Revert 51858 - Disk cache: Switch the disk cache to use the cache_thread. ...

net/disk_cache/in_flight_backend_io.h

-// Copyright (c) 2010 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_IN_FLIGHT_BACKEND_IO_H_
-#define NET_DISK_CACHE_IN_FLIGHT_BACKEND_IO_H_
-
-#include <string>
-
-#include "base/message_loop_proxy.h"
-#include "net/base/completion_callback.h"
-#include "net/base/io_buffer.h"
-#include "net/disk_cache/entry_impl.h"
-#include "net/disk_cache/in_flight_io.h"
-
-namespace disk_cache {
-
-class BackendImpl;
-
-// This class represents a single asynchronous disk cache IO operation while it
-// is being bounced between threads.
-class BackendIO : public BackgroundIO {
- public:
-  BackendIO(InFlightIO* controller, BackendImpl* backend,
-            net::CompletionCallback* callback);
-
-  // Runs the actual operation on the background thread.
-  void ExecuteOperation();
-
-  // Callback implementation.
-  void OnIOComplete(int result);
-
-  // Returns true if this operation is directed to an entry (vs. the backend).
-  bool IsEntryOperation();
-
-  net::CompletionCallback* callback() { return callback_; }
-
-  void ReleaseEntry();
-
-  // The operations we proxy:
-  void Init();
-  void OpenEntry(const std::string& key, Entry** entry);
-  void CreateEntry(const std::string& key, Entry** entry);
-  void DoomEntry(const std::string& key);
-  void DoomAllEntries();
-  void DoomEntriesBetween(const base::Time initial_time,
-                          const base::Time end_time);
-  void DoomEntriesSince(const base::Time initial_time);
-  void OpenNextEntry(void** iter, Entry** next_entry);
-  void OpenPrevEntry(void** iter, Entry** prev_entry);
-  void EndEnumeration(void* iterator);
-  void CloseEntryImpl(EntryImpl* entry);
-  void DoomEntryImpl(EntryImpl* entry);
-  void FlushQueue();  // Dummy operation.
-  void ReadData(EntryImpl* entry, int index, int offset, net::IOBuffer* buf,
-                int buf_len);
-  void WriteData(EntryImpl* entry, int index, int offset, net::IOBuffer* buf,
-                 int buf_len, bool truncate);
-  void ReadSparseData(EntryImpl* entry, int64 offset, net::IOBuffer* buf,
-                      int buf_len);
-  void WriteSparseData(EntryImpl* entry, int64 offset, net::IOBuffer* buf,
-                       int buf_len);
-  void GetAvailableRange(EntryImpl* entry, int64 offset, int len, int64* start);
-  void CancelSparseIO(EntryImpl* entry);
-  void ReadyForSparseIO(EntryImpl* entry);
-
- private:
-  // There are two types of operations to proxy: regular backend operations are
-  // queued so that we don't have more than one operation going on at the same
-  // time (for instance opening an entry and creating the same entry). On the
-  // other hand, operations targeted to a given entry can be long lived and
-  // support multiple simultaneous users (multiple reads or writes to the same
-  // entry), so they are not queued, just posted to the worker thread as they
-  // come.
-  enum Operation {
-    OP_NONE = 0,
-    OP_INIT,
-    OP_OPEN,
-    OP_CREATE,
-    OP_DOOM,
-    OP_DOOM_ALL,
-    OP_DOOM_BETWEEN,
-    OP_DOOM_SINCE,
-    OP_OPEN_NEXT,
-    OP_OPEN_PREV,
-    OP_END_ENUMERATION,
-    OP_CLOSE_ENTRY,
-    OP_DOOM_ENTRY,
-    OP_FLUSH_QUEUE,
-    OP_MAX_BACKEND,
-    OP_READ,
-    OP_WRITE,
-    OP_READ_SPARSE,
-    OP_WRITE_SPARSE,
-    OP_GET_RANGE,
-    OP_CANCEL_IO,
-    OP_IS_READY
-  };
-
-  ~BackendIO() {}
-
-  void ExecuteBackendOperation();
-  void ExecuteEntryOperation();
-
-  BackendImpl* backend_;
-  net::CompletionCallback* callback_;
-  Operation operation_;
-  net::CompletionCallbackImpl<BackendIO> my_callback_;
-
-  // The arguments of all the operations we proxy:
-  std::string key_;
-  Entry** entry_ptr_;
-  base::Time initial_time_;
-  base::Time end_time_;
-  void** iter_ptr_;
-  void* iter_;
-  EntryImpl* entry_;
-  int index_;
-  int offset_;
-  scoped_refptr<net::IOBuffer> buf_;
-  int buf_len_;
-  bool truncate_;
-  int64 offset64_;
-  int64* start_;
-
-  DISALLOW_COPY_AND_ASSIGN(BackendIO);
-};
-
-// The specialized controller that keeps track of current operations.
-class InFlightBackendIO : public InFlightIO {
- public:
-  InFlightBackendIO(BackendImpl* backend,
-                    base::MessageLoopProxy* background_thread)
-      : backend_(backend), background_thread_(background_thread) {}
-  ~InFlightBackendIO() {}
-
-  // The operations we proxy:
-  void Init(net::CompletionCallback* callback);
-  void OpenEntry(const std::string& key, Entry** entry,
-                 net::CompletionCallback* callback);
-  void CreateEntry(const std::string& key, Entry** entry,
-                   net::CompletionCallback* callback);
-  void DoomEntry(const std::string& key, net::CompletionCallback* callback);
-  void DoomAllEntries(net::CompletionCallback* callback);
-  void DoomEntriesBetween(const base::Time initial_time,
-                          const base::Time end_time,
-                          net::CompletionCallback* callback);
-  void DoomEntriesSince(const base::Time initial_time,
-                        net::CompletionCallback* callback);
-  void OpenNextEntry(void** iter, Entry** next_entry,
-                     net::CompletionCallback* callback);
-  void OpenPrevEntry(void** iter, Entry** prev_entry,
-                     net::CompletionCallback* callback);
-  void EndEnumeration(void* iterator);
-  void CloseEntryImpl(EntryImpl* entry);
-  void DoomEntryImpl(EntryImpl* entry);
-  void FlushQueue(net::CompletionCallback* callback);
-  void ReadData(EntryImpl* entry, int index, int offset, net::IOBuffer* buf,
-                int buf_len, net::CompletionCallback* callback);
-  void WriteData(EntryImpl* entry, int index, int offset, net::IOBuffer* buf,
-                 int buf_len, bool truncate, net::CompletionCallback* callback);
-  void ReadSparseData(EntryImpl* entry, int64 offset, net::IOBuffer* buf,
-                      int buf_len, net::CompletionCallback* callback);
-  void WriteSparseData(EntryImpl* entry, int64 offset, net::IOBuffer* buf,
-                       int buf_len, net::CompletionCallback* callback);
-  void GetAvailableRange(EntryImpl* entry, int64 offset, int len, int64* start,
-                         net::CompletionCallback* callback);
-  void CancelSparseIO(EntryImpl* entry);
-  void ReadyForSparseIO(EntryImpl* entry, net::CompletionCallback* callback);
-
-  // Blocks until all operations are cancelled or completed.
-  void WaitForPendingIO();
-
-  scoped_refptr<base::MessageLoopProxy> background_thread() {
-    return background_thread_;
-  }
-
-  // Returns true if the current thread is the background thread.
-  bool BackgroundIsCurrentThread() {
-    return background_thread_->BelongsToCurrentThread();
-  }
-
- protected:
-  virtual void OnOperationComplete(BackgroundIO* operation, bool cancel);
-
- private:
-  typedef std::list<scoped_refptr<BackendIO> > OperationList;
-  void QueueOperation(BackendIO* operation);
-  void PostOperation(BackendIO* operation);
-
-  BackendImpl* backend_;
-  scoped_refptr<base::MessageLoopProxy> background_thread_;
-  OperationList pending_ops_;  // The list of operations to be posted.
-
-  DISALLOW_COPY_AND_ASSIGN(InFlightBackendIO);
-};
-
-}  // namespace disk_cache
-
-#endif  // NET_DISK_CACHE_IN_FLIGHT_BACKEND_IO_H_