/* Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de) Copyright (C) 2001 Dirk Mueller (mueller@kde.org) Copyright (C) 2002 Waldo Bastian (bastian@kde.org) Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com) Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved. This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #include "config.h" #include "CachedResource.h" #include "MemoryCache.h" #include "CachedMetadata.h" #include "CachedResourceClient.h" #include "CachedResourceClientWalker.h" #include "CachedResourceHandle.h" #include "CachedResourceLoader.h" #include "CachedResourceRequest.h" #include "Frame.h" #include "FrameLoaderClient.h" #include "KURL.h" #include "Logging.h" #include "PurgeableBuffer.h" #include "ResourceHandle.h" #include "SharedBuffer.h" #include #include #include #include #include using namespace WTF; namespace WebCore { static ResourceLoadPriority defaultPriorityForResourceType(CachedResource::Type type) { switch (type) { case CachedResource::CSSStyleSheet: #if ENABLE(XSLT) case CachedResource::XSLStyleSheet: #endif return ResourceLoadPriorityHigh; case CachedResource::Script: case CachedResource::FontResource: return ResourceLoadPriorityMedium; case CachedResource::ImageResource: return ResourceLoadPriorityLow; #if ENABLE(LINK_PREFETCH) case CachedResource::LinkResource: return ResourceLoadPriorityVeryLow; #endif } ASSERT_NOT_REACHED(); return ResourceLoadPriorityLow; } #ifndef NDEBUG static RefCountedLeakCounter cachedResourceLeakCounter("CachedResource"); #endif CachedResource::CachedResource(const String& url, Type type) : m_url(url) , m_request(0) , m_loadPriority(defaultPriorityForResourceType(type)) , m_responseTimestamp(currentTime()) , m_lastDecodedAccessTime(0) , m_encodedSize(0) , m_decodedSize(0) , m_accessCount(0) , m_handleCount(0) , m_preloadCount(0) , m_preloadResult(PreloadNotReferenced) , m_inLiveDecodedResourcesList(false) , m_requestedFromNetworkingLayer(false) , m_sendResourceLoadCallbacks(true) , m_inCache(false) , m_loading(false) , m_type(type) , m_status(Pending) #ifndef NDEBUG , m_deleted(false) , m_lruIndex(0) #endif , m_nextInAllResourcesList(0) , m_prevInAllResourcesList(0) , m_nextInLiveResourcesList(0) , m_prevInLiveResourcesList(0) , m_owningCachedResourceLoader(0) , m_resourceToRevalidate(0) , m_proxyResource(0) { #ifndef NDEBUG cachedResourceLeakCounter.increment(); #endif } CachedResource::~CachedResource() { ASSERT(!m_resourceToRevalidate); // Should be true because canDelete() checks this. ASSERT(canDelete()); ASSERT(!inCache()); ASSERT(!m_deleted); ASSERT(url().isNull() || memoryCache()->resourceForURL(KURL(ParsedURLString, url())) != this); #ifndef NDEBUG m_deleted = true; cachedResourceLeakCounter.decrement(); #endif if (m_owningCachedResourceLoader) m_owningCachedResourceLoader->removeCachedResource(this); } void CachedResource::load(CachedResourceLoader* cachedResourceLoader, bool incremental, SecurityCheckPolicy securityCheck, bool sendResourceLoadCallbacks) { m_sendResourceLoadCallbacks = sendResourceLoadCallbacks; cachedResourceLoader->load(this, incremental, securityCheck, sendResourceLoadCallbacks); m_loading = true; } void CachedResource::checkNotify() { if (isLoading()) return; CachedResourceClientWalker w(m_clients); while (CachedResourceClient* c = w.next()) c->notifyFinished(this); } void CachedResource::data(PassRefPtr, bool allDataReceived) { if (!allDataReceived) return; setLoading(false); checkNotify(); } void CachedResource::error(CachedResource::Status status) { setStatus(status); ASSERT(errorOccurred()); m_data.clear(); setLoading(false); checkNotify(); } void CachedResource::finish() { m_status = Cached; } bool CachedResource::isExpired() const { if (m_response.isNull()) return false; return currentAge() > freshnessLifetime(); } double CachedResource::currentAge() const { // RFC2616 13.2.3 // No compensation for latency as that is not terribly important in practice double dateValue = m_response.date(); double apparentAge = isfinite(dateValue) ? max(0., m_responseTimestamp - dateValue) : 0; double ageValue = m_response.age(); double correctedReceivedAge = isfinite(ageValue) ? max(apparentAge, ageValue) : apparentAge; double residentTime = currentTime() - m_responseTimestamp; return correctedReceivedAge + residentTime; } double CachedResource::freshnessLifetime() const { // Cache non-http resources liberally if (!m_response.url().protocolInHTTPFamily()) return std::numeric_limits::max(); // RFC2616 13.2.4 double maxAgeValue = m_response.cacheControlMaxAge(); if (isfinite(maxAgeValue)) return maxAgeValue; double expiresValue = m_response.expires(); double dateValue = m_response.date(); double creationTime = isfinite(dateValue) ? dateValue : m_responseTimestamp; if (isfinite(expiresValue)) return expiresValue - creationTime; double lastModifiedValue = m_response.lastModified(); if (isfinite(lastModifiedValue)) return (creationTime - lastModifiedValue) * 0.1; // If no cache headers are present, the specification leaves the decision to the UA. Other browsers seem to opt for 0. return 0; } void CachedResource::setResponse(const ResourceResponse& response) { m_response = response; m_responseTimestamp = currentTime(); } void CachedResource::setSerializedCachedMetadata(const char* data, size_t size) { // We only expect to receive cached metadata from the platform once. // If this triggers, it indicates an efficiency problem which is most // likely unexpected in code designed to improve performance. ASSERT(!m_cachedMetadata); m_cachedMetadata = CachedMetadata::deserialize(data, size); } void CachedResource::setCachedMetadata(unsigned dataTypeID, const char* data, size_t size) { // Currently, only one type of cached metadata per resource is supported. // If the need arises for multiple types of metadata per resource this could // be enhanced to store types of metadata in a map. ASSERT(!m_cachedMetadata); m_cachedMetadata = CachedMetadata::create(dataTypeID, data, size); ResourceHandle::cacheMetadata(m_response, m_cachedMetadata->serialize()); } CachedMetadata* CachedResource::cachedMetadata(unsigned dataTypeID) const { if (!m_cachedMetadata || m_cachedMetadata->dataTypeID() != dataTypeID) return 0; return m_cachedMetadata.get(); } void CachedResource::setRequest(CachedResourceRequest* request) { if (request && !m_request) m_status = Pending; m_request = request; if (canDelete() && !inCache()) delete this; } void CachedResource::addClient(CachedResourceClient* client) { addClientToSet(client); didAddClient(client); } void CachedResource::didAddClient(CachedResourceClient* c) { if (!isLoading() && !stillNeedsLoad()) c->notifyFinished(this); } void CachedResource::addClientToSet(CachedResourceClient* client) { ASSERT(!isPurgeable()); if (m_preloadResult == PreloadNotReferenced) { if (isLoaded()) m_preloadResult = PreloadReferencedWhileComplete; else if (m_requestedFromNetworkingLayer) m_preloadResult = PreloadReferencedWhileLoading; else m_preloadResult = PreloadReferenced; } if (!hasClients() && inCache()) memoryCache()->addToLiveResourcesSize(this); m_clients.add(client); } void CachedResource::removeClient(CachedResourceClient* client) { ASSERT(m_clients.contains(client)); m_clients.remove(client); if (canDelete() && !inCache()) delete this; else if (!hasClients() && inCache()) { memoryCache()->removeFromLiveResourcesSize(this); memoryCache()->removeFromLiveDecodedResourcesList(this); allClientsRemoved(); if (response().cacheControlContainsNoStore()) { // RFC2616 14.9.2: // "no-store: ... MUST make a best-effort attempt to remove the information from volatile storage as promptly as possible" // "... History buffers MAY store such responses as part of their normal operation." // We allow non-secure content to be reused in history, but we do not allow secure content to be reused. if (protocolIs(url(), "https")) memoryCache()->remove(this); } else memoryCache()->prune(); } // This object may be dead here. } void CachedResource::deleteIfPossible() { if (canDelete() && !inCache()) delete this; } void CachedResource::setDecodedSize(unsigned size) { if (size == m_decodedSize) return; int delta = size - m_decodedSize; // The object must now be moved to a different queue, since its size has been changed. // We have to remove explicitly before updating m_decodedSize, so that we find the correct previous // queue. if (inCache()) memoryCache()->removeFromLRUList(this); m_decodedSize = size; if (inCache()) { // Now insert into the new LRU list. memoryCache()->insertInLRUList(this); // Insert into or remove from the live decoded list if necessary. // When inserting into the LiveDecodedResourcesList it is possible // that the m_lastDecodedAccessTime is still zero or smaller than // the m_lastDecodedAccessTime of the current list head. This is a // violation of the invariant that the list is to be kept sorted // by access time. The weakening of the invariant does not pose // a problem. For more details please see: https://bugs.webkit.org/show_bug.cgi?id=30209 if (m_decodedSize && !m_inLiveDecodedResourcesList && hasClients()) memoryCache()->insertInLiveDecodedResourcesList(this); else if (!m_decodedSize && m_inLiveDecodedResourcesList) memoryCache()->removeFromLiveDecodedResourcesList(this); // Update the cache's size totals. memoryCache()->adjustSize(hasClients(), delta); } } void CachedResource::setEncodedSize(unsigned size) { if (size == m_encodedSize) return; // The size cannot ever shrink (unless it is being nulled out because of an error). If it ever does, assert. ASSERT(size == 0 || size >= m_encodedSize); int delta = size - m_encodedSize; // The object must now be moved to a different queue, since its size has been changed. // We have to remove explicitly before updating m_encodedSize, so that we find the correct previous // queue. if (inCache()) memoryCache()->removeFromLRUList(this); m_encodedSize = size; if (inCache()) { // Now insert into the new LRU list. memoryCache()->insertInLRUList(this); // Update the cache's size totals. memoryCache()->adjustSize(hasClients(), delta); } } void CachedResource::didAccessDecodedData(double timeStamp) { m_lastDecodedAccessTime = timeStamp; if (inCache()) { if (m_inLiveDecodedResourcesList) { memoryCache()->removeFromLiveDecodedResourcesList(this); memoryCache()->insertInLiveDecodedResourcesList(this); } memoryCache()->prune(); } } void CachedResource::setResourceToRevalidate(CachedResource* resource) { ASSERT(resource); ASSERT(!m_resourceToRevalidate); ASSERT(resource != this); ASSERT(m_handlesToRevalidate.isEmpty()); ASSERT(resource->type() == type()); LOG(ResourceLoading, "CachedResource %p setResourceToRevalidate %p", this, resource); // The following assert should be investigated whenever it occurs. Although it should never fire, it currently does in rare circumstances. // https://bugs.webkit.org/show_bug.cgi?id=28604. // So the code needs to be robust to this assert failing thus the "if (m_resourceToRevalidate->m_proxyResource == this)" in CachedResource::clearResourceToRevalidate. ASSERT(!resource->m_proxyResource); resource->m_proxyResource = this; m_resourceToRevalidate = resource; } void CachedResource::clearResourceToRevalidate() { ASSERT(m_resourceToRevalidate); // A resource may start revalidation before this method has been called, so check that this resource is still the proxy resource before clearing it out. if (m_resourceToRevalidate->m_proxyResource == this) { m_resourceToRevalidate->m_proxyResource = 0; m_resourceToRevalidate->deleteIfPossible(); } m_handlesToRevalidate.clear(); m_resourceToRevalidate = 0; deleteIfPossible(); } void CachedResource::switchClientsToRevalidatedResource() { ASSERT(m_resourceToRevalidate); ASSERT(m_resourceToRevalidate->inCache()); ASSERT(!inCache()); LOG(ResourceLoading, "CachedResource %p switchClientsToRevalidatedResource %p", this, m_resourceToRevalidate); HashSet::iterator end = m_handlesToRevalidate.end(); for (HashSet::iterator it = m_handlesToRevalidate.begin(); it != end; ++it) { CachedResourceHandleBase* handle = *it; handle->m_resource = m_resourceToRevalidate; m_resourceToRevalidate->registerHandle(handle); --m_handleCount; } ASSERT(!m_handleCount); m_handlesToRevalidate.clear(); Vector clientsToMove; HashCountedSet::iterator end2 = m_clients.end(); for (HashCountedSet::iterator it = m_clients.begin(); it != end2; ++it) { CachedResourceClient* client = it->first; unsigned count = it->second; while (count) { clientsToMove.append(client); --count; } } // Equivalent of calling removeClient() for all clients m_clients.clear(); unsigned moveCount = clientsToMove.size(); for (unsigned n = 0; n < moveCount; ++n) m_resourceToRevalidate->addClientToSet(clientsToMove[n]); for (unsigned n = 0; n < moveCount; ++n) { // Calling didAddClient for a client may end up removing another client. In that case it won't be in the set anymore. if (m_resourceToRevalidate->m_clients.contains(clientsToMove[n])) m_resourceToRevalidate->didAddClient(clientsToMove[n]); } } void CachedResource::updateResponseAfterRevalidation(const ResourceResponse& validatingResponse) { m_responseTimestamp = currentTime(); DEFINE_STATIC_LOCAL(const AtomicString, contentHeaderPrefix, ("content-")); // RFC2616 10.3.5 // Update cached headers from the 304 response const HTTPHeaderMap& newHeaders = validatingResponse.httpHeaderFields(); HTTPHeaderMap::const_iterator end = newHeaders.end(); for (HTTPHeaderMap::const_iterator it = newHeaders.begin(); it != end; ++it) { // Don't allow 304 response to update content headers, these can't change but some servers send wrong values. if (it->first.startsWith(contentHeaderPrefix, false)) continue; m_response.setHTTPHeaderField(it->first, it->second); } } void CachedResource::registerHandle(CachedResourceHandleBase* h) { ++m_handleCount; if (m_resourceToRevalidate) m_handlesToRevalidate.add(h); } void CachedResource::unregisterHandle(CachedResourceHandleBase* h) { ASSERT(m_handleCount > 0); --m_handleCount; if (m_resourceToRevalidate) m_handlesToRevalidate.remove(h); if (!m_handleCount) deleteIfPossible(); } bool CachedResource::canUseCacheValidator() const { if (m_loading || errorOccurred()) return false; if (m_response.cacheControlContainsNoStore()) return false; return m_response.hasCacheValidatorFields(); } bool CachedResource::mustRevalidateDueToCacheHeaders(CachePolicy cachePolicy) const { ASSERT(cachePolicy == CachePolicyRevalidate || cachePolicy == CachePolicyCache || cachePolicy == CachePolicyVerify); if (cachePolicy == CachePolicyRevalidate) return true; if (m_response.cacheControlContainsNoCache() || m_response.cacheControlContainsNoStore()) { LOG(ResourceLoading, "CachedResource %p mustRevalidate because of m_response.cacheControlContainsNoCache() || m_response.cacheControlContainsNoStore()\n", this); return true; } if (cachePolicy == CachePolicyCache) { if (m_response.cacheControlContainsMustRevalidate() && isExpired()) { LOG(ResourceLoading, "CachedResource %p mustRevalidate because of cachePolicy == CachePolicyCache and m_response.cacheControlContainsMustRevalidate() && isExpired()\n", this); return true; } return false; } // CachePolicyVerify if (isExpired()) { LOG(ResourceLoading, "CachedResource %p mustRevalidate because of isExpired()\n", this); return true; } return false; } bool CachedResource::isSafeToMakePurgeable() const { return !hasClients() && !m_proxyResource && !m_resourceToRevalidate; } bool CachedResource::makePurgeable(bool purgeable) { if (purgeable) { ASSERT(isSafeToMakePurgeable()); if (m_purgeableData) { ASSERT(!m_data); return true; } if (!m_data) return false; // Should not make buffer purgeable if it has refs other than this since we don't want two copies. if (!m_data->hasOneRef()) return false; if (m_data->hasPurgeableBuffer()) { m_purgeableData = m_data->releasePurgeableBuffer(); } else { m_purgeableData = PurgeableBuffer::create(m_data->data(), m_data->size()); if (!m_purgeableData) return false; m_purgeableData->setPurgePriority(purgePriority()); } m_purgeableData->makePurgeable(true); m_data.clear(); return true; } if (!m_purgeableData) return true; ASSERT(!m_data); ASSERT(!hasClients()); if (!m_purgeableData->makePurgeable(false)) return false; m_data = SharedBuffer::adoptPurgeableBuffer(m_purgeableData.release()); return true; } bool CachedResource::isPurgeable() const { return m_purgeableData && m_purgeableData->isPurgeable(); } bool CachedResource::wasPurged() const { return m_purgeableData && m_purgeableData->wasPurged(); } unsigned CachedResource::overheadSize() const { return sizeof(CachedResource) + m_response.memoryUsage() + 576; /* 576 = 192 + // average size of m_url 384; // average size of m_clients hash map */ } void CachedResource::setLoadPriority(ResourceLoadPriority loadPriority) { if (loadPriority == ResourceLoadPriorityUnresolved) return; m_loadPriority = loadPriority; } }