code review 4536076: net: Sendfile for win32.

src/pkg/net/sendfile_windows.go

 // Copyright 2011 The Go 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 net
 
 import (
         "io"
         "os"
         "syscall"
 )
-
-// maxSendfileSize is the largest chunk size we ask the kernel to copy
-// at a time.
-//const maxSendfileSize uint32 = 0x7fffffff
-const maxSendfileSize uint32 = 0x000fffff
 
 type sendfileOp struct {
         anOp
         src int32 // source
         n   uint32
 }
 
 func (o *sendfileOp) Submit() (errno int) {
         return syscall.TransmitFile(int32(o.fd.sysfd), o.src, o.n, 0, &o.o, nil, syscall.TF_WRITE_BEHIND)
 }
@@ skipping 29 matching lines @@
         c.wio.Lock()
         defer c.wio.Unlock()
         c.incref()
         defer c.decref()
 
         var o sendfileOp
         o.Init(c)
         o.n = uint32(n)
         o.src = int32(f.Fd())
         done, err := iosrv.ExecIO(&o, 0)
+        if err != nil {
+                return 0, err, false
+        }
         if lr != nil {
                 lr.N -= int64(done)
         }
-        return int64(done), err, done > 0
+        return int64(done), nil, true
 }