--- /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 <mueller@kde.org>
+ 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 <wtf/HashCountedSet.h>
+#include <wtf/HashSet.h>
+#include <wtf/OwnPtr.h>
+#include <wtf/Vector.h>
+#include <time.h>
+
+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<SharedBuffer> data, bool allDataReceived);
+ virtual void error() { }
+ virtual void httpStatusCodeError() { error(); } // Images keep loading in spite of HTTP errors (for legacy compat with <img>, etc.).
+
+ const String &url() const { return m_url; }
+ Type type() const { return static_cast<Type>(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<PreloadResult>(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<Status>(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<CachedResourceClient*> m_clients;
+
+ String m_url;
+ String m_accept;
+ Request* m_request;
+
+ ResourceResponse m_response;
+ double m_responseTimestamp;
+
+ RefPtr<SharedBuffer> m_data;
+ OwnPtr<PurgeableBuffer> 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<CachedMetadata> 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<CachedResourceHandleBase*> m_handlesToRevalidate;
+};
+
+}
+
+#endif