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// Copyright 2013 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.
#include "base/files/memory_mapped_file.h"
#include "base/files/file_path.h"
#include "base/logging.h"
#include "base/metrics/histogram.h"
#include "base/strings/string16.h"
#include "base/threading/thread_restrictions.h"
namespace base {
MemoryMappedFile::MemoryMappedFile()
: file_(INVALID_HANDLE_VALUE),
file_mapping_(INVALID_HANDLE_VALUE),
data_(NULL),
length_(INVALID_FILE_SIZE) {
}
bool MemoryMappedFile::InitializeAsImageSection(const FilePath& file_name) {
if (IsValid())
return false;
file_ = CreatePlatformFile(file_name, PLATFORM_FILE_OPEN | PLATFORM_FILE_READ,
NULL, NULL);
if (file_ == kInvalidPlatformFileValue) {
DLOG(ERROR) << "Couldn't open " << file_name.AsUTF8Unsafe();
return false;
}
if (!MapFileToMemoryInternalEx(SEC_IMAGE)) {
CloseHandles();
return false;
}
return true;
}
bool MemoryMappedFile::MapFileToMemoryInternal() {
return MapFileToMemoryInternalEx(0);
}
bool MemoryMappedFile::MapFileToMemoryInternalEx(int flags) {
ThreadRestrictions::AssertIOAllowed();
if (file_ == INVALID_HANDLE_VALUE)
return false;
length_ = ::GetFileSize(file_, NULL);
if (length_ == INVALID_FILE_SIZE)
return false;
file_mapping_ = ::CreateFileMapping(file_, NULL, PAGE_READONLY | flags,
0, 0, NULL);
if (!file_mapping_) {
// According to msdn, system error codes are only reserved up to 15999.
// http://msdn.microsoft.com/en-us/library/ms681381(v=VS.85).aspx.
UMA_HISTOGRAM_ENUMERATION("MemoryMappedFile.CreateFileMapping",
logging::GetLastSystemErrorCode(), 16000);
return false;
}
data_ = static_cast<uint8*>(
::MapViewOfFile(file_mapping_, FILE_MAP_READ, 0, 0, 0));
if (!data_) {
UMA_HISTOGRAM_ENUMERATION("MemoryMappedFile.MapViewOfFile",
logging::GetLastSystemErrorCode(), 16000);
}
return data_ != NULL;
}
void MemoryMappedFile::CloseHandles() {
if (data_)
::UnmapViewOfFile(data_);
if (file_mapping_ != INVALID_HANDLE_VALUE)
::CloseHandle(file_mapping_);
if (file_ != INVALID_HANDLE_VALUE)
::CloseHandle(file_);
data_ = NULL;
file_mapping_ = file_ = INVALID_HANDLE_VALUE;
length_ = INVALID_FILE_SIZE;
}
} // namespace base
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