base/files/memory_mapped_file_win.cc

   1 // Copyright 2013 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/files/memory_mapped_file.h"
   6
   7 #include "base/files/file_path.h"
   8 #include "base/strings/string16.h"
   9 #include "base/threading/thread_restrictions.h"
  10
  11 namespace base {
  12
  13 MemoryMappedFile::MemoryMappedFile() : data_(NULL), length_(0), image_(false) {
  14 }
  15
  16 bool MemoryMappedFile::InitializeAsImageSection(const FilePath& file_name) {
  17   image_ = true;
  18   return Initialize(file_name);
  19 }
  20
  21 bool MemoryMappedFile::MapFileToMemory() {
  22   ThreadRestrictions::AssertIOAllowed();
  23
  24   if (!file_.IsValid())
  25     return false;
  26
  27   int64 len = file_.GetLength();
  28   if (len <= 0 || len > kint32max)
  29     return false;
  30   length_ = static_cast<size_t>(len);
  31
  32   int flags = image_ ? SEC_IMAGE | PAGE_READONLY : PAGE_READONLY;
  33
  34   file_mapping_.Set(::CreateFileMapping(file_.GetPlatformFile(), NULL,
  35                                         flags, 0, 0, NULL));
  36   if (!file_mapping_.IsValid())
  37     return false;
  38
  39   data_ = static_cast<uint8*>(::MapViewOfFile(file_mapping_.Get(),
  40                                               FILE_MAP_READ, 0, 0, 0));
  41   return data_ != NULL;
  42 }
  43
  44 void MemoryMappedFile::CloseHandles() {
  45   if (data_)
  46     ::UnmapViewOfFile(data_);
  47   if (file_mapping_.IsValid())
  48     file_mapping_.Close();
  49   if (file_.IsValid())
  50     file_.Close();
  51
  52   data_ = NULL;
  53   length_ = 0;
  54 }
  55
  56 }  // namespace base