webkit/database/database_connections.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_DATABASE_DATABASE_CONNECTIONS_H_
   6 #define WEBKIT_DATABASE_DATABASE_CONNECTIONS_H_
   7
   8 #include <map>
   9 #include <vector>
  10
  11 #include "base/memory/ref_counted.h"
  12 #include "base/string16.h"
  13 #include "base/synchronization/lock.h"
  14 #include "webkit/storage/webkit_storage_export.h"
  15
  16 namespace base {
  17 class MessageLoopProxy;
  18 }
  19
  20 namespace webkit_database {
  21
  22 class WEBKIT_STORAGE_EXPORT DatabaseConnections {
  23  public:
  24   DatabaseConnections();
  25   ~DatabaseConnections();
  26
  27   bool IsEmpty() const;
  28   bool IsDatabaseOpened(const string16& origin_identifier,
  29                         const string16& database_name) const;
  30   bool IsOriginUsed(const string16& origin_identifier) const;
  31
  32   // Returns true if this is the first connection.
  33   bool AddConnection(const string16& origin_identifier,
  34                      const string16& database_name);
  35
  36   // Returns true if the last connection was removed.
  37   bool RemoveConnection(const string16& origin_identifier,
  38                         const string16& database_name);
  39
  40   void RemoveAllConnections();
  41   void RemoveConnections(
  42       const DatabaseConnections& connections,
  43       std::vector<std::pair<string16, string16> >* closed_dbs);
  44
  45   // Database sizes can be kept only if IsDatabaseOpened returns true.
  46   int64 GetOpenDatabaseSize(const string16& origin_identifier,
  47                             const string16& database_name) const;
  48   void SetOpenDatabaseSize(const string16& origin_identifier,
  49                            const string16& database_name,
  50                            int64 size);
  51
  52   // Returns a list of the connections, <origin_id, name>.
  53   void ListConnections(
  54       std::vector<std::pair<string16, string16> > *list) const;
  55
  56  private:
  57   // Mapping from name to <openCount, size>
  58   typedef std::map<string16, std::pair<int, int64> > DBConnections;
  59   typedef std::map<string16, DBConnections> OriginConnections;
  60   mutable OriginConnections connections_;  // mutable for GetOpenDatabaseSize
  61
  62   // Returns true if the last connection was removed.
  63   bool RemoveConnectionsHelper(const string16& origin_identifier,
  64                                const string16& database_name,
  65                                int num_connections);
  66 };
  67
  68 // A wrapper class that provides thread-safety and the
  69 // ability to wait until all connections have closed.
  70 // Intended for use in renderer processes.
  71 class WEBKIT_STORAGE_EXPORT DatabaseConnectionsWrapper
  72     : public base::RefCountedThreadSafe<DatabaseConnectionsWrapper> {
  73  public:
  74   DatabaseConnectionsWrapper();
  75
  76   // The Wait and Has methods should only be called on the
  77   // main thread (the thread on which the wrapper is constructed).
  78   void WaitForAllDatabasesToClose();
  79   bool HasOpenConnections();
  80
  81   // Add and Remove may be called on any thread.
  82   void AddOpenConnection(const string16& origin_identifier,
  83                          const string16& database_name);
  84   void RemoveOpenConnection(const string16& origin_identifier,
  85                             const string16& database_name);
  86  private:
  87   ~DatabaseConnectionsWrapper();
  88   friend class base::RefCountedThreadSafe<DatabaseConnectionsWrapper>;
  89
  90   bool waiting_for_dbs_to_close_;
  91   base::Lock open_connections_lock_;
  92   DatabaseConnections open_connections_;
  93   scoped_refptr<base::MessageLoopProxy> main_thread_;
  94 };
  95
  96 }  // namespace webkit_database
  97
  98 #endif  // WEBKIT_DATABASE_DATABASE_CONNECTIONS_H_