Rust: implement sending for all RPC types.

artiq/runtime.rs/src/proto.rs

@@ -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)
+}

artiq/runtime.rs/src/rpc.rs

@@ -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!(write!(f, ")"))
                     }
                     Tag::List(it) => {

artiq/runtime.rs/src/session_proto.rs

@@ -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.. {