Rust: implement sending for all RPC types.

This commit is contained in:
whitequark 2016-10-06 06:31:27 +00:00
parent 4cfc4e89b9
commit 5a630067cb
3 changed files with 126 additions and 29 deletions

View File

@ -2,6 +2,7 @@
use std::io::{self, Read, Write};
use std::vec::Vec;
use std::string::String;
use byteorder::{ByteOrder, NetworkEndian};
// FIXME: replace these with byteorder core io traits once those are in
@ -63,3 +64,16 @@ pub fn write_bytes(writer: &mut Write, value: &[u8]) -> io::Result<()> {
try!(write_u32(writer, value.len() as u32));
writer.write_all(value)
}
pub fn read_string(reader: &mut Read) -> io::Result<String> {
let mut bytes = try!(read_bytes(reader));
let len = bytes.len() - 1; // length without trailing \0
bytes.resize(len, 0); // FIXME: don't send \0 in the first place
String::from_utf8(bytes).map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
}
pub fn write_string(writer: &mut Write, value: &str) -> io::Result<()> {
try!(write_u32(writer, (value.len() + 1) as u32));
try!(writer.write_all(value.as_bytes()));
write_u8(writer, 0)
}

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@ -1,5 +1,5 @@
use std::io::{self, Read, Write};
use proto::{write_u8, write_bytes};
use proto::*;
use self::tag::{Tag, TagIterator, split_tag};
fn recv_value(reader: &mut Read, tag: Tag, data: &mut *const ()) -> io::Result<()> {
@ -19,10 +19,88 @@ pub fn recv_return(reader: &mut Read, tag_bytes: &[u8], data: *const ()) -> io::
Ok(())
}
fn send_value(writer: &mut Write, tag: Tag, data: &mut *const ()) -> io::Result<()> {
pub unsafe fn from_c_str<'a>(ptr: *const u8) -> &'a str {
use core::{str, slice};
extern { fn strlen(ptr: *const u8) -> usize; }
str::from_utf8_unchecked(slice::from_raw_parts(ptr as *const u8, strlen(ptr)))
}
unsafe fn send_value(writer: &mut Write, tag: Tag, data: &mut *const ()) -> io::Result<()> {
macro_rules! consume_value {
($ty:ty, |$ptr:ident| $map:expr) => ({
let ptr = (*data) as *const $ty;
*data = ptr.offset(1) as *const ();
(|$ptr: *const $ty| $map)(ptr)
})
}
try!(write_u8(writer, tag.as_u8()));
match tag {
Tag::None => write_u8(writer, b'n'),
_ => unreachable!()
Tag::None => Ok(()),
Tag::Bool => {
consume_value!(u8, |ptr|
write_u8(writer, *ptr))
}
Tag::Int32 => {
consume_value!(u32, |ptr|
write_u32(writer, *ptr))
}
Tag::Int64 => {
consume_value!(u64, |ptr|
write_u64(writer, *ptr))
}
Tag::Float64 => {
consume_value!(u64, |ptr|
write_u64(writer, *ptr))
}
Tag::String => {
consume_value!(*const u8, |ptr|
write_string(writer, from_c_str(*ptr)))
}
Tag::Tuple(it, arity) => {
let mut it = it.clone();
try!(write_u8(writer, arity));
for _ in 0..arity {
let tag = it.next().expect("truncated tag");
try!(send_value(writer, tag, data))
}
Ok(())
}
Tag::List(it) | Tag::Array(it) => {
struct List { length: u32, elements: *const () };
consume_value!(List, |ptr| {
try!(write_u32(writer, (*ptr).length));
let tag = it.clone().next().expect("truncated tag");
let mut data = (*ptr).elements;
for _ in 0..(*ptr).length as usize {
try!(send_value(writer, tag, &mut data));
}
Ok(())
})
}
Tag::Range(it) => {
let tag = it.clone().next().expect("truncated tag");
try!(send_value(writer, tag, data));
try!(send_value(writer, tag, data));
try!(send_value(writer, tag, data));
Ok(())
}
Tag::Keyword(it) => {
struct Keyword { name: *const u8, contents: () };
consume_value!(Keyword, |ptr| {
try!(write_string(writer, from_c_str((*ptr).name)));
let tag = it.clone().next().expect("truncated tag");
let mut data = &(*ptr).contents as *const ();
send_value(writer, tag, &mut data)
})
// Tag::Keyword never appears in composite types, so we don't have
// to accurately advance data.
}
Tag::Object => {
struct Object { id: u32 };
consume_value!(*const Object, |ptr|
write_u32(writer, (**ptr).id))
}
}
}
@ -37,7 +115,7 @@ pub fn send_args(writer: &mut Write, tag_bytes: &[u8],
for index in 0.. {
if let Some(arg_tag) = args_it.next() {
let mut data = unsafe { *data.offset(index) };
try!(send_value(writer, arg_tag, &mut data));
try!(unsafe { send_value(writer, arg_tag, &mut data) });
} else {
break
}
@ -61,7 +139,7 @@ mod tag {
(arg_tags_bytes, return_tag_bytes)
}
#[derive(Debug)]
#[derive(Debug, Clone, Copy)]
pub enum Tag<'a> {
None,
Bool,
@ -77,6 +155,25 @@ mod tag {
Object
}
impl<'a> Tag<'a> {
pub fn as_u8(self) -> u8 {
match self {
Tag::None => b'n',
Tag::Bool => b'b',
Tag::Int32 => b'i',
Tag::Int64 => b'I',
Tag::Float64 => b'f',
Tag::String => b's',
Tag::Tuple(_, _) => b't',
Tag::List(_) => b'l',
Tag::Array(_) => b'a',
Tag::Range(_) => b'r',
Tag::Keyword(_) => b'k',
Tag::Object => b'O',
}
}
}
#[derive(Debug, Clone, Copy)]
pub struct TagIterator<'a> {
data: &'a [u8]
@ -104,23 +201,23 @@ mod tag {
b't' => {
let count = self.data[0];
self.data = &self.data[1..];
Tag::Tuple(self.skip(count), count)
Tag::Tuple(self.sub(count), count)
}
b'l' => Tag::List(self.skip(1)),
b'a' => Tag::Array(self.skip(1)),
b'r' => Tag::Range(self.skip(1)),
b'k' => Tag::Keyword(self.skip(1)),
b'l' => Tag::List(self.sub(1)),
b'a' => Tag::Array(self.sub(1)),
b'r' => Tag::Range(self.sub(1)),
b'k' => Tag::Keyword(self.sub(1)),
b'O' => Tag::Object,
_ => unreachable!()
})
}
fn skip(&mut self, count: u8) -> TagIterator<'a> {
let origin = self.clone();
fn sub(&mut self, count: u8) -> TagIterator<'a> {
let data = self.data;
for _ in 0..count {
self.next().expect("truncated tag");
}
origin
TagIterator { data: &data[..(data.len() - self.data.len())] }
}
}
@ -150,10 +247,7 @@ mod tag {
try!(write!(f, "String")),
Tag::Tuple(it, cnt) => {
try!(write!(f, "Tuple("));
for i in 0..cnt {
try!(it.fmt(f));
if i != cnt - 1 { try!(write!(f, ", ")) }
}
try!(it.fmt(f));
try!(write!(f, ")"))
}
Tag::List(it) => {

View File

@ -2,17 +2,6 @@ use std::prelude::v1::*;
use std::io::{self, Read, Write};
use proto::*;
fn read_string(reader: &mut Read) -> io::Result<String> {
let mut bytes = try!(read_bytes(reader));
let len = bytes.len() - 1; // length without trailing \0
bytes.resize(len, 0); // FIXME: don't send \0 in the first place
String::from_utf8(bytes).map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
}
fn write_string(writer: &mut Write, value: &str) -> io::Result<()> {
write_bytes(writer, value.as_bytes())
}
fn read_sync(reader: &mut Read) -> io::Result<()> {
let mut sync = [0; 4];
for i in 0.. {