std: Funnel read_to_end through to one location

This pushes the implementation detail of proxying `read_to_end` through to
`read_to_end_uninitialized` all the way down to the `FileDesc` and `Handle`
implementations on Unix/Windows. This way intermediate layers will also be able
to take advantage of this optimized implementation.

This commit also adds the optimized implementation for `ChildStdout` and
`ChildStderr`.

1 files changed, 21 insertions, 2 deletions

diff --git a/src/libstd/sys/unix/fd.rs b/src/libstd/sys/unix/fd.rs
index 299c6ec2731..a00e6c3eb72 100644
--- a/src/libstd/sys/unix/fd.rs
+++ b/src/libstd/sys/unix/fd.rs
@@ -8,12 +8,15 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use io;
+use prelude::v1::*;
+
+use io::{self, Read};
 use libc::{self, c_int, size_t, c_void};
 use mem;
+use sync::atomic::{AtomicBool, Ordering};
 use sys::cvt;
 use sys_common::AsInner;
-use sync::atomic::{AtomicBool, Ordering};
+use sys_common::io::read_to_end_uninitialized;
 
 pub struct FileDesc {
     fd: c_int,
@@ -42,6 +45,11 @@ impl FileDesc {
         Ok(ret as usize)
     }
 
+    pub fn read_to_end(&self, buf: &mut Vec<u8>) -> io::Result<usize> {
+        let mut me = self;
+        (&mut me).read_to_end(buf)
+    }
+
     pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
         let ret = try!(cvt(unsafe {
             libc::write(self.fd,
@@ -118,6 +126,17 @@ impl FileDesc {
     }
 }
 
+#[unstable(reason = "not public", issue = "0", feature = "fd_read")]
+impl<'a> Read for &'a FileDesc {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        (**self).read(buf)
+    }
+
+    fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
+        unsafe { read_to_end_uninitialized(self, buf) }
+    }
+}
+
 impl AsInner<c_int> for FileDesc {
     fn as_inner(&self) -> &c_int { &self.fd }
 }