webkit/plugins/ppapi/quota_file_io.h

   1 // Copyright (c) 2011 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 WEBKIT_PLUGINS_PPAPI_QUOTA_FILE_IO_H_
   6 #define WEBKIT_PLUGINS_PPAPI_QUOTA_FILE_IO_H_
   7
   8 #include <deque>
   9
  10 #include "base/files/file_util_proxy.h"
  11 #include "base/memory/weak_ptr.h"
  12 #include "base/platform_file.h"
  13 #include "googleurl/src/gurl.h"
  14 #include "ppapi/c/pp_file_info.h"
  15 #include "ppapi/c/pp_instance.h"
  16 #include "webkit/plugins/webkit_plugins_export.h"
  17 #include "webkit/quota/quota_types.h"
  18
  19 namespace webkit {
  20 namespace ppapi {
  21
  22 class PluginDelegate;
  23
  24 // This class is created per PPB_FileIO_Impl instance and provides
  25 // write operations for quota-managed files (i.e. files of
  26 // PP_FILESYSTEMTYPE_LOCAL{PERSISTENT,TEMPORARY}).
  27 class QuotaFileIO {
  28  public:
  29   typedef base::FileUtilProxy::WriteCallback WriteCallback;
  30   typedef base::FileUtilProxy::StatusCallback StatusCallback;
  31
  32   WEBKIT_PLUGINS_EXPORT QuotaFileIO(PP_Instance instance,
  33                                     base::PlatformFile file,
  34                                     const GURL& path_url,
  35                                     PP_FileSystemType type);
  36   WEBKIT_PLUGINS_EXPORT ~QuotaFileIO();
  37
  38   // Performs write or setlength operation with quota checks.
  39   // Returns true when the operation is successfully dispatched.
  40   // |bytes_to_write| must be geater than zero.
  41   // |callback| will be dispatched when the operation completes.
  42   // Otherwise it returns false and |callback| will not be dispatched.
  43   // |callback| will not be dispatched either when this instance is
  44   // destroyed before the operation completes.
  45   // SetLength/WillSetLength cannot be called while there're any in-flight
  46   // operations.  For Write/WillWrite it is guaranteed that |callback| are
  47   // always dispatched in the same order as Write being called.
  48   WEBKIT_PLUGINS_EXPORT bool Write(int64_t offset,
  49                                    const char* buffer,
  50                                    int32_t bytes_to_write,
  51                                    const WriteCallback& callback);
  52   WEBKIT_PLUGINS_EXPORT bool WillWrite(int64_t offset,
  53                                        int32_t bytes_to_write,
  54                                        const WriteCallback& callback);
  55
  56   WEBKIT_PLUGINS_EXPORT bool SetLength(int64_t length,
  57                                        const StatusCallback& callback);
  58   WEBKIT_PLUGINS_EXPORT bool WillSetLength(int64_t length,
  59                                            const StatusCallback& callback);
  60
  61   // Returns the plugin delegate or NULL if the resource has outlived the
  62   // instance.
  63   PluginDelegate* GetPluginDelegate() const;
  64
  65  private:
  66   class PendingOperationBase;
  67   class WriteOperation;
  68   class SetLengthOperation;
  69
  70   bool CheckIfExceedsQuota(int64_t new_file_size) const;
  71   void WillUpdate();
  72   void DidWrite(WriteOperation* op, int64_t written_offset_end);
  73   void DidSetLength(base::PlatformFileError error, int64_t new_file_size);
  74
  75   bool RegisterOperationForQuotaChecks(PendingOperationBase* op);
  76   void DidQueryInfoForQuota(base::PlatformFileError error_code,
  77                             const base::PlatformFileInfo& file_info);
  78   void DidQueryAvailableSpace(int64_t avail_space);
  79   void DidQueryForQuotaCheck();
  80
  81   // The plugin instance that owns this (via PPB_FileIO_Impl).
  82   PP_Instance pp_instance_;
  83
  84   // The file information associated to this instance.
  85   base::PlatformFile file_;
  86   GURL file_url_;
  87   quota::StorageType storage_type_;
  88
  89   // Pending operations that are waiting quota checks and pending
  90   // callbacks that are to be fired after the operation;
  91   // we use two separate queues for them so that we can safely dequeue the
  92   // pending callbacks while enqueueing new operations. (This could
  93   // happen when callbacks are dispatched synchronously due to error etc.)
  94   std::deque<PendingOperationBase*> pending_operations_;
  95   std::deque<PendingOperationBase*> pending_callbacks_;
  96
  97   // Valid only while there're pending quota checks.
  98   int64_t cached_file_size_;
  99   int64_t cached_available_space_;
 100
 101   // Quota-related queries and errors occurred during in-flight quota checks.
 102   int outstanding_quota_queries_;
 103   int outstanding_errors_;
 104
 105   // For parallel writes bookkeeping.
 106   int64_t max_written_offset_;
 107   int inflight_operations_;
 108
 109   base::WeakPtrFactory<QuotaFileIO> weak_factory_;
 110
 111   DISALLOW_COPY_AND_ASSIGN(QuotaFileIO);
 112 };
 113
 114 }  // namespace ppapi
 115 }  // namespace webkit
 116
 117 #endif  // WEBKIT_PLUGINS_PPAPI_QUOTA_FILE_IO_H_