auto merge of #9749 : alexcrichton/rust/less-io, r=brson

This implements a number of the baby steps needed to start eliminating everything inside of `std::io`. It turns out that there are a *lot* of users of that module, so I'm going to try to tackle them separately instead of bringing down the whole system all at once.

This pull implements a large amount of unimplemented functionality inside of `std::rt::io` including:

* Native file I/O (file descriptors, *FILE)
* Native stdio (through the native file descriptors)
* Native processes (extracted from `std::run`)

I also found that there are a number of users of `std::io` which desire to read an input line-by-line, so I added an implementation of `read_until` and `read_line` to `BufferedReader`.

With all of these changes in place, I started to axe various usages of `std::io`. There's a lot of one-off uses here-and-there, but the major use-case remaining that doesn't have a fantastic solution is `extra::json`. I ran into a few compiler bugs when attempting to remove that, so I figured I'd come back to it later instead. 

There is one fairly major change in this pull, and it's moving from native stdio to uv stdio via `print` and `println`. Unfortunately logging still goes through native I/O (via `dumb_println`). This is going to need some thinking, because I still want the goal of logging/printing to be 0 allocations, and this is not possible if `io::stdio::stderr()` is called on each log message. Instead I think that this may need to be cached as the `logger` field inside the `Task` struct, but that will require a little more workings to get right (this is also a similar problem for print/println, do we cache `stdout()` to not have to re-create it every time?).

1 files changed, 25 insertions, 2 deletions

diff --git a/src/libstd/rt/io/mod.rs b/src/libstd/rt/io/mod.rs
index f14f8f28d12..f9542cbf5f9 100644
--- a/src/libstd/rt/io/mod.rs
+++ b/src/libstd/rt/io/mod.rs
@@ -313,8 +313,11 @@ pub mod buffered;
 pub mod native {
     /// Posix file I/O
     pub mod file;
-    /// # XXX - implement this
-    pub mod stdio { }
+    /// Process spawning and child management
+    pub mod process;
+    /// Posix stdio
+    pub mod stdio;
+
     /// Sockets
     /// # XXX - implement this
     pub mod net {
@@ -459,6 +462,16 @@ pub trait Reader {
     fn eof(&mut self) -> bool;
 }
 
+impl Reader for ~Reader {
+    fn read(&mut self, buf: &mut [u8]) -> Option<uint> { self.read(buf) }
+    fn eof(&mut self) -> bool { self.eof() }
+}
+
+impl<'self> Reader for &'self mut Reader {
+    fn read(&mut self, buf: &mut [u8]) -> Option<uint> { self.read(buf) }
+    fn eof(&mut self) -> bool { self.eof() }
+}
+
 pub trait Writer {
     /// Write the given buffer
     ///
@@ -471,6 +484,16 @@ pub trait Writer {
     fn flush(&mut self);
 }
 
+impl Writer for ~Writer {
+    fn write(&mut self, buf: &[u8]) { self.write(buf) }
+    fn flush(&mut self) { self.flush() }
+}
+
+impl<'self> Writer for &'self mut Writer {
+    fn write(&mut self, buf: &[u8]) { self.write(buf) }
+    fn flush(&mut self) { self.flush() }
+}
+
 pub trait Stream: Reader + Writer { }
 
 impl<T: Reader + Writer> Stream for T {}