applicationcachegroup.cpp

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        m_currentHandle->setClient(0);
        m_currentHandle->cancel();
        m_currentHandle = 0;
    }    
    
    m_cacheBeingUpdated = 0;
    m_pendingEntries.clear();
}    

void ApplicationCacheGroup::disassociateDocumentLoader(DocumentLoader* loader)
{
    HashSet<DocumentLoader*>::iterator it = m_associatedDocumentLoaders.find(loader);
    if (it != m_associatedDocumentLoaders.end())
        m_associatedDocumentLoaders.remove(it);

    m_pendingMasterResourceLoaders.remove(loader);

    loader->setApplicationCache(0); // Will set candidate to 0, too.

    if (!m_associatedDocumentLoaders.isEmpty() || !m_pendingMasterResourceLoaders.isEmpty())
        return;

    if (m_caches.isEmpty()) {
        // There is an initial cache attempt in progress.
        ASSERT(!m_newestCache);
        // Delete ourselves, causing the cache attempt to be stopped.
        delete this;
        return;
    }

    ASSERT(m_caches.contains(m_newestCache.get()));

    // Release our reference to the newest cache. This could cause us to be deleted.
    // Any ongoing updates will be stopped from destructor.
    m_newestCache.release();
}

void ApplicationCacheGroup::cacheDestroyed(ApplicationCache* cache)
{
    if (!m_caches.contains(cache))
        return;
    
    m_caches.remove(cache);

    if (m_caches.isEmpty()) {
        ASSERT(m_associatedDocumentLoaders.isEmpty());
        ASSERT(m_pendingMasterResourceLoaders.isEmpty());
        delete this;
    }
}

void ApplicationCacheGroup::setNewestCache(PassRefPtr<ApplicationCache> newestCache)
{
    ASSERT(!m_caches.contains(newestCache.get()));

    m_newestCache = newestCache;

    m_caches.add(m_newestCache.get());
    m_newestCache->setGroup(this);
}

void ApplicationCacheGroup::makeObsolete()
{
    if (isObsolete())
        return;

    m_isObsolete = true;
    cacheStorage().cacheGroupMadeObsolete(this);
    ASSERT(!m_storageID);
}

void ApplicationCacheGroup::update(Frame* frame, ApplicationCacheUpdateOption updateOption)
{
    if (m_updateStatus == Checking || m_updateStatus == Downloading) {
        if (updateOption == ApplicationCacheUpdateWithBrowsingContext) {
            postListenerTask(&DOMApplicationCache::callCheckingListener, frame->loader()->documentLoader());
            if (m_updateStatus == Downloading)
                postListenerTask(&DOMApplicationCache::callDownloadingListener, frame->loader()->documentLoader());
        }
        return;
    }

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

    ASSERT(!m_frame);
    m_frame = frame;

    m_updateStatus = Checking;

    postListenerTask(&DOMApplicationCache::callCheckingListener, m_associatedDocumentLoaders);
    if (!m_newestCache) {
        ASSERT(updateOption == ApplicationCacheUpdateWithBrowsingContext);
        postListenerTask(&DOMApplicationCache::callCheckingListener, frame->loader()->documentLoader());
    }
    
    ASSERT(!m_manifestHandle);
    ASSERT(!m_manifestResource);
    ASSERT(m_completionType == None);

    // FIXME: Handle defer loading
    m_manifestHandle = createResourceHandle(m_manifestURL, m_newestCache ? m_newestCache->manifestResource() : 0);
}

PassRefPtr<ResourceHandle> ApplicationCacheGroup::createResourceHandle(const KURL& url, ApplicationCacheResource* newestCachedResource)
{
    ResourceRequest request(url);
    m_frame->loader()->applyUserAgent(request);
    request.setHTTPHeaderField("Cache-Control", "max-age=0");

    if (newestCachedResource) {
        const String& lastModified = newestCachedResource->response().httpHeaderField("Last-Modified");
        const String& eTag = newestCachedResource->response().httpHeaderField("ETag");
        if (!lastModified.isEmpty() || !eTag.isEmpty()) {
            if (!lastModified.isEmpty())
                request.setHTTPHeaderField("If-Modified-Since", lastModified);
            if (!eTag.isEmpty())
                request.setHTTPHeaderField("If-None-Match", eTag);
        }
    }
    
    return ResourceHandle::create(request, this, m_frame, false, true, false);
}

void ApplicationCacheGroup::didReceiveResponse(ResourceHandle* handle, const ResourceResponse& response)
{
    if (handle == m_manifestHandle) {
        didReceiveManifestResponse(response);
        return;
    }
    
    ASSERT(handle == m_currentHandle);

    const KURL& url = handle->request().url();
    
    ASSERT(!m_currentResource);
    ASSERT(m_pendingEntries.contains(url));
    
    unsigned type = m_pendingEntries.get(url);
    
    // If this is an initial cache attempt, we should not get master resources delivered here.
    if (!m_newestCache)
        ASSERT(!(type & ApplicationCacheResource::Master));

    if (m_newestCache && response.httpStatusCode() == 304) { // Not modified.
        ApplicationCacheResource* newestCachedResource = m_newestCache->resourceForURL(handle->request().url());
        if (newestCachedResource) {
            m_cacheBeingUpdated->addResource(ApplicationCacheResource::create(url, newestCachedResource->response(), type, newestCachedResource->data()));
            m_currentHandle->cancel();
            m_currentHandle = 0;
            // Load the next resource, if any.
            startLoadingEntry();
            return;
        }
        // The server could return 304 for an unconditional request - in this case, we handle the response as a normal error.
    }

    if (response.httpStatusCode() / 100 != 2 || response.url() != m_currentHandle->request().url()) {
        if ((type & ApplicationCacheResource::Explicit) || (type & ApplicationCacheResource::Fallback)) {
            // Note that cacheUpdateFailed() can cause the cache group to be deleted.
            cacheUpdateFailed();
        } else if (response.httpStatusCode() == 404 || response.httpStatusCode() == 410) {
            // Skip this resource. It is dropped from the cache.
            m_currentHandle->cancel();
            m_currentHandle = 0;
            m_pendingEntries.remove(handle->request().url());
            // Load the next resource, if any.
            startLoadingEntry();
        } else {
            // Copy the resource and its metadata from the newest application cache in cache group whose completeness flag is complete, and act
            // as if that was the fetched resource, ignoring the resource obtained from the network.
            ASSERT(m_newestCache);
            ApplicationCacheResource* newestCachedResource = m_newestCache->resourceForURL(handle->request().url());
            ASSERT(newestCachedResource);
            m_cacheBeingUpdated->addResource(ApplicationCacheResource::create(url, newestCachedResource->response(), type, newestCachedResource->data()));
            m_currentHandle->cancel();
            m_currentHandle = 0;
            // Load the next resource, if any.
            startLoadingEntry();
        }
        return;
    }
    
    m_currentResource = ApplicationCacheResource::create(url, response, type);
}

void ApplicationCacheGroup::didReceiveData(ResourceHandle* handle, const char* data, int length, int)
{
    if (handle == m_manifestHandle) {
        didReceiveManifestData(data, length);
        return;
    }
    
    ASSERT(handle == m_currentHandle);
    
    ASSERT(m_currentResource);
    m_currentResource->data()->append(data, length);
}

void ApplicationCacheGroup::didFinishLoading(ResourceHandle* handle)
{
    if (handle == m_manifestHandle) {
        didFinishLoadingManifest();
        return;
    }
 
    ASSERT(m_currentHandle == handle);
    ASSERT(m_pendingEntries.contains(handle->request().url()));
    
    m_pendingEntries.remove(handle->request().url());
    
    ASSERT(m_cacheBeingUpdated);

    m_cacheBeingUpdated->addResource(m_currentResource.release());
    m_currentHandle = 0;
    
    // Load the next resource, if any.
    startLoadingEntry();
}

void ApplicationCacheGroup::didFail(ResourceHandle* handle, const ResourceError&)
{
    if (handle == m_manifestHandle) {
        cacheUpdateFailed();
        return;
    }

    unsigned type = m_currentResource ? m_currentResource->type() : m_pendingEntries.get(handle->request().url());
    const KURL& url = handle->request().url();

    ASSERT(!m_currentResource || !m_pendingEntries.contains(url));
    m_currentResource = 0;
    m_pendingEntries.remove(url);

    if ((type & ApplicationCacheResource::Explicit) || (type & ApplicationCacheResource::Fallback)) {
        // Note that cacheUpdateFailed() can cause the cache group to be deleted.
        cacheUpdateFailed();
    } else {
        // Copy the resource and its metadata from the newest application cache in cache group whose completeness flag is complete, and act
        // as if that was the fetched resource, ignoring the resource obtained from the network.
        ASSERT(m_newestCache);
        ApplicationCacheResource* newestCachedResource = m_newestCache->resourceForURL(url);
        ASSERT(newestCachedResource);
        m_cacheBeingUpdated->addResource(ApplicationCacheResource::create(url, newestCachedResource->response(), type, newestCachedResource->data()));
        // Load the next resource, if any.
        startLoadingEntry();
    }
}

void ApplicationCacheGroup::didReceiveManifestResponse(const ResourceResponse& response)
{
    ASSERT(!m_manifestResource);
    ASSERT(m_manifestHandle);

    if (response.httpStatusCode() == 404 || response.httpStatusCode() == 410) {
        manifestNotFound();
        return;
    }

    if (response.httpStatusCode() == 304)
        return;

    if (response.httpStatusCode() / 100 != 2 || response.url() != m_manifestHandle->request().url() || !equalIgnoringCase(response.mimeType(), "text/cache-manifest")) {
        cacheUpdateFailed();
        return;
    }

    m_manifestResource = ApplicationCacheResource::create(m_manifestHandle->request().url(), response, 
                                                          ApplicationCacheResource::Manifest);
}

void ApplicationCacheGroup::didReceiveManifestData(const char* data, int length)
{
    if (m_manifestResource)
        m_manifestResource->data()->append(data, length);
}

void ApplicationCacheGroup::didFinishLoadingManifest()
{
    bool isUpgradeAttempt = m_newestCache;

    if (!isUpgradeAttempt && !m_manifestResource) {
        // The server returned 304 Not Modified even though we didn't send a conditional request.
        cacheUpdateFailed();
        return;
    }