diff -r 000000000000 -r 4f2f89ce4247 WebCore/loader/CachedResource.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/WebCore/loader/CachedResource.h Fri Sep 17 09:02:29 2010 +0300 @@ -0,0 +1,292 @@ +/* + Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de) + Copyright (C) 2001 Dirk Mueller + Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com) + Copyright (C) 2004, 2005, 2006, 2007 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. +*/ + +#ifndef CachedResource_h +#define CachedResource_h + +#include "CachePolicy.h" +#include "FrameLoaderTypes.h" +#include "PlatformString.h" +#include "ResourceResponse.h" +#include +#include +#include +#include +#include + +namespace WebCore { + +class Cache; +class CachedMetadata; +class CachedResourceClient; +class CachedResourceHandleBase; +class DocLoader; +class Frame; +class InspectorResource; +class Request; +class PurgeableBuffer; + +// A resource that is held in the cache. Classes who want to use this object should derive +// from CachedResourceClient, to get the function calls in case the requested data has arrived. +// This class also does the actual communication with the loader to obtain the resource from the network. +class CachedResource : public Noncopyable { + friend class Cache; + friend class InspectorResource; + +public: + enum Type { + ImageResource, + CSSStyleSheet, + Script, + FontResource +#if ENABLE(XSLT) + , XSLStyleSheet +#endif +#if ENABLE(XBL) + , XBL +#endif +#if ENABLE(LINK_PREFETCH) + , LinkPrefetch +#endif + }; + + enum Status { + NotCached, // this URL is not cached + Unknown, // let cache decide what to do with it + New, // inserting new item + Pending, // only partially loaded + Cached // regular case + }; + + CachedResource(const String& url, Type); + virtual ~CachedResource(); + + virtual void load(DocLoader* docLoader) { load(docLoader, false, DoSecurityCheck, true); } + void load(DocLoader*, bool incremental, SecurityCheckPolicy, bool sendResourceLoadCallbacks); + + virtual void setEncoding(const String&) { } + virtual String encoding() const { return String(); } + virtual void data(PassRefPtr data, bool allDataReceived); + virtual void error() { } + virtual void httpStatusCodeError() { error(); } // Images keep loading in spite of HTTP errors (for legacy compat with , etc.). + + const String &url() const { return m_url; } + Type type() const { return static_cast(m_type); } + + void addClient(CachedResourceClient*); + void removeClient(CachedResourceClient*); + bool hasClients() const { return !m_clients.isEmpty(); } + void deleteIfPossible(); + + enum PreloadResult { + PreloadNotReferenced, + PreloadReferenced, + PreloadReferencedWhileLoading, + PreloadReferencedWhileComplete + }; + PreloadResult preloadResult() const { return static_cast(m_preloadResult); } + void setRequestedFromNetworkingLayer() { m_requestedFromNetworkingLayer = true; } + + virtual void didAddClient(CachedResourceClient*); + virtual void allClientsRemoved() { } + + unsigned count() const { return m_clients.size(); } + + Status status() const { return static_cast(m_status); } + void setStatus(Status status) { m_status = status; } + + unsigned size() const { return encodedSize() + decodedSize() + overheadSize(); } + unsigned encodedSize() const { return m_encodedSize; } + unsigned decodedSize() const { return m_decodedSize; } + unsigned overheadSize() const; + + bool isLoaded() const { return !m_loading; } // FIXME. Method name is inaccurate. Loading might not have started yet. + + bool isLoading() const { return m_loading; } + void setLoading(bool b) { m_loading = b; } + + virtual bool isImage() const { return false; } + bool isPrefetch() const + { +#if ENABLE(LINK_PREFETCH) + return type() == LinkPrefetch; +#else + return false; +#endif + } + + unsigned accessCount() const { return m_accessCount; } + void increaseAccessCount() { m_accessCount++; } + + // Computes the status of an object after loading. + // Updates the expire date on the cache entry file + void finish(); + + // Called by the cache if the object has been removed from the cache + // while still being referenced. This means the object should delete itself + // if the number of clients observing it ever drops to 0. + // The resource can be brought back to cache after successful revalidation. + void setInCache(bool inCache) { m_inCache = inCache; } + bool inCache() const { return m_inCache; } + + void setInLiveDecodedResourcesList(bool b) { m_inLiveDecodedResourcesList = b; } + bool inLiveDecodedResourcesList() { return m_inLiveDecodedResourcesList; } + + void setRequest(Request*); + + SharedBuffer* data() const { ASSERT(!m_purgeableData); return m_data.get(); } + + void setResponse(const ResourceResponse&); + const ResourceResponse& response() const { return m_response; } + + // Sets the serialized metadata retrieved from the platform's cache. + void setSerializedCachedMetadata(const char*, size_t); + + // Caches the given metadata in association with this resource and suggests + // that the platform persist it. The dataTypeID is a pseudo-randomly chosen + // identifier that is used to distinguish data generated by the caller. + void setCachedMetadata(unsigned dataTypeID, const char*, size_t); + + // Returns cached metadata of the given type associated with this resource. + CachedMetadata* cachedMetadata(unsigned dataTypeID) const; + + bool canDelete() const { return !hasClients() && !m_request && !m_preloadCount && !m_handleCount && !m_resourceToRevalidate && !m_proxyResource; } + + bool isExpired() const; + + // List of acceptable MIME types separated by ",". + // A MIME type may contain a wildcard, e.g. "text/*". + String accept() const { return m_accept; } + void setAccept(const String& accept) { m_accept = accept; } + + bool errorOccurred() const { return m_errorOccurred; } + void setErrorOccurred(bool b) { m_errorOccurred = b; } + + bool sendResourceLoadCallbacks() const { return m_sendResourceLoadCallbacks; } + + virtual void destroyDecodedData() { } + + void setDocLoader(DocLoader* docLoader) { m_docLoader = docLoader; } + + bool isPreloaded() const { return m_preloadCount; } + void increasePreloadCount() { ++m_preloadCount; } + void decreasePreloadCount() { ASSERT(m_preloadCount); --m_preloadCount; } + + void registerHandle(CachedResourceHandleBase* h) { ++m_handleCount; if (m_resourceToRevalidate) m_handlesToRevalidate.add(h); } + void unregisterHandle(CachedResourceHandleBase* h) { ASSERT(m_handleCount > 0); --m_handleCount; if (m_resourceToRevalidate) m_handlesToRevalidate.remove(h); if (!m_handleCount) deleteIfPossible(); } + + bool canUseCacheValidator() const; + bool mustRevalidate(CachePolicy) const; + bool isCacheValidator() const { return m_resourceToRevalidate; } + CachedResource* resourceToRevalidate() const { return m_resourceToRevalidate; } + + bool isPurgeable() const; + bool wasPurged() const; + + // This is used by the archive machinery to get at a purged resource without + // triggering a load. We should make it protected again if we can find a + // better way to handle the archive case. + bool makePurgeable(bool purgeable); + +protected: + void setEncodedSize(unsigned); + void setDecodedSize(unsigned); + void didAccessDecodedData(double timeStamp); + + bool isSafeToMakePurgeable() const; + + HashCountedSet m_clients; + + String m_url; + String m_accept; + Request* m_request; + + ResourceResponse m_response; + double m_responseTimestamp; + + RefPtr m_data; + OwnPtr m_purgeableData; + +private: + void addClientToSet(CachedResourceClient*); + + // These are called by the friendly Cache only + void setResourceToRevalidate(CachedResource*); + void switchClientsToRevalidatedResource(); + void clearResourceToRevalidate(); + void updateResponseAfterRevalidation(const ResourceResponse& validatingResponse); + + double currentAge() const; + double freshnessLifetime() const; + + RefPtr m_cachedMetadata; + + double m_lastDecodedAccessTime; // Used as a "thrash guard" in the cache + + unsigned m_encodedSize; + unsigned m_decodedSize; + unsigned m_accessCount; + unsigned m_handleCount; + unsigned m_preloadCount; + + unsigned m_preloadResult : 2; // PreloadResult + + bool m_inLiveDecodedResourcesList : 1; + bool m_requestedFromNetworkingLayer : 1; + bool m_sendResourceLoadCallbacks : 1; + + bool m_errorOccurred : 1; + bool m_inCache : 1; + bool m_loading : 1; + + unsigned m_type : 3; // Type + unsigned m_status : 3; // Status + +#ifndef NDEBUG + bool m_deleted; + unsigned m_lruIndex; +#endif + + CachedResource* m_nextInAllResourcesList; + CachedResource* m_prevInAllResourcesList; + + CachedResource* m_nextInLiveResourcesList; + CachedResource* m_prevInLiveResourcesList; + + DocLoader* m_docLoader; // only non-0 for resources that are not in the cache + + // If this field is non-null we are using the resource as a proxy for checking whether an existing resource is still up to date + // using HTTP If-Modified-Since/If-None-Match headers. If the response is 304 all clients of this resource are moved + // to to be clients of m_resourceToRevalidate and the resource is deleted. If not, the field is zeroed and this + // resources becomes normal resource load. + CachedResource* m_resourceToRevalidate; + + // If this field is non-null, the resource has a proxy for checking whether it is still up to date (see m_resourceToRevalidate). + CachedResource* m_proxyResource; + + // These handles will need to be updated to point to the m_resourceToRevalidate in case we get 304 response. + HashSet m_handlesToRevalidate; +}; + +} + +#endif