base/scoped_bstr_win.cc

   1 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/scoped_bstr_win.h"
   6
   7 #include "base/logging.h"
   8
   9
  10 ScopedBstr::ScopedBstr(const wchar_t* non_bstr)
  11     : bstr_(SysAllocString(non_bstr)) {
  12 }
  13
  14 ScopedBstr::~ScopedBstr() {
  15   COMPILE_ASSERT(sizeof(ScopedBstr) == sizeof(BSTR), ScopedBstrSize);
  16   SysFreeString(bstr_);
  17 }
  18
  19 void ScopedBstr::Reset(BSTR bstr) {
  20   if (bstr != bstr_) {
  21     // if |bstr_| is NULL, SysFreeString does nothing.
  22     SysFreeString(bstr_);
  23     bstr_ = bstr;
  24   }
  25 }
  26
  27 BSTR ScopedBstr::Release() {
  28   BSTR bstr = bstr_;
  29   bstr_ = NULL;
  30   return bstr;
  31 }
  32
  33 void ScopedBstr::Swap(ScopedBstr& bstr2) {
  34   BSTR tmp = bstr_;
  35   bstr_ = bstr2.bstr_;
  36   bstr2.bstr_ = tmp;
  37 }
  38
  39 BSTR* ScopedBstr::Receive() {
  40   DCHECK(bstr_ == NULL) << "BSTR leak.";
  41   return &bstr_;
  42 }
  43
  44 BSTR ScopedBstr::Allocate(const wchar_t* wide_str) {
  45   Reset(SysAllocString(wide_str));
  46   return bstr_;
  47 }
  48
  49 BSTR ScopedBstr::AllocateBytes(int bytes) {
  50   Reset(SysAllocStringByteLen(NULL, bytes));
  51   return bstr_;
  52 }
  53
  54 void ScopedBstr::SetByteLen(uint32 bytes) {
  55   DCHECK(bstr_ != NULL) << "attempting to modify a NULL bstr";
  56   uint32* data = reinterpret_cast<uint32*>(bstr_);
  57   data[-1] = bytes;
  58 }
  59
  60 uint32 ScopedBstr::Length() const {
  61   return SysStringLen(bstr_);
  62 }
  63
  64 uint32 ScopedBstr::ByteLength() const {
  65   return SysStringByteLen(bstr_);
  66 }