Torne (Richard Coles) | 53e740f | 2013-05-09 18:38:43 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2010 Google Inc. All rights reserved. |
| 3 | * |
| 4 | * Redistribution and use in source and binary forms, with or without |
| 5 | * modification, are permitted provided that the following conditions |
| 6 | * are met: |
| 7 | * |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * |
| 14 | * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY |
| 15 | * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| 16 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| 17 | * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY |
| 18 | * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| 19 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| 20 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| 21 | * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 22 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 23 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 24 | */ |
| 25 | |
| 26 | #include "config.h" |
| 27 | #include "modules/indexeddb/IDBTransactionBackendImpl.h" |
| 28 | |
| 29 | #include "modules/indexeddb/IDBBackingStore.h" |
| 30 | #include "modules/indexeddb/IDBCursorBackendImpl.h" |
| 31 | #include "modules/indexeddb/IDBDatabaseBackendImpl.h" |
| 32 | #include "modules/indexeddb/IDBDatabaseCallbacks.h" |
| 33 | #include "modules/indexeddb/IDBDatabaseException.h" |
| 34 | #include "modules/indexeddb/IDBTracing.h" |
| 35 | #include "modules/indexeddb/IDBTransactionCoordinator.h" |
| 36 | |
| 37 | namespace WebCore { |
| 38 | |
| 39 | PassRefPtr<IDBTransactionBackendImpl> IDBTransactionBackendImpl::create(int64_t id, PassRefPtr<IDBDatabaseCallbacks> callbacks, const Vector<int64_t>& objectStoreIds, IndexedDB::TransactionMode mode, IDBDatabaseBackendImpl* database) |
| 40 | { |
| 41 | HashSet<int64_t> objectStoreHashSet; |
| 42 | for (size_t i = 0; i < objectStoreIds.size(); ++i) |
| 43 | objectStoreHashSet.add(objectStoreIds[i]); |
| 44 | |
| 45 | return adoptRef(new IDBTransactionBackendImpl(id, callbacks, objectStoreHashSet, mode, database)); |
| 46 | } |
| 47 | |
| 48 | IDBTransactionBackendImpl::IDBTransactionBackendImpl(int64_t id, PassRefPtr<IDBDatabaseCallbacks> callbacks, const HashSet<int64_t>& objectStoreIds, IndexedDB::TransactionMode mode, IDBDatabaseBackendImpl* database) |
| 49 | : m_id(id) |
| 50 | , m_objectStoreIds(objectStoreIds) |
| 51 | , m_mode(mode) |
| 52 | , m_state(Unused) |
| 53 | , m_commitPending(false) |
| 54 | , m_callbacks(callbacks) |
| 55 | , m_database(database) |
| 56 | , m_transaction(database->backingStore().get()) |
| 57 | , m_taskTimer(this, &IDBTransactionBackendImpl::taskTimerFired) |
| 58 | , m_pendingPreemptiveEvents(0) |
| 59 | { |
| 60 | // We pass a reference of this object before it can be adopted. |
| 61 | relaxAdoptionRequirement(); |
| 62 | |
| 63 | m_database->transactionCoordinator()->didCreateTransaction(this); |
| 64 | } |
| 65 | |
| 66 | IDBTransactionBackendImpl::~IDBTransactionBackendImpl() |
| 67 | { |
| 68 | // It shouldn't be possible for this object to get deleted until it's either complete or aborted. |
| 69 | ASSERT(m_state == Finished); |
| 70 | } |
| 71 | |
| 72 | void IDBTransactionBackendImpl::scheduleTask(IDBDatabaseBackendInterface::TaskType type, PassOwnPtr<Operation> task, PassOwnPtr<Operation> abortTask) |
| 73 | { |
| 74 | if (m_state == Finished) |
| 75 | return; |
| 76 | |
| 77 | if (type == IDBDatabaseBackendInterface::NormalTask) |
| 78 | m_taskQueue.append(task); |
| 79 | else |
| 80 | m_preemptiveTaskQueue.append(task); |
| 81 | |
| 82 | if (abortTask) |
| 83 | m_abortTaskQueue.prepend(abortTask); |
| 84 | |
| 85 | if (m_state == Unused) |
| 86 | start(); |
| 87 | else if (m_state == Running && !m_taskTimer.isActive()) |
| 88 | m_taskTimer.startOneShot(0); |
| 89 | } |
| 90 | |
| 91 | void IDBTransactionBackendImpl::abort() |
| 92 | { |
| 93 | abort(IDBDatabaseError::create(IDBDatabaseException::UnknownError, "Internal error (unknown cause)")); |
| 94 | } |
| 95 | |
| 96 | void IDBTransactionBackendImpl::abort(PassRefPtr<IDBDatabaseError> error) |
| 97 | { |
| 98 | IDB_TRACE("IDBTransactionBackendImpl::abort"); |
| 99 | if (m_state == Finished) |
| 100 | return; |
| 101 | |
| 102 | bool wasRunning = m_state == Running; |
| 103 | |
| 104 | // The last reference to this object may be released while performing the |
| 105 | // abort steps below. We therefore take a self reference to keep ourselves |
| 106 | // alive while executing this method. |
| 107 | RefPtr<IDBTransactionBackendImpl> protect(this); |
| 108 | |
| 109 | m_state = Finished; |
| 110 | m_taskTimer.stop(); |
| 111 | |
| 112 | if (wasRunning) |
| 113 | m_transaction.rollback(); |
| 114 | |
| 115 | // Run the abort tasks, if any. |
| 116 | while (!m_abortTaskQueue.isEmpty()) { |
| 117 | OwnPtr<Operation> task(m_abortTaskQueue.takeFirst()); |
| 118 | task->perform(0); |
| 119 | } |
| 120 | |
| 121 | // Backing store resources (held via cursors) must be released before script callbacks |
| 122 | // are fired, as the script callbacks may release references and allow the backing store |
| 123 | // itself to be released, and order is critical. |
| 124 | closeOpenCursors(); |
| 125 | m_transaction.reset(); |
| 126 | |
| 127 | // Transactions must also be marked as completed before the front-end is notified, as |
| 128 | // the transaction completion unblocks operations like closing connections. |
| 129 | m_database->transactionCoordinator()->didFinishTransaction(this); |
| 130 | ASSERT(!m_database->transactionCoordinator()->isActive(this)); |
| 131 | m_database->transactionFinished(this); |
| 132 | |
| 133 | if (m_callbacks) |
| 134 | m_callbacks->onAbort(m_id, error); |
| 135 | |
| 136 | m_database->transactionFinishedAndAbortFired(this); |
| 137 | |
| 138 | m_database = 0; |
| 139 | } |
| 140 | |
| 141 | bool IDBTransactionBackendImpl::isTaskQueueEmpty() const |
| 142 | { |
| 143 | return m_preemptiveTaskQueue.isEmpty() && m_taskQueue.isEmpty(); |
| 144 | } |
| 145 | |
| 146 | bool IDBTransactionBackendImpl::hasPendingTasks() const |
| 147 | { |
| 148 | return m_pendingPreemptiveEvents || !isTaskQueueEmpty(); |
| 149 | } |
| 150 | |
| 151 | void IDBTransactionBackendImpl::registerOpenCursor(IDBCursorBackendImpl* cursor) |
| 152 | { |
| 153 | m_openCursors.add(cursor); |
| 154 | } |
| 155 | |
| 156 | void IDBTransactionBackendImpl::unregisterOpenCursor(IDBCursorBackendImpl* cursor) |
| 157 | { |
| 158 | m_openCursors.remove(cursor); |
| 159 | } |
| 160 | |
| 161 | void IDBTransactionBackendImpl::run() |
| 162 | { |
| 163 | // TransactionCoordinator has started this transaction. Schedule a timer |
| 164 | // to process the first task. |
| 165 | ASSERT(m_state == StartPending || m_state == Running); |
| 166 | ASSERT(!m_taskTimer.isActive()); |
| 167 | |
| 168 | m_taskTimer.startOneShot(0); |
| 169 | } |
| 170 | |
| 171 | void IDBTransactionBackendImpl::start() |
| 172 | { |
| 173 | ASSERT(m_state == Unused); |
| 174 | |
| 175 | m_state = StartPending; |
| 176 | m_database->transactionCoordinator()->didStartTransaction(this); |
| 177 | m_database->transactionStarted(this); |
| 178 | } |
| 179 | |
| 180 | void IDBTransactionBackendImpl::commit() |
| 181 | { |
| 182 | IDB_TRACE("IDBTransactionBackendImpl::commit"); |
| 183 | |
| 184 | // In multiprocess ports, front-end may have requested a commit but an abort has already |
| 185 | // been initiated asynchronously by the back-end. |
| 186 | if (m_state == Finished) |
| 187 | return; |
| 188 | |
| 189 | ASSERT(m_state == Unused || m_state == Running); |
| 190 | m_commitPending = true; |
| 191 | |
| 192 | // Front-end has requested a commit, but there may be tasks like createIndex which |
| 193 | // are considered synchronous by the front-end but are processed asynchronously. |
| 194 | if (hasPendingTasks()) |
| 195 | return; |
| 196 | |
| 197 | // The last reference to this object may be released while performing the |
| 198 | // commit steps below. We therefore take a self reference to keep ourselves |
| 199 | // alive while executing this method. |
| 200 | RefPtr<IDBTransactionBackendImpl> protect(this); |
| 201 | |
| 202 | bool unused = m_state == Unused; |
| 203 | m_state = Finished; |
| 204 | |
| 205 | bool committed = unused || m_transaction.commit(); |
| 206 | |
| 207 | // Backing store resources (held via cursors) must be released before script callbacks |
| 208 | // are fired, as the script callbacks may release references and allow the backing store |
| 209 | // itself to be released, and order is critical. |
| 210 | closeOpenCursors(); |
| 211 | m_transaction.reset(); |
| 212 | |
| 213 | // Transactions must also be marked as completed before the front-end is notified, as |
| 214 | // the transaction completion unblocks operations like closing connections. |
| 215 | if (!unused) |
| 216 | m_database->transactionCoordinator()->didFinishTransaction(this); |
| 217 | m_database->transactionFinished(this); |
| 218 | |
| 219 | if (committed) { |
| 220 | m_callbacks->onComplete(m_id); |
| 221 | m_database->transactionFinishedAndCompleteFired(this); |
| 222 | } else { |
| 223 | m_callbacks->onAbort(m_id, IDBDatabaseError::create(IDBDatabaseException::UnknownError, "Internal error committing transaction.")); |
| 224 | m_database->transactionFinishedAndAbortFired(this); |
| 225 | } |
| 226 | |
| 227 | m_database = 0; |
| 228 | } |
| 229 | |
| 230 | void IDBTransactionBackendImpl::taskTimerFired(Timer<IDBTransactionBackendImpl>*) |
| 231 | { |
| 232 | IDB_TRACE("IDBTransactionBackendImpl::taskTimerFired"); |
| 233 | ASSERT(!isTaskQueueEmpty()); |
| 234 | |
| 235 | if (m_state == StartPending) { |
| 236 | m_transaction.begin(); |
| 237 | m_state = Running; |
| 238 | } |
| 239 | |
| 240 | // The last reference to this object may be released while performing the |
| 241 | // tasks. Take take a self reference to keep this object alive so that |
| 242 | // the loop termination conditions can be checked. |
| 243 | RefPtr<IDBTransactionBackendImpl> protect(this); |
| 244 | |
| 245 | TaskQueue* taskQueue = m_pendingPreemptiveEvents ? &m_preemptiveTaskQueue : &m_taskQueue; |
| 246 | while (!taskQueue->isEmpty() && m_state != Finished) { |
| 247 | ASSERT(m_state == Running); |
| 248 | OwnPtr<Operation> task(taskQueue->takeFirst()); |
| 249 | task->perform(this); |
| 250 | |
| 251 | // Event itself may change which queue should be processed next. |
| 252 | taskQueue = m_pendingPreemptiveEvents ? &m_preemptiveTaskQueue : &m_taskQueue; |
| 253 | } |
| 254 | |
| 255 | // If there are no pending tasks, we haven't already committed/aborted, |
| 256 | // and the front-end requested a commit, it is now safe to do so. |
| 257 | if (!hasPendingTasks() && m_state != Finished && m_commitPending) |
| 258 | commit(); |
| 259 | } |
| 260 | |
| 261 | void IDBTransactionBackendImpl::closeOpenCursors() |
| 262 | { |
| 263 | for (HashSet<IDBCursorBackendImpl*>::iterator i = m_openCursors.begin(); i != m_openCursors.end(); ++i) |
| 264 | (*i)->close(); |
| 265 | m_openCursors.clear(); |
| 266 | } |
| 267 | |
| 268 | } // namespace WebCore |