Reorganize net/disk_cache into backend specific directories.

net/disk_cache/entry_impl.h

-// 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_ENTRY_IMPL_H_
-#define NET_DISK_CACHE_ENTRY_IMPL_H_
-
-#include "base/memory/scoped_ptr.h"
-#include "net/base/net_log.h"
-#include "net/disk_cache/disk_cache.h"
-#include "net/disk_cache/disk_format.h"
-#include "net/disk_cache/storage_block.h"
-#include "net/disk_cache/storage_block-inl.h"
-
-namespace disk_cache {
-
-class BackendImpl;
-class InFlightBackendIO;
-class SparseControl;
-typedef StorageBlock<EntryStore> CacheEntryBlock;
-typedef StorageBlock<RankingsNode> CacheRankingsBlock;
-
-// This class implements the Entry interface. An object of this
-// class represents a single entry on the cache.
-class NET_EXPORT_PRIVATE EntryImpl
-    : public Entry,
-      public base::RefCounted<EntryImpl> {
-  friend class base::RefCounted<EntryImpl>;
-  friend class SparseControl;
- public:
-  enum Operation {
-    kRead,
-    kWrite,
-    kSparseRead,
-    kSparseWrite,
-    kAsyncIO,
-    kReadAsync1,
-    kWriteAsync1
-  };
-
-  EntryImpl(BackendImpl* backend, Addr address, bool read_only);
-
-  // Background implementation of the Entry interface.
-  void DoomImpl();
-  int ReadDataImpl(int index, int offset, IOBuffer* buf, int buf_len,
-                   const CompletionCallback& callback);
-  int WriteDataImpl(int index, int offset, IOBuffer* buf, int buf_len,
-                    const CompletionCallback& callback, bool truncate);
-  int ReadSparseDataImpl(int64 offset, IOBuffer* buf, int buf_len,
-                         const CompletionCallback& callback);
-  int WriteSparseDataImpl(int64 offset, IOBuffer* buf, int buf_len,
-                          const CompletionCallback& callback);
-  int GetAvailableRangeImpl(int64 offset, int len, int64* start);
-  void CancelSparseIOImpl();
-  int ReadyForSparseIOImpl(const CompletionCallback& callback);
-
-  inline CacheEntryBlock* entry() {
-    return &entry_;
-  }
-
-  inline CacheRankingsBlock* rankings() {
-    return &node_;
-  }
-
-  uint32 GetHash();
-
-  // Performs the initialization of a EntryImpl that will be added to the
-  // cache.
-  bool CreateEntry(Addr node_address, const std::string& key, uint32 hash);
-
-  // Returns true if this entry matches the lookup arguments.
-  bool IsSameEntry(const std::string& key, uint32 hash);
-
-  // Permamently destroys this entry.
-  void InternalDoom();
-
-  // Deletes this entry from disk. If |everything| is false, only the user data
-  // will be removed, leaving the key and control data intact.
-  void DeleteEntryData(bool everything);
-
-  // Returns the address of the next entry on the list of entries with the same
-  // hash.
-  CacheAddr GetNextAddress();
-
-  // Sets the address of the next entry on the list of entries with the same
-  // hash.
-  void SetNextAddress(Addr address);
-
-  // Reloads the rankings node information.
-  bool LoadNodeAddress();
-
-  // Updates the stored data to reflect the run-time information for this entry.
-  // Returns false if the data could not be updated. The purpose of this method
-  // is to be able to detect entries that are currently in use.
-  bool Update();
-
-  bool dirty() {
-    return dirty_;
-  }
-
-  bool doomed() {
-    return doomed_;
-  }
-
-  // Marks this entry as dirty (in memory) if needed. This is intended only for
-  // entries that are being read from disk, to be called during loading.
-  void SetDirtyFlag(int32 current_id);
-
-  // Fixes this entry so it can be treated as valid (to delete it).
-  void SetPointerForInvalidEntry(int32 new_id);
-
-  // Returns true if this entry is so meesed up that not everything is going to
-  // be removed.
-  bool LeaveRankingsBehind();
-
-  // Returns false if the entry is clearly invalid.
-  bool SanityCheck();
-  bool DataSanityCheck();
-
-  // Attempts to make this entry reachable though the key.
-  void FixForDelete();
-
-  // Handle the pending asynchronous IO count.
-  void IncrementIoCount();
-  void DecrementIoCount();
-
-  // This entry is being returned to the user. It is always called from the
-  // primary thread (not the dedicated cache thread).
-  void OnEntryCreated(BackendImpl* backend);
-
-  // Set the access times for this entry. This method provides support for
-  // the upgrade tool.
-  void SetTimes(base::Time last_used, base::Time last_modified);
-
-  // Generates a histogram for the time spent working on this operation.
-  void ReportIOTime(Operation op, const base::TimeTicks& start);
-
-  // Logs a begin event and enables logging for the EntryImpl.  Will also cause
-  // an end event to be logged on destruction.  The EntryImpl must have its key
-  // initialized before this is called.  |created| is true if the Entry was
-  // created rather than opened.
-  void BeginLogging(net::NetLog* net_log, bool created);
-
-  const net::BoundNetLog& net_log() const;
-
-  // Returns the number of blocks needed to store an EntryStore.
-  static int NumBlocksForEntry(int key_size);
-
-  // 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:
-  enum {
-     kNumStreams = 3
-  };
-  class UserBuffer;
-
-  virtual ~EntryImpl();
-
-  // Do all the work for ReadDataImpl and WriteDataImpl.  Implemented as
-  // separate functions to make logging of results simpler.
-  int InternalReadData(int index, int offset, IOBuffer* buf,
-                       int buf_len, const CompletionCallback& callback);
-  int InternalWriteData(int index, int offset, IOBuffer* buf, int buf_len,
-                        const CompletionCallback& callback, bool truncate);
-
-  // Initializes the storage for an internal or external data block.
-  bool CreateDataBlock(int index, int size);
-
-  // Initializes the storage for an internal or external generic block.
-  bool CreateBlock(int size, Addr* address);
-
-  // Deletes the data pointed by address, maybe backed by files_[index].
-  // Note that most likely the caller should delete (and store) the reference to
-  // |address| *before* calling this method because we don't want to have an
-  // entry using an address that is already free.
-  void DeleteData(Addr address, int index);
-
-  // Updates ranking information.
-  void UpdateRank(bool modified);
-
-  // Returns a pointer to the file that stores the given address.
-  File* GetBackingFile(Addr address, int index);
-
-  // Returns a pointer to the file that stores external data.
-  File* GetExternalFile(Addr address, int index);
-
-  // Prepares the target file or buffer for a write of buf_len bytes at the
-  // given offset.
-  bool PrepareTarget(int index, int offset, int buf_len, bool truncate);
-
-  // Adjusts the internal buffer and file handle for a write that truncates this
-  // stream.
-  bool HandleTruncation(int index, int offset, int buf_len);
-
-  // Copies data from disk to the internal buffer.
-  bool CopyToLocalBuffer(int index);
-
-  // Reads from a block data file to this object's memory buffer.
-  bool MoveToLocalBuffer(int index);
-
-  // Loads the external file to this object's memory buffer.
-  bool ImportSeparateFile(int index, int new_size);
-
-  // Makes sure that the internal buffer can handle the a write of |buf_len|
-  // bytes to |offset|.
-  bool PrepareBuffer(int index, int offset, int buf_len);
-
-  // Flushes the in-memory data to the backing storage. The data destination
-  // is determined based on the current data length and |min_len|.
-  bool Flush(int index, int min_len);
-
-  // Updates the size of a given data stream.
-  void UpdateSize(int index, int old_size, int new_size);
-
-  // Initializes the sparse control object. Returns a net error code.
-  int InitSparseData();
-
-  // Adds the provided |flags| to the current EntryFlags for this entry.
-  void SetEntryFlags(uint32 flags);
-
-  // Returns the current EntryFlags for this entry.
-  uint32 GetEntryFlags();
-
-  // Gets the data stored at the given index. If the information is in memory,
-  // a buffer will be allocated and the data will be copied to it (the caller
-  // can find out the size of the buffer before making this call). Otherwise,
-  // the cache address of the data will be returned, and that address will be
-  // removed from the regular book keeping of this entry so the caller is
-  // responsible for deleting the block (or file) from the backing store at some
-  // point; there is no need to report any storage-size change, only to do the
-  // actual cleanup.
-  void GetData(int index, char** buffer, Addr* address);
-
-  // Logs this entry to the internal trace buffer.
-  void Log(const char* msg);
-
-  CacheEntryBlock entry_;     // Key related information for this entry.
-  CacheRankingsBlock node_;   // Rankings related information for this entry.
-  base::WeakPtr<BackendImpl> backend_;  // Back pointer to the cache.
-  base::WeakPtr<InFlightBackendIO> background_queue_;  // In-progress queue.
-  scoped_ptr<UserBuffer> user_buffers_[kNumStreams];  // Stores user data.
-  // Files to store external user data and key.
-  scoped_refptr<File> files_[kNumStreams + 1];
-  mutable std::string key_;           // Copy of the key.
-  int unreported_size_[kNumStreams];  // Bytes not reported yet to the backend.
-  bool doomed_;               // True if this entry was removed from the cache.
-  bool read_only_;            // True if not yet writing.
-  bool dirty_;                // True if we detected that this is a dirty entry.
-  scoped_ptr<SparseControl> sparse_;  // Support for sparse entries.
-
-  net::BoundNetLog net_log_;
-
-  DISALLOW_COPY_AND_ASSIGN(EntryImpl);
-};
-
-}  // namespace disk_cache
-
-#endif  // NET_DISK_CACHE_ENTRY_IMPL_H_