content/browser/indexed_db/indexed_db_transaction.cc

   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 #include "content/browser/indexed_db/indexed_db_transaction.h"
   6
   7 #include "base/bind.h"
   8 #include "base/logging.h"
   9 #include "base/message_loop/message_loop.h"
  10 #include "base/strings/utf_string_conversions.h"
  11 #include "content/browser/indexed_db/indexed_db_backing_store.h"
  12 #include "content/browser/indexed_db/indexed_db_cursor.h"
  13 #include "content/browser/indexed_db/indexed_db_database.h"
  14 #include "content/browser/indexed_db/indexed_db_database_callbacks.h"
  15 #include "content/browser/indexed_db/indexed_db_tracing.h"
  16 #include "content/browser/indexed_db/indexed_db_transaction_coordinator.h"
  17 #include "third_party/WebKit/public/platform/WebIDBDatabaseException.h"
  18
  19 namespace content {
  20
  21 const int64 kInactivityTimeoutPeriodSeconds = 60;
  22
  23 IndexedDBTransaction::TaskQueue::TaskQueue() {}
  24 IndexedDBTransaction::TaskQueue::~TaskQueue() { clear(); }
  25
  26 void IndexedDBTransaction::TaskQueue::clear() {
  27   while (!queue_.empty())
  28     queue_.pop();
  29 }
  30
  31 IndexedDBTransaction::Operation IndexedDBTransaction::TaskQueue::pop() {
  32   DCHECK(!queue_.empty());
  33   Operation task(queue_.front());
  34   queue_.pop();
  35   return task;
  36 }
  37
  38 IndexedDBTransaction::TaskStack::TaskStack() {}
  39 IndexedDBTransaction::TaskStack::~TaskStack() { clear(); }
  40
  41 void IndexedDBTransaction::TaskStack::clear() {
  42   while (!stack_.empty())
  43     stack_.pop();
  44 }
  45
  46 IndexedDBTransaction::Operation IndexedDBTransaction::TaskStack::pop() {
  47   DCHECK(!stack_.empty());
  48   Operation task(stack_.top());
  49   stack_.pop();
  50   return task;
  51 }
  52
  53 IndexedDBTransaction::IndexedDBTransaction(
  54     int64 id,
  55     scoped_refptr<IndexedDBDatabaseCallbacks> callbacks,
  56     const std::set<int64>& object_store_ids,
  57     indexed_db::TransactionMode mode,
  58     IndexedDBDatabase* database,
  59     IndexedDBBackingStore::Transaction* backing_store_transaction)
  60     : id_(id),
  61       object_store_ids_(object_store_ids),
  62       mode_(mode),
  63       used_(false),
  64       state_(CREATED),
  65       commit_pending_(false),
  66       callbacks_(callbacks),
  67       database_(database),
  68       transaction_(backing_store_transaction),
  69       backing_store_transaction_begun_(false),
  70       should_process_queue_(false),
  71       pending_preemptive_events_(0) {
  72   database_->transaction_coordinator().DidCreateTransaction(this);
  73
  74   diagnostics_.tasks_scheduled = 0;
  75   diagnostics_.tasks_completed = 0;
  76   diagnostics_.creation_time = base::Time::Now();
  77 }
  78
  79 IndexedDBTransaction::~IndexedDBTransaction() {
  80   // It shouldn't be possible for this object to get deleted until it's either
  81   // complete or aborted.
  82   DCHECK_EQ(state_, FINISHED);
  83   DCHECK(preemptive_task_queue_.empty());
  84   DCHECK(task_queue_.empty());
  85   DCHECK(abort_task_stack_.empty());
  86 }
  87
  88 void IndexedDBTransaction::ScheduleTask(Operation task, Operation abort_task) {
  89   if (state_ == FINISHED)
  90     return;
  91
  92   timeout_timer_.Stop();
  93   used_ = true;
  94   task_queue_.push(task);
  95   ++diagnostics_.tasks_scheduled;
  96   abort_task_stack_.push(abort_task);
  97   RunTasksIfStarted();
  98 }
  99
 100 void IndexedDBTransaction::ScheduleTask(IndexedDBDatabase::TaskType type,
 101                                         Operation task) {
 102   if (state_ == FINISHED)
 103     return;
 104
 105   timeout_timer_.Stop();
 106   used_ = true;
 107   if (type == IndexedDBDatabase::NORMAL_TASK) {
 108     task_queue_.push(task);
 109     ++diagnostics_.tasks_scheduled;
 110   } else {
 111     preemptive_task_queue_.push(task);
 112   }
 113   RunTasksIfStarted();
 114 }
 115
 116 void IndexedDBTransaction::RunTasksIfStarted() {
 117   DCHECK(used_);
 118
 119   // Not started by the coordinator yet.
 120   if (state_ != STARTED)
 121     return;
 122
 123   // A task is already posted.
 124   if (should_process_queue_)
 125     return;
 126
 127   should_process_queue_ = true;
 128   base::MessageLoop::current()->PostTask(
 129       FROM_HERE, base::Bind(&IndexedDBTransaction::ProcessTaskQueue, this));
 130 }
 131
 132 void IndexedDBTransaction::Abort() {
 133   Abort(IndexedDBDatabaseError(blink::WebIDBDatabaseExceptionUnknownError,
 134                                "Internal error (unknown cause)"));
 135 }
 136
 137 void IndexedDBTransaction::Abort(const IndexedDBDatabaseError& error) {
 138   IDB_TRACE("IndexedDBTransaction::Abort");
 139   if (state_ == FINISHED)
 140     return;
 141
 142   // The last reference to this object may be released while performing the
 143   // abort steps below. We therefore take a self reference to keep ourselves
 144   // alive while executing this method.
 145   scoped_refptr<IndexedDBTransaction> protect(this);
 146
 147   timeout_timer_.Stop();
 148
 149   state_ = FINISHED;
 150   should_process_queue_ = false;
 151
 152   if (backing_store_transaction_begun_)
 153     transaction_->Rollback();
 154
 155   // Run the abort tasks, if any.
 156   while (!abort_task_stack_.empty())
 157     abort_task_stack_.pop().Run(NULL);
 158
 159   preemptive_task_queue_.clear();
 160   task_queue_.clear();
 161
 162   // Backing store resources (held via cursors) must be released
 163   // before script callbacks are fired, as the script callbacks may
 164   // release references and allow the backing store itself to be
 165   // released, and order is critical.
 166   CloseOpenCursors();
 167   transaction_->Reset();
 168
 169   // Transactions must also be marked as completed before the
 170   // front-end is notified, as the transaction completion unblocks
 171   // operations like closing connections.
 172   database_->transaction_coordinator().DidFinishTransaction(this);
 173 #ifndef NDEBUG
 174   DCHECK(!database_->transaction_coordinator().IsActive(this));
 175 #endif
 176
 177   if (callbacks_.get())
 178     callbacks_->OnAbort(id_, error);
 179
 180   database_->TransactionFinished(this, false);
 181
 182   database_ = NULL;
 183 }
 184
 185 bool IndexedDBTransaction::IsTaskQueueEmpty() const {
 186   return preemptive_task_queue_.empty() && task_queue_.empty();
 187 }
 188
 189 bool IndexedDBTransaction::HasPendingTasks() const {
 190   return pending_preemptive_events_ || !IsTaskQueueEmpty();
 191 }
 192
 193 void IndexedDBTransaction::RegisterOpenCursor(IndexedDBCursor* cursor) {
 194   open_cursors_.insert(cursor);
 195 }
 196
 197 void IndexedDBTransaction::UnregisterOpenCursor(IndexedDBCursor* cursor) {
 198   open_cursors_.erase(cursor);
 199 }
 200
 201 void IndexedDBTransaction::Start() {
 202   // TransactionCoordinator has started this transaction.
 203   DCHECK_EQ(CREATED, state_);
 204   state_ = STARTED;
 205   diagnostics_.start_time = base::Time::Now();
 206
 207   if (!used_)
 208     return;
 209
 210   RunTasksIfStarted();
 211 }
 212
 213 void IndexedDBTransaction::Commit() {
 214   IDB_TRACE("IndexedDBTransaction::Commit");
 215
 216   // In multiprocess ports, front-end may have requested a commit but
 217   // an abort has already been initiated asynchronously by the
 218   // back-end.
 219   if (state_ == FINISHED)
 220     return;
 221
 222   DCHECK(!used_ || state_ == STARTED);
 223   commit_pending_ = true;
 224
 225   // Front-end has requested a commit, but there may be tasks like
 226   // create_index which are considered synchronous by the front-end
 227   // but are processed asynchronously.
 228   if (HasPendingTasks())
 229     return;
 230
 231   // The last reference to this object may be released while performing the
 232   // commit steps below. We therefore take a self reference to keep ourselves
 233   // alive while executing this method.
 234   scoped_refptr<IndexedDBTransaction> protect(this);
 235
 236   timeout_timer_.Stop();
 237
 238   state_ = FINISHED;
 239
 240   bool committed = !used_ || transaction_->Commit().ok();
 241
 242   // Backing store resources (held via cursors) must be released
 243   // before script callbacks are fired, as the script callbacks may
 244   // release references and allow the backing store itself to be
 245   // released, and order is critical.
 246   CloseOpenCursors();
 247   transaction_->Reset();
 248
 249   // Transactions must also be marked as completed before the
 250   // front-end is notified, as the transaction completion unblocks
 251   // operations like closing connections.
 252   database_->transaction_coordinator().DidFinishTransaction(this);
 253
 254   if (committed) {
 255     abort_task_stack_.clear();
 256     callbacks_->OnComplete(id_);
 257     database_->TransactionFinished(this, true);
 258   } else {
 259     while (!abort_task_stack_.empty())
 260       abort_task_stack_.pop().Run(NULL);
 261
 262     callbacks_->OnAbort(
 263         id_,
 264         IndexedDBDatabaseError(blink::WebIDBDatabaseExceptionUnknownError,
 265                                "Internal error committing transaction."));
 266     database_->TransactionFinished(this, false);
 267     database_->TransactionCommitFailed();
 268   }
 269
 270   database_ = NULL;
 271 }
 272
 273 void IndexedDBTransaction::ProcessTaskQueue() {
 274   IDB_TRACE("IndexedDBTransaction::ProcessTaskQueue");
 275
 276   // May have been aborted.
 277   if (!should_process_queue_)
 278     return;
 279
 280   DCHECK(!IsTaskQueueEmpty());
 281   should_process_queue_ = false;
 282
 283   if (!backing_store_transaction_begun_) {
 284     transaction_->Begin();
 285     backing_store_transaction_begun_ = true;
 286   }
 287
 288   // The last reference to this object may be released while performing the
 289   // tasks. Take take a self reference to keep this object alive so that
 290   // the loop termination conditions can be checked.
 291   scoped_refptr<IndexedDBTransaction> protect(this);
 292
 293   TaskQueue* task_queue =
 294       pending_preemptive_events_ ? &preemptive_task_queue_ : &task_queue_;
 295   while (!task_queue->empty() && state_ != FINISHED) {
 296     DCHECK_EQ(STARTED, state_);
 297     Operation task(task_queue->pop());
 298     task.Run(this);
 299     if (!pending_preemptive_events_) {
 300       DCHECK(diagnostics_.tasks_completed < diagnostics_.tasks_scheduled);
 301       ++diagnostics_.tasks_completed;
 302     }
 303
 304     // Event itself may change which queue should be processed next.
 305     task_queue =
 306         pending_preemptive_events_ ? &preemptive_task_queue_ : &task_queue_;
 307   }
 308
 309   // If there are no pending tasks, we haven't already committed/aborted,
 310   // and the front-end requested a commit, it is now safe to do so.
 311   if (!HasPendingTasks() && state_ != FINISHED && commit_pending_) {
 312     Commit();
 313     return;
 314   }
 315
 316   // The transaction may have been aborted while processing tasks.
 317   if (state_ == FINISHED)
 318     return;
 319
 320   // Otherwise, start a timer in case the front-end gets wedged and
 321   // never requests further activity. Read-only transactions don't
 322   // block other transactions, so don't time those out.
 323   if (mode_ != indexed_db::TRANSACTION_READ_ONLY) {
 324     timeout_timer_.Start(
 325         FROM_HERE,
 326         base::TimeDelta::FromSeconds(kInactivityTimeoutPeriodSeconds),
 327         base::Bind(&IndexedDBTransaction::Timeout, this));
 328   }
 329 }
 330
 331 void IndexedDBTransaction::Timeout() {
 332   Abort(IndexedDBDatabaseError(
 333       blink::WebIDBDatabaseExceptionTimeoutError,
 334       base::ASCIIToUTF16("Transaction timed out due to inactivity.")));
 335 }
 336
 337 void IndexedDBTransaction::CloseOpenCursors() {
 338   for (std::set<IndexedDBCursor*>::iterator i = open_cursors_.begin();
 339        i != open_cursors_.end();
 340        ++i)
 341     (*i)->Close();
 342   open_cursors_.clear();
 343 }
 344
 345 }  // namespace content