Remove support for "all or none" two-phase data pipe read/write.

examples/go/http_server.go

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package main
 
 import (
         "fmt"
         "log"
         "net"
@@ skipping 17 matching lines @@
 type MojoConnection struct {
         sendStream    system.ProducerHandle
         receiveStream system.ConsumerHandle
         socket        system.MessagePipeHandle
         localAddr     net.Addr
         remoteAddr    net.Addr
 }
 
 // Implements net.Conn.
 func (c *MojoConnection) Read(b []byte) (int, error) {
+        r, read := c.receiveStream.BeginReadData(system.MOJO_READ_DATA_FLAG_NONE)
+        if r != system.MOJO_RESULT_OK {
+                return 0, fmt.Errorf("can't read: %v", r)
+        }
         l := len(b)
-        r, read := c.receiveStream.BeginReadData(l, system.MOJO_READ_DATA_FLAG_NONE)
-        if r != system.MOJO_RESULT_OK {
-                return 0, fmt.Errorf("can't read %v bytes: %v", l, r)
-        }
-        if l > len(read) {
+        if (l > len(read)) {
                 l = len(read)
         }
         copy(b, read[:l])
         if r := c.receiveStream.EndReadData(l); r != system.MOJO_RESULT_OK {
                 return 0, fmt.Errorf("can't read %v bytes: %v", l, r)
         }
         return l, nil
 }
 
 // Implements net.Conn.
 func (c *MojoConnection) Write(b []byte) (int, error) {
+        r, buf := c.sendStream.BeginWriteData(system.MOJO_WRITE_DATA_FLAG_NONE)
+        if r != system.MOJO_RESULT_OK {
+                return 0, fmt.Errorf("can't write: %v", r)
+        }
         l := len(b)
-        r, buf := c.sendStream.BeginWriteData(l, system.MOJO_WRITE_DATA_FLAG_NONE)
-        if r != system.MOJO_RESULT_OK {
-                return 0, fmt.Errorf("can't write %v bytes: %v", l, r)
-        }
         if l > len(buf) {
                 l = len(buf)
         }
         copy(buf, b[:l])
         if r := c.sendStream.EndWriteData(l); r != system.MOJO_RESULT_OK {
                 return 0, fmt.Errorf("can't write %v bytes: %v", l, r)
         }
         return l, nil
 }
 
@@ skipping 168 matching lines @@
 }
 
 //export MojoMain
 func MojoMain(handle C.MojoHandle) C.MojoResult {
         application.Run(&HttpServerDelegate{}, system.MojoHandle(handle))
         return C.MOJO_RESULT_OK
 }
 
 func main() {
 }