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

    m_manifestHandle = 0;

    // Check if the manifest was not modified.
    if (isUpgradeAttempt) {
        ApplicationCacheResource* newestManifest = m_newestCache->manifestResource();
        ASSERT(newestManifest);
    
        if (!m_manifestResource || // The resource will be null if HTTP response was 304 Not Modified.
            newestManifest->data()->size() == m_manifestResource->data()->size() && !memcmp(newestManifest->data()->data(), m_manifestResource->data()->data(), newestManifest->data()->size())) {

            m_completionType = NoUpdate;
            m_manifestResource = 0;
            deliverDelayedMainResources();

            return;
        }
    }
    
    Manifest manifest;
    if (!parseManifest(m_manifestURL, m_manifestResource->data()->data(), m_manifestResource->data()->size(), manifest)) {
        cacheUpdateFailed();
        return;
    }

    ASSERT(!m_cacheBeingUpdated);
    m_cacheBeingUpdated = ApplicationCache::create();
    m_cacheBeingUpdated->setGroup(this);

    HashSet<DocumentLoader*>::const_iterator masterEnd = m_pendingMasterResourceLoaders.end();
    for (HashSet<DocumentLoader*>::const_iterator iter = m_pendingMasterResourceLoaders.begin(); iter != masterEnd; ++iter)
        associateDocumentLoaderWithCache(*iter, m_cacheBeingUpdated.get());

    // We have the manifest, now download the resources.
    m_updateStatus = Downloading;
    
    postListenerTask(&DOMApplicationCache::callDownloadingListener, m_associatedDocumentLoaders);

    ASSERT(m_pendingEntries.isEmpty());

    if (isUpgradeAttempt) {
        ApplicationCache::ResourceMap::const_iterator end = m_newestCache->end();
        for (ApplicationCache::ResourceMap::const_iterator it = m_newestCache->begin(); it != end; ++it) {
            unsigned type = it->second->type();
            if (type & (ApplicationCacheResource::Master | ApplicationCacheResource::Dynamic))
                addEntry(it->first, type);
        }
    }
    
    HashSet<String>::const_iterator end = manifest.explicitURLs.end();
    for (HashSet<String>::const_iterator it = manifest.explicitURLs.begin(); it != end; ++it)
        addEntry(*it, ApplicationCacheResource::Explicit);

    size_t fallbackCount = manifest.fallbackURLs.size();
    for (size_t i = 0; i  < fallbackCount; ++i)
        addEntry(manifest.fallbackURLs[i].second, ApplicationCacheResource::Fallback);
    
    m_cacheBeingUpdated->setOnlineWhitelist(manifest.onlineWhitelistedURLs);
    m_cacheBeingUpdated->setFallbackURLs(manifest.fallbackURLs);
    
    startLoadingEntry();
}

void ApplicationCacheGroup::cacheUpdateFailed()
{
    stopLoading();
    m_manifestResource = 0;

    // Wait for master resource loads to finish.
    m_completionType = Failure;
    deliverDelayedMainResources();
}
    
void ApplicationCacheGroup::manifestNotFound()
{
    makeObsolete();

    postListenerTask(&DOMApplicationCache::callObsoleteListener, m_associatedDocumentLoaders);
    postListenerTask(&DOMApplicationCache::callErrorListener, m_pendingMasterResourceLoaders);

    stopLoading();

    ASSERT(m_pendingEntries.isEmpty());
    m_manifestResource = 0;

    while (!m_pendingMasterResourceLoaders.isEmpty()) {
        HashSet<DocumentLoader*>::iterator it = m_pendingMasterResourceLoaders.begin();
        
        ASSERT((*it)->candidateApplicationCacheGroup() == this);
        ASSERT(!(*it)->applicationCache());
        (*it)->setCandidateApplicationCacheGroup(0);
        m_pendingMasterResourceLoaders.remove(it);
    }

    m_updateStatus = Idle;    
    m_frame = 0;
    
    if (m_caches.isEmpty()) {
        ASSERT(m_associatedDocumentLoaders.isEmpty());
        ASSERT(!m_cacheBeingUpdated);
        delete this;
    }
}

void ApplicationCacheGroup::checkIfLoadIsComplete()
{
    if (m_manifestHandle || !m_pendingEntries.isEmpty() || !m_pendingMasterResourceLoaders.isEmpty())
        return;
    
    // We're done, all resources have finished downloading (successfully or not).

    bool isUpgradeAttempt = m_newestCache;

    switch (m_completionType) {
    case None:
        ASSERT_NOT_REACHED();
        return;
    case NoUpdate:
        ASSERT(isUpgradeAttempt);
        ASSERT(!m_cacheBeingUpdated);
        ASSERT(m_storageID);
        postListenerTask(&DOMApplicationCache::callNoUpdateListener, m_associatedDocumentLoaders);
        break;
    case Failure:
        ASSERT(!m_cacheBeingUpdated);
        postListenerTask(&DOMApplicationCache::callErrorListener, m_associatedDocumentLoaders);
        if (m_caches.isEmpty()) {
            ASSERT(m_associatedDocumentLoaders.isEmpty());
            delete this;
            return;
        }
        break;
    case Completed: {
        // FIXME: Fetch the resource from manifest URL again, and check whether it is identical to the one used for update (in case the application was upgraded server-side in the meanwhile). (<rdar://problem/6467625>)

        ASSERT(m_cacheBeingUpdated);
        m_cacheBeingUpdated->setManifestResource(m_manifestResource.release());

        RefPtr<ApplicationCache> oldNewestCache = (m_newestCache == m_cacheBeingUpdated) ? 0 : m_newestCache;

        setNewestCache(m_cacheBeingUpdated.release());
        cacheStorage().storeNewestCache(this);

        if (oldNewestCache)
            cacheStorage().remove(oldNewestCache.get());

        postListenerTask(isUpgradeAttempt ? &DOMApplicationCache::callUpdateReadyListener : &DOMApplicationCache::callCachedListener, m_associatedDocumentLoaders);
        break;
    }
    }

    m_completionType = None;
    m_updateStatus = Idle;
    m_frame = 0;
}

void ApplicationCacheGroup::startLoadingEntry()
{
    ASSERT(m_cacheBeingUpdated);

    if (m_pendingEntries.isEmpty()) {
        m_completionType = Completed;
        deliverDelayedMainResources();
        return;
    }
    
    EntryMap::const_iterator it = m_pendingEntries.begin();

    postListenerTask(&DOMApplicationCache::callProgressListener, m_associatedDocumentLoaders);

    ASSERT(!m_currentHandle);
    
    m_currentHandle = createResourceHandle(KURL(it->first), m_newestCache ? m_newestCache->resourceForURL(it->first) : 0);
}

void ApplicationCacheGroup::deliverDelayedMainResources()
{
    // Need to copy loaders, because the cache group may be destroyed at the end of iteration.
    Vector<DocumentLoader*> loaders;
    copyToVector(m_pendingMasterResourceLoaders, loaders);
    size_t count = loaders.size();
    for (size_t i = 0; i != count; ++i) {
        DocumentLoader* loader = loaders[i];
        if (loader->isLoadingMainResource())
            continue;

        const ResourceError& error = loader->mainDocumentError();
        if (error.isNull())
            finishedLoadingMainResource(loader);
        else
            failedLoadingMainResource(loader);
    }
    if (!count)
        checkIfLoadIsComplete();
}

void ApplicationCacheGroup::addEntry(const String& url, unsigned type)
{
    ASSERT(m_cacheBeingUpdated);
    
    // Don't add the URL if we already have an master resource in the cache
    // (i.e., the main resource finished loading before the manifest).
    if (ApplicationCacheResource* resource = m_cacheBeingUpdated->resourceForURL(url)) {
        ASSERT(resource->type() & ApplicationCacheResource::Master);
        ASSERT(!m_frame->loader()->documentLoader()->isLoadingMainResource());
    
        resource->addType(type);
        return;
    }

    // Don't add the URL if it's the same as the manifest URL.
    ASSERT(m_manifestResource);
    if (m_manifestResource->url() == url) {
        m_manifestResource->addType(type);
        return;
    }
    
    pair<EntryMap::iterator, bool> result = m_pendingEntries.add(url, type);
    
    if (!result.second)
        result.first->second |= type;
}

void ApplicationCacheGroup::associateDocumentLoaderWithCache(DocumentLoader* loader, ApplicationCache* cache)
{
    // If teardown started already, revive the group.
    if (!m_newestCache && !m_cacheBeingUpdated)
        m_newestCache = cache;

    ASSERT(!m_isObsolete);

    loader->setApplicationCache(cache);

    ASSERT(!m_associatedDocumentLoaders.contains(loader));
    m_associatedDocumentLoaders.add(loader);
}
 
class CallCacheListenerTask : public ScriptExecutionContext::Task {
    typedef void (DOMApplicationCache::*ListenerFunction)();
public:
    static PassRefPtr<CallCacheListenerTask> create(ListenerFunction listenerFunction)
    {
        return adoptRef(new CallCacheListenerTask(listenerFunction));
    }

    virtual void performTask(ScriptExecutionContext* context)
    {
        ASSERT(context->isDocument());
        if (DOMWindow* window = static_cast<Document*>(context)->domWindow()) {
            if (DOMApplicationCache* domCache = window->optionalApplicationCache())
                (domCache->*m_listenerFunction)();
        }
    }

private:
    CallCacheListenerTask(ListenerFunction listenerFunction)
        : m_listenerFunction(listenerFunction)
    {
    }

    ListenerFunction m_listenerFunction;
};

void ApplicationCacheGroup::postListenerTask(ListenerFunction listenerFunction, const HashSet<DocumentLoader*>& loaderSet)
{
    HashSet<DocumentLoader*>::const_iterator loaderSetEnd = loaderSet.end();
    for (HashSet<DocumentLoader*>::const_iterator iter = loaderSet.begin(); iter != loaderSetEnd; ++iter)
        postListenerTask(listenerFunction, *iter);
}

void ApplicationCacheGroup::postListenerTask(ListenerFunction listenerFunction, DocumentLoader* loader)
{
    Frame* frame = loader->frame();
    if (!frame)
        return;
    
    ASSERT(frame->loader()->documentLoader() == loader);

    frame->document()->postTask(CallCacheListenerTask::create(listenerFunction));
}

void ApplicationCacheGroup::clearStorageID()
{
    m_storageID = 0;
    
    HashSet<ApplicationCache*>::const_iterator end = m_caches.end();
    for (HashSet<ApplicationCache*>::const_iterator it = m_caches.begin(); it != end; ++it)
        (*it)->clearStorageID();
}
    

}

#endif // ENABLE(OFFLINE_WEB_APPLICATIONS)