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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/blockfile/mapped_file.h"
#include <stdlib.h>
#include "base/files/file_path.h"
#include "base/logging.h"
namespace disk_cache {
void* MappedFile::Init(const base::FilePath& name, size_t size) {
DCHECK(!init_);
if (init_ || !File::Init(name))
return NULL;
if (!size)
size = GetLength();
buffer_ = malloc(size);
snapshot_ = malloc(size);
if (buffer_ && snapshot_ && Read(buffer_, size, 0)) {
memcpy(snapshot_, buffer_, size);
} else {
free(buffer_);
free(snapshot_);
buffer_ = snapshot_ = 0;
}
init_ = true;
view_size_ = size;
return buffer_;
}
void MappedFile::Flush() {
DCHECK(buffer_);
DCHECK(snapshot_);
const char* buffer_ptr = static_cast<const char*>(buffer_);
char* snapshot_ptr = static_cast<char*>(snapshot_);
const size_t block_size = 4096;
for (size_t offset = 0; offset < view_size_; offset += block_size) {
size_t size = std::min(view_size_ - offset, block_size);
if (memcmp(snapshot_ptr + offset, buffer_ptr + offset, size)) {
memcpy(snapshot_ptr + offset, buffer_ptr + offset, size);
Write(snapshot_ptr + offset, size, offset);
}
}
}
MappedFile::~MappedFile() {
if (!init_)
return;
if (buffer_ && snapshot_) {
Flush();
}
free(buffer_);
free(snapshot_);
}
} // namespace disk_cache
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