1 /*
2  * Copyright (C) 2009 Google Inc. All rights reserved.
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4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions are
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10  *     * Redistributions in binary form must reproduce the above
11  * copyright notice, this list of conditions and the following disclaimer
12  * in the documentation and/or other materials provided with the
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16  * this software without specific prior written permission.
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18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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29  */
30 
31 #ifndef WorkerThreadableLoader_h
32 #define WorkerThreadableLoader_h
33 
34 #if ENABLE(WORKERS)
35 
36 #include "PlatformString.h"
37 #include "ThreadableLoader.h"
38 #include "ThreadableLoaderClient.h"
39 #include "ThreadableLoaderClientWrapper.h"
40 
41 #include <wtf/PassOwnPtr.h>
42 #include <wtf/PassRefPtr.h>
43 #include <wtf/RefCounted.h>
44 #include <wtf/RefPtr.h>
45 #include <wtf/Threading.h>
46 
47 namespace WebCore {
48 
49     class ResourceError;
50     class ResourceRequest;
51     class WorkerContext;
52     class WorkerLoaderProxy;
53     struct CrossThreadResourceResponseData;
54     struct CrossThreadResourceRequestData;
55 
56     class WorkerThreadableLoader : public RefCounted<WorkerThreadableLoader>, public ThreadableLoader {
57         WTF_MAKE_FAST_ALLOCATED;
58     public:
59         static void loadResourceSynchronously(WorkerContext*, const ResourceRequest&, ThreadableLoaderClient&, const ThreadableLoaderOptions&);
create(WorkerContext * workerContext,ThreadableLoaderClient * client,const String & taskMode,const ResourceRequest & request,const ThreadableLoaderOptions & options)60         static PassRefPtr<WorkerThreadableLoader> create(WorkerContext* workerContext, ThreadableLoaderClient* client, const String& taskMode, const ResourceRequest& request, const ThreadableLoaderOptions& options)
61         {
62             return adoptRef(new WorkerThreadableLoader(workerContext, client, taskMode, request, options));
63         }
64 
65         ~WorkerThreadableLoader();
66 
67         virtual void cancel();
68 
done()69         bool done() const { return m_workerClientWrapper->done(); }
70 
71         using RefCounted<WorkerThreadableLoader>::ref;
72         using RefCounted<WorkerThreadableLoader>::deref;
73 
74     protected:
refThreadableLoader()75         virtual void refThreadableLoader() { ref(); }
derefThreadableLoader()76         virtual void derefThreadableLoader() { deref(); }
77 
78     private:
79         // Creates a loader on the main thread and bridges communication between
80         // the main thread and the worker context's thread where WorkerThreadableLoader runs.
81         //
82         // Regarding the bridge and lifetimes of items used in callbacks, there are a few cases:
83         //
84         // all cases. All tasks posted from the worker context's thread are ok because
85         //    the last task posted always is "mainThreadDestroy", so MainThreadBridge is
86         //    around for all tasks that use it on the main thread.
87         //
88         // case 1. worker.terminate is called.
89         //    In this case, no more tasks are posted from the worker object's thread to the worker
90         //    context's thread -- WorkerContextProxy implementation enforces this.
91         //
92         // case 2. xhr gets aborted and the worker context continues running.
93         //    The ThreadableLoaderClientWrapper has the underlying client cleared, so no more calls
94         //    go through it.  All tasks posted from the worker object's thread to the worker context's
95         //    thread do "ThreadableLoaderClientWrapper::ref" (automatically inside of the cross thread copy
96         //    done in createCallbackTask), so the ThreadableLoaderClientWrapper instance is there until all
97         //    tasks are executed.
98         class MainThreadBridge : public ThreadableLoaderClient {
99         public:
100             // All executed on the worker context's thread.
101             MainThreadBridge(PassRefPtr<ThreadableLoaderClientWrapper>, WorkerLoaderProxy&, const String& taskMode, const ResourceRequest&, const ThreadableLoaderOptions&, const String& outgoingReferrer);
102             void cancel();
103             void destroy();
104 
105         private:
106             // Executed on the worker context's thread.
107             void clearClientWrapper();
108 
109             // All executed on the main thread.
110             static void mainThreadDestroy(ScriptExecutionContext*, MainThreadBridge*);
111             ~MainThreadBridge();
112 
113             static void mainThreadCreateLoader(ScriptExecutionContext*, MainThreadBridge*, PassOwnPtr<CrossThreadResourceRequestData>, ThreadableLoaderOptions, const String& outgoingReferrer);
114             static void mainThreadCancel(ScriptExecutionContext*, MainThreadBridge*);
115             virtual void didSendData(unsigned long long bytesSent, unsigned long long totalBytesToBeSent);
116             virtual void didReceiveResponse(const ResourceResponse&);
117             virtual void didReceiveData(const char*, int dataLength);
118             virtual void didReceiveCachedMetadata(const char*, int dataLength);
119             virtual void didFinishLoading(unsigned long identifier, double finishTime);
120             virtual void didFail(const ResourceError&);
121             virtual void didFailRedirectCheck();
122             virtual void didReceiveAuthenticationCancellation(const ResourceResponse&);
123 
124             // Only to be used on the main thread.
125             RefPtr<ThreadableLoader> m_mainThreadLoader;
126 
127             // ThreadableLoaderClientWrapper is to be used on the worker context thread.
128             // The ref counting is done on either thread.
129             RefPtr<ThreadableLoaderClientWrapper> m_workerClientWrapper;
130 
131             // May be used on either thread.
132             WorkerLoaderProxy& m_loaderProxy;
133 
134             // For use on the main thread.
135             String m_taskMode;
136         };
137 
138         WorkerThreadableLoader(WorkerContext*, ThreadableLoaderClient*, const String& taskMode, const ResourceRequest&, const ThreadableLoaderOptions&);
139 
140         RefPtr<WorkerContext> m_workerContext;
141         RefPtr<ThreadableLoaderClientWrapper> m_workerClientWrapper;
142         MainThreadBridge& m_bridge;
143     };
144 
145 } // namespace WebCore
146 
147 #endif // ENABLE(WORKERS)
148 
149 #endif // WorkerThreadableLoader_h
150