1/*
2 * Copyright (C) 2009 Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
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
13 * distribution.
14 *     * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#ifndef WorkerThreadableLoader_h
32#define WorkerThreadableLoader_h
33
34#if ENABLE(WORKERS)
35
36#include "ThreadableLoader.h"
37#include "ThreadableLoaderClient.h"
38#include "ThreadableLoaderClientWrapper.h"
39
40#include <wtf/PassOwnPtr.h>
41#include <wtf/PassRefPtr.h>
42#include <wtf/RefCounted.h>
43#include <wtf/RefPtr.h>
44#include <wtf/Threading.h>
45#include <wtf/text/WTFString.h>
46
47namespace 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&);
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() OVERRIDE;
68
69        bool done() const { return m_workerClientWrapper->done(); }
70
71        using RefCounted<WorkerThreadableLoader>::ref;
72        using RefCounted<WorkerThreadableLoader>::deref;
73
74    protected:
75        virtual void refThreadableLoader() OVERRIDE { ref(); }
76        virtual void derefThreadableLoader() OVERRIDE { 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) OVERRIDE;
116            virtual void didReceiveResponse(unsigned long identifier, const ResourceResponse&) OVERRIDE;
117            virtual void didReceiveData(const char*, int dataLength) OVERRIDE;
118            virtual void didFinishLoading(unsigned long identifier, double finishTime) OVERRIDE;
119            virtual void didFail(const ResourceError&) OVERRIDE;
120            virtual void didFailAccessControlCheck(const ResourceError&) OVERRIDE;
121            virtual void didFailRedirectCheck() OVERRIDE;
122
123            // Only to be used on the main thread.
124            RefPtr<ThreadableLoader> m_mainThreadLoader;
125
126            // ThreadableLoaderClientWrapper is to be used on the worker context thread.
127            // The ref counting is done on either thread.
128            RefPtr<ThreadableLoaderClientWrapper> m_workerClientWrapper;
129
130            // May be used on either thread.
131            WorkerLoaderProxy& m_loaderProxy;
132
133            // For use on the main thread.
134            String m_taskMode;
135        };
136
137        WorkerThreadableLoader(WorkerContext*, ThreadableLoaderClient*, const String& taskMode, const ResourceRequest&, const ThreadableLoaderOptions&);
138
139        RefPtr<WorkerContext> m_workerContext;
140        RefPtr<ThreadableLoaderClientWrapper> m_workerClientWrapper;
141        MainThreadBridge& m_bridge;
142    };
143
144} // namespace WebCore
145
146#endif // ENABLE(WORKERS)
147
148#endif // WorkerThreadableLoader_h
149