Pepper quota support

webkit/plugins/ppapi/quota_file_io.h

+// Copyright (c) 2011 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 WEBKIT_PLUGINS_PPAPI_QUOTA_FILE_IO_H_
+#define WEBKIT_PLUGINS_PPAPI_QUOTA_FILE_IO_H_
+
+#include <deque>
+
+#include "base/file_util_proxy.h"
+#include "base/memory/scoped_callback_factory.h"
+#include "base/platform_file.h"
+#include "googleurl/src/gurl.h"
+#include "ppapi/c/pp_file_info.h"
+#include "webkit/quota/quota_types.h"
+
+namespace webkit {
+namespace ppapi {
+
+class PluginInstance;
+
+// This class is created per PPB_FileIO_Impl instance and provides
+// write operations for quota-managed files (i.e. files of
+// PP_FILESYSTEMTYPE_LOCAL{PERSISTENT,TEMPORARY}).
+class QuotaFileIO {
+ public:
+  typedef base::FileUtilProxy::WriteCallback WriteCallback;
+  typedef base::FileUtilProxy::StatusCallback StatusCallback;
+
+  QuotaFileIO(PluginInstance* instance,
+              base::PlatformFile file,
+              const GURL& path_url,
+              PP_FileSystemType type);
+  ~QuotaFileIO();
+
+  // Performs write or setlength operation with quota checks.
+  // Returns true when the operation is successfully dispatched.
+  // |callback| will be dispatched when the operation completes.
+  // Otherwise it returns false and |callback| will not be dispatched.
+  // |callback| will not be dispatched either when this instance is
+  // destroyed before the operation completes.
+  // SetLength/WillSetLength cannot be called while there're any inflight
+  // operations.  For Write/WillWrite it is guaranteed that |callback| are
+  // always dispatched in the same order as Write being called.
+  bool Write(int64_t offset,
+             const char* buffer,
+             int32_t bytes_to_write,
+             WriteCallback* callback);
+  bool WillWrite(int64_t offset,
+                 int32_t bytes_to_write,
+                 WriteCallback* callback);
+
+  bool SetLength(int64_t length, StatusCallback* callback);
+  bool WillSetLength(int64_t length, StatusCallback* callback);
+
+ private:
+  class PendingOperationBase;
+  class WriteOperation;
+  class SetLengthOperation;
+
+  bool CheckIfExceedsQuota(int64_t new_file_size) const;
+  void WillUpdate();
+  void DidWrite(WriteOperation* op, int64_t written_offset_end);
+  void DidSetLength(base::PlatformFileError error, int64_t new_file_size);
+
+  bool RegisterOperationForQuotaChecks(PendingOperationBase* op);
+  void DidQueryInfoForQuota(base::PlatformFileError error_code,
+                            const base::PlatformFileInfo& file_info);
+  void DidQueryAvailableSpace(int64_t avail_space);
+  void DidQueryForQuotaCheck();
+
+  // The plugin instance that owns this (via PPB_FileIO_Impl).
+  PluginInstance* instance_;
+
+  // The file information associated to this instance.
+  base::PlatformFile file_;
+  GURL file_url_;
+  quota::StorageType storage_type_;
+
+  // Operations waiting for a quota check to finish.
+  std::deque<PendingOperationBase*> pending_operations_;
+
+  // Valid only while there're pending quota checks.
+  int64_t cached_file_size_;
+  int64_t cached_available_space_;
+
+  // Quota-related queries and errors occured during inflight quota checks.
+  int outstanding_quota_queries_;
+  int outstanding_errors_;
+
+  // For parallel writes bookkeeping.
+  int64_t max_written_offset_;
+  int inflight_operations_;
+
+  base::ScopedCallbackFactory<QuotaFileIO> callback_factory_;
+  DISALLOW_COPY_AND_ASSIGN(QuotaFileIO);
+};
+
+}  // namespace ppapi
+}  // namespace webkit
+
+#endif  // WEBKIT_PLUGINS_PPAPI_QUOTA_FILE_IO_H_