the caller - /// must track this information themselves if it is required. - pub fn seek_relative(&mut self, offset: i64) -> io::Result<()> { - let pos = self.pos as u64; - if offset < 0 { - if let Some(new_pos) = pos.checked_sub((-offset) as u64) { - self.pos = new_pos as usize; - return Ok(()); - } - } else { - if let Some(new_pos) = pos.checked_add(offset as u64) { - if new_pos <= self.cap as u64 { - self.pos = new_pos as usize; - return Ok(()); - } - } - } - self.seek(SeekFrom::Current(offset)).map(drop) - } -} - -impl Read for BufReader { - fn read(&mut self, buf: &mut [u8]) -> io::Result { - // If we don't have any buffered data and we're doing a massive read - // (larger than our internal buffer), bypass our internal buffer - // entirely. - if self.pos == self.cap && buf.len() >= self.buf.len() { - self.discard_buffer(); - return self.inner.read(buf); - } - let nread = { - let mut rem = self.fill_buf()?; - rem.read(buf)? - }; - self.consume(nread); - Ok(nread) - } - - // we can't skip unconditionally because of the large buffer case in read. - unsafe fn initializer(&self) -> Initializer { - self.inner.initializer() - } -} - -impl BufRead for BufReader { - fn fill_buf(&mut self) -> io::Result<&[u8]> { - // If we've reached the end of our internal buffer then we need to fetch - // some more data from the underlying reader. - // Branch using `>=` instead of the more correct `==` - // to tell the compiler that the pos..cap slice is always valid. - if self.pos >= self.cap { - debug_assert!(self.pos == self.cap); - self.cap = self.inner.read(&mut self.buf)?; - self.pos = 0; - } - Ok(&self.buf[self.pos..self.cap]) - } - - fn consume(&mut self, amt: usize) { - self.pos = cmp::min(self.pos + amt, self.cap); - } -} - -impl fmt::Debug for BufReader -where - R: fmt::Debug, -{ - fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { - fmt.debug_struct("BufReader") - .field("reader", &self.inner) - .field("buffer", &format_args!("{}/{}", self.cap - self.pos, self.buf.len())) - .finish() - } -} - -impl Seek for BufReader { - /// Seek to an offset, in bytes, in the underlying reader. - /// - /// The position used for seeking with `SeekFrom::Current(_)` is the - /// position the underlying reader would be at if the `BufReader` had no - /// internal buffer. - /// - /// Seeking always discards the internal buffer, even if the seek position - /// would otherwise fall within it. This guarantees that calling - /// `.into_inner()` immediately after a seek yields the underlying reader - /// at the same position. - /// - /// To seek without discarding the internal buffer, use [`BufReader::seek_relative`]. - /// - /// See [`std::io::Seek`] for more details. - /// - /// Note: In the edge case where you're seeking with `SeekFrom::Current(n)` - /// where `n` minus the internal buffer length overflows an `i64`, two - /// seeks will be performed instead of one. If the second seek returns - /// `Err`, the underlying reader will be left at the same position it would - /// have if you called `seek` with `SeekFrom::Current(0)`. - /// - /// [`BufReader::seek_relative`]: struct.BufReader.html#method.seek_relative - /// [`std::io::Seek`]: trait.Seek.html - fn seek(&mut self, pos: SeekFrom) -> io::Result { - let result: u64; - if let SeekFrom::Current(n) = pos { - let remainder = (self.cap - self.pos) as i64; - // it should be safe to assume that remainder fits within an i64 as the alternative - // means we managed to allocate 8 exbibytes and that's absurd. - // But it's not out of the realm of possibility for some weird underlying reader to - // support seeking by i64::min_value() so we need to handle underflow when subtracting - // remainder. - if let Some(offset) = n.checked_sub(remainder) { - result = self.inner.seek(SeekFrom::Current(offset))?; - } else { - // seek backwards by our remainder, and then by the offset - self.inner.seek(SeekFrom::Current(-remainder))?; - self.discard_buffer(); - result = self.inner.seek(SeekFrom::Current(n))?; - } - } else { - // Seeking with Start/End doesn't care about our buffer length. - result = self.inner.seek(pos)?; - } - self.discard_buffer(); - Ok(result) - } -} - -/// Wraps a writer and buffers its output. -/// -/// It can be excessively inefficient to work directly with something that -/// implements [`Write`]. For example, every call to -/// [`write`][`TcpStream::write`] on [`TcpStream`] results in a system call. A -/// `BufWriter` keeps an in-memory buffer of data and writes it to an underlying -/// writer in large, infrequent batches. -/// -/// `BufWriter` can improve the speed of programs that make *small* and -/// *repeated* write calls to the same file or network socket. It does not -/// help when writing very large amounts at once, or writing just one or a few -/// times. It also provides no advantage when writing to a destination that is -/// in memory, like a `Vec`. -/// -/// It is critical to call [`flush`] before `BufWriter` is dropped. Though -/// dropping will attempt to flush the the contents of the buffer, any errors -/// that happen in the process of dropping will be ignored. Calling [`flush`] -/// ensures that the buffer is empty and thus dropping will not even attempt -/// file operations. -/// -/// # Examples -/// -/// Let's write the numbers one through ten to a [`TcpStream`]: -/// -/// ```no_run -/// use std::io::prelude::*; -/// use std::net::TcpStream; -/// -/// let mut stream = TcpStream::connect("127.0.0.1:34254").unwrap(); -/// -/// for i in 0..10 { -/// stream.write(&[i+1]).unwrap(); -/// } -/// ``` -/// -/// Because we're not buffering, we write each one in turn, incurring the -/// overhead of a system call per byte written. We can fix this with a -/// `BufWriter`: -/// -/// ```no_run -/// use std::io::prelude::*; -/// use std::io::BufWriter; -/// use std::net::TcpStream; -/// -/// let mut stream = BufWriter::new(TcpStream::connect("127.0.0.1:34254").unwrap()); -/// -/// for i in 0..10 { -/// stream.write(&[i+1]).unwrap(); -/// } -/// stream.flush().unwrap(); -/// ``` -/// -/// By wrapping the stream with a `BufWriter`, these ten writes are all grouped -/// together by the buffer and will all be written out in one system call when -/// the `stream` is flushed. -/// -/// [`Write`]: ../../std/io/trait.Write.html -/// [`TcpStream::write`]: ../../std/net/struct.TcpStream.html#method.write -/// [`TcpStream`]: ../../std/net/struct.TcpStream.html -/// [`flush`]: #method.flush -pub struct BufWriter { - inner: Option, - buf: Vec, - // #30888: If the inner writer panics in a call to write, we don't want to - // write the buffered data a second time in BufWriter's destructor. This - // flag tells the Drop impl if it should skip the flush. - panicked: bool, -} - -/// An error returned by `into_inner` which combines an error that -/// happened while writing out the buffer, and the buffered writer object -/// which may be used to recover from the condition. -/// -/// # Examples -/// -/// ```no_run -/// use std::io::BufWriter; -/// use std::net::TcpStream; -/// -/// let mut stream = BufWriter::new(TcpStream::connect("127.0.0.1:34254").unwrap()); -/// -/// // do stuff with the stream -/// -/// // we want to get our `TcpStream` back, so let's try: -/// -/// let stream = match stream.into_inner() { -/// Ok(s) => s, -/// Err(e) => { -/// // Here, e is an IntoInnerError -/// panic!("An error occurred"); -/// } -/// }; -/// ``` -#[derive(Debug)] -pub struct IntoInnerError(W, Error); - -impl BufWriter { - /// Creates a new `BufWriter` with a default buffer capacity. The default is currently 8 KB, - /// but may change in the future. - /// - /// # Examples - /// - /// ```no_run - /// use std::io::BufWriter; - /// use std::net::TcpStream; - /// - /// let mut buffer = BufWriter::new(TcpStream::connect("127.0.0.1:34254").unwrap()); - /// ``` - pub fn new(inner: W) -> BufWriter { - BufWriter::with_capacity(DEFAULT_BUF_SIZE, inner) - } - - /// Creates a new `BufWriter` with the specified buffer capacity. - /// - /// # Examples - /// - /// Creating a buffer with a buffer of a hundred bytes. - /// - /// ```no_run - /// use std::io::BufWriter; - /// use std::net::TcpStream; - /// - /// let stream = TcpStream::connect("127.0.0.1:34254").unwrap(); - /// let mut buffer = BufWriter::with_capacity(100, stream); - /// ``` - pub fn with_capacity(capacity: usize, inner: W) -> BufWriter { - BufWriter { inner: Some(inner), buf: Vec::with_capacity(capacity), panicked: false } - } - - fn flush_buf(&mut self) -> io::Result<()> { - let mut written = 0; - let len = self.buf.len(); - let mut ret = Ok(()); - while written < len { - self.panicked = true; - let r = self.inner.as_mut().unwrap().write(&self.buf[written..]); - self.panicked = false; - - match r { - Ok(0) => { - ret = - Err(Error::new(ErrorKind::WriteZero, "failed to write the buffered data")); - break; - } - Ok(n) => written += n, - Err(ref e) if e.kind() == io::ErrorKind::Interrupted => {} - Err(e) => { - ret = Err(e); - break; - } - } - } - if written > 0 { - self.buf.drain(..written); - } - ret - } - - /// Gets a reference to the underlying writer. - /// - /// # Examples - /// - /// ```no_run - /// use std::io::BufWriter; - /// use std::net::TcpStream; - /// - /// let mut buffer = BufWriter::new(TcpStream::connect("127.0.0.1:34254").unwrap()); - /// - /// // we can use reference just like buffer - /// let reference = buffer.get_ref(); - /// ``` - pub fn get_ref(&self) -> &W { - self.inner.as_ref().unwrap() - } - - /// Gets a mutable reference to the underlying writer. - /// - /// It is inadvisable to directly write to the underlying writer. - /// - /// # Examples - /// - /// ```no_run - /// use std::io::BufWriter; - /// use std::net::TcpStream; - /// - /// let mut buffer = BufWriter::new(TcpStream::connect("127.0.0.1:34254").unwrap()); - /// - /// // we can use reference just like buffer - /// let reference = buffer.get_mut(); - /// ``` - pub fn get_mut(&mut self) -> &mut W { - self.inner.as_mut().unwrap() - } - - /// Returns a reference to the internally buffered data. - /// - /// # Examples - /// - /// ```no_run - /// use std::io::BufWriter; - /// use std::net::TcpStream; - /// - /// let buf_writer = BufWriter::new(TcpStream::connect("127.0.0.1:34254").unwrap()); - /// - /// // See how many bytes are currently buffered - /// let bytes_buffered = buf_writer.buffer().len(); - /// ``` - pub fn buffer(&self) -> &[u8] { - &self.buf - } - - /// Returns the number of bytes the internal buffer can hold without flushing. - /// - /// # Examples - /// - /// ```no_run - /// #![feature(buffered_io_capacity)] - /// use std::io::BufWriter; - /// use std::net::TcpStream; - /// - /// let buf_writer = BufWriter::new(TcpStream::connect("127.0.0.1:34254").unwrap()); - /// - /// // Check the capacity of the inner buffer - /// let capacity = buf_writer.capacity(); - /// // Calculate how many bytes can be written without flushing - /// let without_flush = capacity - buf_writer.buffer().len(); - /// ``` - pub fn capacity(&self) -> usize { - self.buf.capacity() - } - - /// Unwraps this `BufWriter`, returning the underlying writer. - /// - /// The buffer is written out before returning the writer. - /// - /// # Errors - /// - /// An `Err` will be returned if an error occurs while flushing the buffer. - /// - /// # Examples - /// - /// ```no_run - /// use std::io::BufWriter; - /// use std::net::TcpStream; - /// - /// let mut buffer = BufWriter::new(TcpStream::connect("127.0.0.1:34254").unwrap()); - /// - /// // unwrap the TcpStream and flush the buffer - /// let stream = buffer.into_inner().unwrap(); - /// ``` - pub fn into_inner(mut self) -> Result>> { - match self.flush_buf() { - Err(e) => Err(IntoInnerError(self, e)), - Ok(()) => Ok(self.inner.take().unwrap()), - } - } -} - -impl Write for BufWriter { - fn write(&mut self, buf: &[u8]) -> io::Result { - if self.buf.len() + buf.len() > self.buf.capacity() { - self.flush_buf()?; - } - if buf.len() >= self.buf.capacity() { - self.panicked = true; - let r = self.get_mut().write(buf); - self.panicked = false; - r - } else { - self.buf.write(buf) - } - } - - fn flush(&mut self) -> io::Result<()> { - self.flush_buf().and_then(|()| self.get_mut().flush()) - } -} - -impl fmt::Debug for BufWriter -where - W: fmt::Debug, -{ - fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { - fmt.debug_struct("BufWriter") - .field("writer", &self.inner.as_ref().unwrap()) - .field("buffer", &format_args!("{}/{}", self.buf.len(), self.buf.capacity())) - .finish() - } -} - -impl Seek for BufWriter { - /// Seek to the offset, in bytes, in the underlying writer. - /// - /// Seeking always writes out the internal buffer before seeking. - fn seek(&mut self, pos: SeekFrom) -> io::Result { - self.flush_buf().and_then(|_| self.get_mut().seek(pos)) - } -} - -impl Drop for BufWriter { - fn drop(&mut self) { - if self.inner.is_some() && !self.panicked { - // dtors should not panic, so we ignore a failed flush - let _r = self.flush_buf(); - } - } -} - -impl IntoInnerError { - /// Returns the error which caused the call to `into_inner()` to fail. - /// - /// This error was returned when attempting to write the internal buffer. - /// - /// # Examples - /// - /// ```no_run - /// use std::io::BufWriter; - /// use std::net::TcpStream; - /// - /// let mut stream = BufWriter::new(TcpStream::connect("127.0.0.1:34254").unwrap()); - /// - /// // do stuff with the stream - /// - /// // we want to get our `TcpStream` back, so let's try: - /// - /// let stream = match stream.into_inner() { - /// Ok(s) => s, - /// Err(e) => { - /// // Here, e is an IntoInnerError, let's log the inner error. - /// // - /// // We'll just 'log' to stdout for this example. - /// println!("{}", e.error()); - /// - /// panic!("An unexpected error occurred."); - /// } - /// }; - /// ``` - pub fn error(&self) -> &Error { - &self.1 - } - - /// Returns the buffered writer instance which generated the error. - /// - /// The returned object can be used for error recovery, such as - /// re-inspecting the buffer. - /// - /// # Examples - /// - /// ```no_run - /// use std::io::BufWriter; - /// use std::net::TcpStream; - /// - /// let mut stream = BufWriter::new(TcpStream::connect("127.0.0.1:34254").unwrap()); - /// - /// // do stuff with the stream - /// - /// // we want to get our `TcpStream` back, so let's try: - /// - /// let stream = match stream.into_inner() { - /// Ok(s) => s, - /// Err(e) => { - /// // Here, e is an IntoInnerError, let's re-examine the buffer: - /// let buffer = e.into_inner(); - /// - /// // do stuff to try to recover - /// - /// // afterwards, let's just return the stream - /// buffer.into_inner().unwrap() - /// } - /// }; - /// ``` - pub fn into_inner(self) -> W { - self.0 - } -} - -impl From> for Error { - fn from(iie: IntoInnerError) -> Error { - iie.1 - } -} - -impl fmt::Display for IntoInnerError { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - self.error().fmt(f) - } -} - -/// Wraps a writer and buffers output to it, flushing whenever a newline -/// (`0x0a`, `'\n'`) is detected. -/// -/// The [`BufWriter`][bufwriter] struct wraps a writer and buffers its output. -/// But it only does this batched write when it goes out of scope, or when the -/// internal buffer is full. Sometimes, you'd prefer to write each line as it's -/// completed, rather than the entire buffer at once. Enter `LineWriter`. It -/// does exactly that. -/// -/// Like [`BufWriter`][bufwriter], a `LineWriter`’s buffer will also be flushed when the -/// `LineWriter` goes out of scope or when its internal buffer is full. -/// -/// [bufwriter]: struct.BufWriter.html -/// -/// If there's still a partial line in the buffer when the `LineWriter` is -/// dropped, it will flush those contents. -/// -/// # Examples -/// -/// We can use `LineWriter` to write one line at a time, significantly -/// reducing the number of actual writes to the file. -/// -/// ```no_run -/// use std::fs::{self, File}; -/// use std::io::prelude::*; -/// use std::io::LineWriter; -/// -/// fn main() -> std::io::Result<()> { -/// let road_not_taken = b"I shall be telling this with a sigh -/// Somewhere ages and ages hence: -/// Two roads diverged in a wood, and I - -/// I took the one less traveled by, -/// And that has made all the difference."; -/// -/// let file = File::create("poem.txt")?; -/// let mut file = LineWriter::new(file); -/// -/// file.write_all(b"I shall be telling this with a sigh")?; -/// -/// // No bytes are written until a newline is encountered (or -/// // the internal buffer is filled). -/// assert_eq!(fs::read_to_string("poem.txt")?, ""); -/// file.write_all(b"\n")?; -/// assert_eq!( -/// fs::read_to_string("poem.txt")?, -/// "I shall be telling this with a sigh\n", -/// ); -/// -/// // Write the rest of the poem. -/// file.write_all(b"Somewhere ages and ages hence: -/// Two roads diverged in a wood, and I - -/// I took the one less traveled by, -/// And that has made all the difference.")?; -/// -/// // The last line of the poem doesn't end in a newline, so -/// // we have to flush or drop the `LineWriter` to finish -/// // writing. -/// file.flush()?; -/// -/// // Confirm the whole poem was written. -/// assert_eq!(fs::read("poem.txt")?, &road_not_taken[..]); -/// Ok(()) -/// } -/// ``` -pub struct LineWriter { - inner: BufWriter, - need_flush: bool, -} - -impl LineWriter { - /// Creates a new `LineWriter`. - /// - /// # Examples - /// - /// ```no_run - /// use std::fs::File; - /// use std::io::LineWriter; - /// - /// fn main() -> std::io::Result<()> { - /// let file = File::create("poem.txt")?; - /// let file = LineWriter::new(file); - /// Ok(()) - /// } - /// ``` - pub fn new(inner: W) -> LineWriter { - // Lines typically aren't that long, don't use a giant buffer - LineWriter::with_capacity(1024, inner) - } - - /// Creates a new `LineWriter` with a specified capacity for the internal - /// buffer. - /// - /// # Examples - /// - /// ```no_run - /// use std::fs::File; - /// use std::io::LineWriter; - /// - /// fn main() -> std::io::Result<()> { - /// let file = File::create("poem.txt")?; - /// let file = LineWriter::with_capacity(100, file); - /// Ok(()) - /// } - /// ``` - pub fn with_capacity(capacity: usize, inner: W) -> LineWriter { - LineWriter { inner: BufWriter::with_capacity(capacity, inner), need_flush: false } - } - - /// Gets a reference to the underlying writer. - /// - /// # Examples - /// - /// ```no_run - /// use std::fs::File; - /// use std::io::LineWriter; - /// - /// fn main() -> std::io::Result<()> { - /// let file = File::create("poem.txt")?; - /// let file = LineWriter::new(file); - /// - /// let reference = file.get_ref(); - /// Ok(()) - /// } - /// ``` - pub fn get_ref(&self) -> &W { - self.inner.get_ref() - } - - /// Gets a mutable reference to the underlying writer. - /// - /// Caution must be taken when calling methods on the mutable reference - /// returned as extra writes could corrupt the output stream. - /// - /// # Examples - /// - /// ```no_run - /// use std::fs::File; - /// use std::io::LineWriter; - /// - /// fn main() -> std::io::Result<()> { - /// let file = File::create("poem.txt")?; - /// let mut file = LineWriter::new(file); - /// - /// // we can use reference just like file - /// let reference = file.get_mut(); - /// Ok(()) - /// } - /// ``` - pub fn get_mut(&mut self) -> &mut W { - self.inner.get_mut() - } - - /// Unwraps this `LineWriter`, returning the underlying writer. - /// - /// The internal buffer is written out before returning the writer. - /// - /// # Errors - /// - /// An `Err` will be returned if an error occurs while flushing the buffer. - /// - /// # Examples - /// - /// ```no_run - /// use std::fs::File; - /// use std::io::LineWriter; - /// - /// fn main() -> std::io::Result<()> { - /// let file = File::create("poem.txt")?; - /// - /// let writer: LineWriter = LineWriter::new(file); - /// - /// let file: File = writer.into_inner()?; - /// Ok(()) - /// } - /// ``` - pub fn into_inner(self) -> Result>> { - self.inner.into_inner().map_err(|IntoInnerError(buf, e)| { - IntoInnerError(LineWriter { inner: buf, need_flush: false }, e) - }) - } -} - -impl Write for LineWriter { - fn write(&mut self, buf: &[u8]) -> io::Result { - if self.need_flush { - self.flush()?; - } - - // Find the last newline character in the buffer provided. If found then - // we're going to write all the data up to that point and then flush, - // otherwise we just write the whole block to the underlying writer. - let i = match memchr::memrchr(b'\n', buf) { - Some(i) => i, - None => return self.inner.write(buf), - }; - - // Ok, we're going to write a partial amount of the data given first - // followed by flushing the newline. After we've successfully written - // some data then we *must* report that we wrote that data, so future - // errors are ignored. We set our internal `need_flush` flag, though, in - // case flushing fails and we need to try it first next time. - let n = self.inner.write(&buf[..=i])?; - self.need_flush = true; - if self.flush().is_err() || n != i + 1 { - return Ok(n); - } - - // At this point we successfully wrote `i + 1` bytes and flushed it out, - // meaning that the entire line is now flushed out on the screen. While - // we can attempt to finish writing the rest of the data provided. - // Remember though that we ignore errors here as we've successfully - // written data, so we need to report that. - match self.inner.write(&buf[i + 1..]) { - Ok(i) => Ok(n + i), - Err(_) => Ok(n), - } - } - - fn flush(&mut self) -> io::Result<()> { - self.inner.flush()?; - self.need_flush = false; - Ok(()) - } -} - -impl fmt::Debug for LineWriter -where - W: fmt::Debug, -{ - fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { - fmt.debug_struct("LineWriter") - .field("writer", &self.inner.inner) - .field( - "buffer", - &format_args!("{}/{}", self.inner.buf.len(), self.inner.buf.capacity()), - ) - .finish() - } -} - -#[cfg(test)] -mod tests { - use crate::io::prelude::*; - use crate::io::{self, BufReader, BufWriter, IoSlice, LineWriter, SeekFrom}; - use crate::sync::atomic::{AtomicUsize, Ordering}; - use crate::thread; - - /// A dummy reader intended at testing short-reads propagation. - pub struct ShortReader { - lengths: Vec, - } - - impl Read for ShortReader { - fn read(&mut self, _: &mut [u8]) -> io::Result { - if self.lengths.is_empty() { Ok(0) } else { Ok(self.lengths.remove(0)) } - } - } - - #[test] - fn test_buffered_reader() { - let inner: &[u8] = &[5, 6, 7, 0, 1, 2, 3, 4]; - let mut reader = BufReader::with_capacity(2, inner); - - let mut buf = [0, 0, 0]; - let nread = reader.read(&mut buf); - assert_eq!(nread.unwrap(), 3); - assert_eq!(buf, [5, 6, 7]); - assert_eq!(reader.buffer(), []); - - let mut buf = [0, 0]; - let nread = reader.read(&mut buf); - assert_eq!(nread.unwrap(), 2); - assert_eq!(buf, [0, 1]); - assert_eq!(reader.buffer(), []); - - let mut buf = [0]; - let nread = reader.read(&mut buf); - assert_eq!(nread.unwrap(), 1); - assert_eq!(buf, [2]); - assert_eq!(reader.buffer(), [3]); - - let mut buf = [0, 0, 0]; - let nread = reader.read(&mut buf); - assert_eq!(nread.unwrap(), 1); - assert_eq!(buf, [3, 0, 0]); - assert_eq!(reader.buffer(), []); - - let nread = reader.read(&mut buf); - assert_eq!(nread.unwrap(), 1); - assert_eq!(buf, [4, 0, 0]); - assert_eq!(reader.buffer(), []); - - assert_eq!(reader.read(&mut buf).unwrap(), 0); - } - - #[test] - fn test_buffered_reader_seek() { - let inner: &[u8] = &[5, 6, 7, 0, 1, 2, 3, 4]; - let mut reader = BufReader::with_capacity(2, io::Cursor::new(inner)); - - assert_eq!(reader.seek(SeekFrom::Start(3)).ok(), Some(3)); - assert_eq!(reader.fill_buf().ok(), Some(&[0, 1][..])); - assert_eq!(reader.seek(SeekFrom::Current(0)).ok(), Some(3)); - assert_eq!(reader.fill_buf().ok(), Some(&[0, 1][..])); - assert_eq!(reader.seek(SeekFrom::Current(1)).ok(), Some(4)); - assert_eq!(reader.fill_buf().ok(), Some(&[1, 2][..])); - reader.consume(1); - assert_eq!(reader.seek(SeekFrom::Current(-2)).ok(), Some(3)); - } - - #[test] - fn test_buffered_reader_seek_relative() { - let inner: &[u8] = &[5, 6, 7, 0, 1, 2, 3, 4]; - let mut reader = BufReader::with_capacity(2, io::Cursor::new(inner)); - - assert!(reader.seek_relative(3).is_ok()); - assert_eq!(reader.fill_buf().ok(), Some(&[0, 1][..])); - assert!(reader.seek_relative(0).is_ok()); - assert_eq!(reader.fill_buf().ok(), Some(&[0, 1][..])); - assert!(reader.seek_relative(1).is_ok()); - assert_eq!(reader.fill_buf().ok(), Some(&[1][..])); - assert!(reader.seek_relative(-1).is_ok()); - assert_eq!(reader.fill_buf().ok(), Some(&[0, 1][..])); - assert!(reader.seek_relative(2).is_ok()); - assert_eq!(reader.fill_buf().ok(), Some(&[2, 3][..])); - } - - #[test] - fn test_buffered_reader_invalidated_after_read() { - let inner: &[u8] = &[5, 6, 7, 0, 1, 2, 3, 4]; - let mut reader = BufReader::with_capacity(3, io::Cursor::new(inner)); - - assert_eq!(reader.fill_buf().ok(), Some(&[5, 6, 7][..])); - reader.consume(3); - - let mut buffer = [0, 0, 0, 0, 0]; - assert_eq!(reader.read(&mut buffer).ok(), Some(5)); - assert_eq!(buffer, [0, 1, 2, 3, 4]); - - assert!(reader.seek_relative(-2).is_ok()); - let mut buffer = [0, 0]; - assert_eq!(reader.read(&mut buffer).ok(), Some(2)); - assert_eq!(buffer, [3, 4]); - } - - #[test] - fn test_buffered_reader_invalidated_after_seek() { - let inner: &[u8] = &[5, 6, 7, 0, 1, 2, 3, 4]; - let mut reader = BufReader::with_capacity(3, io::Cursor::new(inner)); - - assert_eq!(reader.fill_buf().ok(), Some(&[5, 6, 7][..])); - reader.consume(3); - - assert!(reader.seek(SeekFrom::Current(5)).is_ok()); - - assert!(reader.seek_relative(-2).is_ok()); - let mut buffer = [0, 0]; - assert_eq!(reader.read(&mut buffer).ok(), Some(2)); - assert_eq!(buffer, [3, 4]); - } - - #[test] - fn test_buffered_reader_seek_underflow() { - // gimmick reader that yields its position modulo 256 for each byte - struct PositionReader { - pos: u64, - } - impl Read for PositionReader { - fn read(&mut self, buf: &mut [u8]) -> io::Result { - let len = buf.len(); - for x in buf { - *x = self.pos as u8; - self.pos = self.pos.wrapping_add(1); - } - Ok(len) - } - } - impl Seek for PositionReader { - fn seek(&mut self, pos: SeekFrom) -> io::Result { - match pos { - SeekFrom::Start(n) => { - self.pos = n; - } - SeekFrom::Current(n) => { - self.pos = self.pos.wrapping_add(n as u64); - } - SeekFrom::End(n) => { - self.pos = u64::max_value().wrapping_add(n as u64); - } - } - Ok(self.pos) - } - } - - let mut reader = BufReader::with_capacity(5, PositionReader { pos: 0 }); - assert_eq!(reader.fill_buf().ok(), Some(&[0, 1, 2, 3, 4][..])); - assert_eq!(reader.seek(SeekFrom::End(-5)).ok(), Some(u64::max_value() - 5)); - assert_eq!(reader.fill_buf().ok().map(|s| s.len()), Some(5)); - // the following seek will require two underlying seeks - let expected = 9223372036854775802; - assert_eq!(reader.seek(SeekFrom::Current(i64::min_value())).ok(), Some(expected)); - assert_eq!(reader.fill_buf().ok().map(|s| s.len()), Some(5)); - // seeking to 0 should empty the buffer. - assert_eq!(reader.seek(SeekFrom::Current(0)).ok(), Some(expected)); - assert_eq!(reader.get_ref().pos, expected); - } - - #[test] - fn test_buffered_reader_seek_underflow_discard_buffer_between_seeks() { - // gimmick reader that returns Err after first seek - struct ErrAfterFirstSeekReader { - first_seek: bool, - } - impl Read for ErrAfterFirstSeekReader { - fn read(&mut self, buf: &mut [u8]) -> io::Result { - for x in &mut *buf { - *x = 0; - } - Ok(buf.len()) - } - } - impl Seek for ErrAfterFirstSeekReader { - fn seek(&mut self, _: SeekFrom) -> io::Result { - if self.first_seek { - self.first_seek = false; - Ok(0) - } else { - Err(io::Error::new(io::ErrorKind::Other, "oh no!")) - } - } - } - - let mut reader = BufReader::with_capacity(5, ErrAfterFirstSeekReader { first_seek: true }); - assert_eq!(reader.fill_buf().ok(), Some(&[0, 0, 0, 0, 0][..])); - - // The following seek will require two underlying seeks. The first will - // succeed but the second will fail. This should still invalidate the - // buffer. - assert!(reader.seek(SeekFrom::Current(i64::min_value())).is_err()); - assert_eq!(reader.buffer().len(), 0); - } - - #[test] - fn test_buffered_writer() { - let inner = Vec::new(); - let mut writer = BufWriter::with_capacity(2, inner); - - writer.write(&[0, 1]).unwrap(); - assert_eq!(writer.buffer(), []); - assert_eq!(*writer.get_ref(), [0, 1]); - - writer.write(&[2]).unwrap(); - assert_eq!(writer.buffer(), [2]); - assert_eq!(*writer.get_ref(), [0, 1]); - - writer.write(&[3]).unwrap(); - assert_eq!(writer.buffer(), [2, 3]); - assert_eq!(*writer.get_ref(), [0, 1]); - - writer.flush().unwrap(); - assert_eq!(writer.buffer(), []); - assert_eq!(*writer.get_ref(), [0, 1, 2, 3]); - - writer.write(&[4]).unwrap(); - writer.write(&[5]).unwrap(); - assert_eq!(writer.buffer(), [4, 5]); - assert_eq!(*writer.get_ref(), [0, 1, 2, 3]); - - writer.write(&[6]).unwrap(); - assert_eq!(writer.buffer(), [6]); - assert_eq!(*writer.get_ref(), [0, 1, 2, 3, 4, 5]); - - writer.write(&[7, 8]).unwrap(); - assert_eq!(writer.buffer(), []); - assert_eq!(*writer.get_ref(), [0, 1, 2, 3, 4, 5, 6, 7, 8]); - - writer.write(&[9, 10, 11]).unwrap(); - assert_eq!(writer.buffer(), []); - assert_eq!(*writer.get_ref(), [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]); - - writer.flush().unwrap(); - assert_eq!(writer.buffer(), []); - assert_eq!(*writer.get_ref(), [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]); - } - - #[test] - fn test_buffered_writer_inner_flushes() { - let mut w = BufWriter::with_capacity(3, Vec::new()); - w.write(&[0, 1]).unwrap(); - assert_eq!(*w.get_ref(), []); - let w = w.into_inner().unwrap(); - assert_eq!(w, [0, 1]); - } - - #[test] - fn test_buffered_writer_seek() { - let mut w = BufWriter::with_capacity(3, io::Cursor::new(Vec::new())); - w.write_all(&[0, 1, 2, 3, 4, 5]).unwrap(); - w.write_all(&[6, 7]).unwrap(); - assert_eq!(w.seek(SeekFrom::Current(0)).ok(), Some(8)); - assert_eq!(&w.get_ref().get_ref()[..], &[0, 1, 2, 3, 4, 5, 6, 7][..]); - assert_eq!(w.seek(SeekFrom::Start(2)).ok(), Some(2)); - w.write_all(&[8, 9]).unwrap(); - assert_eq!(&w.into_inner().unwrap().into_inner()[..], &[0, 1, 8, 9, 4, 5, 6, 7]); - } - - #[test] - fn test_read_until() { - let inner: &[u8] = &[0, 1, 2, 1, 0]; - let mut reader = BufReader::with_capacity(2, inner); - let mut v = Vec::new(); - reader.read_until(0, &mut v).unwrap(); - assert_eq!(v, [0]); - v.truncate(0); - reader.read_until(2, &mut v).unwrap(); - assert_eq!(v, [1, 2]); - v.truncate(0); - reader.read_until(1, &mut v).unwrap(); - assert_eq!(v, [1]); - v.truncate(0); - reader.read_until(8, &mut v).unwrap(); - assert_eq!(v, [0]); - v.truncate(0); - reader.read_until(9, &mut v).unwrap(); - assert_eq!(v, []); - } - - #[test] - fn test_line_buffer_fail_flush() { - // Issue #32085 - struct FailFlushWriter<'a>(&'a mut Vec); - - impl Write for FailFlushWriter<'_> { - fn write(&mut self, buf: &[u8]) -> io::Result { - self.0.extend_from_slice(buf); - Ok(buf.len()) - } - fn flush(&mut self) -> io::Result<()> { - Err(io::Error::new(io::ErrorKind::Other, "flush failed")) - } - } - - let mut buf = Vec::new(); - { - let mut writer = LineWriter::new(FailFlushWriter(&mut buf)); - let to_write = b"abc\ndef"; - if let Ok(written) = writer.write(to_write) { - assert!(written < to_write.len(), "didn't flush on new line"); - // PASS - return; - } - } - assert!(buf.is_empty(), "write returned an error but wrote data"); - } - - #[test] - fn test_line_buffer() { - let mut writer = LineWriter::new(Vec::new()); - writer.write(&[0]).unwrap(); - assert_eq!(*writer.get_ref(), []); - writer.write(&[1]).unwrap(); - assert_eq!(*writer.get_ref(), []); - writer.flush().unwrap(); - assert_eq!(*writer.get_ref(), [0, 1]); - writer.write(&[0, b'\n', 1, b'\n', 2]).unwrap(); - assert_eq!(*writer.get_ref(), [0, 1, 0, b'\n', 1, b'\n']); - writer.flush().unwrap(); - assert_eq!(*writer.get_ref(), [0, 1, 0, b'\n', 1, b'\n', 2]); - writer.write(&[3, b'\n']).unwrap(); - assert_eq!(*writer.get_ref(), [0, 1, 0, b'\n', 1, b'\n', 2, 3, b'\n']); - } - - #[test] - fn test_read_line() { - let in_buf: &[u8] = b"a\nb\nc"; - let mut reader = BufReader::with_capacity(2, in_buf); - let mut s = String::new(); - reader.read_line(&mut s).unwrap(); - assert_eq!(s, "a\n"); - s.truncate(0); - reader.read_line(&mut s).unwrap(); - assert_eq!(s, "b\n"); - s.truncate(0); - reader.read_line(&mut s).unwrap(); - assert_eq!(s, "c"); - s.truncate(0); - reader.read_line(&mut s).unwrap(); - assert_eq!(s, ""); - } - - #[test] - fn test_lines() { - let in_buf: &[u8] = b"a\nb\nc"; - let reader = BufReader::with_capacity(2, in_buf); - let mut it = reader.lines(); - assert_eq!(it.next().unwrap().unwrap(), "a".to_string()); - assert_eq!(it.next().unwrap().unwrap(), "b".to_string()); - assert_eq!(it.next().unwrap().unwrap(), "c".to_string()); - assert!(it.next().is_none()); - } - - #[test] - fn test_short_reads() { - let inner = ShortReader { lengths: vec![0, 1, 2, 0, 1, 0] }; - let mut reader = BufReader::new(inner); - let mut buf = [0, 0]; - assert_eq!(reader.read(&mut buf).unwrap(), 0); - assert_eq!(reader.read(&mut buf).unwrap(), 1); - assert_eq!(reader.read(&mut buf).unwrap(), 2); - assert_eq!(reader.read(&mut buf).unwrap(), 0); - assert_eq!(reader.read(&mut buf).unwrap(), 1); - assert_eq!(reader.read(&mut buf).unwrap(), 0); - assert_eq!(reader.read(&mut buf).unwrap(), 0); - } - - #[test] - #[should_panic] - fn dont_panic_in_drop_on_panicked_flush() { - struct FailFlushWriter; - - impl Write for FailFlushWriter { - fn write(&mut self, buf: &[u8]) -> io::Result { - Ok(buf.len()) - } - fn flush(&mut self) -> io::Result<()> { - Err(io::Error::last_os_error()) - } - } - - let writer = FailFlushWriter; - let _writer = BufWriter::new(writer); - - // If writer panics *again* due to the flush error then the process will - // abort. - panic!(); - } - - #[test] - #[cfg_attr(target_os = "emscripten", ignore)] - fn panic_in_write_doesnt_flush_in_drop() { - static WRITES: AtomicUsize = AtomicUsize::new(0); - - struct PanicWriter; - - impl Write for PanicWriter { - fn write(&mut self, _: &[u8]) -> io::Result { - WRITES.fetch_add(1, Ordering::SeqCst); - panic!(); - } - fn flush(&mut self) -> io::Result<()> { - Ok(()) - } - } - - thread::spawn(|| { - let mut writer = BufWriter::new(PanicWriter); - let _ = writer.write(b"hello world"); - let _ = writer.flush(); - }) - .join() - .unwrap_err(); - - assert_eq!(WRITES.load(Ordering::SeqCst), 1); - } - - #[bench] - fn bench_buffered_reader(b: &mut test::Bencher) { - b.iter(|| BufReader::new(io::empty())); - } - - #[bench] - fn bench_buffered_writer(b: &mut test::Bencher) { - b.iter(|| BufWriter::new(io::sink())); - } - - struct AcceptOneThenFail { - written: bool, - flushed: bool, - } - - impl Write for AcceptOneThenFail { - fn write(&mut self, data: &[u8]) -> io::Result { - if !self.written { - assert_eq!(data, b"a\nb\n"); - self.written = true; - Ok(data.len()) - } else { - Err(io::Error::new(io::ErrorKind::NotFound, "test")) - } - } - - fn flush(&mut self) -> io::Result<()> { - assert!(self.written); - assert!(!self.flushed); - self.flushed = true; - Err(io::Error::new(io::ErrorKind::Other, "test")) - } - } - - #[test] - fn erroneous_flush_retried() { - let a = AcceptOneThenFail { written: false, flushed: false }; - - let mut l = LineWriter::new(a); - assert_eq!(l.write(b"a\nb\na").unwrap(), 4); - assert!(l.get_ref().written); - assert!(l.get_ref().flushed); - l.get_mut().flushed = false; - - assert_eq!(l.write(b"a").unwrap_err().kind(), io::ErrorKind::Other) - } - - #[test] - fn line_vectored() { - let mut a = LineWriter::new(Vec::new()); - assert_eq!( - a.write_vectored(&[ - IoSlice::new(&[]), - IoSlice::new(b"\n"), - IoSlice::new(&[]), - IoSlice::new(b"a"), - ]) - .unwrap(), - 2, - ); - assert_eq!(a.get_ref(), b"\n"); - - assert_eq!( - a.write_vectored(&[ - IoSlice::new(&[]), - IoSlice::new(b"b"), - IoSlice::new(&[]), - IoSlice::new(b"a"), - IoSlice::new(&[]), - IoSlice::new(b"c"), - ]) - .unwrap(), - 3, - ); - assert_eq!(a.get_ref(), b"\n"); - a.flush().unwrap(); - assert_eq!(a.get_ref(), b"\nabac"); - assert_eq!(a.write_vectored(&[]).unwrap(), 0); - assert_eq!( - a.write_vectored(&[ - IoSlice::new(&[]), - IoSlice::new(&[]), - IoSlice::new(&[]), - IoSlice::new(&[]), - ]) - .unwrap(), - 0, - ); - assert_eq!(a.write_vectored(&[IoSlice::new(b"a\nb"),]).unwrap(), 3); - assert_eq!(a.get_ref(), b"\nabaca\n"); - } - - #[test] - fn line_vectored_partial_and_errors() { - enum Call { - Write { inputs: Vec<&'static [u8]>, output: io::Result }, - Flush { output: io::Result<()> }, - } - struct Writer { - calls: Vec, - } - - impl Write for Writer { - fn write(&mut self, buf: &[u8]) -> io::Result { - self.write_vectored(&[IoSlice::new(buf)]) - } - - fn write_vectored(&mut self, buf: &[IoSlice<'_>]) -> io::Result { - match self.calls.pop().unwrap() { - Call::Write { inputs, output } => { - assert_eq!(inputs, buf.iter().map(|b| &**b).collect::>()); - output - } - _ => panic!("unexpected call to write"), - } - } - - fn flush(&mut self) -> io::Result<()> { - match self.calls.pop().unwrap() { - Call::Flush { output } => output, - _ => panic!("unexpected call to flush"), - } - } - } - - impl Drop for Writer { - fn drop(&mut self) { - if !thread::panicking() { - assert_eq!(self.calls.len(), 0); - } - } - } - - // partial writes keep going - let mut a = LineWriter::new(Writer { calls: Vec::new() }); - a.write_vectored(&[IoSlice::new(&[]), IoSlice::new(b"abc")]).unwrap(); - a.get_mut().calls.push(Call::Flush { output: Ok(()) }); - a.get_mut().calls.push(Call::Write { inputs: vec![b"bcx\n"], output: Ok(4) }); - a.get_mut().calls.push(Call::Write { inputs: vec![b"abcx\n"], output: Ok(1) }); - a.write_vectored(&[IoSlice::new(b"x"), IoSlice::new(b"\n")]).unwrap(); - a.get_mut().calls.push(Call::Flush { output: Ok(()) }); - a.flush().unwrap(); - - // erroneous writes stop and don't write more - a.get_mut().calls.push(Call::Write { inputs: vec![b"x\n"], output: Err(err()) }); - assert_eq!(a.write_vectored(&[IoSlice::new(b"x"), IoSlice::new(b"\na")]).unwrap(), 2); - a.get_mut().calls.push(Call::Flush { output: Ok(()) }); - a.get_mut().calls.push(Call::Write { inputs: vec![b"x\n"], output: Ok(2) }); - a.flush().unwrap(); - - fn err() -> io::Error { - io::Error::new(io::ErrorKind::Other, "x") - } - } - - #[test] - fn line_vectored() { - let mut a = LineWriter::new(Vec::new()); - assert_eq!( - a.write_vectored(&[ - IoSlice::new(&[]), - IoSlice::new(b"\n"), - IoSlice::new(&[]), - IoSlice::new(b"a"), - ]) - .unwrap(), - 2, - ); - assert_eq!(a.get_ref(), b"\n"); - - assert_eq!( - a.write_vectored(&[ - IoSlice::new(&[]), - IoSlice::new(b"b"), - IoSlice::new(&[]), - IoSlice::new(b"a"), - IoSlice::new(&[]), - IoSlice::new(b"c"), - ]) - .unwrap(), - 3, - ); - assert_eq!(a.get_ref(), b"\n"); - a.flush().unwrap(); - assert_eq!(a.get_ref(), b"\nabac"); - assert_eq!(a.write_vectored(&[]).unwrap(), 0); - assert_eq!( - a.write_vectored(&[ - IoSlice::new(&[]), - IoSlice::new(&[]), - IoSlice::new(&[]), - IoSlice::new(&[]), - ]) - .unwrap(), - 0, - ); - assert_eq!(a.write_vectored(&[IoSlice::new(b"a\nb"),]).unwrap(), 3); - assert_eq!(a.get_ref(), b"\nabaca\n"); - } - - #[test] - fn line_vectored_partial_and_errors() { - enum Call { - Write { inputs: Vec<&'static [u8]>, output: io::Result }, - Flush { output: io::Result<()> }, - } - struct Writer { - calls: Vec, - } - - impl Write for Writer { - fn write(&mut self, buf: &[u8]) -> io::Result { - self.write_vectored(&[IoSlice::new(buf)]) - } - - fn write_vectored(&mut self, buf: &[IoSlice<'_>]) -> io::Result { - match self.calls.pop().unwrap() { - Call::Write { inputs, output } => { - assert_eq!(inputs, buf.iter().map(|b| &**b).collect::>()); - output - } - _ => panic!("unexpected call to write"), - } - } - - fn flush(&mut self) -> io::Result<()> { - match self.calls.pop().unwrap() { - Call::Flush { output } => output, - _ => panic!("unexpected call to flush"), - } - } - } - - impl Drop for Writer { - fn drop(&mut self) { - if !thread::panicking() { - assert_eq!(self.calls.len(), 0); - } - } - } - - // partial writes keep going - let mut a = LineWriter::new(Writer { calls: Vec::new() }); - a.write_vectored(&[IoSlice::new(&[]), IoSlice::new(b"abc")]).unwrap(); - a.get_mut().calls.push(Call::Flush { output: Ok(()) }); - a.get_mut().calls.push(Call::Write { inputs: vec![b"bcx\n"], output: Ok(4) }); - a.get_mut().calls.push(Call::Write { inputs: vec![b"abcx\n"], output: Ok(1) }); - a.write_vectored(&[IoSlice::new(b"x"), IoSlice::new(b"\n")]).unwrap(); - a.get_mut().calls.push(Call::Flush { output: Ok(()) }); - a.flush().unwrap(); - - // erroneous writes stop and don't write more - a.get_mut().calls.push(Call::Write { inputs: vec![b"x\n"], output: Err(err()) }); - assert_eq!(a.write_vectored(&[IoSlice::new(b"x"), IoSlice::new(b"\na")]).unwrap(), 2); - a.get_mut().calls.push(Call::Flush { output: Ok(()) }); - a.get_mut().calls.push(Call::Write { inputs: vec![b"x\n"], output: Ok(2) }); - a.flush().unwrap(); - - fn err() -> io::Error { - io::Error::new(io::ErrorKind::Other, "x") - } - } -} diff --git a/libcoreio/src/io/cursor.rs b/libcoreio/src/io/cursor.rs deleted file mode 100644 index 82dd1f7..0000000 --- a/libcoreio/src/io/cursor.rs +++ /dev/null @@ -1,896 +0,0 @@ -use crate::io::prelude::*; - -use core::cmp; -use crate::io::{self, Error, ErrorKind, Initializer, SeekFrom}; - -#[cfg(feature = "collections")] -use core::convert::TryInto; - -#[cfg(feature="collections")] -use collections::vec::Vec; - -#[cfg(feature = "alloc")] -use alloc::boxed::Box; - -/// A `Cursor` wraps an in-memory buffer and provides it with a -/// [`Seek`] implementation. -/// -/// `Cursor`s are used with in-memory buffers, anything implementing -/// `AsRef<[u8]>`, to allow them to implement [`Read`] and/or [`Write`], -/// allowing these buffers to be used anywhere you might use a reader or writer -/// that does actual I/O. -/// -/// The standard library implements some I/O traits on various types which -/// are commonly used as a buffer, like `Cursor<`[`Vec`]`>` and -/// `Cursor<`[`&[u8]`][bytes]`>`. -/// -/// # Examples -/// -/// We may want to write bytes to a [`File`] in our production -/// code, but use an in-memory buffer in our tests. We can do this with -/// `Cursor`: -/// -/// [`Seek`]: trait.Seek.html -/// [`Read`]: ../../std/io/trait.Read.html -/// [`Write`]: ../../std/io/trait.Write.html -/// [`Vec`]: ../../std/vec/struct.Vec.html -/// [bytes]: ../../std/primitive.slice.html -/// [`File`]: ../fs/struct.File.html -/// -/// ```no_run -/// use std::io::prelude::*; -/// use std::io::{self, SeekFrom}; -/// use std::fs::File; -/// -/// // a library function we've written -/// fn write_ten_bytes_at_end(writer: &mut W) -> io::Result<()> { -/// writer.seek(SeekFrom::End(-10))?; -/// -/// for i in 0..10 { -/// writer.write(&[i])?; -/// } -/// -/// // all went well -/// Ok(()) -/// } -/// -/// # fn foo() -> io::Result<()> { -/// // Here's some code that uses this library function. -/// // -/// // We might want to use a BufReader here for efficiency, but let's -/// // keep this example focused. -/// let mut file = File::create("foo.txt")?; -/// -/// write_ten_bytes_at_end(&mut file)?; -/// # Ok(()) -/// # } -/// -/// // now let's write a test -/// #[test] -/// fn test_writes_bytes() { -/// // setting up a real File is much slower than an in-memory buffer, -/// // let's use a cursor instead -/// use std::io::Cursor; -/// let mut buff = Cursor::new(vec![0; 15]); -/// -/// write_ten_bytes_at_end(&mut buff).unwrap(); -/// -/// assert_eq!(&buff.get_ref()[5..15], &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]); -/// } -/// ``` -#[derive(Clone, Debug, Default, Eq, PartialEq)] -pub struct Cursor { - inner: T, - pos: u64, -} - -impl Cursor { - /// Creates a new cursor wrapping the provided underlying in-memory buffer. - /// - /// Cursor initial position is `0` even if underlying buffer (e.g., `Vec`) - /// is not empty. So writing to cursor starts with overwriting `Vec` - /// content, not with appending to it. - /// - /// # Examples - /// - /// ``` - /// use std::io::Cursor; - /// - /// let buff = Cursor::new(Vec::new()); - /// # fn force_inference(_: &Cursor>) {} - /// # force_inference(&buff); - /// ``` - pub fn new(inner: T) -> Cursor { - Cursor { pos: 0, inner } - } - - /// Consumes this cursor, returning the underlying value. - /// - /// # Examples - /// - /// ``` - /// use std::io::Cursor; - /// - /// let buff = Cursor::new(Vec::new()); - /// # fn force_inference(_: &Cursor>) {} - /// # force_inference(&buff); - /// - /// let vec = buff.into_inner(); - /// ``` - pub fn into_inner(self) -> T { - self.inner - } - - /// Gets a reference to the underlying value in this cursor. - /// - /// # Examples - /// - /// ``` - /// use std::io::Cursor; - /// - /// let buff = Cursor::new(Vec::new()); - /// # fn force_inference(_: &Cursor>) {} - /// # force_inference(&buff); - /// - /// let reference = buff.get_ref(); - /// ``` - pub fn get_ref(&self) -> &T { - &self.inner - } - - /// Gets a mutable reference to the underlying value in this cursor. - /// - /// Care should be taken to avoid modifying the internal I/O state of the - /// underlying value as it may corrupt this cursor's position. - /// - /// # Examples - /// - /// ``` - /// use std::io::Cursor; - /// - /// let mut buff = Cursor::new(Vec::new()); - /// # fn force_inference(_: &Cursor>) {} - /// # force_inference(&buff); - /// - /// let reference = buff.get_mut(); - /// ``` - pub fn get_mut(&mut self) -> &mut T { - &mut self.inner - } - - /// Returns the current position of this cursor. - /// - /// # Examples - /// - /// ``` - /// use std::io::Cursor; - /// use std::io::prelude::*; - /// use std::io::SeekFrom; - /// - /// let mut buff = Cursor::new(vec![1, 2, 3, 4, 5]); - /// - /// assert_eq!(buff.position(), 0); - /// - /// buff.seek(SeekFrom::Current(2)).unwrap(); - /// assert_eq!(buff.position(), 2); - /// - /// buff.seek(SeekFrom::Current(-1)).unwrap(); - /// assert_eq!(buff.position(), 1); - /// ``` - pub fn position(&self) -> u64 { - self.pos - } - - /// Sets the position of this cursor. - /// - /// # Examples - /// - /// ``` - /// use std::io::Cursor; - /// - /// let mut buff = Cursor::new(vec![1, 2, 3, 4, 5]); - /// - /// assert_eq!(buff.position(), 0); - /// - /// buff.set_position(2); - /// assert_eq!(buff.position(), 2); - /// - /// buff.set_position(4); - /// assert_eq!(buff.position(), 4); - /// ``` - pub fn set_position(&mut self, pos: u64) { - self.pos = pos; - } -} - -impl io::Seek for Cursor -where - T: AsRef<[u8]>, -{ - fn seek(&mut self, style: SeekFrom) -> io::Result { - let (base_pos, offset) = match style { - SeekFrom::Start(n) => { - self.pos = n; - return Ok(n); - } - SeekFrom::End(n) => (self.inner.as_ref().len() as u64, n), - SeekFrom::Current(n) => (self.pos, n), - }; - let new_pos = if offset >= 0 { - base_pos.checked_add(offset as u64) - } else { - base_pos.checked_sub((offset.wrapping_neg()) as u64) - }; - match new_pos { - Some(n) => { - self.pos = n; - Ok(self.pos) - } - None => Err(Error::new( - ErrorKind::InvalidInput, - "invalid seek to a negative or overflowing position", - )), - } - } - - fn stream_len(&mut self) -> io::Result { - Ok(self.inner.as_ref().len() as u64) - } - - fn stream_position(&mut self) -> io::Result { - Ok(self.pos) - } -} - -impl Read for Cursor -where - T: AsRef<[u8]>, -{ - fn read(&mut self, buf: &mut [u8]) -> io::Result { - let n = Read::read(&mut self.get_ref().as_ref(), buf)?; - self.pos += n as u64; - Ok(n) - } - - fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> { - let n = buf.len(); - Read::read_exact(&mut self.get_ref().as_ref(), buf)?; - self.pos += n as u64; - Ok(()) - } - - #[inline] - unsafe fn initializer(&self) -> Initializer { - Initializer::nop() - } -} - -#[cfg(feature = "collections")] -impl BufRead for Cursor -where - T: AsRef<[u8]>, -{ - fn fill_buf(&mut self) -> io::Result<&[u8]> { - let amt = cmp::min(self.pos, self.inner.as_ref().len() as u64); - Ok(&self.inner.as_ref()[(amt as usize)..]) - } - fn consume(&mut self, amt: usize) { - self.pos += amt as u64; - } -} - -// Non-resizing write implementation -#[inline] -fn slice_write(pos_mut: &mut u64, slice: &mut [u8], buf: &[u8]) -> io::Result { - let pos = cmp::min(*pos_mut, slice.len() as u64); - let amt = (&mut slice[(pos as usize)..]).write(buf)?; - *pos_mut += amt as u64; - Ok(amt) -} - -// Resizing write implementation -#[cfg(feature = "collections")] -fn vec_write(pos_mut: &mut u64, vec: &mut Vec, buf: &[u8]) -> io::Result { - let pos: usize = (*pos_mut).try_into().map_err(|_| { - Error::new( - ErrorKind::InvalidInput, - "cursor position exceeds maximum possible vector length", - ) - })?; - // Make sure the internal buffer is as least as big as where we - // currently are - let len = vec.len(); - if len < pos { - // use `resize` so that the zero filling is as efficient as possible - vec.resize(pos, 0); - } - // Figure out what bytes will be used to overwrite what's currently - // there (left), and what will be appended on the end (right) - { - let space = vec.len() - pos; - let (left, right) = buf.split_at(cmp::min(space, buf.len())); - vec[pos..pos + left.len()].copy_from_slice(left); - vec.extend_from_slice(right); - } - - // Bump us forward - *pos_mut = (pos + buf.len()) as u64; - Ok(buf.len()) -} - -impl Write for Cursor<&mut [u8]> { - #[inline] - fn write(&mut self, buf: &[u8]) -> io::Result { - slice_write(&mut self.pos, self.inner, buf) - } - - #[inline] - fn flush(&mut self) -> io::Result<()> { - Ok(()) - } -} - -#[cfg(feature = "collections")] -impl Write for Cursor<&mut Vec> { - fn write(&mut self, buf: &[u8]) -> io::Result { - vec_write(&mut self.pos, self.inner, buf) - } - - #[inline] - fn flush(&mut self) -> io::Result<()> { - Ok(()) - } -} - -#[cfg(feature = "collections")] -impl Write for Cursor> { - fn write(&mut self, buf: &[u8]) -> io::Result { - vec_write(&mut self.pos, &mut self.inner, buf) - } - - #[inline] - fn flush(&mut self) -> io::Result<()> { - Ok(()) - } -} - -#[cfg(feature = "alloc")] -impl Write for Cursor> { - #[inline] - fn write(&mut self, buf: &[u8]) -> io::Result { - slice_write(&mut self.pos, &mut self.inner, buf) - } - - #[inline] - fn flush(&mut self) -> io::Result<()> { - Ok(()) - } -} - -#[cfg(test)] -mod tests { - use crate::io::prelude::*; - use crate::io::{Cursor, IoSlice, IoSliceMut, SeekFrom}; - - #[test] - fn test_vec_writer() { - let mut writer = Vec::new(); - assert_eq!(writer.write(&[0]).unwrap(), 1); - assert_eq!(writer.write(&[1, 2, 3]).unwrap(), 3); - assert_eq!(writer.write(&[4, 5, 6, 7]).unwrap(), 4); - assert_eq!( - writer - .write_vectored(&[IoSlice::new(&[]), IoSlice::new(&[8, 9]), IoSlice::new(&[10])],) - .unwrap(), - 3 - ); - let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]; - assert_eq!(writer, b); - } - - #[test] - fn test_mem_writer() { - let mut writer = Cursor::new(Vec::new()); - assert_eq!(writer.write(&[0]).unwrap(), 1); - assert_eq!(writer.write(&[1, 2, 3]).unwrap(), 3); - assert_eq!(writer.write(&[4, 5, 6, 7]).unwrap(), 4); - assert_eq!( - writer - .write_vectored(&[IoSlice::new(&[]), IoSlice::new(&[8, 9]), IoSlice::new(&[10])],) - .unwrap(), - 3 - ); - let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]; - assert_eq!(&writer.get_ref()[..], b); - } - - #[test] - fn test_mem_mut_writer() { - let mut vec = Vec::new(); - let mut writer = Cursor::new(&mut vec); - assert_eq!(writer.write(&[0]).unwrap(), 1); - assert_eq!(writer.write(&[1, 2, 3]).unwrap(), 3); - assert_eq!(writer.write(&[4, 5, 6, 7]).unwrap(), 4); - assert_eq!( - writer - .write_vectored(&[IoSlice::new(&[]), IoSlice::new(&[8, 9]), IoSlice::new(&[10])],) - .unwrap(), - 3 - ); - let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]; - assert_eq!(&writer.get_ref()[..], b); - } - - #[test] - fn test_box_slice_writer() { - let mut writer = Cursor::new(vec![0u8; 9].into_boxed_slice()); - assert_eq!(writer.position(), 0); - assert_eq!(writer.write(&[0]).unwrap(), 1); - assert_eq!(writer.position(), 1); - assert_eq!(writer.write(&[1, 2, 3]).unwrap(), 3); - assert_eq!(writer.write(&[4, 5, 6, 7]).unwrap(), 4); - assert_eq!(writer.position(), 8); - assert_eq!(writer.write(&[]).unwrap(), 0); - assert_eq!(writer.position(), 8); - - assert_eq!(writer.write(&[8, 9]).unwrap(), 1); - assert_eq!(writer.write(&[10]).unwrap(), 0); - let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8]; - assert_eq!(&**writer.get_ref(), b); - } - - #[test] - fn test_box_slice_writer_vectored() { - let mut writer = Cursor::new(vec![0u8; 9].into_boxed_slice()); - assert_eq!(writer.position(), 0); - assert_eq!(writer.write_vectored(&[IoSlice::new(&[0])]).unwrap(), 1); - assert_eq!(writer.position(), 1); - assert_eq!( - writer - .write_vectored(&[IoSlice::new(&[1, 2, 3]), IoSlice::new(&[4, 5, 6, 7]),]) - .unwrap(), - 7, - ); - assert_eq!(writer.position(), 8); - assert_eq!(writer.write_vectored(&[]).unwrap(), 0); - assert_eq!(writer.position(), 8); - - assert_eq!(writer.write_vectored(&[IoSlice::new(&[8, 9])]).unwrap(), 1); - assert_eq!(writer.write_vectored(&[IoSlice::new(&[10])]).unwrap(), 0); - let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8]; - assert_eq!(&**writer.get_ref(), b); - } - - #[test] - fn test_buf_writer() { - let mut buf = [0 as u8; 9]; - { - let mut writer = Cursor::new(&mut buf[..]); - assert_eq!(writer.position(), 0); - assert_eq!(writer.write(&[0]).unwrap(), 1); - assert_eq!(writer.position(), 1); - assert_eq!(writer.write(&[1, 2, 3]).unwrap(), 3); - assert_eq!(writer.write(&[4, 5, 6, 7]).unwrap(), 4); - assert_eq!(writer.position(), 8); - assert_eq!(writer.write(&[]).unwrap(), 0); - assert_eq!(writer.position(), 8); - - assert_eq!(writer.write(&[8, 9]).unwrap(), 1); - assert_eq!(writer.write(&[10]).unwrap(), 0); - } - let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8]; - assert_eq!(buf, b); - } - - #[test] - fn test_buf_writer_vectored() { - let mut buf = [0 as u8; 9]; - { - let mut writer = Cursor::new(&mut buf[..]); - assert_eq!(writer.position(), 0); - assert_eq!(writer.write_vectored(&[IoSlice::new(&[0])]).unwrap(), 1); - assert_eq!(writer.position(), 1); - assert_eq!( - writer - .write_vectored(&[IoSlice::new(&[1, 2, 3]), IoSlice::new(&[4, 5, 6, 7])],) - .unwrap(), - 7, - ); - assert_eq!(writer.position(), 8); - assert_eq!(writer.write_vectored(&[]).unwrap(), 0); - assert_eq!(writer.position(), 8); - - assert_eq!(writer.write_vectored(&[IoSlice::new(&[8, 9])]).unwrap(), 1); - assert_eq!(writer.write_vectored(&[IoSlice::new(&[10])]).unwrap(), 0); - } - let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8]; - assert_eq!(buf, b); - } - - #[test] - fn test_buf_writer_seek() { - let mut buf = [0 as u8; 8]; - { - let mut writer = Cursor::new(&mut buf[..]); - assert_eq!(writer.position(), 0); - assert_eq!(writer.write(&[1]).unwrap(), 1); - assert_eq!(writer.position(), 1); - - assert_eq!(writer.seek(SeekFrom::Start(2)).unwrap(), 2); - assert_eq!(writer.position(), 2); - assert_eq!(writer.write(&[2]).unwrap(), 1); - assert_eq!(writer.position(), 3); - - assert_eq!(writer.seek(SeekFrom::Current(-2)).unwrap(), 1); - assert_eq!(writer.position(), 1); - assert_eq!(writer.write(&[3]).unwrap(), 1); - assert_eq!(writer.position(), 2); - - assert_eq!(writer.seek(SeekFrom::End(-1)).unwrap(), 7); - assert_eq!(writer.position(), 7); - assert_eq!(writer.write(&[4]).unwrap(), 1); - assert_eq!(writer.position(), 8); - } - let b: &[_] = &[1, 3, 2, 0, 0, 0, 0, 4]; - assert_eq!(buf, b); - } - - #[test] - fn test_buf_writer_error() { - let mut buf = [0 as u8; 2]; - let mut writer = Cursor::new(&mut buf[..]); - assert_eq!(writer.write(&[0]).unwrap(), 1); - assert_eq!(writer.write(&[0, 0]).unwrap(), 1); - assert_eq!(writer.write(&[0, 0]).unwrap(), 0); - } - - #[test] - fn test_mem_reader() { - let mut reader = Cursor::new(vec![0, 1, 2, 3, 4, 5, 6, 7]); - let mut buf = []; - assert_eq!(reader.read(&mut buf).unwrap(), 0); - assert_eq!(reader.position(), 0); - let mut buf = [0]; - assert_eq!(reader.read(&mut buf).unwrap(), 1); - assert_eq!(reader.position(), 1); - let b: &[_] = &[0]; - assert_eq!(buf, b); - let mut buf = [0; 4]; - assert_eq!(reader.read(&mut buf).unwrap(), 4); - assert_eq!(reader.position(), 5); - let b: &[_] = &[1, 2, 3, 4]; - assert_eq!(buf, b); - assert_eq!(reader.read(&mut buf).unwrap(), 3); - let b: &[_] = &[5, 6, 7]; - assert_eq!(&buf[..3], b); - assert_eq!(reader.read(&mut buf).unwrap(), 0); - } - - #[test] - fn test_mem_reader_vectored() { - let mut reader = Cursor::new(vec![0, 1, 2, 3, 4, 5, 6, 7]); - let mut buf = []; - assert_eq!(reader.read_vectored(&mut [IoSliceMut::new(&mut buf)]).unwrap(), 0); - assert_eq!(reader.position(), 0); - let mut buf = [0]; - assert_eq!( - reader - .read_vectored(&mut [IoSliceMut::new(&mut []), IoSliceMut::new(&mut buf),]) - .unwrap(), - 1, - ); - assert_eq!(reader.position(), 1); - let b: &[_] = &[0]; - assert_eq!(buf, b); - let mut buf1 = [0; 4]; - let mut buf2 = [0; 4]; - assert_eq!( - reader - .read_vectored(&mut [IoSliceMut::new(&mut buf1), IoSliceMut::new(&mut buf2),]) - .unwrap(), - 7, - ); - let b1: &[_] = &[1, 2, 3, 4]; - let b2: &[_] = &[5, 6, 7]; - assert_eq!(buf1, b1); - assert_eq!(&buf2[..3], b2); - assert_eq!(reader.read(&mut buf).unwrap(), 0); - } - - #[test] - fn test_boxed_slice_reader() { - let mut reader = Cursor::new(vec![0, 1, 2, 3, 4, 5, 6, 7].into_boxed_slice()); - let mut buf = []; - assert_eq!(reader.read(&mut buf).unwrap(), 0); - assert_eq!(reader.position(), 0); - let mut buf = [0]; - assert_eq!(reader.read(&mut buf).unwrap(), 1); - assert_eq!(reader.position(), 1); - let b: &[_] = &[0]; - assert_eq!(buf, b); - let mut buf = [0; 4]; - assert_eq!(reader.read(&mut buf).unwrap(), 4); - assert_eq!(reader.position(), 5); - let b: &[_] = &[1, 2, 3, 4]; - assert_eq!(buf, b); - assert_eq!(reader.read(&mut buf).unwrap(), 3); - let b: &[_] = &[5, 6, 7]; - assert_eq!(&buf[..3], b); - assert_eq!(reader.read(&mut buf).unwrap(), 0); - } - - #[test] - fn test_boxed_slice_reader_vectored() { - let mut reader = Cursor::new(vec![0, 1, 2, 3, 4, 5, 6, 7].into_boxed_slice()); - let mut buf = []; - assert_eq!(reader.read_vectored(&mut [IoSliceMut::new(&mut buf)]).unwrap(), 0); - assert_eq!(reader.position(), 0); - let mut buf = [0]; - assert_eq!( - reader - .read_vectored(&mut [IoSliceMut::new(&mut []), IoSliceMut::new(&mut buf),]) - .unwrap(), - 1, - ); - assert_eq!(reader.position(), 1); - let b: &[_] = &[0]; - assert_eq!(buf, b); - let mut buf1 = [0; 4]; - let mut buf2 = [0; 4]; - assert_eq!( - reader - .read_vectored(&mut [IoSliceMut::new(&mut buf1), IoSliceMut::new(&mut buf2)],) - .unwrap(), - 7, - ); - let b1: &[_] = &[1, 2, 3, 4]; - let b2: &[_] = &[5, 6, 7]; - assert_eq!(buf1, b1); - assert_eq!(&buf2[..3], b2); - assert_eq!(reader.read(&mut buf).unwrap(), 0); - } - - #[test] - fn read_to_end() { - let mut reader = Cursor::new(vec![0, 1, 2, 3, 4, 5, 6, 7]); - let mut v = Vec::new(); - reader.read_to_end(&mut v).unwrap(); - assert_eq!(v, [0, 1, 2, 3, 4, 5, 6, 7]); - } - - #[test] - fn test_slice_reader() { - let in_buf = vec![0, 1, 2, 3, 4, 5, 6, 7]; - let reader = &mut &in_buf[..]; - let mut buf = []; - assert_eq!(reader.read(&mut buf).unwrap(), 0); - let mut buf = [0]; - assert_eq!(reader.read(&mut buf).unwrap(), 1); - assert_eq!(reader.len(), 7); - let b: &[_] = &[0]; - assert_eq!(&buf[..], b); - let mut buf = [0; 4]; - assert_eq!(reader.read(&mut buf).unwrap(), 4); - assert_eq!(reader.len(), 3); - let b: &[_] = &[1, 2, 3, 4]; - assert_eq!(&buf[..], b); - assert_eq!(reader.read(&mut buf).unwrap(), 3); - let b: &[_] = &[5, 6, 7]; - assert_eq!(&buf[..3], b); - assert_eq!(reader.read(&mut buf).unwrap(), 0); - } - - #[test] - fn test_slice_reader_vectored() { - let in_buf = vec![0, 1, 2, 3, 4, 5, 6, 7]; - let reader = &mut &in_buf[..]; - let mut buf = []; - assert_eq!(reader.read_vectored(&mut [IoSliceMut::new(&mut buf)]).unwrap(), 0); - let mut buf = [0]; - assert_eq!( - reader - .read_vectored(&mut [IoSliceMut::new(&mut []), IoSliceMut::new(&mut buf),]) - .unwrap(), - 1, - ); - assert_eq!(reader.len(), 7); - let b: &[_] = &[0]; - assert_eq!(buf, b); - let mut buf1 = [0; 4]; - let mut buf2 = [0; 4]; - assert_eq!( - reader - .read_vectored(&mut [IoSliceMut::new(&mut buf1), IoSliceMut::new(&mut buf2)],) - .unwrap(), - 7, - ); - let b1: &[_] = &[1, 2, 3, 4]; - let b2: &[_] = &[5, 6, 7]; - assert_eq!(buf1, b1); - assert_eq!(&buf2[..3], b2); - assert_eq!(reader.read(&mut buf).unwrap(), 0); - } - - #[test] - fn test_read_exact() { - let in_buf = vec![0, 1, 2, 3, 4, 5, 6, 7]; - let reader = &mut &in_buf[..]; - let mut buf = []; - assert!(reader.read_exact(&mut buf).is_ok()); - let mut buf = [8]; - assert!(reader.read_exact(&mut buf).is_ok()); - assert_eq!(buf[0], 0); - assert_eq!(reader.len(), 7); - let mut buf = [0, 0, 0, 0, 0, 0, 0]; - assert!(reader.read_exact(&mut buf).is_ok()); - assert_eq!(buf, [1, 2, 3, 4, 5, 6, 7]); - assert_eq!(reader.len(), 0); - let mut buf = [0]; - assert!(reader.read_exact(&mut buf).is_err()); - } - - #[test] - fn test_buf_reader() { - let in_buf = vec![0, 1, 2, 3, 4, 5, 6, 7]; - let mut reader = Cursor::new(&in_buf[..]); - let mut buf = []; - assert_eq!(reader.read(&mut buf).unwrap(), 0); - assert_eq!(reader.position(), 0); - let mut buf = [0]; - assert_eq!(reader.read(&mut buf).unwrap(), 1); - assert_eq!(reader.position(), 1); - let b: &[_] = &[0]; - assert_eq!(buf, b); - let mut buf = [0; 4]; - assert_eq!(reader.read(&mut buf).unwrap(), 4); - assert_eq!(reader.position(), 5); - let b: &[_] = &[1, 2, 3, 4]; - assert_eq!(buf, b); - assert_eq!(reader.read(&mut buf).unwrap(), 3); - let b: &[_] = &[5, 6, 7]; - assert_eq!(&buf[..3], b); - assert_eq!(reader.read(&mut buf).unwrap(), 0); - } - - #[test] - fn seek_past_end() { - let buf = [0xff]; - let mut r = Cursor::new(&buf[..]); - assert_eq!(r.seek(SeekFrom::Start(10)).unwrap(), 10); - assert_eq!(r.read(&mut [0]).unwrap(), 0); - - let mut r = Cursor::new(vec![10]); - assert_eq!(r.seek(SeekFrom::Start(10)).unwrap(), 10); - assert_eq!(r.read(&mut [0]).unwrap(), 0); - - let mut buf = [0]; - let mut r = Cursor::new(&mut buf[..]); - assert_eq!(r.seek(SeekFrom::Start(10)).unwrap(), 10); - assert_eq!(r.write(&[3]).unwrap(), 0); - - let mut r = Cursor::new(vec![10].into_boxed_slice()); - assert_eq!(r.seek(SeekFrom::Start(10)).unwrap(), 10); - assert_eq!(r.write(&[3]).unwrap(), 0); - } - - #[test] - fn seek_past_i64() { - let buf = [0xff]; - let mut r = Cursor::new(&buf[..]); - assert_eq!(r.seek(SeekFrom::Start(6)).unwrap(), 6); - assert_eq!(r.seek(SeekFrom::Current(0x7ffffffffffffff0)).unwrap(), 0x7ffffffffffffff6); - assert_eq!(r.seek(SeekFrom::Current(0x10)).unwrap(), 0x8000000000000006); - assert_eq!(r.seek(SeekFrom::Current(0)).unwrap(), 0x8000000000000006); - assert!(r.seek(SeekFrom::Current(0x7ffffffffffffffd)).is_err()); - assert_eq!(r.seek(SeekFrom::Current(-0x8000000000000000)).unwrap(), 6); - - let mut r = Cursor::new(vec![10]); - assert_eq!(r.seek(SeekFrom::Start(6)).unwrap(), 6); - assert_eq!(r.seek(SeekFrom::Current(0x7ffffffffffffff0)).unwrap(), 0x7ffffffffffffff6); - assert_eq!(r.seek(SeekFrom::Current(0x10)).unwrap(), 0x8000000000000006); - assert_eq!(r.seek(SeekFrom::Current(0)).unwrap(), 0x8000000000000006); - assert!(r.seek(SeekFrom::Current(0x7ffffffffffffffd)).is_err()); - assert_eq!(r.seek(SeekFrom::Current(-0x8000000000000000)).unwrap(), 6); - - let mut buf = [0]; - let mut r = Cursor::new(&mut buf[..]); - assert_eq!(r.seek(SeekFrom::Start(6)).unwrap(), 6); - assert_eq!(r.seek(SeekFrom::Current(0x7ffffffffffffff0)).unwrap(), 0x7ffffffffffffff6); - assert_eq!(r.seek(SeekFrom::Current(0x10)).unwrap(), 0x8000000000000006); - assert_eq!(r.seek(SeekFrom::Current(0)).unwrap(), 0x8000000000000006); - assert!(r.seek(SeekFrom::Current(0x7ffffffffffffffd)).is_err()); - assert_eq!(r.seek(SeekFrom::Current(-0x8000000000000000)).unwrap(), 6); - - let mut r = Cursor::new(vec![10].into_boxed_slice()); - assert_eq!(r.seek(SeekFrom::Start(6)).unwrap(), 6); - assert_eq!(r.seek(SeekFrom::Current(0x7ffffffffffffff0)).unwrap(), 0x7ffffffffffffff6); - assert_eq!(r.seek(SeekFrom::Current(0x10)).unwrap(), 0x8000000000000006); - assert_eq!(r.seek(SeekFrom::Current(0)).unwrap(), 0x8000000000000006); - assert!(r.seek(SeekFrom::Current(0x7ffffffffffffffd)).is_err()); - assert_eq!(r.seek(SeekFrom::Current(-0x8000000000000000)).unwrap(), 6); - } - - #[test] - fn seek_before_0() { - let buf = [0xff]; - let mut r = Cursor::new(&buf[..]); - assert!(r.seek(SeekFrom::End(-2)).is_err()); - - let mut r = Cursor::new(vec![10]); - assert!(r.seek(SeekFrom::End(-2)).is_err()); - - let mut buf = [0]; - let mut r = Cursor::new(&mut buf[..]); - assert!(r.seek(SeekFrom::End(-2)).is_err()); - - let mut r = Cursor::new(vec![10].into_boxed_slice()); - assert!(r.seek(SeekFrom::End(-2)).is_err()); - } - - #[test] - fn test_seekable_mem_writer() { - let mut writer = Cursor::new(Vec::::new()); - assert_eq!(writer.position(), 0); - assert_eq!(writer.write(&[0]).unwrap(), 1); - assert_eq!(writer.position(), 1); - assert_eq!(writer.write(&[1, 2, 3]).unwrap(), 3); - assert_eq!(writer.write(&[4, 5, 6, 7]).unwrap(), 4); - assert_eq!(writer.position(), 8); - let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7]; - assert_eq!(&writer.get_ref()[..], b); - - assert_eq!(writer.seek(SeekFrom::Start(0)).unwrap(), 0); - assert_eq!(writer.position(), 0); - assert_eq!(writer.write(&[3, 4]).unwrap(), 2); - let b: &[_] = &[3, 4, 2, 3, 4, 5, 6, 7]; - assert_eq!(&writer.get_ref()[..], b); - - assert_eq!(writer.seek(SeekFrom::Current(1)).unwrap(), 3); - assert_eq!(writer.write(&[0, 1]).unwrap(), 2); - let b: &[_] = &[3, 4, 2, 0, 1, 5, 6, 7]; - assert_eq!(&writer.get_ref()[..], b); - - assert_eq!(writer.seek(SeekFrom::End(-1)).unwrap(), 7); - assert_eq!(writer.write(&[1, 2]).unwrap(), 2); - let b: &[_] = &[3, 4, 2, 0, 1, 5, 6, 1, 2]; - assert_eq!(&writer.get_ref()[..], b); - - assert_eq!(writer.seek(SeekFrom::End(1)).unwrap(), 10); - assert_eq!(writer.write(&[1]).unwrap(), 1); - let b: &[_] = &[3, 4, 2, 0, 1, 5, 6, 1, 2, 0, 1]; - assert_eq!(&writer.get_ref()[..], b); - } - - #[test] - fn vec_seek_past_end() { - let mut r = Cursor::new(Vec::new()); - assert_eq!(r.seek(SeekFrom::Start(10)).unwrap(), 10); - assert_eq!(r.write(&[3]).unwrap(), 1); - } - - #[test] - fn vec_seek_before_0() { - let mut r = Cursor::new(Vec::new()); - assert!(r.seek(SeekFrom::End(-2)).is_err()); - } - - #[test] - #[cfg(target_pointer_width = "32")] - fn vec_seek_and_write_past_usize_max() { - let mut c = Cursor::new(Vec::new()); - c.set_position(::max_value() as u64 + 1); - assert!(c.write_all(&[1, 2, 3]).is_err()); - } - - #[test] - fn test_partial_eq() { - assert_eq!(Cursor::new(Vec::::new()), Cursor::new(Vec::::new())); - } - - #[test] - fn test_eq() { - struct AssertEq(pub T); - - let _: AssertEq>> = AssertEq(Cursor::new(Vec::new())); - } -} diff --git a/libcoreio/src/io/error.rs b/libcoreio/src/io/error.rs deleted file mode 100644 index 0d3945d..0000000 --- a/libcoreio/src/io/error.rs +++ /dev/null @@ -1,551 +0,0 @@ -#[cfg(feature="alloc")] use alloc::boxed::Box; -#[cfg(not(feature="alloc"))] use ::FakeBox as Box; -use core::convert::Into; -use core::fmt; -use core::marker::{Send, Sync}; -use core::option::Option::{self, Some, None}; -use core::result; -#[cfg(feature="collections")] use collections::string::String; -#[cfg(not(feature="collections"))] use ::ErrorString as String; -use core::convert::From; - -/// A specialized [`Result`](../result/enum.Result.html) type for I/O -/// operations. -/// -/// This type is broadly used across [`std::io`] for any operation which may -/// produce an error. -/// -/// This typedef is generally used to avoid writing out [`io::Error`] directly and -/// is otherwise a direct mapping to [`Result`]. -/// -/// While usual Rust style is to import types directly, aliases of [`Result`] -/// often are not, to make it easier to distinguish between them. [`Result`] is -/// generally assumed to be [`std::result::Result`][`Result`], and so users of this alias -/// will generally use `io::Result` instead of shadowing the prelude's import -/// of [`std::result::Result`][`Result`]. -/// -/// [`std::io`]: ../io/index.html -/// [`io::Error`]: ../io/struct.Error.html -/// [`Result`]: ../result/enum.Result.html -/// -/// # Examples -/// -/// A convenience function that bubbles an `io::Result` to its caller: -/// -/// ``` -/// use std::io; -/// -/// fn get_string() -> io::Result { -/// let mut buffer = String::new(); -/// -/// io::stdin().read_line(&mut buffer)?; -/// -/// Ok(buffer) -/// } -/// ``` -pub type Result = result::Result; - -/// The error type for I/O operations of the [`Read`], [`Write`], [`Seek`], and -/// associated traits. -/// -/// Errors mostly originate from the underlying OS, but custom instances of -/// `Error` can be created with crafted error messages and a particular value of -/// [`ErrorKind`]. -/// -/// [`Read`]: ../io/trait.Read.html -/// [`Write`]: ../io/trait.Write.html -/// [`Seek`]: ../io/trait.Seek.html -/// [`ErrorKind`]: enum.ErrorKind.html -pub struct Error { - repr: Repr, -} - -impl fmt::Debug for Error { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - fmt::Debug::fmt(&self.repr, f) - } -} - -enum Repr { - Os(i32), - Simple(ErrorKind), - #[cfg(feature="alloc")] - Custom(Box), - #[cfg(not(feature="alloc"))] - Custom(Custom), -} - -#[derive(Debug)] -struct Custom { - kind: ErrorKind, - error: String, -} - -/// A list specifying general categories of I/O error. -/// -/// This list is intended to grow over time and it is not recommended to -/// exhaustively match against it. -/// -/// It is used with the [`io::Error`] type. -/// -/// [`io::Error`]: struct.Error.html -#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)] -#[allow(deprecated)] -#[non_exhaustive] -pub enum ErrorKind { - /// An entity was not found, often a file. - NotFound, - /// The operation lacked the necessary privileges to complete. - PermissionDenied, - /// The connection was refused by the remote server. - ConnectionRefused, - /// The connection was reset by the remote server. - ConnectionReset, - /// The connection was aborted (terminated) by the remote server. - ConnectionAborted, - /// The network operation failed because it was not connected yet. - NotConnected, - /// A socket address could not be bound because the address is already in - /// use elsewhere. - AddrInUse, - /// A nonexistent interface was requested or the requested address was not - /// local. - AddrNotAvailable, - /// The operation failed because a pipe was closed. - BrokenPipe, - /// An entity already exists, often a file. - AlreadyExists, - /// The operation needs to block to complete, but the blocking operation was - /// requested to not occur. - WouldBlock, - /// A parameter was incorrect. - InvalidInput, - /// Data not valid for the operation were encountered. - /// - /// Unlike [`InvalidInput`], this typically means that the operation - /// parameters were valid, however the error was caused by malformed - /// input data. - /// - /// For example, a function that reads a file into a string will error with - /// `InvalidData` if the file's contents are not valid UTF-8. - /// - /// [`InvalidInput`]: #variant.InvalidInput - InvalidData, - /// The I/O operation's timeout expired, causing it to be canceled. - TimedOut, - /// An error returned when an operation could not be completed because a - /// call to [`write`] returned [`Ok(0)`]. - /// - /// This typically means that an operation could only succeed if it wrote a - /// particular number of bytes but only a smaller number of bytes could be - /// written. - /// - /// [`write`]: ../../std/io/trait.Write.html#tymethod.write - /// [`Ok(0)`]: ../../std/io/type.Result.html - WriteZero, - /// This operation was interrupted. - /// - /// Interrupted operations can typically be retried. - Interrupted, - /// Any I/O error not part of this list. - Other, - - /// An error returned when an operation could not be completed because an - /// "end of file" was reached prematurely. - /// - /// This typically means that an operation could only succeed if it read a - /// particular number of bytes but only a smaller number of bytes could be - /// read. - UnexpectedEof, -} - -impl ErrorKind { - pub(crate) fn as_str(&self) -> &'static str { - match *self { - ErrorKind::NotFound => "entity not found", - ErrorKind::PermissionDenied => "permission denied", - ErrorKind::ConnectionRefused => "connection refused", - ErrorKind::ConnectionReset => "connection reset", - ErrorKind::ConnectionAborted => "connection aborted", - ErrorKind::NotConnected => "not connected", - ErrorKind::AddrInUse => "address in use", - ErrorKind::AddrNotAvailable => "address not available", - ErrorKind::BrokenPipe => "broken pipe", - ErrorKind::AlreadyExists => "entity already exists", - ErrorKind::WouldBlock => "operation would block", - ErrorKind::InvalidInput => "invalid input parameter", - ErrorKind::InvalidData => "invalid data", - ErrorKind::TimedOut => "timed out", - ErrorKind::WriteZero => "write zero", - ErrorKind::Interrupted => "operation interrupted", - ErrorKind::Other => "other os error", - ErrorKind::UnexpectedEof => "unexpected end of file", - } - } -} - -/// Intended for use for errors not exposed to the user, where allocating onto -/// the heap (for normal construction via Error::new) is too costly. -impl From for Error { - /// Converts an [`ErrorKind`] into an [`Error`]. - /// - /// This conversion allocates a new error with a simple representation of error kind. - /// - /// # Examples - /// - /// ``` - /// use std::io::{Error, ErrorKind}; - /// - /// let not_found = ErrorKind::NotFound; - /// let error = Error::from(not_found); - /// assert_eq!("entity not found", format!("{}", error)); - /// ``` - /// - /// [`ErrorKind`]: ../../std/io/enum.ErrorKind.html - /// [`Error`]: ../../std/io/struct.Error.html - #[inline] - fn from(kind: ErrorKind) -> Error { - Error { repr: Repr::Simple(kind) } - } -} - -impl Error { - /// Creates a new I/O error from a known kind of error as well as an - /// arbitrary error payload. - /// - /// This function is used to generically create I/O errors which do not - /// originate from the OS itself. The `error` argument is an arbitrary - /// payload which will be contained in this `Error`. - /// - /// # Examples - /// - /// ``` - /// use std::io::{Error, ErrorKind}; - /// - /// // errors can be created from strings - /// let custom_error = Error::new(ErrorKind::Other, "oh no!"); - /// - /// // errors can also be created from other errors - /// let custom_error2 = Error::new(ErrorKind::Interrupted, custom_error); - /// ``` - pub fn new(kind: ErrorKind, error: E) -> Error - where - E: Into, - { - Self::_new(kind, error.into()) - } - - fn _new(kind: ErrorKind, error: String) -> Error { - Error { repr: Repr::Custom(Box::new(Custom { kind, error })) } - } - - /// Creates a new instance of an `Error` from a particular OS error code. - /// - /// # Examples - /// - /// On Linux: - /// - /// ``` - /// # if cfg!(target_os = "linux") { - /// use std::io; - /// - /// let error = io::Error::from_raw_os_error(22); - /// assert_eq!(error.kind(), io::ErrorKind::InvalidInput); - /// # } - /// ``` - /// - /// On Windows: - /// - /// ``` - /// # if cfg!(windows) { - /// use std::io; - /// - /// let error = io::Error::from_raw_os_error(10022); - /// assert_eq!(error.kind(), io::ErrorKind::InvalidInput); - /// # } - /// ``` - pub fn from_raw_os_error(code: i32) -> Error { - Error { repr: Repr::Os(code) } - } - - /// Returns the OS error that this error represents (if any). - /// - /// If this `Error` was constructed via `last_os_error` or - /// `from_raw_os_error`, then this function will return `Some`, otherwise - /// it will return `None`. - /// - /// # Examples - /// - /// ``` - /// use std::io::{Error, ErrorKind}; - /// - /// fn print_os_error(err: &Error) { - /// if let Some(raw_os_err) = err.raw_os_error() { - /// println!("raw OS error: {:?}", raw_os_err); - /// } else { - /// println!("Not an OS error"); - /// } - /// } - /// - /// fn main() { - /// // Will print "raw OS error: ...". - /// print_os_error(&Error::last_os_error()); - /// // Will print "Not an OS error". - /// print_os_error(&Error::new(ErrorKind::Other, "oh no!")); - /// } - /// ``` - pub fn raw_os_error(&self) -> Option { - match self.repr { - Repr::Os(i) => Some(i), - Repr::Custom(..) => None, - Repr::Simple(..) => None, - } - } - - /// Returns a reference to the inner error wrapped by this error (if any). - /// - /// If this `Error` was constructed via `new` then this function will - /// return `Some`, otherwise it will return `None`. - /// - /// # Examples - /// - /// ``` - /// use std::io::{Error, ErrorKind}; - /// - /// fn print_error(err: &Error) { - /// if let Some(inner_err) = err.get_ref() { - /// println!("Inner error: {:?}", inner_err); - /// } else { - /// println!("No inner error"); - /// } - /// } - /// - /// fn main() { - /// // Will print "No inner error". - /// print_error(&Error::last_os_error()); - /// // Will print "Inner error: ...". - /// print_error(&Error::new(ErrorKind::Other, "oh no!")); - /// } - /// ``` - pub fn get_ref(&self) -> Option<&String> { - match self.repr { - Repr::Os(..) => None, - Repr::Simple(..) => None, - Repr::Custom(ref c) => Some(&c.error), - } - } - - /// Returns a mutable reference to the inner error wrapped by this error - /// (if any). - /// - /// If this `Error` was constructed via `new` then this function will - /// return `Some`, otherwise it will return `None`. - /// - /// # Examples - /// - /// ``` - /// use std::io::{Error, ErrorKind}; - /// use std::{error, fmt}; - /// use std::fmt::Display; - /// - /// #[derive(Debug)] - /// struct MyError { - /// v: String, - /// } - /// - /// impl MyError { - /// fn new() -> MyError { - /// MyError { - /// v: "oh no!".to_string() - /// } - /// } - /// - /// fn change_message(&mut self, new_message: &str) { - /// self.v = new_message.to_string(); - /// } - /// } - /// - /// impl error::Error for MyError {} - /// - /// impl Display for MyError { - /// fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - /// write!(f, "MyError: {}", &self.v) - /// } - /// } - /// - /// fn change_error(mut err: Error) -> Error { - /// if let Some(inner_err) = err.get_mut() { - /// inner_err.downcast_mut::().unwrap().change_message("I've been changed!"); - /// } - /// err - /// } - /// - /// fn print_error(err: &Error) { - /// if let Some(inner_err) = err.get_ref() { - /// println!("Inner error: {}", inner_err); - /// } else { - /// println!("No inner error"); - /// } - /// } - /// - /// fn main() { - /// // Will print "No inner error". - /// print_error(&change_error(Error::last_os_error())); - /// // Will print "Inner error: ...". - /// print_error(&change_error(Error::new(ErrorKind::Other, MyError::new()))); - /// } - /// ``` - pub fn get_mut(&mut self) -> Option<&mut String> { - match self.repr { - Repr::Os(..) => None, - Repr::Simple(..) => None, - Repr::Custom(ref mut c) => Some(&mut c.error), - } - } - - /// Consumes the `Error`, returning its inner error (if any). - /// - /// If this `Error` was constructed via `new` then this function will - /// return `Some`, otherwise it will return `None`. - /// - /// # Examples - /// - /// ``` - /// use std::io::{Error, ErrorKind}; - /// - /// fn print_error(err: Error) { - /// if let Some(inner_err) = err.into_inner() { - /// println!("Inner error: {}", inner_err); - /// } else { - /// println!("No inner error"); - /// } - /// } - /// - /// fn main() { - /// // Will print "No inner error". - /// print_error(Error::last_os_error()); - /// // Will print "Inner error: ...". - /// print_error(Error::new(ErrorKind::Other, "oh no!")); - /// } - /// ``` - pub fn into_inner(self) -> Option { - match self.repr { - Repr::Os(..) => None, - Repr::Simple(..) => None, - Repr::Custom(c) => Some(c.error), - } - } - - /// Returns the corresponding `ErrorKind` for this error. - /// - /// # Examples - /// - /// ``` - /// use std::io::{Error, ErrorKind}; - /// - /// fn print_error(err: Error) { - /// println!("{:?}", err.kind()); - /// } - /// - /// fn main() { - /// // Will print "No inner error". - /// print_error(Error::last_os_error()); - /// // Will print "Inner error: ...". - /// print_error(Error::new(ErrorKind::AddrInUse, "oh no!")); - /// } - /// ``` - pub fn kind(&self) -> ErrorKind { - match self.repr { - Repr::Os(_code) => ErrorKind::Other, - Repr::Custom(ref c) => c.kind, - Repr::Simple(kind) => kind, - } - } -} - -impl fmt::Debug for Repr { - fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { - match *self { - Repr::Os(code) => fmt - .debug_struct("Os") - .field("code", &code) - .finish(), - Repr::Custom(ref c) => fmt::Debug::fmt(&c, fmt), - Repr::Simple(kind) => fmt.debug_tuple("Kind").field(&kind).finish(), - } - } -} - -impl fmt::Display for Error { - fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { - match self.repr { - Repr::Os(code) => { - write!(fmt, "os error {}", code) - } - Repr::Custom(ref c) => c.error.fmt(fmt), - Repr::Simple(kind) => write!(fmt, "{}", kind.as_str()), - } - } -} - -fn _assert_error_is_sync_send() { - fn _is_sync_send() {} - _is_sync_send::(); -} - -#[cfg(test)] -mod test { - use super::{Custom, Error, ErrorKind, Repr}; - use crate::error; - use crate::fmt; - use crate::sys::decode_error_kind; - use crate::sys::os::error_string; - - #[test] - fn test_debug_error() { - let code = 6; - let msg = error_string(code); - let kind = decode_error_kind(code); - let err = Error { - repr: Repr::Custom(box Custom { - kind: ErrorKind::InvalidInput, - error: box Error { repr: super::Repr::Os(code) }, - }), - }; - let expected = format!( - "Custom {{ \ - kind: InvalidInput, \ - error: Os {{ \ - code: {:?}, \ - kind: {:?}, \ - message: {:?} \ - }} \ - }}", - code, kind, msg - ); - assert_eq!(format!("{:?}", err), expected); - } - - #[test] - fn test_downcasting() { - #[derive(Debug)] - struct TestError; - - impl fmt::Display for TestError { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - f.write_str("asdf") - } - } - - impl error::Error for TestError {} - - // we have to call all of these UFCS style right now since method - // resolution won't implicitly drop the Send+Sync bounds - let mut err = Error::new(ErrorKind::Other, TestError); - assert!(err.get_ref().unwrap().is::()); - assert_eq!("asdf", err.get_ref().unwrap().to_string()); - assert!(err.get_mut().unwrap().is::()); - let extracted = err.into_inner().unwrap(); - extracted.downcast::().unwrap(); - } -} diff --git a/libcoreio/src/io/impls.rs b/libcoreio/src/io/impls.rs deleted file mode 100644 index a51d20b..0000000 --- a/libcoreio/src/io/impls.rs +++ /dev/null @@ -1,378 +0,0 @@ -use core::cmp; -use core::fmt; -use crate::io::{ - self, Error, ErrorKind, Initializer, Read, Seek, SeekFrom, Write, -}; -#[cfg(feature = "collections")] use crate::io::BufRead; -use core::mem; - -#[cfg(feature="collections")] -use collections::{ - vec::Vec, - string::String, -}; -#[cfg(feature = "alloc")] -use alloc::boxed::Box; - -// ============================================================================= -// Forwarding implementations - -impl Read for &mut R { - #[inline] - fn read(&mut self, buf: &mut [u8]) -> io::Result { - (**self).read(buf) - } - - #[inline] - unsafe fn initializer(&self) -> Initializer { - (**self).initializer() - } - - #[cfg(feature="collections")] - #[inline] - fn read_to_end(&mut self, buf: &mut Vec) -> io::Result { - (**self).read_to_end(buf) - } - - #[cfg(feature="collections")] - #[inline] - fn read_to_string(&mut self, buf: &mut String) -> io::Result { - (**self).read_to_string(buf) - } - - #[inline] - fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> { - (**self).read_exact(buf) - } -} -impl Write for &mut W { - #[inline] - fn write(&mut self, buf: &[u8]) -> io::Result { - (**self).write(buf) - } - - #[inline] - fn flush(&mut self) -> io::Result<()> { - (**self).flush() - } - - #[inline] - fn write_all(&mut self, buf: &[u8]) -> io::Result<()> { - (**self).write_all(buf) - } - - #[inline] - fn write_fmt(&mut self, fmt: fmt::Arguments<'_>) -> io::Result<()> { - (**self).write_fmt(fmt) - } -} -impl Seek for &mut S { - #[inline] - fn seek(&mut self, pos: SeekFrom) -> io::Result { - (**self).seek(pos) - } -} -#[cfg(feature = "collections")] -impl BufRead for &mut B { - #[inline] - fn fill_buf(&mut self) -> io::Result<&[u8]> { - (**self).fill_buf() - } - - #[inline] - fn consume(&mut self, amt: usize) { - (**self).consume(amt) - } - - #[cfg(feature="collections")] - #[inline] - fn read_until(&mut self, byte: u8, buf: &mut Vec) -> io::Result { - (**self).read_until(byte, buf) - } - - #[cfg(feature="collections")] - #[inline] - fn read_line(&mut self, buf: &mut String) -> io::Result { - (**self).read_line(buf) - } -} - -#[cfg(feature="alloc")] -#[cfg(feature="collections")] -impl Read for Box { - #[inline] - fn read(&mut self, buf: &mut [u8]) -> io::Result { - (**self).read(buf) - } - - #[cfg(feature="collections")] - #[inline] - fn read_to_end(&mut self, buf: &mut Vec) -> io::Result { - (**self).read_to_end(buf) - } - - #[cfg(feature="collections")] - #[inline] - fn read_to_string(&mut self, buf: &mut String) -> io::Result { - (**self).read_to_string(buf) - } - - #[inline] - fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> { - (**self).read_exact(buf) - } -} -#[cfg(feature="alloc")] -#[cfg(feature="collections")] -impl Write for Box { - #[inline] - fn write(&mut self, buf: &[u8]) -> io::Result { - (**self).write(buf) - } - - #[inline] - fn flush(&mut self) -> io::Result<()> { - (**self).flush() - } - - #[inline] - fn write_all(&mut self, buf: &[u8]) -> io::Result<()> { - (**self).write_all(buf) - } - - #[inline] - fn write_fmt(&mut self, fmt: fmt::Arguments<'_>) -> io::Result<()> { - (**self).write_fmt(fmt) - } -} -#[cfg(feature="collections")] -impl Seek for Box { - #[inline] - fn seek(&mut self, pos: SeekFrom) -> io::Result { - (**self).seek(pos) - } -} -#[cfg(feature="collections")] -impl BufRead for Box { - #[inline] - fn fill_buf(&mut self) -> io::Result<&[u8]> { - (**self).fill_buf() - } - - #[inline] - fn consume(&mut self, amt: usize) { - (**self).consume(amt) - } - - #[inline] - fn read_until(&mut self, byte: u8, buf: &mut Vec) -> io::Result { - (**self).read_until(byte, buf) - } - - #[inline] - fn read_line(&mut self, buf: &mut String) -> io::Result { - (**self).read_line(buf) - } -} - -// Used by panicking::default_hook -#[cfg(test)] -/// This impl is only used by printing logic, so any error returned is always -/// of kind `Other`, and should be ignored. -#[cfg(feature="collections")] -impl Write for Box { - fn write(&mut self, buf: &[u8]) -> io::Result { - (**self).write(buf).map_err(|_| ErrorKind::Other.into()) - } - - fn flush(&mut self) -> io::Result<()> { - (**self).flush().map_err(|_| ErrorKind::Other.into()) - } -} - -// ============================================================================= -// In-memory buffer implementations - -/// Read is implemented for `&[u8]` by copying from the slice. -/// -/// Note that reading updates the slice to point to the yet unread part. -/// The slice will be empty when EOF is reached. -impl Read for &[u8] { - #[inline] - fn read(&mut self, buf: &mut [u8]) -> io::Result { - let amt = cmp::min(buf.len(), self.len()); - let (a, b) = self.split_at(amt); - - // First check if the amount of bytes we want to read is small: - // `copy_from_slice` will generally expand to a call to `memcpy`, and - // for a single byte the overhead is significant. - if amt == 1 { - buf[0] = a[0]; - } else { - buf[..amt].copy_from_slice(a); - } - - *self = b; - Ok(amt) - } - - #[inline] - unsafe fn initializer(&self) -> Initializer { - Initializer::nop() - } - - #[inline] - fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> { - if buf.len() > self.len() { - return Err(Error::new(ErrorKind::UnexpectedEof, "failed to fill whole buffer")); - } - let (a, b) = self.split_at(buf.len()); - - // First check if the amount of bytes we want to read is small: - // `copy_from_slice` will generally expand to a call to `memcpy`, and - // for a single byte the overhead is significant. - if buf.len() == 1 { - buf[0] = a[0]; - } else { - buf.copy_from_slice(a); - } - - *self = b; - Ok(()) - } - - #[cfg(feature="collections")] - #[inline] - fn read_to_end(&mut self, buf: &mut Vec) -> io::Result { - buf.extend_from_slice(*self); - let len = self.len(); - *self = &self[len..]; - Ok(len) - } -} - -#[cfg(feature="collections")] -impl BufRead for &[u8] { - #[inline] - fn fill_buf(&mut self) -> io::Result<&[u8]> { - Ok(*self) - } - - #[inline] - fn consume(&mut self, amt: usize) { - *self = &self[amt..]; - } -} - -/// Write is implemented for `&mut [u8]` by copying into the slice, overwriting -/// its data. -/// -/// Note that writing updates the slice to point to the yet unwritten part. -/// The slice will be empty when it has been completely overwritten. -impl Write for &mut [u8] { - #[inline] - fn write(&mut self, data: &[u8]) -> io::Result { - let amt = cmp::min(data.len(), self.len()); - let (a, b) = mem::replace(self, &mut []).split_at_mut(amt); - a.copy_from_slice(&data[..amt]); - *self = b; - Ok(amt) - } - - #[inline] - fn write_all(&mut self, data: &[u8]) -> io::Result<()> { - if self.write(data)? == data.len() { - Ok(()) - } else { - Err(Error::new(ErrorKind::WriteZero, "failed to write whole buffer")) - } - } - - #[inline] - fn flush(&mut self) -> io::Result<()> { - Ok(()) - } -} - -/// Write is implemented for `Vec` by appending to the vector. -/// The vector will grow as needed. -#[cfg(feature="collections")] -impl Write for Vec { - #[inline] - fn write(&mut self, buf: &[u8]) -> io::Result { - self.extend_from_slice(buf); - Ok(buf.len()) - } - - #[inline] - fn write_all(&mut self, buf: &[u8]) -> io::Result<()> { - self.extend_from_slice(buf); - Ok(()) - } - - #[inline] - fn flush(&mut self) -> io::Result<()> { - Ok(()) - } -} - -#[cfg(test)] -mod tests { - use crate::io::prelude::*; - - #[bench] - fn bench_read_slice(b: &mut test::Bencher) { - let buf = [5; 1024]; - let mut dst = [0; 128]; - - b.iter(|| { - let mut rd = &buf[..]; - for _ in 0..8 { - let _ = rd.read(&mut dst); - test::black_box(&dst); - } - }) - } - - #[bench] - fn bench_write_slice(b: &mut test::Bencher) { - let mut buf = [0; 1024]; - let src = [5; 128]; - - b.iter(|| { - let mut wr = &mut buf[..]; - for _ in 0..8 { - let _ = wr.write_all(&src); - test::black_box(&wr); - } - }) - } - - #[bench] - fn bench_read_vec(b: &mut test::Bencher) { - let buf = vec![5; 1024]; - let mut dst = [0; 128]; - - b.iter(|| { - let mut rd = &buf[..]; - for _ in 0..8 { - let _ = rd.read(&mut dst); - test::black_box(&dst); - } - }) - } - - #[bench] - fn bench_write_vec(b: &mut test::Bencher) { - let mut buf = Vec::with_capacity(1024); - let src = [5; 128]; - - b.iter(|| { - let mut wr = &mut buf[..]; - for _ in 0..8 { - let _ = wr.write_all(&src); - test::black_box(&wr); - } - }) - } -} diff --git a/libcoreio/src/io/mod.rs b/libcoreio/src/io/mod.rs deleted file mode 100644 index b058265..0000000 --- a/libcoreio/src/io/mod.rs +++ /dev/null @@ -1,2664 +0,0 @@ -//! Traits, helpers, and type definitions for core I/O functionality. -//! -//! The `std::io` module contains a number of common things you'll need -//! when doing input and output. The most core part of this module is -//! the [`Read`] and [`Write`] traits, which provide the -//! most general interface for reading and writing input and output. -//! -//! # Read and Write -//! -//! Because they are traits, [`Read`] and [`Write`] are implemented by a number -//! of other types, and you can implement them for your types too. As such, -//! you'll see a few different types of I/O throughout the documentation in -//! this module: [`File`]s, [`TcpStream`]s, and sometimes even [`Vec`]s. For -//! example, [`Read`] adds a [`read`][`Read::read`] method, which we can use on -//! [`File`]s: -//! -//! ```no_run -//! use std::io; -//! use std::io::prelude::*; -//! use std::fs::File; -//! -//! fn main() -> io::Result<()> { -//! let mut f = File::open("foo.txt")?; -//! let mut buffer = [0; 10]; -//! -//! // read up to 10 bytes -//! let n = f.read(&mut buffer)?; -//! -//! println!("The bytes: {:?}", &buffer[..n]); -//! Ok(()) -//! } -//! ``` -//! -//! [`Read`] and [`Write`] are so important, implementors of the two traits have a -//! nickname: readers and writers. So you'll sometimes see 'a reader' instead -//! of 'a type that implements the [`Read`] trait'. Much easier! -//! -//! ## Seek and BufRead -//! -//! Beyond that, there are two important traits that are provided: [`Seek`] -//! and [`BufRead`]. Both of these build on top of a reader to control -//! how the reading happens. [`Seek`] lets you control where the next byte is -//! coming from: -//! -//! ```no_run -//! use std::io; -//! use std::io::prelude::*; -//! use std::io::SeekFrom; -//! use std::fs::File; -//! -//! fn main() -> io::Result<()> { -//! let mut f = File::open("foo.txt")?; -//! let mut buffer = [0; 10]; -//! -//! // skip to the last 10 bytes of the file -//! f.seek(SeekFrom::End(-10))?; -//! -//! // read up to 10 bytes -//! let n = f.read(&mut buffer)?; -//! -//! println!("The bytes: {:?}", &buffer[..n]); -//! Ok(()) -//! } -//! ``` -//! -//! [`BufRead`] uses an internal buffer to provide a number of other ways to read, but -//! to show it off, we'll need to talk about buffers in general. Keep reading! -//! -//! ## BufReader and BufWriter -//! -//! Byte-based interfaces are unwieldy and can be inefficient, as we'd need to be -//! making near-constant calls to the operating system. To help with this, -//! `std::io` comes with two structs, [`BufReader`] and [`BufWriter`], which wrap -//! readers and writers. The wrapper uses a buffer, reducing the number of -//! calls and providing nicer methods for accessing exactly what you want. -//! -//! For example, [`BufReader`] works with the [`BufRead`] trait to add extra -//! methods to any reader: -//! -//! ```no_run -//! use std::io; -//! use std::io::prelude::*; -//! use std::io::BufReader; -//! use std::fs::File; -//! -//! fn main() -> io::Result<()> { -//! let f = File::open("foo.txt")?; -//! let mut reader = BufReader::new(f); -//! let mut buffer = String::new(); -//! -//! // read a line into buffer -//! reader.read_line(&mut buffer)?; -//! -//! println!("{}", buffer); -//! Ok(()) -//! } -//! ``` -//! -//! [`BufWriter`] doesn't add any new ways of writing; it just buffers every call -//! to [`write`][`Write::write`]: -//! -//! ```no_run -//! use std::io; -//! use std::io::prelude::*; -//! use std::io::BufWriter; -//! use std::fs::File; -//! -//! fn main() -> io::Result<()> { -//! let f = File::create("foo.txt")?; -//! { -//! let mut writer = BufWriter::new(f); -//! -//! // write a byte to the buffer -//! writer.write(&[42])?; -//! -//! } // the buffer is flushed once writer goes out of scope -//! -//! Ok(()) -//! } -//! ``` -//! -//! ## Standard input and output -//! -//! A very common source of input is standard input: -//! -//! ```no_run -//! use std::io; -//! -//! fn main() -> io::Result<()> { -//! let mut input = String::new(); -//! -//! io::stdin().read_line(&mut input)?; -//! -//! println!("You typed: {}", input.trim()); -//! Ok(()) -//! } -//! ``` -//! -//! Note that you cannot use the [`?` operator] in functions that do not return -//! a [`Result`][`Result`]. Instead, you can call [`.unwrap()`] -//! or `match` on the return value to catch any possible errors: -//! -//! ```no_run -//! use std::io; -//! -//! let mut input = String::new(); -//! -//! io::stdin().read_line(&mut input).unwrap(); -//! ``` -//! -//! And a very common source of output is standard output: -//! -//! ```no_run -//! use std::io; -//! use std::io::prelude::*; -//! -//! fn main() -> io::Result<()> { -//! io::stdout().write(&[42])?; -//! Ok(()) -//! } -//! ``` -//! -//! Of course, using [`io::stdout`] directly is less common than something like -//! [`println!`]. -//! -//! ## Iterator types -//! -//! A large number of the structures provided by `std::io` are for various -//! ways of iterating over I/O. For example, [`Lines`] is used to split over -//! lines: -//! -//! ```no_run -//! use std::io; -//! use std::io::prelude::*; -//! use std::io::BufReader; -//! use std::fs::File; -//! -//! fn main() -> io::Result<()> { -//! let f = File::open("foo.txt")?; -//! let reader = BufReader::new(f); -//! -//! for line in reader.lines() { -//! println!("{}", line?); -//! } -//! Ok(()) -//! } -//! ``` -//! -//! ## Functions -//! -//! There are a number of [functions][functions-list] that offer access to various -//! features. For example, we can use three of these functions to copy everything -//! from standard input to standard output: -//! -//! ```no_run -//! use std::io; -//! -//! fn main() -> io::Result<()> { -//! io::copy(&mut io::stdin(), &mut io::stdout())?; -//! Ok(()) -//! } -//! ``` -//! -//! [functions-list]: #functions-1 -//! -//! ## io::Result -//! -//! Last, but certainly not least, is [`io::Result`]. This type is used -//! as the return type of many `std::io` functions that can cause an error, and -//! can be returned from your own functions as well. Many of the examples in this -//! module use the [`?` operator]: -//! -//! ``` -//! use std::io; -//! -//! fn read_input() -> io::Result<()> { -//! let mut input = String::new(); -//! -//! io::stdin().read_line(&mut input)?; -//! -//! println!("You typed: {}", input.trim()); -//! -//! Ok(()) -//! } -//! ``` -//! -//! The return type of `read_input()`, [`io::Result<()>`][`io::Result`], is a very -//! common type for functions which don't have a 'real' return value, but do want to -//! return errors if they happen. In this case, the only purpose of this function is -//! to read the line and print it, so we use `()`. -//! -//! ## Platform-specific behavior -//! -//! Many I/O functions throughout the standard library are documented to indicate -//! what various library or syscalls they are delegated to. This is done to help -//! applications both understand what's happening under the hood as well as investigate -//! any possibly unclear semantics. Note, however, that this is informative, not a binding -//! contract. The implementation of many of these functions are subject to change over -//! time and may call fewer or more syscalls/library functions. -//! -//! [`Read`]: trait.Read.html -//! [`Write`]: trait.Write.html -//! [`Seek`]: trait.Seek.html -//! [`BufRead`]: trait.BufRead.html -//! [`File`]: ../fs/struct.File.html -//! [`TcpStream`]: ../net/struct.TcpStream.html -//! [`Vec`]: ../vec/struct.Vec.html -//! [`BufReader`]: struct.BufReader.html -//! [`BufWriter`]: struct.BufWriter.html -//! [`Write::write`]: trait.Write.html#tymethod.write -//! [`io::stdout`]: fn.stdout.html -//! [`println!`]: ../macro.println.html -//! [`Lines`]: struct.Lines.html -//! [`io::Result`]: type.Result.html -//! [`?` operator]: ../../book/appendix-02-operators.html -//! [`Read::read`]: trait.Read.html#tymethod.read -//! [`Result`]: ../result/enum.Result.html -//! [`.unwrap()`]: ../result/enum.Result.html#method.unwrap - -use core::cmp; -use core::fmt; -use core::ptr; -use core::slice; -use core::str; - -#[cfg(feature="collections")] pub use self::buffered::IntoInnerError; -#[cfg(feature="collections")] pub use self::buffered::{BufReader, BufWriter, LineWriter}; - -pub use self::cursor::Cursor; -pub use self::error::{Error, ErrorKind, Result}; -pub use self::util::{copy, empty, repeat, sink, Empty, Repeat, Sink}; - -#[cfg(feature="collections")] mod buffered; -mod cursor; -mod error; -mod impls; -pub mod prelude; -mod util; - -#[cfg(feature="collections")] -use collections::{ - vec::Vec, - string::String, -}; - -const DEFAULT_BUF_SIZE: usize = 8 * 1024; - -#[cfg(feature="collections")] -struct Guard<'a> { - buf: &'a mut Vec, - len: usize, -} - -#[cfg(feature="collections")] -impl Drop for Guard<'_> { - fn drop(&mut self) { - unsafe { - self.buf.set_len(self.len); - } - } -} - -// A few methods below (read_to_string, read_line) will append data into a -// `String` buffer, but we need to be pretty careful when doing this. The -// implementation will just call `.as_mut_vec()` and then delegate to a -// byte-oriented reading method, but we must ensure that when returning we never -// leave `buf` in a state such that it contains invalid UTF-8 in its bounds. -// -// To this end, we use an RAII guard (to protect against panics) which updates -// the length of the string when it is dropped. This guard initially truncates -// the string to the prior length and only after we've validated that the -// new contents are valid UTF-8 do we allow it to set a longer length. -// -// The unsafety in this function is twofold: -// -// 1. We're looking at the raw bytes of `buf`, so we take on the burden of UTF-8 -// checks. -// 2. We're passing a raw buffer to the function `f`, and it is expected that -// the function only *appends* bytes to the buffer. We'll get undefined -// behavior if existing bytes are overwritten to have non-UTF-8 data. -#[cfg(feature="collections")] -fn append_to_string(buf: &mut String, f: F) -> Result -where - F: FnOnce(&mut Vec) -> Result, -{ - unsafe { - let mut g = Guard { len: buf.len(), buf: buf.as_mut_vec() }; - let ret = f(g.buf); - if str::from_utf8(&g.buf[g.len..]).is_err() { - ret.and_then(|_| { - Err(Error::new(ErrorKind::InvalidData, "stream did not contain valid UTF-8")) - }) - } else { - g.len = g.buf.len(); - ret - } - } -} - -// This uses an adaptive system to extend the vector when it fills. We want to -// avoid paying to allocate and zero a huge chunk of memory if the reader only -// has 4 bytes while still making large reads if the reader does have a ton -// of data to return. Simply tacking on an extra DEFAULT_BUF_SIZE space every -// time is 4,500 times (!) slower than a default reservation size of 32 if the -// reader has a very small amount of data to return. -// -// Because we're extending the buffer with uninitialized data for trusted -// readers, we need to make sure to truncate that if any of this panics. -#[cfg(feature="collections")] -fn read_to_end(r: &mut R, buf: &mut Vec) -> Result { - read_to_end_with_reservation(r, buf, |_| 32) -} - -#[cfg(feature="collections")] -fn read_to_end_with_reservation( - r: &mut R, - buf: &mut Vec, - mut reservation_size: F, -) -> Result -where - R: Read + ?Sized, - F: FnMut(&R) -> usize, -{ - let start_len = buf.len(); - let mut g = Guard { len: buf.len(), buf }; - let ret; - loop { - if g.len == g.buf.len() { - unsafe { - // FIXME(danielhenrymantilla): #42788 - // - // - This creates a (mut) reference to a slice of - // _uninitialized_ integers, which is **undefined behavior** - // - // - Only the standard library gets to soundly "ignore" this, - // based on its privileged knowledge of unstable rustc - // internals; - g.buf.reserve(reservation_size(r)); - let capacity = g.buf.capacity(); - g.buf.set_len(capacity); - r.initializer().initialize(&mut g.buf[g.len..]); - } - } - - match r.read(&mut g.buf[g.len..]) { - Ok(0) => { - ret = Ok(g.len - start_len); - break; - } - Ok(n) => g.len += n, - Err(ref e) if e.kind() == ErrorKind::Interrupted => {} - Err(e) => { - ret = Err(e); - break; - } - } - } - - ret -} - -/// The `Read` trait allows for reading bytes from a source. -/// -/// Implementors of the `Read` trait are called 'readers'. -/// -/// Readers are defined by one required method, [`read()`]. Each call to [`read()`] -/// will attempt to pull bytes from this source into a provided buffer. A -/// number of other methods are implemented in terms of [`read()`], giving -/// implementors a number of ways to read bytes while only needing to implement -/// a single method. -/// -/// Readers are intended to be composable with one another. Many implementors -/// throughout [`std::io`] take and provide types which implement the `Read` -/// trait. -/// -/// Please note that each call to [`read()`] may involve a system call, and -/// therefore, using something that implements [`BufRead`], such as -/// [`BufReader`], will be more efficient. -/// -/// # Examples -/// -/// [`File`]s implement `Read`: -/// -/// ```no_run -/// use std::io; -/// use std::io::prelude::*; -/// use std::fs::File; -/// -/// fn main() -> io::Result<()> { -/// let mut f = File::open("foo.txt")?; -/// let mut buffer = [0; 10]; -/// -/// // read up to 10 bytes -/// f.read(&mut buffer)?; -/// -/// let mut buffer = Vec::new(); -/// // read the whole file -/// f.read_to_end(&mut buffer)?; -/// -/// // read into a String, so that you don't need to do the conversion. -/// let mut buffer = String::new(); -/// f.read_to_string(&mut buffer)?; -/// -/// // and more! See the other methods for more details. -/// Ok(()) -/// } -/// ``` -/// -/// Read from [`&str`] because [`&[u8]`][slice] implements `Read`: -/// -/// ```no_run -/// # use std::io; -/// use std::io::prelude::*; -/// -/// fn main() -> io::Result<()> { -/// let mut b = "This string will be read".as_bytes(); -/// let mut buffer = [0; 10]; -/// -/// // read up to 10 bytes -/// b.read(&mut buffer)?; -/// -/// // etc... it works exactly as a File does! -/// Ok(()) -/// } -/// ``` -/// -/// [`read()`]: trait.Read.html#tymethod.read -/// [`std::io`]: ../../std/io/index.html -/// [`File`]: ../fs/struct.File.html -/// [`BufRead`]: trait.BufRead.html -/// [`BufReader`]: struct.BufReader.html -/// [`&str`]: ../../std/primitive.str.html -/// [slice]: ../../std/primitive.slice.html -pub trait Read { - /// Pull some bytes from this source into the specified buffer, returning - /// how many bytes were read. - /// - /// This function does not provide any guarantees about whether it blocks - /// waiting for data, but if an object needs to block for a read and cannot, - /// it will typically signal this via an [`Err`] return value. - /// - /// If the return value of this method is [`Ok(n)`], then it must be - /// guaranteed that `0 <= n <= buf.len()`. A nonzero `n` value indicates - /// that the buffer `buf` has been filled in with `n` bytes of data from this - /// source. If `n` is `0`, then it can indicate one of two scenarios: - /// - /// 1. This reader has reached its "end of file" and will likely no longer - /// be able to produce bytes. Note that this does not mean that the - /// reader will *always* no longer be able to produce bytes. - /// 2. The buffer specified was 0 bytes in length. - /// - /// No guarantees are provided about the contents of `buf` when this - /// function is called, implementations cannot rely on any property of the - /// contents of `buf` being true. It is recommended that *implementations* - /// only write data to `buf` instead of reading its contents. - /// - /// Correspondingly, however, *callers* of this method may not assume any guarantees - /// about how the implementation uses `buf`. The trait is safe to implement, - /// so it is possible that the code that's supposed to write to the buffer might also read - /// from it. It is your responsibility to make sure that `buf` is initialized - /// before calling `read`. Calling `read` with an uninitialized `buf` (of the kind one - /// obtains via [`MaybeUninit`]) is not safe, and can lead to undefined behavior. - /// - /// [`MaybeUninit`]: ../mem/union.MaybeUninit.html - /// - /// # Errors - /// - /// If this function encounters any form of I/O or other error, an error - /// variant will be returned. If an error is returned then it must be - /// guaranteed that no bytes were read. - /// - /// An error of the [`ErrorKind::Interrupted`] kind is non-fatal and the read - /// operation should be retried if there is nothing else to do. - /// - /// # Examples - /// - /// [`File`]s implement `Read`: - /// - /// [`Err`]: ../../std/result/enum.Result.html#variant.Err - /// [`Ok(n)`]: ../../std/result/enum.Result.html#variant.Ok - /// [`ErrorKind::Interrupted`]: ../../std/io/enum.ErrorKind.html#variant.Interrupted - /// [`File`]: ../fs/struct.File.html - /// - /// ```no_run - /// use std::io; - /// use std::io::prelude::*; - /// use std::fs::File; - /// - /// fn main() -> io::Result<()> { - /// let mut f = File::open("foo.txt")?; - /// let mut buffer = [0; 10]; - /// - /// // read up to 10 bytes - /// let n = f.read(&mut buffer[..])?; - /// - /// println!("The bytes: {:?}", &buffer[..n]); - /// Ok(()) - /// } - /// ``` - fn read(&mut self, buf: &mut [u8]) -> Result; - - /// Determines if this `Read`er can work with buffers of uninitialized - /// memory. - /// - /// The default implementation returns an initializer which will zero - /// buffers. - /// - /// If a `Read`er guarantees that it can work properly with uninitialized - /// memory, it should call [`Initializer::nop()`]. See the documentation for - /// [`Initializer`] for details. - /// - /// The behavior of this method must be independent of the state of the - /// `Read`er - the method only takes `&self` so that it can be used through - /// trait objects. - /// - /// # Safety - /// - /// This method is unsafe because a `Read`er could otherwise return a - /// non-zeroing `Initializer` from another `Read` type without an `unsafe` - /// block. - /// - /// [`Initializer::nop()`]: ../../std/io/struct.Initializer.html#method.nop - /// [`Initializer`]: ../../std/io/struct.Initializer.html - #[inline] - unsafe fn initializer(&self) -> Initializer { - Initializer::zeroing() - } - - /// Read all bytes until EOF in this source, placing them into `buf`. - /// - /// All bytes read from this source will be appended to the specified buffer - /// `buf`. This function will continuously call [`read()`] to append more data to - /// `buf` until [`read()`] returns either [`Ok(0)`] or an error of - /// non-[`ErrorKind::Interrupted`] kind. - /// - /// If successful, this function will return the total number of bytes read. - /// - /// # Errors - /// - /// If this function encounters an error of the kind - /// [`ErrorKind::Interrupted`] then the error is ignored and the operation - /// will continue. - /// - /// If any other read error is encountered then this function immediately - /// returns. Any bytes which have already been read will be appended to - /// `buf`. - /// - /// # Examples - /// - /// [`File`]s implement `Read`: - /// - /// [`read()`]: trait.Read.html#tymethod.read - /// [`Ok(0)`]: ../../std/result/enum.Result.html#variant.Ok - /// [`ErrorKind::Interrupted`]: ../../std/io/enum.ErrorKind.html#variant.Interrupted - /// [`File`]: ../fs/struct.File.html - /// - /// ```no_run - /// use std::io; - /// use std::io::prelude::*; - /// use std::fs::File; - /// - /// fn main() -> io::Result<()> { - /// let mut f = File::open("foo.txt")?; - /// let mut buffer = Vec::new(); - /// - /// // read the whole file - /// f.read_to_end(&mut buffer)?; - /// Ok(()) - /// } - /// ``` - /// - /// (See also the [`std::fs::read`] convenience function for reading from a - /// file.) - /// - /// [`std::fs::read`]: ../fs/fn.read.html - #[cfg(feature="collections")] - fn read_to_end(&mut self, buf: &mut Vec) -> Result { - read_to_end(self, buf) - } - - /// Read all bytes until EOF in this source, appending them to `buf`. - /// - /// If successful, this function returns the number of bytes which were read - /// and appended to `buf`. - /// - /// # Errors - /// - /// If the data in this stream is *not* valid UTF-8 then an error is - /// returned and `buf` is unchanged. - /// - /// See [`read_to_end`][readtoend] for other error semantics. - /// - /// [readtoend]: #method.read_to_end - /// - /// # Examples - /// - /// [`File`][file]s implement `Read`: - /// - /// [file]: ../fs/struct.File.html - /// - /// ```no_run - /// use std::io; - /// use std::io::prelude::*; - /// use std::fs::File; - /// - /// fn main() -> io::Result<()> { - /// let mut f = File::open("foo.txt")?; - /// let mut buffer = String::new(); - /// - /// f.read_to_string(&mut buffer)?; - /// Ok(()) - /// } - /// ``` - /// - /// (See also the [`std::fs::read_to_string`] convenience function for - /// reading from a file.) - /// - /// [`std::fs::read_to_string`]: ../fs/fn.read_to_string.html - #[cfg(feature="collections")] - fn read_to_string(&mut self, buf: &mut String) -> Result { - // Note that we do *not* call `.read_to_end()` here. We are passing - // `&mut Vec` (the raw contents of `buf`) into the `read_to_end` - // method to fill it up. An arbitrary implementation could overwrite the - // entire contents of the vector, not just append to it (which is what - // we are expecting). - // - // To prevent extraneously checking the UTF-8-ness of the entire buffer - // we pass it to our hardcoded `read_to_end` implementation which we - // know is guaranteed to only read data into the end of the buffer. - append_to_string(buf, |b| read_to_end(self, b)) - } - - /// Read the exact number of bytes required to fill `buf`. - /// - /// This function reads as many bytes as necessary to completely fill the - /// specified buffer `buf`. - /// - /// No guarantees are provided about the contents of `buf` when this - /// function is called, implementations cannot rely on any property of the - /// contents of `buf` being true. It is recommended that implementations - /// only write data to `buf` instead of reading its contents. - /// - /// # Errors - /// - /// If this function encounters an error of the kind - /// [`ErrorKind::Interrupted`] then the error is ignored and the operation - /// will continue. - /// - /// If this function encounters an "end of file" before completely filling - /// the buffer, it returns an error of the kind [`ErrorKind::UnexpectedEof`]. - /// The contents of `buf` are unspecified in this case. - /// - /// If any other read error is encountered then this function immediately - /// returns. The contents of `buf` are unspecified in this case. - /// - /// If this function returns an error, it is unspecified how many bytes it - /// has read, but it will never read more than would be necessary to - /// completely fill the buffer. - /// - /// # Examples - /// - /// [`File`]s implement `Read`: - /// - /// [`File`]: ../fs/struct.File.html - /// [`ErrorKind::Interrupted`]: ../../std/io/enum.ErrorKind.html#variant.Interrupted - /// [`ErrorKind::UnexpectedEof`]: ../../std/io/enum.ErrorKind.html#variant.UnexpectedEof - /// - /// ```no_run - /// use std::io; - /// use std::io::prelude::*; - /// use std::fs::File; - /// - /// fn main() -> io::Result<()> { - /// let mut f = File::open("foo.txt")?; - /// let mut buffer = [0; 10]; - /// - /// // read exactly 10 bytes - /// f.read_exact(&mut buffer)?; - /// Ok(()) - /// } - /// ``` - fn read_exact(&mut self, mut buf: &mut [u8]) -> Result<()> { - while !buf.is_empty() { - match self.read(buf) { - Ok(0) => break, - Ok(n) => { - let tmp = buf; - buf = &mut tmp[n..]; - } - Err(ref e) if e.kind() == ErrorKind::Interrupted => {} - Err(e) => return Err(e), - } - } - if !buf.is_empty() { - Err(Error::new(ErrorKind::UnexpectedEof, "failed to fill whole buffer")) - } else { - Ok(()) - } - } - - /// Creates a "by reference" adaptor for this instance of `Read`. - /// - /// The returned adaptor also implements `Read` and will simply borrow this - /// current reader. - /// - /// # Examples - /// - /// [`File`][file]s implement `Read`: - /// - /// [file]: ../fs/struct.File.html - /// - /// ```no_run - /// use std::io; - /// use std::io::Read; - /// use std::fs::File; - /// - /// fn main() -> io::Result<()> { - /// let mut f = File::open("foo.txt")?; - /// let mut buffer = Vec::new(); - /// let mut other_buffer = Vec::new(); - /// - /// { - /// let reference = f.by_ref(); - /// - /// // read at most 5 bytes - /// reference.take(5).read_to_end(&mut buffer)?; - /// - /// } // drop our &mut reference so we can use f again - /// - /// // original file still usable, read the rest - /// f.read_to_end(&mut other_buffer)?; - /// Ok(()) - /// } - /// ``` - fn by_ref(&mut self) -> &mut Self - where - Self: Sized, - { - self - } - - /// Transforms this `Read` instance to an [`Iterator`] over its bytes. - /// - /// The returned type implements [`Iterator`] where the `Item` is - /// [`Result`]`<`[`u8`]`, `[`io::Error`]`>`. - /// The yielded item is [`Ok`] if a byte was successfully read and [`Err`] - /// otherwise. EOF is mapped to returning [`None`] from this iterator. - /// - /// # Examples - /// - /// [`File`][file]s implement `Read`: - /// - /// [file]: ../fs/struct.File.html - /// [`Iterator`]: ../../std/iter/trait.Iterator.html - /// [`Result`]: ../../std/result/enum.Result.html - /// [`io::Error`]: ../../std/io/struct.Error.html - /// [`u8`]: ../../std/primitive.u8.html - /// [`Ok`]: ../../std/result/enum.Result.html#variant.Ok - /// [`Err`]: ../../std/result/enum.Result.html#variant.Err - /// [`None`]: ../../std/option/enum.Option.html#variant.None - /// - /// ```no_run - /// use std::io; - /// use std::io::prelude::*; - /// use std::fs::File; - /// - /// fn main() -> io::Result<()> { - /// let mut f = File::open("foo.txt")?; - /// - /// for byte in f.bytes() { - /// println!("{}", byte.unwrap()); - /// } - /// Ok(()) - /// } - /// ``` - fn bytes(self) -> Bytes - where - Self: Sized, - { - Bytes { inner: self } - } - - /// Creates an adaptor which will chain this stream with another. - /// - /// The returned `Read` instance will first read all bytes from this object - /// until EOF is encountered. Afterwards the output is equivalent to the - /// output of `next`. - /// - /// # Examples - /// - /// [`File`][file]s implement `Read`: - /// - /// [file]: ../fs/struct.File.html - /// - /// ```no_run - /// use std::io; - /// use std::io::prelude::*; - /// use std::fs::File; - /// - /// fn main() -> io::Result<()> { - /// let mut f1 = File::open("foo.txt")?; - /// let mut f2 = File::open("bar.txt")?; - /// - /// let mut handle = f1.chain(f2); - /// let mut buffer = String::new(); - /// - /// // read the value into a String. We could use any Read method here, - /// // this is just one example. - /// handle.read_to_string(&mut buffer)?; - /// Ok(()) - /// } - /// ``` - fn chain(self, next: R) -> Chain - where - Self: Sized, - { - Chain { first: self, second: next, done_first: false } - } - - /// Creates an adaptor which will read at most `limit` bytes from it. - /// - /// This function returns a new instance of `Read` which will read at most - /// `limit` bytes, after which it will always return EOF ([`Ok(0)`]). Any - /// read errors will not count towards the number of bytes read and future - /// calls to [`read()`] may succeed. - /// - /// # Examples - /// - /// [`File`]s implement `Read`: - /// - /// [`File`]: ../fs/struct.File.html - /// [`Ok(0)`]: ../../std/result/enum.Result.html#variant.Ok - /// [`read()`]: trait.Read.html#tymethod.read - /// - /// ```no_run - /// use std::io; - /// use std::io::prelude::*; - /// use std::fs::File; - /// - /// fn main() -> io::Result<()> { - /// let mut f = File::open("foo.txt")?; - /// let mut buffer = [0; 5]; - /// - /// // read at most five bytes - /// let mut handle = f.take(5); - /// - /// handle.read(&mut buffer)?; - /// Ok(()) - /// } - /// ``` - fn take(self, limit: u64) -> Take - where - Self: Sized, - { - Take { inner: self, limit } - } -} - -/// A type used to conditionally initialize buffers passed to `Read` methods. -#[derive(Debug)] -pub struct Initializer(bool); - -impl Initializer { - /// Returns a new `Initializer` which will zero out buffers. - #[inline] - pub fn zeroing() -> Initializer { - Initializer(true) - } - - /// Returns a new `Initializer` which will not zero out buffers. - /// - /// # Safety - /// - /// This may only be called by `Read`ers which guarantee that they will not - /// read from buffers passed to `Read` methods, and that the return value of - /// the method accurately reflects the number of bytes that have been - /// written to the head of the buffer. - #[inline] - pub unsafe fn nop() -> Initializer { - Initializer(false) - } - - /// Indicates if a buffer should be initialized. - #[inline] - pub fn should_initialize(&self) -> bool { - self.0 - } - - /// Initializes a buffer if necessary. - #[inline] - pub fn initialize(&self, buf: &mut [u8]) { - if self.should_initialize() { - unsafe { ptr::write_bytes(buf.as_mut_ptr(), 0, buf.len()) } - } - } -} - -/// A trait for objects which are byte-oriented sinks. -/// -/// Implementors of the `Write` trait are sometimes called 'writers'. -/// -/// Writers are defined by two required methods, [`write`] and [`flush`]: -/// -/// * The [`write`] method will attempt to write some data into the object, -/// returning how many bytes were successfully written. -/// -/// * The [`flush`] method is useful for adaptors and explicit buffers -/// themselves for ensuring that all buffered data has been pushed out to the -/// 'true sink'. -/// -/// Writers are intended to be composable with one another. Many implementors -/// throughout [`std::io`] take and provide types which implement the `Write` -/// trait. -/// -/// [`write`]: #tymethod.write -/// [`flush`]: #tymethod.flush -/// [`std::io`]: index.html -/// -/// # Examples -/// -/// ```no_run -/// use std::io::prelude::*; -/// use std::fs::File; -/// -/// fn main() -> std::io::Result<()> { -/// let data = b"some bytes"; -/// -/// let mut pos = 0; -/// let mut buffer = File::create("foo.txt")?; -/// -/// while pos < data.len() { -/// let bytes_written = buffer.write(&data[pos..])?; -/// pos += bytes_written; -/// } -/// Ok(()) -/// } -/// ``` -/// -/// The trait also provides convenience methods like [`write_all`], which calls -/// `write` in a loop until its entire input has been written. -/// -/// [`write_all`]: #method.write_all -pub trait Write { - /// Write a buffer into this writer, returning how many bytes were written. - /// - /// This function will attempt to write the entire contents of `buf`, but - /// the entire write may not succeed, or the write may also generate an - /// error. A call to `write` represents *at most one* attempt to write to - /// any wrapped object. - /// - /// Calls to `write` are not guaranteed to block waiting for data to be - /// written, and a write which would otherwise block can be indicated through - /// an [`Err`] variant. - /// - /// If the return value is [`Ok(n)`] then it must be guaranteed that - /// `n <= buf.len()`. A return value of `0` typically means that the - /// underlying object is no longer able to accept bytes and will likely not - /// be able to in the future as well, or that the buffer provided is empty. - /// - /// # Errors - /// - /// Each call to `write` may generate an I/O error indicating that the - /// operation could not be completed. If an error is returned then no bytes - /// in the buffer were written to this writer. - /// - /// It is **not** considered an error if the entire buffer could not be - /// written to this writer. - /// - /// An error of the [`ErrorKind::Interrupted`] kind is non-fatal and the - /// write operation should be retried if there is nothing else to do. - /// - /// [`Err`]: ../../std/result/enum.Result.html#variant.Err - /// [`Ok(n)`]: ../../std/result/enum.Result.html#variant.Ok - /// [`ErrorKind::Interrupted`]: ../../std/io/enum.ErrorKind.html#variant.Interrupted - /// - /// # Examples - /// - /// ```no_run - /// use std::io::prelude::*; - /// use std::fs::File; - /// - /// fn main() -> std::io::Result<()> { - /// let mut buffer = File::create("foo.txt")?; - /// - /// // Writes some prefix of the byte string, not necessarily all of it. - /// buffer.write(b"some bytes")?; - /// Ok(()) - /// } - /// ``` - fn write(&mut self, buf: &[u8]) -> Result; - - /// Flush this output stream, ensuring that all intermediately buffered - /// contents reach their destination. - /// - /// # Errors - /// - /// It is considered an error if not all bytes could be written due to - /// I/O errors or EOF being reached. - /// - /// # Examples - /// - /// ```no_run - /// use std::io::prelude::*; - /// use std::io::BufWriter; - /// use std::fs::File; - /// - /// fn main() -> std::io::Result<()> { - /// let mut buffer = BufWriter::new(File::create("foo.txt")?); - /// - /// buffer.write_all(b"some bytes")?; - /// buffer.flush()?; - /// Ok(()) - /// } - /// ``` - fn flush(&mut self) -> Result<()>; - - /// Attempts to write an entire buffer into this writer. - /// - /// This method will continuously call [`write`] until there is no more data - /// to be written or an error of non-[`ErrorKind::Interrupted`] kind is - /// returned. This method will not return until the entire buffer has been - /// successfully written or such an error occurs. The first error that is - /// not of [`ErrorKind::Interrupted`] kind generated from this method will be - /// returned. - /// - /// If the buffer contains no data, this will never call [`write`]. - /// - /// # Errors - /// - /// This function will return the first error of - /// non-[`ErrorKind::Interrupted`] kind that [`write`] returns. - /// - /// [`ErrorKind::Interrupted`]: ../../std/io/enum.ErrorKind.html#variant.Interrupted - /// [`write`]: #tymethod.write - /// - /// # Examples - /// - /// ```no_run - /// use std::io::prelude::*; - /// use std::fs::File; - /// - /// fn main() -> std::io::Result<()> { - /// let mut buffer = File::create("foo.txt")?; - /// - /// buffer.write_all(b"some bytes")?; - /// Ok(()) - /// } - /// ``` - fn write_all(&mut self, mut buf: &[u8]) -> Result<()> { - while !buf.is_empty() { - match self.write(buf) { - Ok(0) => { - return Err(Error::new(ErrorKind::WriteZero, "failed to write whole buffer")); - } - Ok(n) => buf = &buf[n..], - Err(ref e) if e.kind() == ErrorKind::Interrupted => {} - Err(e) => return Err(e), - } - } - Ok(()) - } - - /// Attempts to write multiple buffers into this writer. - /// - /// This method will continuously call [`write_vectored`] until there is no - /// more data to be written or an error of non-[`ErrorKind::Interrupted`] - /// kind is returned. This method will not return until all buffers have - /// been successfully written or such an error occurs. The first error that - /// is not of [`ErrorKind::Interrupted`] kind generated from this method - /// will be returned. - /// - /// If the buffer contains no data, this will never call [`write_vectored`]. - /// - /// [`write_vectored`]: #method.write_vectored - /// [`ErrorKind::Interrupted`]: ../../std/io/enum.ErrorKind.html#variant.Interrupted - /// - /// # Notes - /// - /// - /// Unlike `io::Write::write_vectored`, this takes a *mutable* reference to - /// a slice of `IoSlice`s, not an immutable one. That's because we need to - /// modify the slice to keep track of the bytes already written. - /// - /// Once this function returns, the contents of `bufs` are unspecified, as - /// this depends on how many calls to `write_vectored` were necessary. It is - /// best to understand this function as taking ownership of `bufs` and to - /// not use `bufs` afterwards. The underlying buffers, to which the - /// `IoSlice`s point (but not the `IoSlice`s themselves), are unchanged and - /// can be reused. - /// - /// # Examples - /// - /// ``` - /// #![feature(write_all_vectored)] - /// # fn main() -> std::io::Result<()> { - /// - /// use std::io::{Write, IoSlice}; - /// - /// let mut writer = Vec::new(); - /// let bufs = &mut [ - /// IoSlice::new(&[1]), - /// IoSlice::new(&[2, 3]), - /// IoSlice::new(&[4, 5, 6]), - /// ]; - /// - /// writer.write_all_vectored(bufs)?; - /// // Note: the contents of `bufs` is now undefined, see the Notes section. - /// - /// assert_eq!(writer, &[1, 2, 3, 4, 5, 6]); - /// # Ok(()) } - /// ``` - /*fn write_all_vectored(&mut self, mut bufs: &mut [IoSlice<'_>]) -> Result<()> { - while !bufs.is_empty() { - match self.write_vectored(bufs) { - Ok(0) => { - return Err(Error::new(ErrorKind::WriteZero, "failed to write whole buffer")); - } - Ok(n) => bufs = IoSlice::advance(mem::take(&mut bufs), n), - Err(ref e) if e.kind() == ErrorKind::Interrupted => {} - Err(e) => return Err(e), - } - } - Ok(()) - }*/ - - /// Writes a formatted string into this writer, returning any error - /// encountered. - /// - /// This method is primarily used to interface with the - /// [`format_args!`][formatargs] macro, but it is rare that this should - /// explicitly be called. The [`write!`][write] macro should be favored to - /// invoke this method instead. - /// - /// [formatargs]: ../macro.format_args.html - /// [write]: ../macro.write.html - /// - /// This function internally uses the [`write_all`][writeall] method on - /// this trait and hence will continuously write data so long as no errors - /// are received. This also means that partial writes are not indicated in - /// this signature. - /// - /// [writeall]: #method.write_all - /// - /// # Errors - /// - /// This function will return any I/O error reported while formatting. - /// - /// # Examples - /// - /// ```no_run - /// use std::io::prelude::*; - /// use std::fs::File; - /// - /// fn main() -> std::io::Result<()> { - /// let mut buffer = File::create("foo.txt")?; - /// - /// // this call - /// write!(buffer, "{:.*}", 2, 1.234567)?; - /// // turns into this: - /// buffer.write_fmt(format_args!("{:.*}", 2, 1.234567))?; - /// Ok(()) - /// } - /// ``` - fn write_fmt(&mut self, fmt: fmt::Arguments<'_>) -> Result<()> { - // Create a shim which translates a Write to a fmt::Write and saves - // off I/O errors. instead of discarding them - struct Adaptor<'a, T: ?Sized + 'a> { - inner: &'a mut T, - error: Result<()>, - } - - impl fmt::Write for Adaptor<'_, T> { - fn write_str(&mut self, s: &str) -> fmt::Result { - match self.inner.write_all(s.as_bytes()) { - Ok(()) => Ok(()), - Err(e) => { - self.error = Err(e); - Err(fmt::Error) - } - } - } - } - - let mut output = Adaptor { inner: self, error: Ok(()) }; - match fmt::write(&mut output, fmt) { - Ok(()) => Ok(()), - Err(..) => { - // check if the error came from the underlying `Write` or not - if output.error.is_err() { - output.error - } else { - Err(Error::new(ErrorKind::Other, "formatter error")) - } - } - } - } - - /// Creates a "by reference" adaptor for this instance of `Write`. - /// - /// The returned adaptor also implements `Write` and will simply borrow this - /// current writer. - /// - /// # Examples - /// - /// ```no_run - /// use std::io::Write; - /// use std::fs::File; - /// - /// fn main() -> std::io::Result<()> { - /// let mut buffer = File::create("foo.txt")?; - /// - /// let reference = buffer.by_ref(); - /// - /// // we can use reference just like our original buffer - /// reference.write_all(b"some bytes")?; - /// Ok(()) - /// } - /// ``` - fn by_ref(&mut self) -> &mut Self - where - Self: Sized, - { - self - } -} - -/// The `Seek` trait provides a cursor which can be moved within a stream of -/// bytes. -/// -/// The stream typically has a fixed size, allowing seeking relative to either -/// end or the current offset. -/// -/// # Examples -/// -/// [`File`][file]s implement `Seek`: -/// -/// [file]: ../fs/struct.File.html -/// -/// ```no_run -/// use std::io; -/// use std::io::prelude::*; -/// use std::fs::File; -/// use std::io::SeekFrom; -/// -/// fn main() -> io::Result<()> { -/// let mut f = File::open("foo.txt")?; -/// -/// // move the cursor 42 bytes from the start of the file -/// f.seek(SeekFrom::Start(42))?; -/// Ok(()) -/// } -/// ``` -pub trait Seek { - /// Seek to an offset, in bytes, in a stream. - /// - /// A seek beyond the end of a stream is allowed, but behavior is defined - /// by the implementation. - /// - /// If the seek operation completed successfully, - /// this method returns the new position from the start of the stream. - /// That position can be used later with [`SeekFrom::Start`]. - /// - /// # Errors - /// - /// Seeking to a negative offset is considered an error. - /// - /// [`SeekFrom::Start`]: enum.SeekFrom.html#variant.Start - fn seek(&mut self, pos: SeekFrom) -> Result; - - /// Returns the length of this stream (in bytes). - /// - /// This method is implemented using up to three seek operations. If this - /// method returns successfully, the seek position is unchanged (i.e. the - /// position before calling this method is the same as afterwards). - /// However, if this method returns an error, the seek position is - /// unspecified. - /// - /// If you need to obtain the length of *many* streams and you don't care - /// about the seek position afterwards, you can reduce the number of seek - /// operations by simply calling `seek(SeekFrom::End(0))` and using its - /// return value (it is also the stream length). - /// - /// Note that length of a stream can change over time (for example, when - /// data is appended to a file). So calling this method multiple times does - /// not necessarily return the same length each time. - /// - /// - /// # Example - /// - /// ```no_run - /// #![feature(seek_convenience)] - /// use std::{ - /// io::{self, Seek}, - /// fs::File, - /// }; - /// - /// fn main() -> io::Result<()> { - /// let mut f = File::open("foo.txt")?; - /// - /// let len = f.stream_len()?; - /// println!("The file is currently {} bytes long", len); - /// Ok(()) - /// } - /// ``` - fn stream_len(&mut self) -> Result { - let old_pos = self.stream_position()?; - let len = self.seek(SeekFrom::End(0))?; - - // Avoid seeking a third time when we were already at the end of the - // stream. The branch is usually way cheaper than a seek operation. - if old_pos != len { - self.seek(SeekFrom::Start(old_pos))?; - } - - Ok(len) - } - - /// Returns the current seek position from the start of the stream. - /// - /// This is equivalent to `self.seek(SeekFrom::Current(0))`. - /// - /// - /// # Example - /// - /// ```no_run - /// #![feature(seek_convenience)] - /// use std::{ - /// io::{self, BufRead, BufReader, Seek}, - /// fs::File, - /// }; - /// - /// fn main() -> io::Result<()> { - /// let mut f = BufReader::new(File::open("foo.txt")?); - /// - /// let before = f.stream_position()?; - /// f.read_line(&mut String::new())?; - /// let after = f.stream_position()?; - /// - /// println!("The first line was {} bytes long", after - before); - /// Ok(()) - /// } - /// ``` - fn stream_position(&mut self) -> Result { - self.seek(SeekFrom::Current(0)) - } -} - -/// Enumeration of possible methods to seek within an I/O object. -/// -/// It is used by the [`Seek`] trait. -/// -/// [`Seek`]: trait.Seek.html -#[derive(Copy, PartialEq, Eq, Clone, Debug)] -pub enum SeekFrom { - /// Sets the offset to the provided number of bytes. - Start(u64), - /// Sets the offset to the size of this object plus the specified number of - /// bytes. - /// - /// It is possible to seek beyond the end of an object, but it's an error to - /// seek before byte 0. - End(i64), - /// Sets the offset to the current position plus the specified number of - /// bytes. - /// - /// It is possible to seek beyond the end of an object, but it's an error to - /// seek before byte 0. - Current(i64), -} - -#[cfg(feature="collections")] -fn read_until(r: &mut R, delim: u8, buf: &mut Vec) -> Result { - let mut read = 0; - loop { - let (done, used) = { - let available = match r.fill_buf() { - Ok(n) => n, - Err(ref e) if e.kind() == ErrorKind::Interrupted => continue, - Err(e) => return Err(e), - }; - match memchr::memchr(delim, available) { - Some(i) => { - buf.extend_from_slice(&available[..=i]); - (true, i + 1) - } - None => { - buf.extend_from_slice(available); - (false, available.len()) - } - } - }; - r.consume(used); - read += used; - if done || used == 0 { - return Ok(read); - } - } -} - -/// A `BufRead` is a type of `Read`er which has an internal buffer, allowing it -/// to perform extra ways of reading. -/// -/// For example, reading line-by-line is inefficient without using a buffer, so -/// if you want to read by line, you'll need `BufRead`, which includes a -/// [`read_line`] method as well as a [`lines`] iterator. -/// -/// # Examples -/// -/// A locked standard input implements `BufRead`: -/// -/// ```no_run -/// use std::io; -/// use std::io::prelude::*; -/// -/// let stdin = io::stdin(); -/// for line in stdin.lock().lines() { -/// println!("{}", line.unwrap()); -/// } -/// ``` -/// -/// If you have something that implements [`Read`], you can use the [`BufReader` -/// type][`BufReader`] to turn it into a `BufRead`. -/// -/// For example, [`File`] implements [`Read`], but not `BufRead`. -/// [`BufReader`] to the rescue! -/// -/// [`BufReader`]: struct.BufReader.html -/// [`File`]: ../fs/struct.File.html -/// [`read_line`]: #method.read_line -/// [`lines`]: #method.lines -/// [`Read`]: trait.Read.html -/// -/// ```no_run -/// use std::io::{self, BufReader}; -/// use std::io::prelude::*; -/// use std::fs::File; -/// -/// fn main() -> io::Result<()> { -/// let f = File::open("foo.txt")?; -/// let f = BufReader::new(f); -/// -/// for line in f.lines() { -/// println!("{}", line.unwrap()); -/// } -/// -/// Ok(()) -/// } -/// ``` -/// -#[cfg(feature="collections")] -pub trait BufRead: Read { - /// Returns the contents of the internal buffer, filling it with more data - /// from the inner reader if it is empty. - /// - /// This function is a lower-level call. It needs to be paired with the - /// [`consume`] method to function properly. When calling this - /// method, none of the contents will be "read" in the sense that later - /// calling `read` may return the same contents. As such, [`consume`] must - /// be called with the number of bytes that are consumed from this buffer to - /// ensure that the bytes are never returned twice. - /// - /// [`consume`]: #tymethod.consume - /// - /// An empty buffer returned indicates that the stream has reached EOF. - /// - /// # Errors - /// - /// This function will return an I/O error if the underlying reader was - /// read, but returned an error. - /// - /// # Examples - /// - /// A locked standard input implements `BufRead`: - /// - /// ```no_run - /// use std::io; - /// use std::io::prelude::*; - /// - /// let stdin = io::stdin(); - /// let mut stdin = stdin.lock(); - /// - /// let buffer = stdin.fill_buf().unwrap(); - /// - /// // work with buffer - /// println!("{:?}", buffer); - /// - /// // ensure the bytes we worked with aren't returned again later - /// let length = buffer.len(); - /// stdin.consume(length); - /// ``` - fn fill_buf(&mut self) -> Result<&[u8]>; - - /// Tells this buffer that `amt` bytes have been consumed from the buffer, - /// so they should no longer be returned in calls to `read`. - /// - /// This function is a lower-level call. It needs to be paired with the - /// [`fill_buf`] method to function properly. This function does - /// not perform any I/O, it simply informs this object that some amount of - /// its buffer, returned from [`fill_buf`], has been consumed and should - /// no longer be returned. As such, this function may do odd things if - /// [`fill_buf`] isn't called before calling it. - /// - /// The `amt` must be `<=` the number of bytes in the buffer returned by - /// [`fill_buf`]. - /// - /// # Examples - /// - /// Since `consume()` is meant to be used with [`fill_buf`], - /// that method's example includes an example of `consume()`. - /// - /// [`fill_buf`]: #tymethod.fill_buf - fn consume(&mut self, amt: usize); - - /// Read all bytes into `buf` until the delimiter `byte` or EOF is reached. - /// - /// This function will read bytes from the underlying stream until the - /// delimiter or EOF is found. Once found, all bytes up to, and including, - /// the delimiter (if found) will be appended to `buf`. - /// - /// If successful, this function will return the total number of bytes read. - /// - /// # Errors - /// - /// This function will ignore all instances of [`ErrorKind::Interrupted`] and - /// will otherwise return any errors returned by [`fill_buf`]. - /// - /// If an I/O error is encountered then all bytes read so far will be - /// present in `buf` and its length will have been adjusted appropriately. - /// - /// [`fill_buf`]: #tymethod.fill_buf - /// [`ErrorKind::Interrupted`]: enum.ErrorKind.html#variant.Interrupted - /// - /// # Examples - /// - /// [`std::io::Cursor`][`Cursor`] is a type that implements `BufRead`. In - /// this example, we use [`Cursor`] to read all the bytes in a byte slice - /// in hyphen delimited segments: - /// - /// [`Cursor`]: struct.Cursor.html - /// - /// ``` - /// use std::io::{self, BufRead}; - /// - /// let mut cursor = io::Cursor::new(b"lorem-ipsum"); - /// let mut buf = vec![]; - /// - /// // cursor is at 'l' - /// let num_bytes = cursor.read_until(b'-', &mut buf) - /// .expect("reading from cursor won't fail"); - /// assert_eq!(num_bytes, 6); - /// assert_eq!(buf, b"lorem-"); - /// buf.clear(); - /// - /// // cursor is at 'i' - /// let num_bytes = cursor.read_until(b'-', &mut buf) - /// .expect("reading from cursor won't fail"); - /// assert_eq!(num_bytes, 5); - /// assert_eq!(buf, b"ipsum"); - /// buf.clear(); - /// - /// // cursor is at EOF - /// let num_bytes = cursor.read_until(b'-', &mut buf) - /// .expect("reading from cursor won't fail"); - /// assert_eq!(num_bytes, 0); - /// assert_eq!(buf, b""); - /// ``` - fn read_until(&mut self, byte: u8, buf: &mut Vec) -> Result { - read_until(self, byte, buf) - } - - /// Read all bytes until a newline (the 0xA byte) is reached, and append - /// them to the provided buffer. - /// - /// This function will read bytes from the underlying stream until the - /// newline delimiter (the 0xA byte) or EOF is found. Once found, all bytes - /// up to, and including, the delimiter (if found) will be appended to - /// `buf`. - /// - /// If successful, this function will return the total number of bytes read. - /// - /// If this function returns `Ok(0)`, the stream has reached EOF. - /// - /// # Errors - /// - /// This function has the same error semantics as [`read_until`] and will - /// also return an error if the read bytes are not valid UTF-8. If an I/O - /// error is encountered then `buf` may contain some bytes already read in - /// the event that all data read so far was valid UTF-8. - /// - /// [`read_until`]: #method.read_until - /// - /// # Examples - /// - /// [`std::io::Cursor`][`Cursor`] is a type that implements `BufRead`. In - /// this example, we use [`Cursor`] to read all the lines in a byte slice: - /// - /// [`Cursor`]: struct.Cursor.html - /// - /// ``` - /// use std::io::{self, BufRead}; - /// - /// let mut cursor = io::Cursor::new(b"foo\nbar"); - /// let mut buf = String::new(); - /// - /// // cursor is at 'f' - /// let num_bytes = cursor.read_line(&mut buf) - /// .expect("reading from cursor won't fail"); - /// assert_eq!(num_bytes, 4); - /// assert_eq!(buf, "foo\n"); - /// buf.clear(); - /// - /// // cursor is at 'b' - /// let num_bytes = cursor.read_line(&mut buf) - /// .expect("reading from cursor won't fail"); - /// assert_eq!(num_bytes, 3); - /// assert_eq!(buf, "bar"); - /// buf.clear(); - /// - /// // cursor is at EOF - /// let num_bytes = cursor.read_line(&mut buf) - /// .expect("reading from cursor won't fail"); - /// assert_eq!(num_bytes, 0); - /// assert_eq!(buf, ""); - /// ``` - fn read_line(&mut self, buf: &mut String) -> Result { - // Note that we are not calling the `.read_until` method here, but - // rather our hardcoded implementation. For more details as to why, see - // the comments in `read_to_end`. - append_to_string(buf, |b| read_until(self, b'\n', b)) - } - - /// Returns an iterator over the contents of this reader split on the byte - /// `byte`. - /// - /// The iterator returned from this function will return instances of - /// [`io::Result`]`<`[`Vec`]`>`. Each vector returned will *not* have - /// the delimiter byte at the end. - /// - /// This function will yield errors whenever [`read_until`] would have - /// also yielded an error. - /// - /// [`io::Result`]: type.Result.html - /// [`Vec`]: ../vec/struct.Vec.html - /// [`read_until`]: #method.read_until - /// - /// # Examples - /// - /// [`std::io::Cursor`][`Cursor`] is a type that implements `BufRead`. In - /// this example, we use [`Cursor`] to iterate over all hyphen delimited - /// segments in a byte slice - /// - /// [`Cursor`]: struct.Cursor.html - /// - /// ``` - /// use std::io::{self, BufRead}; - /// - /// let cursor = io::Cursor::new(b"lorem-ipsum-dolor"); - /// - /// let mut split_iter = cursor.split(b'-').map(|l| l.unwrap()); - /// assert_eq!(split_iter.next(), Some(b"lorem".to_vec())); - /// assert_eq!(split_iter.next(), Some(b"ipsum".to_vec())); - /// assert_eq!(split_iter.next(), Some(b"dolor".to_vec())); - /// assert_eq!(split_iter.next(), None); - /// ``` - fn split(self, byte: u8) -> Split - where - Self: Sized, - { - Split { buf: self, delim: byte } - } - - /// Returns an iterator over the lines of this reader. - /// - /// The iterator returned from this function will yield instances of - /// [`io::Result`]`<`[`String`]`>`. Each string returned will *not* have a newline - /// byte (the 0xA byte) or CRLF (0xD, 0xA bytes) at the end. - /// - /// [`io::Result`]: type.Result.html - /// [`String`]: ../string/struct.String.html - /// - /// # Examples - /// - /// [`std::io::Cursor`][`Cursor`] is a type that implements `BufRead`. In - /// this example, we use [`Cursor`] to iterate over all the lines in a byte - /// slice. - /// - /// [`Cursor`]: struct.Cursor.html - /// - /// ``` - /// use std::io::{self, BufRead}; - /// - /// let cursor = io::Cursor::new(b"lorem\nipsum\r\ndolor"); - /// - /// let mut lines_iter = cursor.lines().map(|l| l.unwrap()); - /// assert_eq!(lines_iter.next(), Some(String::from("lorem"))); - /// assert_eq!(lines_iter.next(), Some(String::from("ipsum"))); - /// assert_eq!(lines_iter.next(), Some(String::from("dolor"))); - /// assert_eq!(lines_iter.next(), None); - /// ``` - /// - /// # Errors - /// - /// Each line of the iterator has the same error semantics as [`BufRead::read_line`]. - /// - /// [`BufRead::read_line`]: trait.BufRead.html#method.read_line - fn lines(self) -> Lines - where - Self: Sized, - { - Lines { buf: self } - } -} - -/// Adaptor to chain together two readers. -/// -/// This struct is generally created by calling [`chain`] on a reader. -/// Please see the documentation of [`chain`] for more details. -/// -/// [`chain`]: trait.Read.html#method.chain -pub struct Chain { - first: T, - second: U, - done_first: bool, -} - -impl Chain { - /// Consumes the `Chain`, returning the wrapped readers. - /// - /// # Examples - /// - /// ```no_run - /// use std::io; - /// use std::io::prelude::*; - /// use std::fs::File; - /// - /// fn main() -> io::Result<()> { - /// let mut foo_file = File::open("foo.txt")?; - /// let mut bar_file = File::open("bar.txt")?; - /// - /// let chain = foo_file.chain(bar_file); - /// let (foo_file, bar_file) = chain.into_inner(); - /// Ok(()) - /// } - /// ``` - pub fn into_inner(self) -> (T, U) { - (self.first, self.second) - } - - /// Gets references to the underlying readers in this `Chain`. - /// - /// # Examples - /// - /// ```no_run - /// use std::io; - /// use std::io::prelude::*; - /// use std::fs::File; - /// - /// fn main() -> io::Result<()> { - /// let mut foo_file = File::open("foo.txt")?; - /// let mut bar_file = File::open("bar.txt")?; - /// - /// let chain = foo_file.chain(bar_file); - /// let (foo_file, bar_file) = chain.get_ref(); - /// Ok(()) - /// } - /// ``` - pub fn get_ref(&self) -> (&T, &U) { - (&self.first, &self.second) - } - - /// Gets mutable references to the underlying readers in this `Chain`. - /// - /// Care should be taken to avoid modifying the internal I/O state of the - /// underlying readers as doing so may corrupt the internal state of this - /// `Chain`. - /// - /// # Examples - /// - /// ```no_run - /// use std::io; - /// use std::io::prelude::*; - /// use std::fs::File; - /// - /// fn main() -> io::Result<()> { - /// let mut foo_file = File::open("foo.txt")?; - /// let mut bar_file = File::open("bar.txt")?; - /// - /// let mut chain = foo_file.chain(bar_file); - /// let (foo_file, bar_file) = chain.get_mut(); - /// Ok(()) - /// } - /// ``` - pub fn get_mut(&mut self) -> (&mut T, &mut U) { - (&mut self.first, &mut self.second) - } -} - -impl fmt::Debug for Chain { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - f.debug_struct("Chain").field("t", &self.first).field("u", &self.second).finish() - } -} - -impl Read for Chain { - fn read(&mut self, buf: &mut [u8]) -> Result { - if !self.done_first { - match self.first.read(buf)? { - 0 if !buf.is_empty() => self.done_first = true, - n => return Ok(n), - } - } - self.second.read(buf) - } - - unsafe fn initializer(&self) -> Initializer { - let initializer = self.first.initializer(); - if initializer.should_initialize() { initializer } else { self.second.initializer() } - } -} - -#[cfg(feature="collections")] -impl BufRead for Chain { - fn fill_buf(&mut self) -> Result<&[u8]> { - if !self.done_first { - match self.first.fill_buf()? { - buf if buf.is_empty() => { - self.done_first = true; - } - buf => return Ok(buf), - } - } - self.second.fill_buf() - } - - fn consume(&mut self, amt: usize) { - if !self.done_first { self.first.consume(amt) } else { self.second.consume(amt) } - } -} - -/// Reader adaptor which limits the bytes read from an underlying reader. -/// -/// This struct is generally created by calling [`take`] on a reader. -/// Please see the documentation of [`take`] for more details. -/// -/// [`take`]: trait.Read.html#method.take -#[derive(Debug)] -pub struct Take { - inner: T, - limit: u64, -} - -impl Take { - /// Returns the number of bytes that can be read before this instance will - /// return EOF. - /// - /// # Note - /// - /// This instance may reach `EOF` after reading fewer bytes than indicated by - /// this method if the underlying [`Read`] instance reaches EOF. - /// - /// [`Read`]: ../../std/io/trait.Read.html - /// - /// # Examples - /// - /// ```no_run - /// use std::io; - /// use std::io::prelude::*; - /// use std::fs::File; - /// - /// fn main() -> io::Result<()> { - /// let f = File::open("foo.txt")?; - /// - /// // read at most five bytes - /// let handle = f.take(5); - /// - /// println!("limit: {}", handle.limit()); - /// Ok(()) - /// } - /// ``` - pub fn limit(&self) -> u64 { - self.limit - } - - /// Sets the number of bytes that can be read before this instance will - /// return EOF. This is the same as constructing a new `Take` instance, so - /// the amount of bytes read and the previous limit value don't matter when - /// calling this method. - /// - /// # Examples - /// - /// ```no_run - /// use std::io; - /// use std::io::prelude::*; - /// use std::fs::File; - /// - /// fn main() -> io::Result<()> { - /// let f = File::open("foo.txt")?; - /// - /// // read at most five bytes - /// let mut handle = f.take(5); - /// handle.set_limit(10); - /// - /// assert_eq!(handle.limit(), 10); - /// Ok(()) - /// } - /// ``` - pub fn set_limit(&mut self, limit: u64) { - self.limit = limit; - } - - /// Consumes the `Take`, returning the wrapped reader. - /// - /// # Examples - /// - /// ```no_run - /// use std::io; - /// use std::io::prelude::*; - /// use std::fs::File; - /// - /// fn main() -> io::Result<()> { - /// let mut file = File::open("foo.txt")?; - /// - /// let mut buffer = [0; 5]; - /// let mut handle = file.take(5); - /// handle.read(&mut buffer)?; - /// - /// let file = handle.into_inner(); - /// Ok(()) - /// } - /// ``` - pub fn into_inner(self) -> T { - self.inner - } - - /// Gets a reference to the underlying reader. - /// - /// # Examples - /// - /// ```no_run - /// use std::io; - /// use std::io::prelude::*; - /// use std::fs::File; - /// - /// fn main() -> io::Result<()> { - /// let mut file = File::open("foo.txt")?; - /// - /// let mut buffer = [0; 5]; - /// let mut handle = file.take(5); - /// handle.read(&mut buffer)?; - /// - /// let file = handle.get_ref(); - /// Ok(()) - /// } - /// ``` - pub fn get_ref(&self) -> &T { - &self.inner - } - - /// Gets a mutable reference to the underlying reader. - /// - /// Care should be taken to avoid modifying the internal I/O state of the - /// underlying reader as doing so may corrupt the internal limit of this - /// `Take`. - /// - /// # Examples - /// - /// ```no_run - /// use std::io; - /// use std::io::prelude::*; - /// use std::fs::File; - /// - /// fn main() -> io::Result<()> { - /// let mut file = File::open("foo.txt")?; - /// - /// let mut buffer = [0; 5]; - /// let mut handle = file.take(5); - /// handle.read(&mut buffer)?; - /// - /// let file = handle.get_mut(); - /// Ok(()) - /// } - /// ``` - pub fn get_mut(&mut self) -> &mut T { - &mut self.inner - } -} - -impl Read for Take { - fn read(&mut self, buf: &mut [u8]) -> Result { - // Don't call into inner reader at all at EOF because it may still block - if self.limit == 0 { - return Ok(0); - } - - let max = cmp::min(buf.len() as u64, self.limit) as usize; - let n = self.inner.read(&mut buf[..max])?; - self.limit -= n as u64; - Ok(n) - } - - unsafe fn initializer(&self) -> Initializer { - self.inner.initializer() - } - - #[cfg(feature="collections")] - fn read_to_end(&mut self, buf: &mut Vec) -> Result { - // Pass in a reservation_size closure that respects the current value - // of limit for each read. If we hit the read limit, this prevents the - // final zero-byte read from allocating again. - read_to_end_with_reservation(self, buf, |self_| cmp::min(self_.limit, 32) as usize) - } -} - -#[cfg(feature="collections")] -impl BufRead for Take { - fn fill_buf(&mut self) -> Result<&[u8]> { - // Don't call into inner reader at all at EOF because it may still block - if self.limit == 0 { - return Ok(&[]); - } - - let buf = self.inner.fill_buf()?; - let cap = cmp::min(buf.len() as u64, self.limit) as usize; - Ok(&buf[..cap]) - } - - fn consume(&mut self, amt: usize) { - // Don't let callers reset the limit by passing an overlarge value - let amt = cmp::min(amt as u64, self.limit) as usize; - self.limit -= amt as u64; - self.inner.consume(amt); - } -} - -/// An iterator over `u8` values of a reader. -/// -/// This struct is generally created by calling [`bytes`] on a reader. -/// Please see the documentation of [`bytes`] for more details. -/// -/// [`bytes`]: trait.Read.html#method.bytes -#[derive(Debug)] -pub struct Bytes { - inner: R, -} - -impl Iterator for Bytes { - type Item = Result; - - fn next(&mut self) -> Option> { - let mut byte = 0; - loop { - return match self.inner.read(slice::from_mut(&mut byte)) { - Ok(0) => None, - Ok(..) => Some(Ok(byte)), - Err(ref e) if e.kind() == ErrorKind::Interrupted => continue, - Err(e) => Some(Err(e)), - }; - } - } -} - -/// An iterator over the contents of an instance of `BufRead` split on a -/// particular byte. -/// -/// This struct is generally created by calling [`split`] on a `BufRead`. -/// Please see the documentation of [`split`] for more details. -/// -/// [`split`]: trait.BufRead.html#method.split -#[derive(Debug)] -#[cfg(feature="collections")] -pub struct Split { - buf: B, - delim: u8, -} - -#[cfg(feature="collections")] -impl Iterator for Split { - type Item = Result>; - - fn next(&mut self) -> Option>> { - let mut buf = Vec::new(); - match self.buf.read_until(self.delim, &mut buf) { - Ok(0) => None, - Ok(_n) => { - if buf[buf.len() - 1] == self.delim { - buf.pop(); - } - Some(Ok(buf)) - } - Err(e) => Some(Err(e)), - } - } -} - -/// An iterator over the lines of an instance of `BufRead`. -/// -/// This struct is generally created by calling [`lines`] on a `BufRead`. -/// Please see the documentation of [`lines`] for more details. -/// -/// [`lines`]: trait.BufRead.html#method.lines -#[derive(Debug)] -#[cfg(feature="collections")] -pub struct Lines { - buf: B, -} - -#[cfg(feature="collections")] -impl Iterator for Lines { - type Item = Result; - - fn next(&mut self) -> Option> { - let mut buf = String::new(); - match self.buf.read_line(&mut buf) { - Ok(0) => None, - Ok(_n) => { - if buf.ends_with('\n') { - buf.pop(); - if buf.ends_with('\r') { - buf.pop(); - } - } - Some(Ok(buf)) - } - Err(e) => Some(Err(e)), - } - } -} - -#[cfg(test)] -mod tests { - use super::{repeat, Cursor, SeekFrom}; - use crate::cmp::{self, min}; - use crate::io::prelude::*; - use crate::io::{self, IoSlice, IoSliceMut}; - use crate::ops::Deref; - - #[test] - #[cfg_attr(target_os = "emscripten", ignore)] - fn read_until() { - let mut buf = Cursor::new(&b"12"[..]); - let mut v = Vec::new(); - assert_eq!(buf.read_until(b'3', &mut v).unwrap(), 2); - assert_eq!(v, b"12"); - - let mut buf = Cursor::new(&b"1233"[..]); - let mut v = Vec::new(); - assert_eq!(buf.read_until(b'3', &mut v).unwrap(), 3); - assert_eq!(v, b"123"); - v.truncate(0); - assert_eq!(buf.read_until(b'3', &mut v).unwrap(), 1); - assert_eq!(v, b"3"); - v.truncate(0); - assert_eq!(buf.read_until(b'3', &mut v).unwrap(), 0); - assert_eq!(v, []); - } - - #[test] - fn split() { - let buf = Cursor::new(&b"12"[..]); - let mut s = buf.split(b'3'); - assert_eq!(s.next().unwrap().unwrap(), vec![b'1', b'2']); - assert!(s.next().is_none()); - - let buf = Cursor::new(&b"1233"[..]); - let mut s = buf.split(b'3'); - assert_eq!(s.next().unwrap().unwrap(), vec![b'1', b'2']); - assert_eq!(s.next().unwrap().unwrap(), vec![]); - assert!(s.next().is_none()); - } - - #[test] - fn read_line() { - let mut buf = Cursor::new(&b"12"[..]); - let mut v = String::new(); - assert_eq!(buf.read_line(&mut v).unwrap(), 2); - assert_eq!(v, "12"); - - let mut buf = Cursor::new(&b"12\n\n"[..]); - let mut v = String::new(); - assert_eq!(buf.read_line(&mut v).unwrap(), 3); - assert_eq!(v, "12\n"); - v.truncate(0); - assert_eq!(buf.read_line(&mut v).unwrap(), 1); - assert_eq!(v, "\n"); - v.truncate(0); - assert_eq!(buf.read_line(&mut v).unwrap(), 0); - assert_eq!(v, ""); - } - - #[test] - fn lines() { - let buf = Cursor::new(&b"12\r"[..]); - let mut s = buf.lines(); - assert_eq!(s.next().unwrap().unwrap(), "12\r".to_string()); - assert!(s.next().is_none()); - - let buf = Cursor::new(&b"12\r\n\n"[..]); - let mut s = buf.lines(); - assert_eq!(s.next().unwrap().unwrap(), "12".to_string()); - assert_eq!(s.next().unwrap().unwrap(), "".to_string()); - assert!(s.next().is_none()); - } - - #[test] - fn read_to_end() { - let mut c = Cursor::new(&b""[..]); - let mut v = Vec::new(); - assert_eq!(c.read_to_end(&mut v).unwrap(), 0); - assert_eq!(v, []); - - let mut c = Cursor::new(&b"1"[..]); - let mut v = Vec::new(); - assert_eq!(c.read_to_end(&mut v).unwrap(), 1); - assert_eq!(v, b"1"); - - let cap = 1024 * 1024; - let data = (0..cap).map(|i| (i / 3) as u8).collect::>(); - let mut v = Vec::new(); - let (a, b) = data.split_at(data.len() / 2); - assert_eq!(Cursor::new(a).read_to_end(&mut v).unwrap(), a.len()); - assert_eq!(Cursor::new(b).read_to_end(&mut v).unwrap(), b.len()); - assert_eq!(v, data); - } - - #[test] - fn read_to_string() { - let mut c = Cursor::new(&b""[..]); - let mut v = String::new(); - assert_eq!(c.read_to_string(&mut v).unwrap(), 0); - assert_eq!(v, ""); - - let mut c = Cursor::new(&b"1"[..]); - let mut v = String::new(); - assert_eq!(c.read_to_string(&mut v).unwrap(), 1); - assert_eq!(v, "1"); - - let mut c = Cursor::new(&b"\xff"[..]); - let mut v = String::new(); - assert!(c.read_to_string(&mut v).is_err()); - } - - #[test] - fn read_exact() { - let mut buf = [0; 4]; - - let mut c = Cursor::new(&b""[..]); - assert_eq!(c.read_exact(&mut buf).unwrap_err().kind(), io::ErrorKind::UnexpectedEof); - - let mut c = Cursor::new(&b"123"[..]).chain(Cursor::new(&b"456789"[..])); - c.read_exact(&mut buf).unwrap(); - assert_eq!(&buf, b"1234"); - c.read_exact(&mut buf).unwrap(); - assert_eq!(&buf, b"5678"); - assert_eq!(c.read_exact(&mut buf).unwrap_err().kind(), io::ErrorKind::UnexpectedEof); - } - - #[test] - fn read_exact_slice() { - let mut buf = [0; 4]; - - let mut c = &b""[..]; - assert_eq!(c.read_exact(&mut buf).unwrap_err().kind(), io::ErrorKind::UnexpectedEof); - - let mut c = &b"123"[..]; - assert_eq!(c.read_exact(&mut buf).unwrap_err().kind(), io::ErrorKind::UnexpectedEof); - // make sure the optimized (early returning) method is being used - assert_eq!(&buf, &[0; 4]); - - let mut c = &b"1234"[..]; - c.read_exact(&mut buf).unwrap(); - assert_eq!(&buf, b"1234"); - - let mut c = &b"56789"[..]; - c.read_exact(&mut buf).unwrap(); - assert_eq!(&buf, b"5678"); - assert_eq!(c, b"9"); - } - - #[test] - fn take_eof() { - struct R; - - impl Read for R { - fn read(&mut self, _: &mut [u8]) -> io::Result { - Err(io::Error::new(io::ErrorKind::Other, "")) - } - } - impl BufRead for R { - fn fill_buf(&mut self) -> io::Result<&[u8]> { - Err(io::Error::new(io::ErrorKind::Other, "")) - } - fn consume(&mut self, _amt: usize) {} - } - - let mut buf = [0; 1]; - assert_eq!(0, R.take(0).read(&mut buf).unwrap()); - assert_eq!(b"", R.take(0).fill_buf().unwrap()); - } - - fn cmp_bufread(mut br1: Br1, mut br2: Br2, exp: &[u8]) { - let mut cat = Vec::new(); - loop { - let consume = { - let buf1 = br1.fill_buf().unwrap(); - let buf2 = br2.fill_buf().unwrap(); - let minlen = if buf1.len() < buf2.len() { buf1.len() } else { buf2.len() }; - assert_eq!(buf1[..minlen], buf2[..minlen]); - cat.extend_from_slice(&buf1[..minlen]); - minlen - }; - if consume == 0 { - break; - } - br1.consume(consume); - br2.consume(consume); - } - assert_eq!(br1.fill_buf().unwrap().len(), 0); - assert_eq!(br2.fill_buf().unwrap().len(), 0); - assert_eq!(&cat[..], &exp[..]) - } - - #[test] - fn chain_bufread() { - let testdata = b"ABCDEFGHIJKL"; - let chain1 = - (&testdata[..3]).chain(&testdata[3..6]).chain(&testdata[6..9]).chain(&testdata[9..]); - let chain2 = (&testdata[..4]).chain(&testdata[4..8]).chain(&testdata[8..]); - cmp_bufread(chain1, chain2, &testdata[..]); - } - - #[test] - fn chain_zero_length_read_is_not_eof() { - let a = b"A"; - let b = b"B"; - let mut s = String::new(); - let mut chain = (&a[..]).chain(&b[..]); - chain.read(&mut []).unwrap(); - chain.read_to_string(&mut s).unwrap(); - assert_eq!("AB", s); - } - - #[bench] - #[cfg_attr(target_os = "emscripten", ignore)] - fn bench_read_to_end(b: &mut test::Bencher) { - b.iter(|| { - let mut lr = repeat(1).take(10000000); - let mut vec = Vec::with_capacity(1024); - super::read_to_end(&mut lr, &mut vec) - }); - } - - #[test] - fn seek_len() -> io::Result<()> { - let mut c = Cursor::new(vec![0; 15]); - assert_eq!(c.stream_len()?, 15); - - c.seek(SeekFrom::End(0))?; - let old_pos = c.stream_position()?; - assert_eq!(c.stream_len()?, 15); - assert_eq!(c.stream_position()?, old_pos); - - c.seek(SeekFrom::Start(7))?; - c.seek(SeekFrom::Current(2))?; - let old_pos = c.stream_position()?; - assert_eq!(c.stream_len()?, 15); - assert_eq!(c.stream_position()?, old_pos); - - Ok(()) - } - - #[test] - fn seek_position() -> io::Result<()> { - // All `asserts` are duplicated here to make sure the method does not - // change anything about the seek state. - let mut c = Cursor::new(vec![0; 15]); - assert_eq!(c.stream_position()?, 0); - assert_eq!(c.stream_position()?, 0); - - c.seek(SeekFrom::End(0))?; - assert_eq!(c.stream_position()?, 15); - assert_eq!(c.stream_position()?, 15); - - c.seek(SeekFrom::Start(7))?; - c.seek(SeekFrom::Current(2))?; - assert_eq!(c.stream_position()?, 9); - assert_eq!(c.stream_position()?, 9); - - c.seek(SeekFrom::End(-3))?; - c.seek(SeekFrom::Current(1))?; - c.seek(SeekFrom::Current(-5))?; - assert_eq!(c.stream_position()?, 8); - assert_eq!(c.stream_position()?, 8); - - Ok(()) - } - - // A simple example reader which uses the default implementation of - // read_to_end. - struct ExampleSliceReader<'a> { - slice: &'a [u8], - } - - impl<'a> Read for ExampleSliceReader<'a> { - fn read(&mut self, buf: &mut [u8]) -> io::Result { - let len = cmp::min(self.slice.len(), buf.len()); - buf[..len].copy_from_slice(&self.slice[..len]); - self.slice = &self.slice[len..]; - Ok(len) - } - } - - #[test] - fn test_read_to_end_capacity() -> io::Result<()> { - let input = &b"foo"[..]; - - // read_to_end() generally needs to over-allocate, both for efficiency - // and so that it can distinguish EOF. Assert that this is the case - // with this simple ExampleSliceReader struct, which uses the default - // implementation of read_to_end. Even though vec1 is allocated with - // exactly enough capacity for the read, read_to_end will allocate more - // space here. - let mut vec1 = Vec::with_capacity(input.len()); - ExampleSliceReader { slice: input }.read_to_end(&mut vec1)?; - assert_eq!(vec1.len(), input.len()); - assert!(vec1.capacity() > input.len(), "allocated more"); - - // However, std::io::Take includes an implementation of read_to_end - // that will not allocate when the limit has already been reached. In - // this case, vec2 never grows. - let mut vec2 = Vec::with_capacity(input.len()); - ExampleSliceReader { slice: input }.take(input.len() as u64).read_to_end(&mut vec2)?; - assert_eq!(vec2.len(), input.len()); - assert_eq!(vec2.capacity(), input.len(), "did not allocate more"); - - Ok(()) - } - - #[test] - fn io_slice_mut_advance() { - let mut buf1 = [1; 8]; - let mut buf2 = [2; 16]; - let mut buf3 = [3; 8]; - let mut bufs = &mut [ - IoSliceMut::new(&mut buf1), - IoSliceMut::new(&mut buf2), - IoSliceMut::new(&mut buf3), - ][..]; - - // Only in a single buffer.. - bufs = IoSliceMut::advance(bufs, 1); - assert_eq!(bufs[0].deref(), [1; 7].as_ref()); - assert_eq!(bufs[1].deref(), [2; 16].as_ref()); - assert_eq!(bufs[2].deref(), [3; 8].as_ref()); - - // Removing a buffer, leaving others as is. - bufs = IoSliceMut::advance(bufs, 7); - assert_eq!(bufs[0].deref(), [2; 16].as_ref()); - assert_eq!(bufs[1].deref(), [3; 8].as_ref()); - - // Removing a buffer and removing from the next buffer. - bufs = IoSliceMut::advance(bufs, 18); - assert_eq!(bufs[0].deref(), [3; 6].as_ref()); - } - - #[test] - fn io_slice_mut_advance_empty_slice() { - let empty_bufs = &mut [][..]; - // Shouldn't panic. - IoSliceMut::advance(empty_bufs, 1); - } - - #[test] - fn io_slice_mut_advance_beyond_total_length() { - let mut buf1 = [1; 8]; - let mut bufs = &mut [IoSliceMut::new(&mut buf1)][..]; - - // Going beyond the total length should be ok. - bufs = IoSliceMut::advance(bufs, 9); - assert!(bufs.is_empty()); - } - - #[test] - fn io_slice_advance() { - let buf1 = [1; 8]; - let buf2 = [2; 16]; - let buf3 = [3; 8]; - let mut bufs = &mut [IoSlice::new(&buf1), IoSlice::new(&buf2), IoSlice::new(&buf3)][..]; - - // Only in a single buffer.. - bufs = IoSlice::advance(bufs, 1); - assert_eq!(bufs[0].deref(), [1; 7].as_ref()); - assert_eq!(bufs[1].deref(), [2; 16].as_ref()); - assert_eq!(bufs[2].deref(), [3; 8].as_ref()); - - // Removing a buffer, leaving others as is. - bufs = IoSlice::advance(bufs, 7); - assert_eq!(bufs[0].deref(), [2; 16].as_ref()); - assert_eq!(bufs[1].deref(), [3; 8].as_ref()); - - // Removing a buffer and removing from the next buffer. - bufs = IoSlice::advance(bufs, 18); - assert_eq!(bufs[0].deref(), [3; 6].as_ref()); - } - - #[test] - fn io_slice_advance_empty_slice() { - let empty_bufs = &mut [][..]; - // Shouldn't panic. - IoSlice::advance(empty_bufs, 1); - } - - #[test] - fn io_slice_advance_beyond_total_length() { - let buf1 = [1; 8]; - let mut bufs = &mut [IoSlice::new(&buf1)][..]; - - // Going beyond the total length should be ok. - bufs = IoSlice::advance(bufs, 9); - assert!(bufs.is_empty()); - } - - /// Create a new writer that reads from at most `n_bufs` and reads - /// `per_call` bytes (in total) per call to write. - fn test_writer(n_bufs: usize, per_call: usize) -> TestWriter { - TestWriter { n_bufs, per_call, written: Vec::new() } - } - - struct TestWriter { - n_bufs: usize, - per_call: usize, - written: Vec, - } - - impl Write for TestWriter { - fn write(&mut self, buf: &[u8]) -> io::Result { - self.write_vectored(&[IoSlice::new(buf)]) - } - - fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result { - let mut left = self.per_call; - let mut written = 0; - for buf in bufs.iter().take(self.n_bufs) { - let n = min(left, buf.len()); - self.written.extend_from_slice(&buf[0..n]); - left -= n; - written += n; - } - Ok(written) - } - - fn flush(&mut self) -> io::Result<()> { - Ok(()) - } - } - - #[test] - fn test_writer_read_from_one_buf() { - let mut writer = test_writer(1, 2); - - assert_eq!(writer.write(&[]).unwrap(), 0); - assert_eq!(writer.write_vectored(&[]).unwrap(), 0); - - // Read at most 2 bytes. - assert_eq!(writer.write(&[1, 1, 1]).unwrap(), 2); - let bufs = &[IoSlice::new(&[2, 2, 2])]; - assert_eq!(writer.write_vectored(bufs).unwrap(), 2); - - // Only read from first buf. - let bufs = &[IoSlice::new(&[3]), IoSlice::new(&[4, 4])]; - assert_eq!(writer.write_vectored(bufs).unwrap(), 1); - - assert_eq!(writer.written, &[1, 1, 2, 2, 3]); - } - - #[test] - fn test_writer_read_from_multiple_bufs() { - let mut writer = test_writer(3, 3); - - // Read at most 3 bytes from two buffers. - let bufs = &[IoSlice::new(&[1]), IoSlice::new(&[2, 2, 2])]; - assert_eq!(writer.write_vectored(bufs).unwrap(), 3); - - // Read at most 3 bytes from three buffers. - let bufs = &[IoSlice::new(&[3]), IoSlice::new(&[4]), IoSlice::new(&[5, 5])]; - assert_eq!(writer.write_vectored(bufs).unwrap(), 3); - - assert_eq!(writer.written, &[1, 2, 2, 3, 4, 5]); - } - - #[test] - fn test_write_all_vectored() { - #[rustfmt::skip] // Becomes unreadable otherwise. - let tests: Vec<(_, &'static [u8])> = vec![ - (vec![], &[]), - (vec![IoSlice::new(&[1])], &[1]), - (vec![IoSlice::new(&[1, 2])], &[1, 2]), - (vec![IoSlice::new(&[1, 2, 3])], &[1, 2, 3]), - (vec![IoSlice::new(&[1, 2, 3, 4])], &[1, 2, 3, 4]), - (vec![IoSlice::new(&[1, 2, 3, 4, 5])], &[1, 2, 3, 4, 5]), - (vec![IoSlice::new(&[1]), IoSlice::new(&[2])], &[1, 2]), - (vec![IoSlice::new(&[1]), IoSlice::new(&[2, 2])], &[1, 2, 2]), - (vec![IoSlice::new(&[1, 1]), IoSlice::new(&[2, 2])], &[1, 1, 2, 2]), - (vec![IoSlice::new(&[1, 1]), IoSlice::new(&[2, 2, 2])], &[1, 1, 2, 2, 2]), - (vec![IoSlice::new(&[1, 1]), IoSlice::new(&[2, 2, 2])], &[1, 1, 2, 2, 2]), - (vec![IoSlice::new(&[1, 1, 1]), IoSlice::new(&[2, 2, 2])], &[1, 1, 1, 2, 2, 2]), - (vec![IoSlice::new(&[1, 1, 1]), IoSlice::new(&[2, 2, 2, 2])], &[1, 1, 1, 2, 2, 2, 2]), - (vec![IoSlice::new(&[1, 1, 1, 1]), IoSlice::new(&[2, 2, 2, 2])], &[1, 1, 1, 1, 2, 2, 2, 2]), - (vec![IoSlice::new(&[1]), IoSlice::new(&[2]), IoSlice::new(&[3])], &[1, 2, 3]), - (vec![IoSlice::new(&[1, 1]), IoSlice::new(&[2, 2]), IoSlice::new(&[3, 3])], &[1, 1, 2, 2, 3, 3]), - (vec![IoSlice::new(&[1]), IoSlice::new(&[2, 2]), IoSlice::new(&[3, 3, 3])], &[1, 2, 2, 3, 3, 3]), - (vec![IoSlice::new(&[1, 1, 1]), IoSlice::new(&[2, 2, 2]), IoSlice::new(&[3, 3, 3])], &[1, 1, 1, 2, 2, 2, 3, 3, 3]), - ]; - - let writer_configs = &[(1, 1), (1, 2), (1, 3), (2, 2), (2, 3), (3, 3)]; - - for (n_bufs, per_call) in writer_configs.iter().copied() { - for (mut input, wanted) in tests.clone().into_iter() { - let mut writer = test_writer(n_bufs, per_call); - assert!(writer.write_all_vectored(&mut *input).is_ok()); - assert_eq!(&*writer.written, &*wanted); - } - } - } -} diff --git a/libcoreio/src/io/prelude.rs b/libcoreio/src/io/prelude.rs deleted file mode 100644 index 94146bf..0000000 --- a/libcoreio/src/io/prelude.rs +++ /dev/null @@ -1,13 +0,0 @@ -//! The I/O Prelude -//! -//! The purpose of this module is to alleviate imports of many common I/O traits -//! by adding a glob import to the top of I/O heavy modules: -//! -//! ``` -//! # #![allow(unused_imports)] -//! use std::io::prelude::*; -//! ``` - - -pub use super::{Read, Seek, Write}; -#[cfg(feature = "collections")] pub use super::BufRead; diff --git a/libcoreio/src/io/util.rs b/libcoreio/src/io/util.rs deleted file mode 100644 index 515e1da..0000000 --- a/libcoreio/src/io/util.rs +++ /dev/null @@ -1,269 +0,0 @@ -#![allow(missing_copy_implementations)] - -use core::fmt; -use core::mem; -use crate::io::{self, ErrorKind, Initializer, Read, Write}; -#[cfg(feature = "collections")] use crate::io::BufRead; - -/// Copies the entire contents of a reader into a writer. -/// -/// This function will continuously read data from `reader` and then -/// write it into `writer` in a streaming fashion until `reader` -/// returns EOF. -/// -/// On success, the total number of bytes that were copied from -/// `reader` to `writer` is returned. -/// -/// If you’re wanting to copy the contents of one file to another and you’re -/// working with filesystem paths, see the [`fs::copy`] function. -/// -/// [`fs::copy`]: ../fs/fn.copy.html -/// -/// # Errors -/// -/// This function will return an error immediately if any call to `read` or -/// `write` returns an error. All instances of `ErrorKind::Interrupted` are -/// handled by this function and the underlying operation is retried. -/// -/// # Examples -/// -/// ``` -/// use std::io; -/// -/// fn main() -> io::Result<()> { -/// let mut reader: &[u8] = b"hello"; -/// let mut writer: Vec = vec![]; -/// -/// io::copy(&mut reader, &mut writer)?; -/// -/// assert_eq!(&b"hello"[..], &writer[..]); -/// Ok(()) -/// } -/// ``` -pub fn copy(reader: &mut R, writer: &mut W) -> io::Result -where - R: Read, - W: Write, -{ - let mut buf = unsafe { - #[allow(deprecated)] - let mut buf: [u8; super::DEFAULT_BUF_SIZE] = mem::uninitialized(); - reader.initializer().initialize(&mut buf); - buf - }; - - let mut written = 0; - loop { - let len = match reader.read(&mut buf) { - Ok(0) => return Ok(written), - Ok(len) => len, - Err(ref e) if e.kind() == ErrorKind::Interrupted => continue, - Err(e) => return Err(e), - }; - writer.write_all(&buf[..len])?; - written += len as u64; - } -} - -/// A reader which is always at EOF. -/// -/// This struct is generally created by calling [`empty`]. Please see -/// the documentation of [`empty()`][`empty`] for more details. -/// -/// [`empty`]: fn.empty.html -pub struct Empty { - _priv: (), -} - -/// Constructs a new handle to an empty reader. -/// -/// All reads from the returned reader will return [`Ok`]`(0)`. -/// -/// [`Ok`]: ../result/enum.Result.html#variant.Ok -/// -/// # Examples -/// -/// A slightly sad example of not reading anything into a buffer: -/// -/// ``` -/// use std::io::{self, Read}; -/// -/// let mut buffer = String::new(); -/// io::empty().read_to_string(&mut buffer).unwrap(); -/// assert!(buffer.is_empty()); -/// ``` -pub fn empty() -> Empty { - Empty { _priv: () } -} - -impl Read for Empty { - #[inline] - fn read(&mut self, _buf: &mut [u8]) -> io::Result { - Ok(0) - } - - #[inline] - unsafe fn initializer(&self) -> Initializer { - Initializer::nop() - } -} - -#[cfg(feature="collections")] -impl BufRead for Empty { - #[inline] - fn fill_buf(&mut self) -> io::Result<&[u8]> { - Ok(&[]) - } - #[inline] - fn consume(&mut self, _n: usize) {} -} - -impl fmt::Debug for Empty { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - f.pad("Empty { .. }") - } -} - -/// A reader which yields one byte over and over and over and over and over and... -/// -/// This struct is generally created by calling [`repeat`][repeat]. Please -/// see the documentation of `repeat()` for more details. -/// -/// [repeat]: fn.repeat.html -pub struct Repeat { - byte: u8, -} - -/// Creates an instance of a reader that infinitely repeats one byte. -/// -/// All reads from this reader will succeed by filling the specified buffer with -/// the given byte. -/// -/// # Examples -/// -/// ``` -/// use std::io::{self, Read}; -/// -/// let mut buffer = [0; 3]; -/// io::repeat(0b101).read_exact(&mut buffer).unwrap(); -/// assert_eq!(buffer, [0b101, 0b101, 0b101]); -/// ``` -pub fn repeat(byte: u8) -> Repeat { - Repeat { byte } -} - -impl Read for Repeat { - #[inline] - fn read(&mut self, buf: &mut [u8]) -> io::Result { - for slot in &mut *buf { - *slot = self.byte; - } - Ok(buf.len()) - } - - #[inline] - unsafe fn initializer(&self) -> Initializer { - Initializer::nop() - } -} - -impl fmt::Debug for Repeat { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - f.pad("Repeat { .. }") - } -} - -/// A writer which will move data into the void. -/// -/// This struct is generally created by calling [`sink`][sink]. Please -/// see the documentation of `sink()` for more details. -/// -/// [sink]: fn.sink.html -pub struct Sink { - _priv: (), -} - -/// Creates an instance of a writer which will successfully consume all data. -/// -/// All calls to `write` on the returned instance will return `Ok(buf.len())` -/// and the contents of the buffer will not be inspected. -/// -/// # Examples -/// -/// ```rust -/// use std::io::{self, Write}; -/// -/// let buffer = vec![1, 2, 3, 5, 8]; -/// let num_bytes = io::sink().write(&buffer).unwrap(); -/// assert_eq!(num_bytes, 5); -/// ``` -pub fn sink() -> Sink { - Sink { _priv: () } -} - -impl Write for Sink { - #[inline] - fn write(&mut self, buf: &[u8]) -> io::Result { - Ok(buf.len()) - } - - #[inline] - fn flush(&mut self) -> io::Result<()> { - Ok(()) - } -} - -impl fmt::Debug for Sink { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - f.pad("Sink { .. }") - } -} - -#[cfg(test)] -mod tests { - use crate::io::prelude::*; - use crate::io::{copy, empty, repeat, sink}; - - #[test] - fn copy_copies() { - let mut r = repeat(0).take(4); - let mut w = sink(); - assert_eq!(copy(&mut r, &mut w).unwrap(), 4); - - let mut r = repeat(0).take(1 << 17); - assert_eq!(copy(&mut r as &mut dyn Read, &mut w as &mut dyn Write).unwrap(), 1 << 17); - } - - #[test] - fn sink_sinks() { - let mut s = sink(); - assert_eq!(s.write(&[]).unwrap(), 0); - assert_eq!(s.write(&[0]).unwrap(), 1); - assert_eq!(s.write(&[0; 1024]).unwrap(), 1024); - assert_eq!(s.by_ref().write(&[0; 1024]).unwrap(), 1024); - } - - #[test] - fn empty_reads() { - let mut e = empty(); - assert_eq!(e.read(&mut []).unwrap(), 0); - assert_eq!(e.read(&mut [0]).unwrap(), 0); - assert_eq!(e.read(&mut [0; 1024]).unwrap(), 0); - assert_eq!(e.by_ref().read(&mut [0; 1024]).unwrap(), 0); - } - - #[test] - fn repeat_repeats() { - let mut r = repeat(4); - let mut b = [0; 1024]; - assert_eq!(r.read(&mut b).unwrap(), 1024); - assert!(b.iter().all(|b| *b == 4)); - } - - #[test] - fn take_some_bytes() { - assert_eq!(repeat(4).take(100).bytes().count(), 100); - assert_eq!(repeat(4).take(100).bytes().next().unwrap().unwrap(), 4); - assert_eq!(repeat(1).take(10).chain(repeat(2).take(10)).bytes().count(), 20); - } -} diff --git a/libcoreio/src/lib.rs b/libcoreio/src/lib.rs deleted file mode 100644 index 53fb28c..0000000 --- a/libcoreio/src/lib.rs +++ /dev/null @@ -1,51 +0,0 @@ -//!

-//! This is just a listing of the functionality available in this crate. See -//! the [std documentation](https://doc.rust-lang.org/nightly/std/io/index.html) -//! for a full description of the functionality. -#![allow(stable_features,unused_features)] -#![feature(question_mark,const_fn,copy_from_slice,try_from,str_internals,align_offset,slice_internals)] -#![cfg_attr(any(feature="alloc",feature="collections"),feature(alloc))] -#![cfg_attr(pattern_guards,feature(bind_by_move_pattern_guards,nll))] -#![cfg_attr(non_exhaustive,feature(non_exhaustive))] -#![cfg_attr(unicode,feature(str_char))] -#![cfg_attr(unicode,feature(unicode))] -#![no_std] - -#[cfg_attr(feature="collections",macro_use)] -#[cfg_attr(feature="collections",allow(unused_imports))] -#[cfg(feature="collections")] extern crate alloc as collections; -#[cfg(feature="alloc")] extern crate alloc; -#[cfg(rustc_unicode)] -extern crate rustc_unicode; -#[cfg(std_unicode)] -extern crate std_unicode; - -#[cfg(not(feature="collections"))] -pub type ErrorString = &'static str; - -// Provide Box::new wrapper -#[cfg(not(feature="alloc"))] -struct FakeBox(core::marker::PhantomData); -#[cfg(not(feature="alloc"))] -impl FakeBox { - fn new(val: T) -> T { - val - } -} - -// Needed for older compilers, to ignore vec!/format! macros in tests -#[cfg(not(feature="collections"))] -#[allow(unused)] -macro_rules! vec ( - ( $ elem : expr ; $ n : expr ) => { () }; - ( $ ( $ x : expr ) , * ) => { () }; - ( $ ( $ x : expr , ) * ) => { () }; -); -#[cfg(not(feature="collections"))] -#[allow(unused)] -macro_rules! format { - ( $ ( $ arg : tt ) * ) => { () }; -} - -mod io; -pub use io::*;