Merge WebKit at r71558: Initial merge by git.

Change-Id: Ib345578fa29df7e4bc72b4f00e4a6fddcb754c4c

1 files changed, 565 insertions, 0 deletions

diff --git a/WebCore/loader/cache/CachedResource.cpp b/WebCore/loader/cache/CachedResource.cpp
new file mode 100644
index 0000000..c440ec9
--- /dev/null
+++ b/WebCore/loader/cache/CachedResource.cpp
@@ -0,0 +1,565 @@
+/*
+    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 "Frame.h"
+#include "FrameLoaderClient.h"
+#include "KURL.h"
+#include "Logging.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_cachedResourceLoader(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_cachedResourceLoader)
+        m_cachedResourceLoader->removeCachedResource(this);
+}
+
+void CachedResource::load(CachedResourceLoader* cachedResourceLoader, bool incremental, SecurityCheckPolicy securityCheck, bool sendResourceLoadCallbacks)
+{
+    m_sendResourceLoadCallbacks = sendResourceLoadCallbacks;
+    cache()->loader()->load(cachedResourceLoader, 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());
+
+    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<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);
+    }
+}
+
+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 || 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) {
+        LOG(ResourceLoading, "CachedResource %p mustRevalidate because of m_errorOccurred\n", this);
+        return true;
+    }
+
+    if (m_loading)
+        return false;
+    
+    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;
+    }
+
+    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
+    */
+}
+
+}