Esempio n. 1
0
void ScriptRunner::queueScriptForExecution(ScriptElement* scriptElement, CachedResourceHandle<CachedScript> cachedScript, ExecutionType executionType)
{
    ASSERT(scriptElement);
    ASSERT(cachedScript.get());

    Element* element = scriptElement->element();
    ASSERT(element);
    ASSERT(element->inDocument());

    m_document->incrementLoadEventDelayCount();

    switch (executionType) {
    case ASYNC_EXECUTION:
        m_scriptsToExecuteSoon.append(PendingScript(element, cachedScript.get()));
        if (!m_timer.isActive())
            m_timer.startOneShot(0);
        break;

    case IN_ORDER_EXECUTION:
        m_scriptsToExecuteInOrder.append(PendingScript(element, cachedScript.get()));
        break;

    default:
        ASSERT_NOT_REACHED();
    }
}
Esempio n. 2
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void ScriptRunner::queueScriptForExecution(ScriptElement* scriptElement, CachedResourceHandle<CachedScript> cachedScript, ExecutionType executionType)
{
    ASSERT(scriptElement);
    
    // Temporary: intended to help debug how null CachedScript objects can even get queued for execution, which
    // seems to sometimes happen (see http://code.google.com/p/chromium/issues/detail?id=75604 )
    if (!cachedScript.get())
        CRASH();

    Element* element = scriptElement->element();
    ASSERT(element);
    ASSERT(element->inDocument());

    m_document->incrementLoadEventDelayCount();

    switch (executionType) {
    case ASYNC_EXECUTION:
        m_scriptsToExecuteSoon.append(PendingScript(element, cachedScript.get()));
        if (!m_timer.isActive())
            m_timer.startOneShot(0);
        break;

    case IN_ORDER_EXECUTION:
        m_scriptsToExecuteInOrder.append(PendingScript(element, cachedScript.get()));
        break;

    default:
        ASSERT_NOT_REACHED();
    }
}
Esempio n. 3
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CachedResourceHandle<CachedCSSStyleSheet> CachedResourceLoader::requestUserCSSStyleSheet(CachedResourceRequest& request)
{
    KURL url = MemoryCache::removeFragmentIdentifierIfNeeded(request.resourceRequest().url());

#if ENABLE(CACHE_PARTITIONING)
    request.mutableResourceRequest().setCachePartition(document()->topOrigin()->cachePartition());
#endif

    if (CachedResource* existing = memoryCache()->resourceForRequest(request.resourceRequest())) {
        if (existing->type() == CachedResource::CSSStyleSheet)
            return static_cast<CachedCSSStyleSheet*>(existing);
        memoryCache()->remove(existing);
    }
    if (url.string() != request.resourceRequest().url())
        request.mutableResourceRequest().setURL(url);

    CachedResourceHandle<CachedCSSStyleSheet> userSheet = new CachedCSSStyleSheet(request.resourceRequest(), request.charset());

    memoryCache()->add(userSheet.get());
    // FIXME: loadResource calls setOwningCachedResourceLoader() if the resource couldn't be added to cache. Does this function need to call it, too?

    userSheet->load(this, ResourceLoaderOptions(DoNotSendCallbacks, SniffContent, BufferData, AllowStoredCredentials, AskClientForCrossOriginCredentials, SkipSecurityCheck));
    
    return userSheet;
}
Esempio n. 4
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void CachedResourceLoader::storeResourceTimingInitiatorInformation(const CachedResourceHandle<CachedResource>& resource, const CachedResourceRequest& request)
{
    if (resource->type() == CachedResource::MainResource) {
        // <iframe>s should report the initial navigation requested by the parent document, but not subsequent navigations.
        if (frame()->ownerElement() && m_documentLoader->frameLoader()->stateMachine()->committingFirstRealLoad()) {
            InitiatorInfo info = { frame()->ownerElement()->localName(), monotonicallyIncreasingTime() };
            m_initiatorMap.add(resource.get(), info);
        }
    } else {
        InitiatorInfo info = { request.initiatorName(), monotonicallyIncreasingTime() };
        m_initiatorMap.add(resource.get(), info);
    }
}
Esempio n. 5
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void CSSFilterImageValue::loadSubimages(CachedResourceLoader* cachedResourceLoader)
{
    CachedResourceHandle<CachedImage> oldCachedImage = m_cachedImage;

    m_cachedImage = CSSImageGeneratorValue::cachedImageForCSSValue(m_imageValue.get(), cachedResourceLoader);

    if (m_cachedImage != oldCachedImage) {
        if (oldCachedImage)
            oldCachedImage->removeClient(&m_filterSubimageObserver);
        if (m_cachedImage)
            m_cachedImage->addClient(&m_filterSubimageObserver);
    }

    m_filterSubimageObserver.setReady(true);
}
Esempio n. 6
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CachedResourceHandle<CachedResource> CachedResourceLoader::loadResource(CachedResource::Type type, CachedResourceRequest& request, const String& charset)
{
    ASSERT(!memoryCache()->resourceForRequest(request.resourceRequest()));

    LOG(ResourceLoading, "Loading CachedResource for '%s'.", request.resourceRequest().url().elidedString().latin1().data());

    CachedResourceHandle<CachedResource> resource = createResource(type, request.mutableResourceRequest(), charset);

    if (!memoryCache()->add(resource.get()))
        resource->setOwningCachedResourceLoader(this);
#if ENABLE(RESOURCE_TIMING)
    storeResourceTimingInitiatorInformation(resource, request);
#endif
    return resource;
}
MediaResource::MediaResource(MediaResourceLoader& loader, CachedResourceHandle<CachedRawResource> resource)
    : m_loader(loader)
    , m_resource(resource)
{
    ASSERT(resource);
    resource->addClient(this);
}
void ResourceTimingInformation::storeResourceTimingInitiatorInformation(const CachedResourceHandle<CachedResource>& resource, const CachedResourceRequest& request, Frame* frame)
{
    ASSERT(RuntimeEnabledFeatures::sharedFeatures().resourceTimingEnabled());
    ASSERT(resource.get());
    if (resource->type() == CachedResource::MainResource) {
        // <iframe>s should report the initial navigation requested by the parent document, but not subsequent navigations.
        ASSERT(frame);
        if (frame->ownerElement()) {
            InitiatorInfo info = { frame->ownerElement()->localName(), monotonicallyIncreasingTime(), NotYetAdded };
            m_initiatorMap.add(resource.get(), info);
        }
    } else {
        InitiatorInfo info = { request.initiatorName(), monotonicallyIncreasingTime(), NotYetAdded };
        m_initiatorMap.add(resource.get(), info);
    }
}
Esempio n. 9
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void ScriptRunner::queueScriptForExecution(ScriptElement* scriptElement, CachedResourceHandle<CachedScript> cachedScript, ExecutionType executionType)
{
    ASSERT(scriptElement);
    ASSERT(cachedScript.get());

    Element& element = scriptElement->element();
    ASSERT(element.inDocument());

    m_document.incrementLoadEventDelayCount();

    switch (executionType) {
    case ASYNC_EXECUTION:
        m_pendingAsyncScripts.add(scriptElement, PendingScript(&element, cachedScript.get()));
        break;

    case IN_ORDER_EXECUTION:
        m_scriptsToExecuteInOrder.append(PendingScript(&element, cachedScript.get()));
        break;
    }
}
Esempio n. 10
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void CachedResourceLoader::requestPreload(CachedResource::Type type, CachedResourceRequest& request, const String& charset)
{
    String encoding;
    if (type == CachedResource::Script || type == CachedResource::CSSStyleSheet)
        encoding = charset.isEmpty() ? m_document->charset() : charset;

    request.setCharset(encoding);
    request.setForPreload(true);

    CachedResourceHandle<CachedResource> resource = requestResource(type, request);
    if (!resource || (m_preloads && m_preloads->contains(resource.get())))
        return;
    resource->increasePreloadCount();

    if (!m_preloads)
        m_preloads = adoptPtr(new ListHashSet<CachedResource*>);
    m_preloads->add(resource.get());

#if PRELOAD_DEBUG
    printf("PRELOADING %s\n",  resource->url().latin1().data());
#endif
}
void AsyncScriptRunner::executeScriptSoon(ScriptElement* scriptElement, CachedResourceHandle<CachedScript> cachedScript)
{
    ASSERT_ARG(scriptElement, scriptElement);

    Element* element = scriptElement->element();
    ASSERT(element);
    ASSERT(element->inDocument());

    m_document->incrementLoadEventDelayCount();
    m_scriptsToExecuteSoon.append(PendingScript(element, cachedScript.get()));
    if (!m_timer.isActive())
        m_timer.startOneShot(0);
}
Esempio n. 12
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void ScriptRunner::queueScriptForExecution(ScriptElement* scriptElement, CachedResourceHandle<CachedScript> cachedScript, ExecutionType executionType)
{
    ASSERT(scriptElement);
    ASSERT(cachedScript.get());

    Element* element = scriptElement->element();
    ASSERT(element);
    ASSERT(element->inDocument());

    m_document->incrementLoadEventDelayCount();

    switch (executionType) {
    case ASYNC_EXECUTION:
        m_pendingAsyncScripts.add(scriptElement, PendingScript(element, cachedScript.get()));
        break;

    case IN_ORDER_EXECUTION:
        m_scriptsToExecuteInOrder.append(PendingScript(element, cachedScript.get()));
        ActionLogFormat(ActionLog::WRITE_MEMORY, "ScriptRunner-%p-%p",
        		static_cast<void*>(this), static_cast<void*>(scriptElement));
        break;
    }
}
Esempio n. 13
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CachedResourceHandle<CachedResource> CachedResourceLoader::revalidateResource(const CachedResourceRequest& request, CachedResource* resource)
{
    ASSERT(resource);
    ASSERT(resource->inCache());
    ASSERT(!memoryCache()->disabled());
    ASSERT(resource->canUseCacheValidator());
    ASSERT(!resource->resourceToRevalidate());
    
    // Copy the URL out of the resource to be revalidated in case it gets deleted by the remove() call below.
    String url = resource->url();
    CachedResourceHandle<CachedResource> newResource = createResource(resource->type(), resource->resourceRequest(), resource->encoding());
    
    LOG(ResourceLoading, "Resource %p created to revalidate %p", newResource.get(), resource);
    newResource->setResourceToRevalidate(resource);
    
    memoryCache()->remove(resource);
    memoryCache()->add(newResource.get());
#if ENABLE(RESOURCE_TIMING)
    storeResourceTimingInitiatorInformation(resource, request);
#else
    UNUSED_PARAM(request);
#endif
    return newResource;
}
Esempio n. 14
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void CSSCrossfadeValue::loadSubimages(CachedResourceLoader* cachedResourceLoader)
{
    CachedResourceHandle<CachedImage> oldCachedFromImage = m_cachedFromImage;
    CachedResourceHandle<CachedImage> oldCachedToImage = m_cachedToImage;

    m_cachedFromImage = cachedImageForCSSValue(m_fromValue.get(), cachedResourceLoader);
    m_cachedToImage = cachedImageForCSSValue(m_toValue.get(), cachedResourceLoader);

    if (m_cachedFromImage != oldCachedFromImage) {
        if (oldCachedFromImage)
            oldCachedFromImage->removeClient(&m_crossfadeSubimageObserver);
        if (m_cachedFromImage)
            m_cachedFromImage->addClient(&m_crossfadeSubimageObserver);
    }

    if (m_cachedToImage != oldCachedToImage) {
        if (oldCachedToImage)
            oldCachedToImage->removeClient(&m_crossfadeSubimageObserver);
        if (m_cachedToImage)
            m_cachedToImage->addClient(&m_crossfadeSubimageObserver);
    }

    m_crossfadeSubimageObserver.setReady(true);
}
Esempio n. 15
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void CSSCrossfadeValue::loadSubimages(CachedResourceLoader& cachedResourceLoader, const ResourceLoaderOptions& options)
{
    CachedResourceHandle<CachedImage> oldCachedFromImage = m_cachedFromImage;
    CachedResourceHandle<CachedImage> oldCachedToImage = m_cachedToImage;

    m_cachedFromImage = CSSImageGeneratorValue::cachedImageForCSSValue(m_fromValue, cachedResourceLoader, options);
    m_cachedToImage = CSSImageGeneratorValue::cachedImageForCSSValue(m_toValue, cachedResourceLoader, options);

    if (m_cachedFromImage != oldCachedFromImage) {
        if (oldCachedFromImage)
            oldCachedFromImage->removeClient(&m_crossfadeSubimageObserver);
        if (m_cachedFromImage)
            m_cachedFromImage->addClient(&m_crossfadeSubimageObserver);
    }

    if (m_cachedToImage != oldCachedToImage) {
        if (oldCachedToImage)
            oldCachedToImage->removeClient(&m_crossfadeSubimageObserver);
        if (m_cachedToImage)
            m_cachedToImage->addClient(&m_crossfadeSubimageObserver);
    }

    m_crossfadeSubimageObserver.setReady(true);
}
Esempio n. 16
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void ImageLoader::updateFromElement()
{
    // If we're not making renderers for the page, then don't load images.  We don't want to slow
    // down the raw HTML parsing case by loading images we don't intend to display.
    Document* document = m_element->document();
    if (!document->renderer())
        return;

    AtomicString attr = m_element->imageSourceURL();

    if (attr == m_failedLoadURL)
        return;

    // Do not load any image if the 'src' attribute is missing or if it is
    // an empty string.
    CachedResourceHandle<CachedImage> newImage = 0;
    if (!attr.isNull() && !stripLeadingAndTrailingHTMLSpaces(attr).isEmpty()) {
        CachedResourceRequest request(ResourceRequest(document->completeURL(sourceURI(attr))));
        request.setInitiator(element());

        String crossOriginMode = m_element->fastGetAttribute(HTMLNames::crossoriginAttr);
        if (!crossOriginMode.isNull()) {
            StoredCredentials allowCredentials = equalIgnoringCase(crossOriginMode, "use-credentials") ? AllowStoredCredentials : DoNotAllowStoredCredentials;
            updateRequestForAccessControl(request.mutableResourceRequest(), document->securityOrigin(), allowCredentials);
        }

        if (m_loadManually) {
            bool autoLoadOtherImages = document->cachedResourceLoader()->autoLoadImages();
            document->cachedResourceLoader()->setAutoLoadImages(false);
            newImage = new CachedImage(request.resourceRequest());
            newImage->setLoading(true);
            newImage->setOwningCachedResourceLoader(document->cachedResourceLoader());
            document->cachedResourceLoader()->m_documentResources.set(newImage->url(), newImage.get());
            document->cachedResourceLoader()->setAutoLoadImages(autoLoadOtherImages);
        } else
            newImage = document->cachedResourceLoader()->requestImage(request);

        // If we do not have an image here, it means that a cross-site
        // violation occurred, or that the image was blocked via Content
        // Security Policy, or the page is being dismissed. Trigger an
        // error event if the page is not being dismissed.
        if (!newImage && !pageIsBeingDismissed(document)) {
            m_failedLoadURL = attr;
            m_hasPendingErrorEvent = true;
            errorEventSender().dispatchEventSoon(this);
        } else
            clearFailedLoadURL();
    } else if (!attr.isNull()) {
        // Fire an error event if the url is empty.
        // FIXME: Should we fire this event asynchronoulsy via errorEventSender()?
        m_element->dispatchEvent(Event::create(eventNames().errorEvent, false, false));
    }
    
    CachedImage* oldImage = m_image.get();
    if (newImage != oldImage) {
        if (m_hasPendingBeforeLoadEvent) {
            beforeLoadEventSender().cancelEvent(this);
            m_hasPendingBeforeLoadEvent = false;
        }
        if (m_hasPendingLoadEvent) {
            loadEventSender().cancelEvent(this);
            m_hasPendingLoadEvent = false;
        }

        // Cancel error events that belong to the previous load, which is now cancelled by changing the src attribute.
        // If newImage is null and m_hasPendingErrorEvent is true, we know the error event has been just posted by
        // this load and we should not cancel the event.
        // FIXME: If both previous load and this one got blocked with an error, we can receive one error event instead of two.
        if (m_hasPendingErrorEvent && newImage) {
            errorEventSender().cancelEvent(this);
            m_hasPendingErrorEvent = false;
        }

        m_image = newImage;
        m_hasPendingBeforeLoadEvent = !m_element->document()->isImageDocument() && newImage;
        m_hasPendingLoadEvent = newImage;
        m_imageComplete = !newImage;

        if (newImage) {
            if (!m_element->document()->isImageDocument()) {
                if (!m_element->document()->hasListenerType(Document::BEFORELOAD_LISTENER))
                    dispatchPendingBeforeLoadEvent();
                else
                    beforeLoadEventSender().dispatchEventSoon(this);
            } else
                updateRenderer();

            // If newImage is cached, addClient() will result in the load event
            // being queued to fire. Ensure this happens after beforeload is
            // dispatched.
            newImage->addClient(this);
        }
        if (oldImage)
            oldImage->removeClient(this);
    }

    if (RenderImageResource* imageResource = renderImageResource())
        imageResource->resetAnimation();

    // Only consider updating the protection ref-count of the Element immediately before returning
    // from this function as doing so might result in the destruction of this ImageLoader.
    updatedHasPendingEvent();
}
Esempio n. 17
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void DragImageLoader::stopLoading(CachedResourceHandle<WebCore::CachedImage>& image)
{
    image->removeClient(this);
}
Esempio n. 18
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void DragImageLoader::startLoading(CachedResourceHandle<WebCore::CachedImage>& image)
{
    // FIXME: Does this really trigger a load? Does it need to?
    image->addClient(this);
}
Esempio n. 19
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void MemoryCache::pruneDeadResourcesToSize(unsigned targetSize)
{
    if (m_inPruneResources)
        return;
    TemporaryChange<bool> reentrancyProtector(m_inPruneResources, true);
 
    if (targetSize && m_deadSize <= targetSize)
        return;

    bool canShrinkLRULists = true;
    for (int i = m_allResources.size() - 1; i >= 0; i--) {
        LRUList& list = *m_allResources[i];

        // First flush all the decoded data in this queue.
        // Remove from the head, since this is the least frequently accessed of the objects.
        auto it = list.begin();
        while (it != list.end()) {
            CachedResource& current = **it;

            // Increment the iterator now as the call to destroyDecodedData() below may
            // invalidate the current iterator.
            ++it;

            // Protect 'next' so it can't get deleted during destroyDecodedData().
            CachedResourceHandle<CachedResource> next = it != list.end() ? *it : nullptr;
            ASSERT(!next || next->inCache());
            if (!current.hasClients() && !current.isPreloaded() && current.isLoaded()) {
                // Destroy our decoded data. This will remove us from 
                // m_liveDecodedResources, and possibly move us to a different 
                // LRU list in m_allResources.
                current.destroyDecodedData();

                if (targetSize && m_deadSize <= targetSize)
                    return;
            }
            // Decoded data may reference other resources. Stop iterating if 'next' somehow got
            // kicked out of cache during destroyDecodedData().
            if (next && !next->inCache())
                break;
        }

        // Now evict objects from this list.
        // Remove from the head, since this is the least frequently accessed of the objects.
        it = list.begin();
        while (it != list.end()) {
            CachedResource& current = **it;

            // Increment the iterator now as the call to remove() below will
            // invalidate the current iterator.
            ++it;

            CachedResourceHandle<CachedResource> next = it != list.end() ? *it : nullptr;
            ASSERT(!next || next->inCache());
            if (!current.hasClients() && !current.isPreloaded() && !current.isCacheValidator()) {
                remove(current);
                if (targetSize && m_deadSize <= targetSize)
                    return;
            }
            if (next && !next->inCache())
                break;
        }
            
        // Shrink the vector back down so we don't waste time inspecting
        // empty LRU lists on future prunes.
        if (!m_allResources[i]->isEmpty())
            canShrinkLRULists = false;
        else if (canShrinkLRULists)
            m_allResources.shrink(i);
    }
}
Esempio n. 20
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CachedResourceHandle<CachedResource> CachedResourceLoader::requestResource(CachedResource::Type type, CachedResourceRequest& request)
{
    KURL url = request.resourceRequest().url();
    
    LOG(ResourceLoading, "CachedResourceLoader::requestResource '%s', charset '%s', priority=%d, forPreload=%u", url.elidedString().latin1().data(), request.charset().latin1().data(), request.priority(), request.forPreload());
    
    // If only the fragment identifiers differ, it is the same resource.
    url = MemoryCache::removeFragmentIdentifierIfNeeded(url);

    if (!url.isValid())
        return 0;

    if (!canRequest(type, url, request.forPreload()))
        return 0;

    if (Frame* f = frame())
        f->loader()->client()->dispatchWillRequestResource(&request);

    if (memoryCache()->disabled()) {
        DocumentResourceMap::iterator it = m_documentResources.find(url.string());
        if (it != m_documentResources.end()) {
            it->value->setOwningCachedResourceLoader(0);
            m_documentResources.remove(it);
        }
    }

    // See if we can use an existing resource from the cache.
    CachedResourceHandle<CachedResource> resource;
#if ENABLE(CACHE_PARTITIONING)
    if (document())
        request.mutableResourceRequest().setCachePartition(document()->topOrigin()->cachePartition());
#endif

    resource = memoryCache()->resourceForRequest(request.resourceRequest());

    const RevalidationPolicy policy = determineRevalidationPolicy(type, request.mutableResourceRequest(), request.forPreload(), resource.get(), request.defer());
    switch (policy) {
    case Reload:
        memoryCache()->remove(resource.get());
        // Fall through
    case Load:
        resource = loadResource(type, request, request.charset());
        break;
    case Revalidate:
        resource = revalidateResource(request, resource.get());
        break;
    case Use:
        memoryCache()->resourceAccessed(resource.get());
        notifyLoadedFromMemoryCache(resource.get());
        break;
    }

    if (!resource)
        return 0;

    if (!request.forPreload() || policy != Use)
        resource->setLoadPriority(request.priority());

    if ((policy != Use || resource->stillNeedsLoad()) && CachedResourceRequest::NoDefer == request.defer()) {
        resource->load(this, request.options());

        // We don't support immediate loads, but we do support immediate failure.
        if (resource->errorOccurred()) {
            if (resource->inCache())
                memoryCache()->remove(resource.get());
            return 0;
        }
    }

#if PLATFORM(CHROMIUM)
    // FIXME: Temporarily leave main resource caching disabled for chromium, see https://bugs.webkit.org/show_bug.cgi?id=107962
    // Ensure main resources aren't preloaded, and other main resource loads are removed from cache to prevent reuse.
    if (type == CachedResource::MainResource) {
        ASSERT(policy != Use);
        ASSERT(policy != Revalidate);
        memoryCache()->remove(resource.get());
        if (request.forPreload())
            return 0;
    }
#endif

    if (!request.resourceRequest().url().protocolIsData())
        m_validatedURLs.add(request.resourceRequest().url());

    ASSERT(resource->url() == url.string());
    m_documentResources.set(resource->url(), resource);
    return resource;
}
Esempio n. 21
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void MemoryCache::pruneDeadResourcesToSize(unsigned targetSize)
{
    if (m_inPruneResources)
        return;
    TemporaryChange<bool> reentrancyProtector(m_inPruneResources, true);

    int size = m_allResources.size();
 
    // See if we have any purged resources we can evict.
    for (int i = 0; i < size; i++) {
        CachedResource* current = m_allResources[i].m_tail;
        while (current) {
            CachedResource* prev = current->m_prevInAllResourcesList;
            if (current->wasPurged()) {
                ASSERT(!current->hasClients());
                ASSERT(!current->isPreloaded());
                evict(current);
            }
            current = prev;
        }
    }
    if (targetSize && m_deadSize <= targetSize)
        return;

    bool canShrinkLRULists = true;
    for (int i = size - 1; i >= 0; i--) {
        // Remove from the tail, since this is the least frequently accessed of the objects.
        CachedResource* current = m_allResources[i].m_tail;
        
        // First flush all the decoded data in this queue.
        while (current) {
            // Protect 'previous' so it can't get deleted during destroyDecodedData().
            CachedResourceHandle<CachedResource> previous = current->m_prevInAllResourcesList;
            ASSERT(!previous || previous->inCache());
            if (!current->hasClients() && !current->isPreloaded() && current->isLoaded()) {
                // Destroy our decoded data. This will remove us from 
                // m_liveDecodedResources, and possibly move us to a different 
                // LRU list in m_allResources.
                current->destroyDecodedData();

                if (targetSize && m_deadSize <= targetSize)
                    return;
            }
            // Decoded data may reference other resources. Stop iterating if 'previous' somehow got
            // kicked out of cache during destroyDecodedData().
            if (previous && !previous->inCache())
                break;
            current = previous.get();
        }

        // Now evict objects from this queue.
        current = m_allResources[i].m_tail;
        while (current) {
            CachedResourceHandle<CachedResource> previous = current->m_prevInAllResourcesList;
            ASSERT(!previous || previous->inCache());
            if (!current->hasClients() && !current->isPreloaded() && !current->isCacheValidator()) {
                if (!makeResourcePurgeable(current))
                    evict(current);

                if (targetSize && m_deadSize <= targetSize)
                    return;
            }
            if (previous && !previous->inCache())
                break;
            current = previous.get();
        }
            
        // Shrink the vector back down so we don't waste time inspecting
        // empty LRU lists on future prunes.
        if (m_allResources[i].m_head)
            canShrinkLRULists = false;
        else if (canShrinkLRULists)
            m_allResources.resize(i);
    }
}