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// Copyright (c) 2012 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 "net/disk_cache/mapped_file.h"
#include <errno.h>
#include <sys/mman.h>
#include "base/file_path.h"
#include "base/logging.h"
#include "net/disk_cache/disk_cache.h"
namespace disk_cache {
void* MappedFile::Init(const FilePath& name, size_t size) {
DCHECK(!init_);
if (init_ || !File::Init(name))
return NULL;
size_t temp_len = size ? size : 4096;
if (!size)
size = GetLength();
buffer_ = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED,
platform_file(), 0);
init_ = true;
view_size_ = size;
DCHECK(reinterpret_cast<intptr_t>(buffer_) != -1);
if (reinterpret_cast<intptr_t>(buffer_) == -1)
buffer_ = 0;
// Make sure we detect hardware failures reading the headers.
scoped_array<char> temp(new char[temp_len]);
if (!Read(temp.get(), temp_len, 0))
return NULL;
return buffer_;
}
bool MappedFile::Load(const FileBlock* block) {
size_t offset = block->offset() + view_size_;
return Read(block->buffer(), block->size(), offset);
}
bool MappedFile::Store(const FileBlock* block) {
size_t offset = block->offset() + view_size_;
return Write(block->buffer(), block->size(), offset);
}
void MappedFile::Flush() {
}
MappedFile::~MappedFile() {
if (!init_)
return;
if (buffer_) {
int ret = munmap(buffer_, view_size_);
DCHECK_EQ(0, ret);
}
}
} // namespace disk_cache
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