storage/browser/fileapi/file_system_usage_cache.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef STORAGE_BROWSER_FILEAPI_FILE_SYSTEM_USAGE_CACHE_H_
   6 #define STORAGE_BROWSER_FILEAPI_FILE_SYSTEM_USAGE_CACHE_H_
   7
   8 #include <map>
   9
  10 #include "base/basictypes.h"
  11 #include "base/files/file.h"
  12 #include "base/files/file_path.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/memory/weak_ptr.h"
  15 #include "base/sequenced_task_runner.h"
  16 #include "storage/browser/storage_browser_export.h"
  17
  18 namespace storage {
  19
  20 class TimedTaskHelper;
  21
  22 class STORAGE_EXPORT_PRIVATE FileSystemUsageCache {
  23  public:
  24   explicit FileSystemUsageCache(base::SequencedTaskRunner* task_runner);
  25   ~FileSystemUsageCache();
  26
  27   // Gets the size described in the .usage file even if dirty > 0 or
  28   // is_valid == false.  Returns true if the .usage file is available.
  29   bool GetUsage(const base::FilePath& usage_file_path, int64* usage);
  30
  31   // Gets the dirty count in the .usage file.
  32   // Returns true if the .usage file is available.
  33   bool GetDirty(const base::FilePath& usage_file_path, uint32* dirty);
  34
  35   // Increments or decrements the "dirty" entry in the .usage file.
  36   // Returns false if no .usage is available.
  37   bool IncrementDirty(const base::FilePath& usage_file_path);
  38   bool DecrementDirty(const base::FilePath& usage_file_path);
  39
  40   // Notifies quota system that it needs to recalculate the usage cache of the
  41   // origin.  Returns false if no .usage is available.
  42   bool Invalidate(const base::FilePath& usage_file_path);
  43   bool IsValid(const base::FilePath& usage_file_path);
  44
  45   // Updates the size described in the .usage file.
  46   bool UpdateUsage(const base::FilePath& usage_file_path, int64 fs_usage);
  47
  48   // Updates the size described in the .usage file by delta with keeping dirty
  49   // even if dirty > 0.
  50   bool AtomicUpdateUsageByDelta(const base::FilePath& usage_file_path,
  51                                 int64 delta);
  52
  53   bool Exists(const base::FilePath& usage_file_path);
  54   bool Delete(const base::FilePath& usage_file_path);
  55
  56   void CloseCacheFiles();
  57
  58   static const base::FilePath::CharType kUsageFileName[];
  59   static const char kUsageFileHeader[];
  60   static const int kUsageFileSize;
  61   static const int kUsageFileHeaderSize;
  62
  63  private:
  64   typedef std::map<base::FilePath, base::File*> CacheFiles;
  65
  66   // Read the size, validity and the "dirty" entry described in the .usage file.
  67   // Returns less than zero if no .usage file is available.
  68   bool Read(const base::FilePath& usage_file_path,
  69             bool* is_valid,
  70             uint32* dirty,
  71             int64* usage);
  72
  73   bool Write(const base::FilePath& usage_file_path,
  74              bool is_valid,
  75              int32 dirty,
  76              int64 fs_usage);
  77
  78   base::File* GetFile(const base::FilePath& file_path);
  79
  80   bool ReadBytes(const base::FilePath& file_path,
  81                  char* buffer,
  82                  int64 buffer_size);
  83   bool WriteBytes(const base::FilePath& file_path,
  84                   const char* buffer,
  85                   int64 buffer_size);
  86   bool FlushFile(const base::FilePath& file_path);
  87   void ScheduleCloseTimer();
  88
  89   bool HasCacheFileHandle(const base::FilePath& file_path);
  90
  91   bool CalledOnValidThread();
  92
  93   scoped_ptr<TimedTaskHelper> timer_;
  94   CacheFiles cache_files_;
  95
  96   scoped_refptr<base::SequencedTaskRunner> task_runner_;
  97
  98   base::WeakPtrFactory<FileSystemUsageCache> weak_factory_;
  99
 100   DISALLOW_COPY_AND_ASSIGN(FileSystemUsageCache);
 101 };
 102
 103 }  // namespace storage
 104
 105 #endif  // STORAGE_BROWSER_FILEAPI_FILE_SYSTEM_USAGE_CACHE_H_