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1 // Copyright 2013 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #include "content/child/fileapi/webfilewriter_impl.h"
6 
7 #include "base/bind.h"
8 #include "base/synchronization/waitable_event.h"
9 #include "content/child/child_thread.h"
10 #include "content/child/fileapi/file_system_dispatcher.h"
11 #include "content/child/worker_task_runner.h"
12 
13 namespace content {
14 
15 namespace {
16 
GetFileSystemDispatcher()17 FileSystemDispatcher* GetFileSystemDispatcher() {
18   return ChildThread::current() ?
19       ChildThread::current()->file_system_dispatcher() : NULL;
20 }
21 
22 }  // namespace
23 
24 typedef FileSystemDispatcher::StatusCallback StatusCallback;
25 typedef FileSystemDispatcher::WriteCallback WriteCallback;
26 
27 // This instance may be created outside main thread but runs mainly
28 // on main thread.
29 class WebFileWriterImpl::WriterBridge
30     : public base::RefCountedThreadSafe<WriterBridge> {
31  public:
WriterBridge(WebFileWriterImpl::Type type)32   WriterBridge(WebFileWriterImpl::Type type)
33       : request_id_(0),
34         thread_id_(WorkerTaskRunner::Instance()->CurrentWorkerId()),
35         written_bytes_(0) {
36     if (type == WebFileWriterImpl::TYPE_SYNC)
37       waitable_event_.reset(new base::WaitableEvent(false, false));
38   }
39 
Truncate(const GURL & path,int64 offset,const StatusCallback & status_callback)40   void Truncate(const GURL& path, int64 offset,
41                 const StatusCallback& status_callback) {
42     status_callback_ = status_callback;
43     if (!GetFileSystemDispatcher())
44       return;
45     ChildThread::current()->file_system_dispatcher()->Truncate(
46         path, offset, &request_id_,
47         base::Bind(&WriterBridge::DidFinish, this));
48   }
49 
Write(const GURL & path,const std::string & id,int64 offset,const WriteCallback & write_callback,const StatusCallback & error_callback)50   void Write(const GURL& path, const std::string& id, int64 offset,
51              const WriteCallback& write_callback,
52              const StatusCallback& error_callback) {
53     write_callback_ = write_callback;
54     status_callback_ = error_callback;
55     if (!GetFileSystemDispatcher())
56       return;
57     ChildThread::current()->file_system_dispatcher()->Write(
58         path, id, offset, &request_id_,
59         base::Bind(&WriterBridge::DidWrite, this),
60         base::Bind(&WriterBridge::DidFinish, this));
61   }
62 
Cancel(const StatusCallback & status_callback)63   void Cancel(const StatusCallback& status_callback) {
64     status_callback_ = status_callback;
65     if (!GetFileSystemDispatcher())
66       return;
67     ChildThread::current()->file_system_dispatcher()->Cancel(
68         request_id_,
69         base::Bind(&WriterBridge::DidFinish, this));
70   }
71 
waitable_event()72   base::WaitableEvent* waitable_event() {
73     return waitable_event_.get();
74   }
75 
WaitAndRun()76   void WaitAndRun() {
77     waitable_event_->Wait();
78     DCHECK(!results_closure_.is_null());
79     results_closure_.Run();
80   }
81 
82  private:
83   friend class base::RefCountedThreadSafe<WriterBridge>;
~WriterBridge()84   virtual ~WriterBridge() {}
85 
DidWrite(int64 bytes,bool complete)86   void DidWrite(int64 bytes, bool complete) {
87     written_bytes_ += bytes;
88     if (waitable_event_ && !complete)
89       return;
90     PostTaskToWorker(base::Bind(write_callback_, written_bytes_, complete));
91   }
92 
DidFinish(base::File::Error status)93   void DidFinish(base::File::Error status) {
94     PostTaskToWorker(base::Bind(status_callback_, status));
95   }
96 
PostTaskToWorker(const base::Closure & closure)97   void PostTaskToWorker(const base::Closure& closure) {
98     written_bytes_ = 0;
99     if (!thread_id_) {
100       DCHECK(!waitable_event_);
101       closure.Run();
102       return;
103     }
104     if (waitable_event_) {
105       results_closure_ = closure;
106       waitable_event_->Signal();
107       return;
108     }
109     WorkerTaskRunner::Instance()->PostTask(thread_id_, closure);
110   }
111 
112   StatusCallback status_callback_;
113   WriteCallback write_callback_;
114   int request_id_;
115   int thread_id_;
116   int written_bytes_;
117   scoped_ptr<base::WaitableEvent> waitable_event_;
118   base::Closure results_closure_;
119 };
120 
WebFileWriterImpl(const GURL & path,blink::WebFileWriterClient * client,Type type,base::MessageLoopProxy * main_thread_loop)121 WebFileWriterImpl::WebFileWriterImpl(
122      const GURL& path, blink::WebFileWriterClient* client,
123      Type type,
124      base::MessageLoopProxy* main_thread_loop)
125   : WebFileWriterBase(path, client),
126     main_thread_loop_(main_thread_loop),
127     bridge_(new WriterBridge(type)) {
128 }
129 
~WebFileWriterImpl()130 WebFileWriterImpl::~WebFileWriterImpl() {
131 }
132 
DoTruncate(const GURL & path,int64 offset)133 void WebFileWriterImpl::DoTruncate(const GURL& path, int64 offset) {
134   RunOnMainThread(base::Bind(&WriterBridge::Truncate, bridge_,
135       path, offset,
136       base::Bind(&WebFileWriterImpl::DidFinish, AsWeakPtr())));
137 }
138 
DoWrite(const GURL & path,const std::string & blob_id,int64 offset)139 void WebFileWriterImpl::DoWrite(
140     const GURL& path, const std::string& blob_id, int64 offset) {
141   RunOnMainThread(base::Bind(&WriterBridge::Write, bridge_,
142       path, blob_id, offset,
143       base::Bind(&WebFileWriterImpl::DidWrite, AsWeakPtr()),
144       base::Bind(&WebFileWriterImpl::DidFinish, AsWeakPtr())));
145 }
146 
DoCancel()147 void WebFileWriterImpl::DoCancel() {
148   RunOnMainThread(base::Bind(&WriterBridge::Cancel, bridge_,
149       base::Bind(&WebFileWriterImpl::DidFinish, AsWeakPtr())));
150 }
151 
RunOnMainThread(const base::Closure & closure)152 void WebFileWriterImpl::RunOnMainThread(const base::Closure& closure) {
153   if (main_thread_loop_->RunsTasksOnCurrentThread()) {
154     DCHECK(!bridge_->waitable_event());
155     closure.Run();
156     return;
157   }
158   main_thread_loop_->PostTask(FROM_HERE, closure);
159   if (bridge_->waitable_event())
160     bridge_->WaitAndRun();
161 }
162 
163 }  // namespace content
164