applicationcachegroup.cpp

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * Copyright (C) 2008, 2009 Apple 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.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 INC. OR
 * 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 "ApplicationCacheGroup.h"

#if ENABLE(OFFLINE_WEB_APPLICATIONS)

#include "ApplicationCache.h"
#include "ApplicationCacheResource.h"
#include "ApplicationCacheStorage.h"
#include "DocumentLoader.h"
#include "DOMApplicationCache.h"
#include "DOMWindow.h"
#include "Frame.h"
#include "FrameLoader.h"
#include "MainResourceLoader.h"
#include "ManifestParser.h"
#include "Page.h"
#include "Settings.h"
#include <wtf/HashMap.h>

namespace WebCore {

ApplicationCacheGroup::ApplicationCacheGroup(const KURL& manifestURL, bool isCopy)
    : m_manifestURL(manifestURL)
    , m_updateStatus(Idle)
    , m_frame(0)
    , m_storageID(0)
    , m_isObsolete(false)
    , m_completionType(None)
    , m_isCopy(isCopy)
{
}

ApplicationCacheGroup::~ApplicationCacheGroup()
{
    if (m_isCopy) {
        ASSERT(m_newestCache);
        ASSERT(m_caches.size() == 1);
        ASSERT(m_caches.contains(m_newestCache.get()));
        ASSERT(!m_cacheBeingUpdated);
        ASSERT(m_associatedDocumentLoaders.isEmpty());
        ASSERT(m_pendingMasterResourceLoaders.isEmpty());
        ASSERT(m_newestCache->group() == this);
        
        return;
    }
               
    ASSERT(!m_newestCache);
    ASSERT(m_caches.isEmpty());
    
    stopLoading();
    
    cacheStorage().cacheGroupDestroyed(this);
}
    
ApplicationCache* ApplicationCacheGroup::cacheForMainRequest(const ResourceRequest& request, DocumentLoader*)
{
    if (!ApplicationCache::requestIsHTTPOrHTTPSGet(request))
        return 0;

    if (ApplicationCacheGroup* group = cacheStorage().cacheGroupForURL(request.url())) {
        ASSERT(group->newestCache());
        ASSERT(!group->isObsolete());
        
        return group->newestCache();
    }
    
    return 0;
}
    
ApplicationCache* ApplicationCacheGroup::fallbackCacheForMainRequest(const ResourceRequest& request, DocumentLoader*)
{
    if (!ApplicationCache::requestIsHTTPOrHTTPSGet(request))
        return 0;

    if (ApplicationCacheGroup* group = cacheStorage().fallbackCacheGroupForURL(request.url())) {
        ASSERT(group->newestCache());
        ASSERT(!group->isObsolete());

        return group->newestCache();
    }
    
    return 0;
}

void ApplicationCacheGroup::selectCache(Frame* frame, const KURL& manifestURL)
{
    ASSERT(frame && frame->page());
    
    if (!frame->settings()->offlineWebApplicationCacheEnabled())
        return;
    
    DocumentLoader* documentLoader = frame->loader()->documentLoader();
    ASSERT(!documentLoader->applicationCache());

    if (manifestURL.isNull()) {
        selectCacheWithoutManifestURL(frame);        
        return;
    }
    
    ApplicationCache* mainResourceCache = documentLoader->mainResourceApplicationCache();
    
    if (mainResourceCache) {
        if (manifestURL == mainResourceCache->group()->m_manifestURL) {
            mainResourceCache->group()->associateDocumentLoaderWithCache(documentLoader, mainResourceCache);
            mainResourceCache->group()->update(frame, ApplicationCacheUpdateWithBrowsingContext);
        } else {
            // The main resource was loaded from cache, so the cache must have an entry for it. Mark it as foreign.
            ApplicationCacheResource* resource = mainResourceCache->resourceForURL(documentLoader->url());
            bool inStorage = resource->storageID();
            resource->addType(ApplicationCacheResource::Foreign);
            if (inStorage)
                cacheStorage().storeUpdatedType(resource, mainResourceCache);

            // Restart the current navigation from the top of the navigation algorithm, undoing any changes that were made
            // as part of the initial load.
            // The navigation will not result in the same resource being loaded, because "foreign" entries are never picked during navigation.
            frame->loader()->scheduleLocationChange(documentLoader->url(), frame->loader()->referrer(), true);
        }
        
        return;
    }
    
    // The resource was loaded from the network, check if it is a HTTP/HTTPS GET.    
    const ResourceRequest& request = frame->loader()->activeDocumentLoader()->request();

    if (!ApplicationCache::requestIsHTTPOrHTTPSGet(request))
        return;

    // Check that the resource URL has the same scheme/host/port as the manifest URL.
    if (!protocolHostAndPortAreEqual(manifestURL, request.url()))
        return;

    // Don't change anything on disk if private browsing is enabled.
    if (!frame->settings() || frame->settings()->privateBrowsingEnabled()) {
        postListenerTask(&DOMApplicationCache::callCheckingListener, documentLoader);
        postListenerTask(&DOMApplicationCache::callErrorListener, documentLoader);
        return;
    }

    ApplicationCacheGroup* group = cacheStorage().findOrCreateCacheGroup(manifestURL);

    documentLoader->setCandidateApplicationCacheGroup(group);
    group->m_pendingMasterResourceLoaders.add(documentLoader);

    ASSERT(!group->m_cacheBeingUpdated || group->m_updateStatus != Idle);
    group->update(frame, ApplicationCacheUpdateWithBrowsingContext);
}

void ApplicationCacheGroup::selectCacheWithoutManifestURL(Frame* frame)
{
    if (!frame->settings()->offlineWebApplicationCacheEnabled())
        return;

    DocumentLoader* documentLoader = frame->loader()->documentLoader();
    ASSERT(!documentLoader->applicationCache());

    ApplicationCache* mainResourceCache = documentLoader->mainResourceApplicationCache();

    if (mainResourceCache) {
        mainResourceCache->group()->associateDocumentLoaderWithCache(documentLoader, mainResourceCache);
        mainResourceCache->group()->update(frame, ApplicationCacheUpdateWithBrowsingContext);
    }
}

void ApplicationCacheGroup::finishedLoadingMainResource(DocumentLoader* loader)
{
    ASSERT(m_pendingMasterResourceLoaders.contains(loader));
    ASSERT(m_completionType == None || m_pendingEntries.isEmpty());
    const KURL& url = loader->url();

    switch (m_completionType) {
    case None:
        // The main resource finished loading before the manifest was ready. It will be handled via dispatchMainResources() later.
        return;
    case NoUpdate:
        ASSERT(!m_cacheBeingUpdated);
        associateDocumentLoaderWithCache(loader, m_newestCache.get());

        if (ApplicationCacheResource* resource = m_newestCache->resourceForURL(url)) {
            if (!(resource->type() & ApplicationCacheResource::Master)) {
                resource->addType(ApplicationCacheResource::Master);
                ASSERT(!resource->storageID());
            }
        } else
            m_newestCache->addResource(ApplicationCacheResource::create(url, loader->response(), ApplicationCacheResource::Master, loader->mainResourceData()));

        break;
    case Failure:
        // Cache update has been a failure, so there is no reason to keep the document associated with the incomplete cache
        // (its main resource was not cached yet, so it is likely that the application changed significantly server-side).
        ASSERT(!m_cacheBeingUpdated); // Already cleared out by stopLoading().
        loader->setApplicationCache(0); // Will unset candidate, too.
        m_associatedDocumentLoaders.remove(loader);
        postListenerTask(&DOMApplicationCache::callErrorListener, loader);
        break;
    case Completed:
        ASSERT(m_associatedDocumentLoaders.contains(loader));

        if (ApplicationCacheResource* resource = m_cacheBeingUpdated->resourceForURL(url)) {
            if (!(resource->type() & ApplicationCacheResource::Master)) {
                resource->addType(ApplicationCacheResource::Master);
                ASSERT(!resource->storageID());
            }
        } else
            m_cacheBeingUpdated->addResource(ApplicationCacheResource::create(url, loader->response(), ApplicationCacheResource::Master, loader->mainResourceData()));
        // The "cached" event will be posted to all associated documents once update is complete.
        break;
    }

    m_pendingMasterResourceLoaders.remove(loader);
    checkIfLoadIsComplete();
}

void ApplicationCacheGroup::failedLoadingMainResource(DocumentLoader* loader)
{
    ASSERT(m_pendingMasterResourceLoaders.contains(loader));
    ASSERT(m_completionType == None || m_pendingEntries.isEmpty());

    switch (m_completionType) {
    case None:
        // The main resource finished loading before the manifest was ready. It will be handled via dispatchMainResources() later.
        return;
    case NoUpdate:
        ASSERT(!m_cacheBeingUpdated);

        // The manifest didn't change, and we have a relevant cache - but the main resource download failed mid-way, so it cannot be stored to the cache,
        // and the loader does not get associated to it. If there are other main resources being downloaded for this cache group, they may still succeed.
        postListenerTask(&DOMApplicationCache::callErrorListener, loader);

        break;
    case Failure:
        // Cache update failed, too.
        ASSERT(!m_cacheBeingUpdated); // Already cleared out by stopLoading().
        ASSERT(!loader->applicationCache() || loader->applicationCache() == m_cacheBeingUpdated);

        loader->setApplicationCache(0); // Will unset candidate, too.
        m_associatedDocumentLoaders.remove(loader);
        postListenerTask(&DOMApplicationCache::callErrorListener, loader);
        break;
    case Completed:
        // The cache manifest didn't list this main resource, and all cache entries were already updated successfully - but the main resource failed to load,
        // so it cannot be stored to the cache. If there are other main resources being downloaded for this cache group, they may still succeed.
        ASSERT(m_associatedDocumentLoaders.contains(loader));
        ASSERT(loader->applicationCache() == m_cacheBeingUpdated);
        ASSERT(!loader->candidateApplicationCacheGroup());
        m_associatedDocumentLoaders.remove(loader);
        loader->setApplicationCache(0);

        postListenerTask(&DOMApplicationCache::callErrorListener, loader);

        break;
    }

    m_pendingMasterResourceLoaders.remove(loader);
    checkIfLoadIsComplete();
}

void ApplicationCacheGroup::stopLoading()
{
    if (m_manifestHandle) {
        ASSERT(!m_currentHandle);

        m_manifestHandle->setClient(0);
        m_manifestHandle->cancel();
        m_manifestHandle = 0;
    }
    
    if (m_currentHandle) {
        ASSERT(!m_manifestHandle);
        ASSERT(m_cacheBeingUpdated);