root/Source/modules/indexeddb/IDBRequest.cpp

DEFINITIONS

1. create
2. m_requestState
3. result
4. error
5. source
6. readyState
7. abort
8. setCursorDetails
9. setPendingCursor
10. getResultCursor
11. setResultCursor
12. checkForReferenceCycle
13. shouldEnqueueEvent
14. onError
15. onSuccess
16. onSuccess
17. onSuccess
18. onSuccess
19. effectiveObjectStore
20. onSuccess
21. onSuccess
22. onSuccess
23. onSuccessInternal
24. setResult
25. onSuccess
26. hasPendingActivity
27. stop
28. interfaceName
29. executionContext
30. dispatchEvent
31. uncaughtExceptionInEventHandler
32. transactionDidFinishAndDispatch
33. enqueueEvent
34. dequeueEvent

/*
 * Copyright (C) 2010 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "modules/indexeddb/IDBRequest.h"

#include "bindings/v8/ExceptionState.h"
#include "bindings/v8/ExceptionStatePlaceholder.h"
#include "bindings/v8/IDBBindingUtilities.h"
#include "core/dom/ExecutionContext.h"
#include "core/events/EventQueue.h"
#include "modules/indexeddb/IDBCursorWithValue.h"
#include "modules/indexeddb/IDBDatabase.h"
#include "modules/indexeddb/IDBEventDispatcher.h"
#include "modules/indexeddb/IDBTracing.h"
#include "platform/SharedBuffer.h"

using blink::WebIDBCursor;

namespace WebCore {

PassRefPtr<IDBRequest> IDBRequest::create(ExecutionContext* context, PassRefPtr<IDBAny> source, IDBTransaction* transaction)
{
    RefPtr<IDBRequest> request(adoptRef(new IDBRequest(context, source, transaction)));
    request->suspendIfNeeded();
    // Requests associated with IDBFactory (open/deleteDatabase/getDatabaseNames) are not associated with transactions.
    if (transaction)
        transaction->registerRequest(request.get());
    return request.release();
}

IDBRequest::IDBRequest(ExecutionContext* context, PassRefPtr<IDBAny> source, IDBTransaction* transaction)
    : ActiveDOMObject(context)
    , m_contextStopped(false)
    , m_transaction(transaction)
    , m_readyState(PENDING)
    , m_requestAborted(false)
    , m_source(source)
    , m_hasPendingActivity(true)
    , m_cursorType(IndexedDB::CursorKeyAndValue)
    , m_cursorDirection(blink::WebIDBCursor::Next)
    , m_pendingCursor(nullptr)
    , m_didFireUpgradeNeededEvent(false)
    , m_preventPropagation(false)
    , m_resultDirty(true)
    , m_requestState(context)
{
    ScriptWrappable::init(this);
}

IDBRequest::~IDBRequest()
{
    ASSERT(m_readyState == DONE || m_readyState == EarlyDeath || !executionContext());
}

ScriptValue IDBRequest::result(ExceptionState& exceptionState)
{
    if (m_readyState != DONE) {
        exceptionState.throwDOMException(InvalidStateError, IDBDatabase::requestNotFinishedErrorMessage);
        return ScriptValue();
    }
    if (m_contextStopped || !executionContext())
        return ScriptValue();
    m_resultDirty = false;
    return idbAnyToScriptValue(&m_requestState, m_result);
}

PassRefPtrWillBeRawPtr<DOMError> IDBRequest::error(ExceptionState& exceptionState) const
{
    if (m_readyState != DONE) {
        exceptionState.throwDOMException(InvalidStateError, IDBDatabase::requestNotFinishedErrorMessage);
        return nullptr;
    }
    return m_error;
}

ScriptValue IDBRequest::source(ExecutionContext* context) const
{
    if (m_contextStopped || !executionContext())
        return ScriptValue();

    DOMRequestState requestState(context);
    return idbAnyToScriptValue(&requestState, m_source);
}

const String& IDBRequest::readyState() const
{
    ASSERT(m_readyState == PENDING || m_readyState == DONE);
    DEFINE_STATIC_LOCAL(AtomicString, pending, ("pending", AtomicString::ConstructFromLiteral));
    DEFINE_STATIC_LOCAL(AtomicString, done, ("done", AtomicString::ConstructFromLiteral));

    if (m_readyState == PENDING)
        return pending;

    return done;
}

void IDBRequest::abort()
{
    ASSERT(!m_requestAborted);
    if (m_contextStopped || !executionContext())
        return;
    ASSERT(m_readyState == PENDING || m_readyState == DONE);
    if (m_readyState == DONE)
        return;

    // Enqueued events may be the only reference to this object.
    RefPtr<IDBRequest> self(this);

    EventQueue* eventQueue = executionContext()->eventQueue();
    for (size_t i = 0; i < m_enqueuedEvents.size(); ++i) {
        bool removed = eventQueue->cancelEvent(m_enqueuedEvents[i].get());
        ASSERT_UNUSED(removed, removed);
    }
    m_enqueuedEvents.clear();

    m_error.clear();
    m_result.clear();
    onError(DOMError::create(AbortError, "The transaction was aborted, so the request cannot be fulfilled."));
    m_requestAborted = true;
}

void IDBRequest::setCursorDetails(IndexedDB::CursorType cursorType, WebIDBCursor::Direction direction)
{
    ASSERT(m_readyState == PENDING);
    ASSERT(!m_pendingCursor);
    m_cursorType = cursorType;
    m_cursorDirection = direction;
}

void IDBRequest::setPendingCursor(PassRefPtr<IDBCursor> cursor)
{
    ASSERT(m_readyState == DONE);
    ASSERT(executionContext());
    ASSERT(m_transaction);
    ASSERT(!m_pendingCursor);
    ASSERT(cursor == getResultCursor());

    m_hasPendingActivity = true;
    m_pendingCursor = cursor;
    setResult(PassRefPtr<IDBAny>(nullptr));
    m_readyState = PENDING;
    m_error.clear();
    m_transaction->registerRequest(this);
}

IDBCursor* IDBRequest::getResultCursor() const
{
    if (!m_result)
        return 0;
    if (m_result->type() == IDBAny::IDBCursorType)
        return m_result->idbCursor();
    if (m_result->type() == IDBAny::IDBCursorWithValueType)
        return m_result->idbCursorWithValue();
    return 0;
}

void IDBRequest::setResultCursor(PassRefPtr<IDBCursor> cursor, PassRefPtr<IDBKey> key, PassRefPtr<IDBKey> primaryKey, PassRefPtr<SharedBuffer> value)
{
    ASSERT(m_readyState == PENDING);
    m_cursorKey = key;
    m_cursorPrimaryKey = primaryKey;
    m_cursorValue = value;

    onSuccessInternal(IDBAny::create(cursor));
}

void IDBRequest::checkForReferenceCycle()
{
    // If this request and its cursor have the only references
    // to each other, then explicitly break the cycle.
    IDBCursor* cursor = getResultCursor();
    if (!cursor || cursor->request() != this)
        return;

    if (!hasOneRef() || !cursor->hasOneRef())
        return;

    m_result.clear();
}

bool IDBRequest::shouldEnqueueEvent() const
{
    if (m_contextStopped || !executionContext())
        return false;
    ASSERT(m_readyState == PENDING || m_readyState == DONE);
    if (m_requestAborted)
        return false;
    ASSERT(m_readyState == PENDING);
    ASSERT(!m_error && !m_result);
    return true;
}

void IDBRequest::onError(PassRefPtrWillBeRawPtr<DOMError> error)
{
    IDB_TRACE("IDBRequest::onError()");
    if (!shouldEnqueueEvent())
        return;

    m_error = error;
    m_pendingCursor.clear();
    enqueueEvent(Event::createCancelableBubble(EventTypeNames::error));
}

void IDBRequest::onSuccess(const Vector<String>& stringList)
{
    IDB_TRACE("IDBRequest::onSuccess(StringList)");
    if (!shouldEnqueueEvent())
        return;

    RefPtr<DOMStringList> domStringList = DOMStringList::create();
    for (size_t i = 0; i < stringList.size(); ++i)
        domStringList->append(stringList[i]);
    onSuccessInternal(IDBAny::create(domStringList.release()));
}

void IDBRequest::onSuccess(PassOwnPtr<blink::WebIDBCursor> backend, PassRefPtr<IDBKey> key, PassRefPtr<IDBKey> primaryKey, PassRefPtr<SharedBuffer> value)
{
    IDB_TRACE("IDBRequest::onSuccess(IDBCursor)");
    if (!shouldEnqueueEvent())
        return;

    ASSERT(!m_pendingCursor);
    RefPtr<IDBCursor> cursor;
    switch (m_cursorType) {
    case IndexedDB::CursorKeyOnly:
        cursor = IDBCursor::create(backend, m_cursorDirection, this, m_source.get(), m_transaction.get());
        break;
    case IndexedDB::CursorKeyAndValue:
        cursor = IDBCursorWithValue::create(backend, m_cursorDirection, this, m_source.get(), m_transaction.get());
        break;
    default:
        ASSERT_NOT_REACHED();
    }
    setResultCursor(cursor, key, primaryKey, value);
}

void IDBRequest::onSuccess(PassRefPtr<IDBKey> idbKey)
{
    IDB_TRACE("IDBRequest::onSuccess(IDBKey)");
    if (!shouldEnqueueEvent())
        return;

    if (idbKey && idbKey->isValid())
        onSuccessInternal(IDBAny::create(idbKey));
    else
        onSuccessInternal(IDBAny::createUndefined());
}

void IDBRequest::onSuccess(PassRefPtr<SharedBuffer> valueBuffer)
{
    IDB_TRACE("IDBRequest::onSuccess(SharedBuffer)");
    if (!shouldEnqueueEvent())
        return;

    if (m_pendingCursor) {
        // Value should be null, signifying the end of the cursor's range.
        ASSERT(!valueBuffer.get());
        m_pendingCursor->close();
        m_pendingCursor.clear();
    }

    onSuccessInternal(IDBAny::create(valueBuffer));
}

#ifndef NDEBUG
static PassRefPtr<IDBObjectStore> effectiveObjectStore(PassRefPtr<IDBAny> source)
{
    if (source->type() == IDBAny::IDBObjectStoreType)
        return source->idbObjectStore();
    if (source->type() == IDBAny::IDBIndexType)
        return source->idbIndex()->objectStore();

    ASSERT_NOT_REACHED();
    return nullptr;
}
#endif

void IDBRequest::onSuccess(PassRefPtr<SharedBuffer> prpValueBuffer, PassRefPtr<IDBKey> prpPrimaryKey, const IDBKeyPath& keyPath)
{
    IDB_TRACE("IDBRequest::onSuccess(SharedBuffer, IDBKey, IDBKeyPath)");
    if (!shouldEnqueueEvent())
        return;

#ifndef NDEBUG
    ASSERT(keyPath == effectiveObjectStore(m_source)->metadata().keyPath);
#endif

    RefPtr<SharedBuffer> valueBuffer = prpValueBuffer;
    RefPtr<IDBKey> primaryKey = prpPrimaryKey;

#ifndef NDEBUG
    assertPrimaryKeyValidOrInjectable(&m_requestState, valueBuffer, primaryKey, keyPath);
#endif

    onSuccessInternal(IDBAny::create(valueBuffer, primaryKey, keyPath));
}

void IDBRequest::onSuccess(int64_t value)
{
    IDB_TRACE("IDBRequest::onSuccess(int64_t)");
    if (!shouldEnqueueEvent())
        return;
    onSuccessInternal(IDBAny::create(value));
}

void IDBRequest::onSuccess()
{
    IDB_TRACE("IDBRequest::onSuccess()");
    if (!shouldEnqueueEvent())
        return;
    onSuccessInternal(IDBAny::createUndefined());
}

void IDBRequest::onSuccessInternal(PassRefPtr<IDBAny> result)
{
    ASSERT(!m_contextStopped);
    ASSERT(!m_pendingCursor);
    setResult(result);
    enqueueEvent(Event::create(EventTypeNames::success));
}

void IDBRequest::setResult(PassRefPtr<IDBAny> result)
{
    m_result = result;
    m_resultDirty = true;
}

void IDBRequest::onSuccess(PassRefPtr<IDBKey> key, PassRefPtr<IDBKey> primaryKey, PassRefPtr<SharedBuffer> value)
{
    IDB_TRACE("IDBRequest::onSuccess(key, primaryKey, value)");
    if (!shouldEnqueueEvent())
        return;

    ASSERT(m_pendingCursor);
    setResultCursor(m_pendingCursor.release(), key, primaryKey, value);
}

bool IDBRequest::hasPendingActivity() const
{
    // FIXME: In an ideal world, we should return true as long as anyone has a or can
    //        get a handle to us and we have event listeners. This is order to handle
    //        user generated events properly.
    return m_hasPendingActivity && !m_contextStopped;
}

void IDBRequest::stop()
{
    if (m_contextStopped)
        return;

    m_contextStopped = true;
    m_requestState.clear();

    RefPtr<IDBRequest> protect(this);

    if (m_readyState == PENDING) {
        m_readyState = EarlyDeath;
        if (m_transaction) {
            m_transaction->unregisterRequest(this);
            m_transaction.clear();
        }
    }

    m_enqueuedEvents.clear();
}

const AtomicString& IDBRequest::interfaceName() const
{
    return EventTargetNames::IDBRequest;
}

ExecutionContext* IDBRequest::executionContext() const
{
    return ActiveDOMObject::executionContext();
}

bool IDBRequest::dispatchEvent(PassRefPtrWillBeRawPtr<Event> event)
{
    IDB_TRACE("IDBRequest::dispatchEvent");
    if (m_contextStopped || !executionContext())
        return false;
    ASSERT(m_requestState.isValid());
    ASSERT(m_readyState == PENDING);
    ASSERT(m_hasPendingActivity);
    ASSERT(m_enqueuedEvents.size());
    ASSERT(event->target() == this);

    DOMRequestState::Scope scope(m_requestState);

    if (event->type() != EventTypeNames::blocked)
        m_readyState = DONE;
    dequeueEvent(event.get());

    Vector<RefPtr<EventTarget> > targets;
    targets.append(this);
    if (m_transaction && !m_preventPropagation) {
        targets.append(m_transaction);
        // If there ever are events that are associated with a database but
        // that do not have a transaction, then this will not work and we need
        // this object to actually hold a reference to the database (to ensure
        // it stays alive).
        targets.append(m_transaction->db());
    }

    // Cursor properties should not be updated until the success event is being dispatched.
    RefPtr<IDBCursor> cursorToNotify;
    if (event->type() == EventTypeNames::success) {
        cursorToNotify = getResultCursor();
        if (cursorToNotify)
            cursorToNotify->setValueReady(m_cursorKey.release(), m_cursorPrimaryKey.release(), m_cursorValue.release());
    }

    if (event->type() == EventTypeNames::upgradeneeded) {
        ASSERT(!m_didFireUpgradeNeededEvent);
        m_didFireUpgradeNeededEvent = true;
    }

    // FIXME: When we allow custom event dispatching, this will probably need to change.
    ASSERT_WITH_MESSAGE(event->type() == EventTypeNames::success || event->type() == EventTypeNames::error || event->type() == EventTypeNames::blocked || event->type() == EventTypeNames::upgradeneeded, "event type was %s", event->type().utf8().data());
    const bool setTransactionActive = m_transaction && (event->type() == EventTypeNames::success || event->type() == EventTypeNames::upgradeneeded || (event->type() == EventTypeNames::error && !m_requestAborted));

    if (setTransactionActive)
        m_transaction->setActive(true);

    bool dontPreventDefault = IDBEventDispatcher::dispatch(event.get(), targets);

    if (m_transaction) {
        if (m_readyState == DONE)
            m_transaction->unregisterRequest(this);

        // Possibly abort the transaction. This must occur after unregistering (so this request
        // doesn't receive a second error) and before deactivating (which might trigger commit).
        if (event->type() == EventTypeNames::error && dontPreventDefault && !m_requestAborted) {
            m_transaction->setError(m_error);
            m_transaction->abort(IGNORE_EXCEPTION);
        }

        // If this was the last request in the transaction's list, it may commit here.
        if (setTransactionActive)
            m_transaction->setActive(false);
    }

    if (cursorToNotify)
        cursorToNotify->postSuccessHandlerCallback();

    // An upgradeneeded event will always be followed by a success or error event, so must
    // be kept alive.
    if (m_readyState == DONE && event->type() != EventTypeNames::upgradeneeded)
        m_hasPendingActivity = false;

    return dontPreventDefault;
}

void IDBRequest::uncaughtExceptionInEventHandler()
{
    if (m_transaction && !m_requestAborted) {
        m_transaction->setError(DOMError::create(AbortError, "Uncaught exception in event handler."));
        m_transaction->abort(IGNORE_EXCEPTION);
    }
}

void IDBRequest::transactionDidFinishAndDispatch()
{
    ASSERT(m_transaction);
    ASSERT(m_transaction->isVersionChange());
    ASSERT(m_didFireUpgradeNeededEvent);
    ASSERT(m_readyState == DONE);
    ASSERT(executionContext());
    m_transaction.clear();

    if (m_contextStopped)
        return;

    m_readyState = PENDING;
}

void IDBRequest::enqueueEvent(PassRefPtrWillBeRawPtr<Event> event)
{
    ASSERT(m_readyState == PENDING || m_readyState == DONE);

    if (m_contextStopped || !executionContext())
        return;

    ASSERT_WITH_MESSAGE(m_readyState == PENDING || m_didFireUpgradeNeededEvent, "When queueing event %s, m_readyState was %d", event->type().utf8().data(), m_readyState);

    EventQueue* eventQueue = executionContext()->eventQueue();
    event->setTarget(this);

    // Keep track of enqueued events in case we need to abort prior to dispatch,
    // in which case these must be cancelled. If the events not dispatched for
    // other reasons they must be removed from this list via dequeueEvent().
    if (eventQueue->enqueueEvent(event.get()))
        m_enqueuedEvents.append(event);
}

void IDBRequest::dequeueEvent(Event* event)
{
    for (size_t i = 0; i < m_enqueuedEvents.size(); ++i) {
        if (m_enqueuedEvents[i].get() == event)
            m_enqueuedEvents.remove(i);
    }
}

} // namespace WebCore