Exemplo n.º 1
0
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);
    }
}
Exemplo n.º 2
0
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);
    }
}
Exemplo n.º 3
0
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;
}