content/browser/indexed_db/indexed_db_transaction.h

   1 // Copyright (c) 2013 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 CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_TRANSACTION_H_
   6 #define CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_TRANSACTION_H_
   7
   8 #include <queue>
   9 #include <set>
  10 #include <stack>
  11
  12 #include "base/basictypes.h"
  13 #include "base/memory/ref_counted.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "base/time/time.h"
  16 #include "base/timer/timer.h"
  17 #include "content/browser/indexed_db/indexed_db_backing_store.h"
  18 #include "content/browser/indexed_db/indexed_db_database.h"
  19 #include "content/browser/indexed_db/indexed_db_database_error.h"
  20
  21 namespace content {
  22
  23 class IndexedDBCursor;
  24 class IndexedDBDatabaseCallbacks;
  25
  26 class CONTENT_EXPORT IndexedDBTransaction
  27     : public NON_EXPORTED_BASE(base::RefCounted<IndexedDBTransaction>) {
  28  public:
  29   typedef base::Callback<void(IndexedDBTransaction*)> Operation;
  30
  31   IndexedDBTransaction(
  32       int64 id,
  33       scoped_refptr<IndexedDBDatabaseCallbacks> callbacks,
  34       const std::set<int64>& object_store_ids,
  35       indexed_db::TransactionMode,
  36       IndexedDBDatabase* db,
  37       IndexedDBBackingStore::Transaction* backing_store_transaction);
  38
  39   virtual void Abort();
  40   void Commit();
  41   void Abort(const IndexedDBDatabaseError& error);
  42
  43   // Called by the transaction coordinator when this transaction is unblocked.
  44   void Start();
  45
  46   indexed_db::TransactionMode mode() const { return mode_; }
  47   const std::set<int64>& scope() const { return object_store_ids_; }
  48
  49   void ScheduleTask(Operation task) {
  50     ScheduleTask(IndexedDBDatabase::NORMAL_TASK, task);
  51   }
  52   void ScheduleTask(Operation task, Operation abort_task);
  53   void ScheduleTask(IndexedDBDatabase::TaskType, Operation task);
  54   void RegisterOpenCursor(IndexedDBCursor* cursor);
  55   void UnregisterOpenCursor(IndexedDBCursor* cursor);
  56   void AddPreemptiveEvent() { pending_preemptive_events_++; }
  57   void DidCompletePreemptiveEvent() {
  58     pending_preemptive_events_--;
  59     DCHECK_GE(pending_preemptive_events_, 0);
  60   }
  61   IndexedDBBackingStore::Transaction* BackingStoreTransaction() {
  62     return transaction_.get();
  63   }
  64   int64 id() const { return id_; }
  65
  66   IndexedDBDatabase* database() const { return database_; }
  67   IndexedDBDatabaseCallbacks* connection() const { return callbacks_; }
  68
  69   enum State {
  70     CREATED,   // Created, but not yet started by coordinator.
  71     STARTED,   // Started by the coordinator.
  72     FINISHED,  // Either aborted or committed.
  73   };
  74
  75   State state() const { return state_; }
  76   bool IsTimeoutTimerRunning() const { return timeout_timer_.IsRunning(); }
  77
  78   struct Diagnostics {
  79     base::Time creation_time;
  80     base::Time start_time;
  81     int tasks_scheduled;
  82     int tasks_completed;
  83   };
  84
  85   const Diagnostics& diagnostics() const { return diagnostics_; }
  86
  87  private:
  88   friend class base::RefCounted<IndexedDBTransaction>;
  89   virtual ~IndexedDBTransaction();
  90
  91   void RunTasksIfStarted();
  92
  93   bool IsTaskQueueEmpty() const;
  94   bool HasPendingTasks() const;
  95
  96   void ProcessTaskQueue();
  97   void CloseOpenCursors();
  98   void Timeout();
  99
 100   const int64 id_;
 101   const std::set<int64> object_store_ids_;
 102   const indexed_db::TransactionMode mode_;
 103
 104   bool used_;
 105   State state_;
 106   bool commit_pending_;
 107   scoped_refptr<IndexedDBDatabaseCallbacks> callbacks_;
 108   scoped_refptr<IndexedDBDatabase> database_;
 109
 110   class TaskQueue {
 111    public:
 112     TaskQueue();
 113     ~TaskQueue();
 114     bool empty() const { return queue_.empty(); }
 115     void push(Operation task) { queue_.push(task); }
 116     Operation pop();
 117     void clear();
 118
 119    private:
 120     std::queue<Operation> queue_;
 121   };
 122
 123   class TaskStack {
 124    public:
 125     TaskStack();
 126     ~TaskStack();
 127     bool empty() const { return stack_.empty(); }
 128     void push(Operation task) { stack_.push(task); }
 129     Operation pop();
 130     void clear();
 131
 132    private:
 133     std::stack<Operation> stack_;
 134   };
 135
 136   TaskQueue task_queue_;
 137   TaskQueue preemptive_task_queue_;
 138   TaskStack abort_task_stack_;
 139
 140   scoped_ptr<IndexedDBBackingStore::Transaction> transaction_;
 141   bool backing_store_transaction_begun_;
 142
 143   bool should_process_queue_;
 144   int pending_preemptive_events_;
 145
 146   std::set<IndexedDBCursor*> open_cursors_;
 147
 148   // This timer is started after requests have been processed. If no subsequent
 149   // requests are processed before the timer fires, assume the script is
 150   // unresponsive and abort to unblock the transaction queue.
 151   base::OneShotTimer<IndexedDBTransaction> timeout_timer_;
 152
 153   Diagnostics diagnostics_;
 154 };
 155
 156 }  // namespace content
 157
 158 #endif  // CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_TRANSACTION_H_