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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/sys_info.h"
namespace base {
const MemoryMappedFile::Region MemoryMappedFile::Region::kWholeFile(
base::LINKER_INITIALIZED);
MemoryMappedFile::Region::Region(base::LinkerInitialized) : offset(0), size(0) {
}
MemoryMappedFile::Region::Region(int64 offset, int64 size)
: offset(offset), size(size) {
DCHECK_GE(offset, 0);
DCHECK_GT(size, 0);
}
bool MemoryMappedFile::Region::operator==(
const MemoryMappedFile::Region& other) const {
return other.offset == offset && other.size == size;
}
MemoryMappedFile::~MemoryMappedFile() {
CloseHandles();
}
#if !defined(OS_NACL)
bool MemoryMappedFile::Initialize(const FilePath& file_name) {
if (IsValid())
return false;
file_.Initialize(file_name, File::FLAG_OPEN | File::FLAG_READ);
if (!file_.IsValid()) {
DLOG(ERROR) << "Couldn't open " << file_name.AsUTF8Unsafe();
return false;
}
if (!MapFileRegionToMemory(Region::kWholeFile)) {
CloseHandles();
return false;
}
return true;
}
bool MemoryMappedFile::Initialize(File file) {
return Initialize(file.Pass(), Region::kWholeFile);
}
bool MemoryMappedFile::Initialize(File file, const Region& region) {
if (IsValid())
return false;
file_ = file.Pass();
if (!MapFileRegionToMemory(region)) {
CloseHandles();
return false;
}
return true;
}
bool MemoryMappedFile::IsValid() const {
return data_ != NULL;
}
// static
void MemoryMappedFile::CalculateVMAlignedBoundaries(int64 start,
int64 size,
int64* aligned_start,
int64* aligned_size,
int32* offset) {
// Sadly, on Windows, the mmap alignment is not just equal to the page size.
const int64 mask = static_cast<int64>(SysInfo::VMAllocationGranularity()) - 1;
DCHECK_LT(mask, std::numeric_limits<int32>::max());
*offset = start & mask;
*aligned_start = start & ~mask;
*aligned_size = (size + *offset + mask) & ~mask;
}
#endif
} // namespace base
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