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`.

5 files changed, 68 insertions, 2 deletions

diff --git a/src/libstd/sys/windows/fs.rs b/src/libstd/sys/windows/fs.rs
index 95fb1e7c600..624fef097fc 100644
--- a/src/libstd/sys/windows/fs.rs
+++ b/src/libstd/sys/windows/fs.rs
@@ -8,6 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use prelude::v1::*;
 use io::prelude::*;
 use os::windows::prelude::*;
 
@@ -312,6 +313,10 @@ impl File {
         self.handle.read(buf)
     }
 
+    pub fn read_to_end(&self, buf: &mut Vec<u8>) -> io::Result<usize> {
+        self.handle.read_to_end(buf)
+    }
+
     pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
         self.handle.write(buf)
     }
diff --git a/src/libstd/sys/windows/handle.rs b/src/libstd/sys/windows/handle.rs
index 47676a927f6..f4b8b2754c5 100644
--- a/src/libstd/sys/windows/handle.rs
+++ b/src/libstd/sys/windows/handle.rs
@@ -8,14 +8,17 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use prelude::v1::*;
+
 use cmp;
-use io::ErrorKind;
+use io::{ErrorKind, Read};
 use io;
 use mem;
 use ops::Deref;
 use ptr;
 use sys::c;
 use sys::cvt;
+use sys_common::io::read_to_end_uninitialized;
 use u32;
 
 /// An owned container for `HANDLE` object, closing them on Drop.
@@ -87,6 +90,11 @@ impl RawHandle {
         }
     }
 
+    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 mut amt = 0;
         // WriteFile takes a DWORD (u32) for the length so it only supports
@@ -111,3 +119,14 @@ impl RawHandle {
         Ok(Handle::new(ret))
     }
 }
+
+#[unstable(reason = "not public", issue = "0", feature = "fd_read")]
+impl<'a> Read for &'a RawHandle {
+    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) }
+    }
+}
diff --git a/src/libstd/sys/windows/net.rs b/src/libstd/sys/windows/net.rs
index dfa44a651e6..01e3a6cd8ed 100644
--- a/src/libstd/sys/windows/net.rs
+++ b/src/libstd/sys/windows/net.rs
@@ -8,8 +8,10 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use prelude::v1::*;
+
 use cmp;
-use io;
+use io::{self, Read};
 use libc::{c_int, c_void, c_ulong};
 use mem;
 use net::{SocketAddr, Shutdown};
@@ -20,6 +22,7 @@ use sync::Once;
 use sys::c;
 use sys;
 use sys_common::{self, AsInner, FromInner, IntoInner};
+use sys_common::io::read_to_end_uninitialized;
 use sys_common::net;
 use time::Duration;
 
@@ -142,6 +145,11 @@ impl Socket {
         }
     }
 
+    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 set_timeout(&self, dur: Option<Duration>,
                        kind: c_int) -> io::Result<()> {
         let timeout = match dur {
@@ -206,6 +214,17 @@ impl Socket {
     }
 }
 
+#[unstable(reason = "not public", issue = "0", feature = "fd_read")]
+impl<'a> Read for &'a Socket {
+    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 Drop for Socket {
     fn drop(&mut self) {
         let _ = unsafe { c::closesocket(self.0) };
diff --git a/src/libstd/sys/windows/pipe.rs b/src/libstd/sys/windows/pipe.rs
index aec41885f3b..8c3171d2470 100644
--- a/src/libstd/sys/windows/pipe.rs
+++ b/src/libstd/sys/windows/pipe.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use prelude::v1::*;
+
 use io;
 use ptr;
 use sys::cvt;
@@ -41,6 +43,10 @@ impl AnonPipe {
         self.inner.read(buf)
     }
 
+    pub fn read_to_end(&self, buf: &mut Vec<u8>) -> io::Result<usize> {
+        self.inner.read_to_end(buf)
+    }
+
     pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
         self.inner.write(buf)
     }
diff --git a/src/libstd/sys/windows/stdio.rs b/src/libstd/sys/windows/stdio.rs
index 1cd05b61d25..5a8705bf0cb 100644
--- a/src/libstd/sys/windows/stdio.rs
+++ b/src/libstd/sys/windows/stdio.rs
@@ -18,6 +18,7 @@ use sync::Mutex;
 use sys::c;
 use sys::cvt;
 use sys::handle::Handle;
+use sys_common::io::read_to_end_uninitialized;
 
 pub struct NoClose(Option<Handle>);
 
@@ -113,6 +114,22 @@ impl Stdin {
         // MemReader shouldn't error here since we just filled it
         utf8.read(buf)
     }
+
+    pub fn read_to_end(&self, buf: &mut Vec<u8>) -> io::Result<usize> {
+        let mut me = self;
+        (&mut me).read_to_end(buf)
+    }
+}
+
+#[unstable(reason = "not public", issue = "0", feature = "fd_read")]
+impl<'a> Read for &'a Stdin {
+    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 Stdout {