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#include "ThreadableLoader.h"
35#include "ThreadableLoaderClient.h"
36#include "ThreadableLoaderClientWrapper.h"
37
38#include <wtf/PassOwnPtr.h>
39#include <wtf/PassRefPtr.h>
40#include <wtf/RefCounted.h>
41#include <wtf/RefPtr.h>
42#include <wtf/Threading.h>
43#include <wtf/text/WTFString.h>
44
45namespace WebCore {
46
47    class ResourceError;
48    class ResourceRequest;
49    class WorkerGlobalScope;
50    class WorkerLoaderProxy;
51    struct CrossThreadResourceResponseData;
52    struct CrossThreadResourceRequestData;
53
54    class WorkerThreadableLoader : public RefCounted<WorkerThreadableLoader>, public ThreadableLoader {
55        WTF_MAKE_FAST_ALLOCATED;
56    public:
57        static void loadResourceSynchronously(WorkerGlobalScope*, const ResourceRequest&, ThreadableLoaderClient&, const ThreadableLoaderOptions&);
58        static PassRefPtr<WorkerThreadableLoader> create(WorkerGlobalScope* workerGlobalScope, ThreadableLoaderClient* client, const String& taskMode, const ResourceRequest& request, const ThreadableLoaderOptions& options)
59        {
60            return adoptRef(new WorkerThreadableLoader(workerGlobalScope, client, taskMode, request, options));
61        }
62
63        ~WorkerThreadableLoader();
64
65        virtual void cancel() override;
66
67        bool done() const { return m_workerClientWrapper->done(); }
68
69        using RefCounted<WorkerThreadableLoader>::ref;
70        using RefCounted<WorkerThreadableLoader>::deref;
71
72    protected:
73        virtual void refThreadableLoader() override { ref(); }
74        virtual void derefThreadableLoader() override { deref(); }
75
76    private:
77        // Creates a loader on the main thread and bridges communication between
78        // the main thread and the worker context's thread where WorkerThreadableLoader runs.
79        //
80        // Regarding the bridge and lifetimes of items used in callbacks, there are a few cases:
81        //
82        // all cases. All tasks posted from the worker context's thread are ok because
83        //    the last task posted always is "mainThreadDestroy", so MainThreadBridge is
84        //    around for all tasks that use it on the main thread.
85        //
86        // case 1. worker.terminate is called.
87        //    In this case, no more tasks are posted from the worker object's thread to the worker
88        //    context's thread -- WorkerGlobalScopeProxy implementation enforces this.
89        //
90        // case 2. xhr gets aborted and the worker context continues running.
91        //    The ThreadableLoaderClientWrapper has the underlying client cleared, so no more calls
92        //    go through it.  All tasks posted from the worker object's thread to the worker context's
93        //    thread do "ThreadableLoaderClientWrapper::ref" (automatically inside of the cross thread copy
94        //    done in CrossThreadTask), so the ThreadableLoaderClientWrapper instance is there until all
95        //    tasks are executed.
96        class MainThreadBridge : public ThreadableLoaderClient {
97        public:
98            // All executed on the worker context's thread.
99            MainThreadBridge(PassRefPtr<ThreadableLoaderClientWrapper>, WorkerLoaderProxy&, const String& taskMode, const ResourceRequest&, const ThreadableLoaderOptions&, const String& outgoingReferrer);
100            void cancel();
101            void destroy();
102
103        private:
104            // Executed on the worker context's thread.
105            void clearClientWrapper();
106
107            // All executed on the main thread.
108            static void mainThreadDestroy(ScriptExecutionContext&, MainThreadBridge*);
109            ~MainThreadBridge();
110
111            static void mainThreadCreateLoader(ScriptExecutionContext&, MainThreadBridge*, PassOwnPtr<CrossThreadResourceRequestData>, ThreadableLoaderOptions, const String& outgoingReferrer);
112            static void mainThreadCancel(ScriptExecutionContext&, MainThreadBridge*);
113            virtual void didSendData(unsigned long long bytesSent, unsigned long long totalBytesToBeSent) override;
114            virtual void didReceiveResponse(unsigned long identifier, const ResourceResponse&) override;
115            virtual void didReceiveData(const char*, int dataLength) override;
116            virtual void didFinishLoading(unsigned long identifier, double finishTime) override;
117            virtual void didFail(const ResourceError&) override;
118            virtual void didFailAccessControlCheck(const ResourceError&) override;
119            virtual void didFailRedirectCheck() override;
120
121            // Only to be used on the main thread.
122            RefPtr<ThreadableLoader> m_mainThreadLoader;
123
124            // ThreadableLoaderClientWrapper is to be used on the worker context thread.
125            // The ref counting is done on either thread.
126            RefPtr<ThreadableLoaderClientWrapper> m_workerClientWrapper;
127
128            // May be used on either thread.
129            WorkerLoaderProxy& m_loaderProxy;
130
131            // For use on the main thread.
132            String m_taskMode;
133        };
134
135        WorkerThreadableLoader(WorkerGlobalScope*, ThreadableLoaderClient*, const String& taskMode, const ResourceRequest&, const ThreadableLoaderOptions&);
136
137        RefPtr<WorkerGlobalScope> m_workerGlobalScope;
138        RefPtr<ThreadableLoaderClientWrapper> m_workerClientWrapper;
139        MainThreadBridge& m_bridge;
140    };
141
142} // namespace WebCore
143
144#endif // WorkerThreadableLoader_h
145