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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.
#ifndef NET_DISK_CACHE_FLASH_ENTRY_IMPL_H_
#define NET_DISK_CACHE_FLASH_ENTRY_IMPL_H_
#include <string>
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "net/base/net_export.h"
#include "net/disk_cache/disk_cache.h"
#include "net/disk_cache/flash/internal_entry.h"
namespace base {
class MessageLoopProxy;
} // namespace base
namespace disk_cache {
class InternalEntry;
class IOBuffer;
class LogStore;
// We use split objects to minimize the context switches between the main thread
// and the cache thread in the most common case of creating a new entry.
//
// All calls on a new entry are served synchronously. When an object is
// destructed (via final Close() call), a message is posted to the cache thread
// to save the object to storage.
//
// When an entry is not new, every asynchronous call is posted to the cache
// thread, just as before; synchronous calls like GetKey() and GetDataSize() are
// served from the main thread.
class NET_EXPORT_PRIVATE FlashEntryImpl
: public Entry,
public base::RefCountedThreadSafe<FlashEntryImpl> {
friend class base::RefCountedThreadSafe<FlashEntryImpl>;
public:
FlashEntryImpl(const std::string& key,
LogStore* store,
base::MessageLoopProxy* cache_thread);
FlashEntryImpl(int32 id,
LogStore* store,
base::MessageLoopProxy* cache_thread);
int Init(const CompletionCallback& callback);
// disk_cache::Entry interface.
virtual void Doom() OVERRIDE;
virtual void Close() OVERRIDE;
virtual std::string GetKey() const OVERRIDE;
virtual base::Time GetLastUsed() const OVERRIDE;
virtual base::Time GetLastModified() const OVERRIDE;
virtual int32 GetDataSize(int index) const OVERRIDE;
virtual int ReadData(int index, int offset, IOBuffer* buf, int buf_len,
const CompletionCallback& callback) OVERRIDE;
virtual int WriteData(int index, int offset, IOBuffer* buf, int buf_len,
const CompletionCallback& callback,
bool truncate) OVERRIDE;
virtual int ReadSparseData(int64 offset, IOBuffer* buf, int buf_len,
const CompletionCallback& callback) OVERRIDE;
virtual int WriteSparseData(int64 offset, IOBuffer* buf, int buf_len,
const CompletionCallback& callback) OVERRIDE;
virtual int GetAvailableRange(int64 offset, int len, int64* start,
const CompletionCallback& callback) OVERRIDE;
virtual bool CouldBeSparse() const OVERRIDE;
virtual void CancelSparseIO() OVERRIDE;
virtual int ReadyForSparseIO(const CompletionCallback& callback) OVERRIDE;
private:
void OnInitComplete(scoped_ptr<KeyAndStreamSizes> key_and_stream_sizes);
virtual ~FlashEntryImpl();
bool init_;
std::string key_;
int stream_sizes_[kFlashLogStoreEntryNumStreams];
// Used if |this| is an newly created entry.
scoped_refptr<InternalEntry> new_internal_entry_;
// Used if |this| is an existing entry.
scoped_refptr<InternalEntry> old_internal_entry_;
// Copy of the callback for asynchronous calls on |old_internal_entry_|.
CompletionCallback callback_;
scoped_refptr<base::MessageLoopProxy> cache_thread_;
DISALLOW_COPY_AND_ASSIGN(FlashEntryImpl);
};
} // namespace disk_cache
#endif // NET_DISK_CACHE_FLASH_ENTRY_IMPL_H_
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