--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/loader/CachedResource.cpp Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,531 @@
+/*
+ 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 "Cache.h"
+#include "CachedMetadata.h"
+#include "CachedResourceClient.h"
+#include "CachedResourceClientWalker.h"
+#include "CachedResourceHandle.h"
+#include "DocLoader.h"
+#include "Frame.h"
+#include "FrameLoaderClient.h"
+#include "KURL.h"
+#include "PurgeableBuffer.h"
+#include "Request.h"
+#include "ResourceHandle.h"
+#include "SharedBuffer.h"
+#include <wtf/CurrentTime.h>
+#include <wtf/MathExtras.h>
+#include <wtf/RefCountedLeakCounter.h>
+#include <wtf/StdLibExtras.h>
+#include <wtf/Vector.h>
+
+using namespace WTF;
+
+namespace WebCore {
+
+#ifndef NDEBUG
+static RefCountedLeakCounter cachedResourceLeakCounter("CachedResource");
+#endif
+
+CachedResource::CachedResource(const String& url, Type type)
+ : m_url(url)
+ , m_request(0)
+ , 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_errorOccurred(false)
+ , 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_docLoader(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() || cache()->resourceForURL(url()) != this);
+#ifndef NDEBUG
+ m_deleted = true;
+ cachedResourceLeakCounter.decrement();
+#endif
+
+ if (m_docLoader)
+ m_docLoader->removeCachedResource(this);
+}
+
+void CachedResource::load(DocLoader* docLoader, bool incremental, SecurityCheckPolicy securityCheck, bool sendResourceLoadCallbacks)
+{
+ m_sendResourceLoadCallbacks = sendResourceLoadCallbacks;
+ cache()->loader()->load(docLoader, this, incremental, securityCheck, sendResourceLoadCallbacks);
+ m_loading = true;
+}
+
+void CachedResource::data(PassRefPtr<SharedBuffer>, bool allDataReceived)
+{
+ if (!allDataReceived)
+ return;
+
+ CachedResourceClientWalker w(m_clients);
+ while (CachedResourceClient* c = w.next())
+ c->notifyFinished(this);
+}
+
+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<double>::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(Request* 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())
+ 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())
+ cache()->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()) {
+ cache()->removeFromLiveResourcesSize(this);
+ cache()->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"
+ cache()->remove(this);
+ } else
+ cache()->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())
+ cache()->removeFromLRUList(this);
+
+ m_decodedSize = size;
+
+ if (inCache()) {
+ // Now insert into the new LRU list.
+ cache()->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())
+ cache()->insertInLiveDecodedResourcesList(this);
+ else if (!m_decodedSize && m_inLiveDecodedResourcesList)
+ cache()->removeFromLiveDecodedResourcesList(this);
+
+ // Update the cache's size totals.
+ cache()->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())
+ cache()->removeFromLRUList(this);
+
+ m_encodedSize = size;
+
+ if (inCache()) {
+ // Now insert into the new LRU list.
+ cache()->insertInLRUList(this);
+
+ // Update the cache's size totals.
+ cache()->adjustSize(hasClients(), delta);
+ }
+}
+
+void CachedResource::didAccessDecodedData(double timeStamp)
+{
+ m_lastDecodedAccessTime = timeStamp;
+
+ if (inCache()) {
+ if (m_inLiveDecodedResourcesList) {
+ cache()->removeFromLiveDecodedResourcesList(this);
+ cache()->insertInLiveDecodedResourcesList(this);
+ }
+ cache()->prune();
+ }
+}
+
+void CachedResource::setResourceToRevalidate(CachedResource* resource)
+{
+ ASSERT(resource);
+ ASSERT(!m_resourceToRevalidate);
+ ASSERT(resource != this);
+ ASSERT(m_handlesToRevalidate.isEmpty());
+ ASSERT(resource->type() == type());
+
+ // 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());
+
+ HashSet<CachedResourceHandleBase*>::iterator end = m_handlesToRevalidate.end();
+ for (HashSet<CachedResourceHandleBase*>::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<CachedResourceClient*> clientsToMove;
+ HashCountedSet<CachedResourceClient*>::iterator end2 = m_clients.end();
+ for (HashCountedSet<CachedResourceClient*>::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);
+ }
+}
+
+bool CachedResource::canUseCacheValidator() const
+{
+ if (m_loading || m_errorOccurred)
+ return false;
+
+ if (m_response.cacheControlContainsNoStore())
+ return false;
+
+ DEFINE_STATIC_LOCAL(const AtomicString, lastModifiedHeader, ("last-modified"));
+ DEFINE_STATIC_LOCAL(const AtomicString, eTagHeader, ("etag"));
+ return !m_response.httpHeaderField(lastModifiedHeader).isEmpty() || !m_response.httpHeaderField(eTagHeader).isEmpty();
+}
+
+bool CachedResource::mustRevalidate(CachePolicy cachePolicy) const
+{
+ if (m_errorOccurred)
+ return true;
+
+ if (m_loading)
+ return false;
+
+ if (m_response.cacheControlContainsNoCache() || m_response.cacheControlContainsNoStore())
+ return true;
+
+ if (cachePolicy == CachePolicyCache)
+ return m_response.cacheControlContainsMustRevalidate() && isExpired();
+
+ return isExpired();
+}
+
+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;
+
+ // Purgeable buffers are allocated in multiples of the page size (4KB in common CPUs) so it does not make sense for very small buffers.
+ const size_t purgeableThreshold = 4 * 4096;
+ if (m_data->size() < purgeableThreshold)
+ 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->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
+ */
+}
+
+}