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 "PlatformString.h"
37#include "ThreadableLoader.h"
38#include "ThreadableLoaderClient.h"
39#include "ThreadableLoaderClientWrapper.h"
40
41#include <memory>
42#include <wtf/PassRefPtr.h>
43#include <wtf/RefCounted.h>
44#include <wtf/RefPtr.h>
45#include <wtf/Threading.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    public:
58        static void loadResourceSynchronously(WorkerContext*, const ResourceRequest&, ThreadableLoaderClient&, const ThreadableLoaderOptions&);
59        static PassRefPtr<WorkerThreadableLoader> create(WorkerContext* workerContext, ThreadableLoaderClient* client, const String& taskMode, const ResourceRequest& request, const ThreadableLoaderOptions& options)
60        {
61            return adoptRef(new WorkerThreadableLoader(workerContext, client, taskMode, request, options));
62        }
63
64        ~WorkerThreadableLoader();
65
66        virtual void cancel();
67
68        bool done() const { return m_workerClientWrapper->done(); }
69
70        using RefCounted<WorkerThreadableLoader>::ref;
71        using RefCounted<WorkerThreadableLoader>::deref;
72
73    protected:
74        virtual void refThreadableLoader() { ref(); }
75        virtual void derefThreadableLoader() { deref(); }
76
77    private:
78        // Creates a loader on the main thread and bridges communication between
79        // the main thread and the worker context's thread where WorkerThreadableLoader runs.
80        //
81        // Regarding the bridge and lifetimes of items used in callbacks, there are a few cases:
82        //
83        // all cases. All tasks posted from the worker context's thread are ok because
84        //    the last task posted always is "mainThreadDestroy", so MainThreadBridge is
85        //    around for all tasks that use it on the main thread.
86        //
87        // case 1. worker.terminate is called.
88        //    In this case, no more tasks are posted from the worker object's thread to the worker
89        //    context's thread -- WorkerContextProxy implementation enforces this.
90        //
91        // case 2. xhr gets aborted and the worker context continues running.
92        //    The ThreadableLoaderClientWrapper has the underlying client cleared, so no more calls
93        //    go through it.  All tasks posted from the worker object's thread to the worker context's
94        //    thread do "ThreadableLoaderClientWrapper::ref" (automatically inside of the cross thread copy
95        //    done in createCallbackTask), so the ThreadableLoaderClientWrapper instance is there until all
96        //    tasks are executed.
97        class MainThreadBridge : public ThreadableLoaderClient {
98        public:
99            // All executed on the worker context's thread.
100            MainThreadBridge(PassRefPtr<ThreadableLoaderClientWrapper>, WorkerLoaderProxy&, const String& taskMode, const ResourceRequest&, const ThreadableLoaderOptions&);
101            void cancel();
102            void destroy();
103
104        private:
105            // Executed on the worker context's thread.
106            void clearClientWrapper();
107
108            // All executed on the main thread.
109            static void mainThreadDestroy(ScriptExecutionContext*, MainThreadBridge*);
110            ~MainThreadBridge();
111
112            static void mainThreadCreateLoader(ScriptExecutionContext*, MainThreadBridge*, std::auto_ptr<CrossThreadResourceRequestData>, ThreadableLoaderOptions);
113            static void mainThreadCancel(ScriptExecutionContext*, MainThreadBridge*);
114            virtual void didSendData(unsigned long long bytesSent, unsigned long long totalBytesToBeSent);
115            virtual void didReceiveResponse(const ResourceResponse&);
116            virtual void didReceiveData(const char*, int lengthReceived);
117            virtual void didFinishLoading(unsigned long identifier);
118            virtual void didFail(const ResourceError&);
119            virtual void didFailRedirectCheck();
120            virtual void didReceiveAuthenticationCancellation(const ResourceResponse&);
121
122            // Only to be used on the main thread.
123            RefPtr<ThreadableLoader> m_mainThreadLoader;
124
125            // ThreadableLoaderClientWrapper is to be used on the worker context thread.
126            // The ref counting is done on either thread.
127            RefPtr<ThreadableLoaderClientWrapper> m_workerClientWrapper;
128
129            // May be used on either thread.
130            WorkerLoaderProxy& m_loaderProxy;
131
132            // For use on the main thread.
133            String m_taskMode;
134        };
135
136        WorkerThreadableLoader(WorkerContext*, ThreadableLoaderClient*, const String& taskMode, const ResourceRequest&, const ThreadableLoaderOptions&);
137
138        RefPtr<WorkerContext> m_workerContext;
139        RefPtr<ThreadableLoaderClientWrapper> m_workerClientWrapper;
140        MainThreadBridge& m_bridge;
141    };
142
143} // namespace WebCore
144
145#endif // ENABLE(WORKERS)
146
147#endif // WorkerThreadableLoader_h
148