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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/platform_file.h"
9 #include "base/synchronization/waitable_event.h"
10 #include "content/child/child_thread.h"
11 #include "content/child/fileapi/file_system_dispatcher.h"
12 #include "webkit/child/worker_task_runner.h"
13 
14 using webkit_glue::WorkerTaskRunner;
15 
16 namespace content {
17 
18 namespace {
19 
GetFileSystemDispatcher()20 FileSystemDispatcher* GetFileSystemDispatcher() {
21   return ChildThread::current() ?
22       ChildThread::current()->file_system_dispatcher() : NULL;
23 }
24 
25 }  // namespace
26 
27 typedef FileSystemDispatcher::StatusCallback StatusCallback;
28 typedef FileSystemDispatcher::WriteCallback WriteCallback;
29 
30 // This instance may be created outside main thread but runs mainly
31 // on main thread.
32 class WebFileWriterImpl::WriterBridge
33     : public base::RefCountedThreadSafe<WriterBridge> {
34  public:
WriterBridge(WebFileWriterImpl::Type type)35   WriterBridge(WebFileWriterImpl::Type type)
36       : request_id_(0),
37         thread_id_(WorkerTaskRunner::Instance()->CurrentWorkerId()),
38         written_bytes_(0) {
39     if (type == WebFileWriterImpl::TYPE_SYNC)
40       waitable_event_.reset(new base::WaitableEvent(false, false));
41   }
42 
Truncate(const GURL & path,int64 offset,const StatusCallback & status_callback)43   void Truncate(const GURL& path, int64 offset,
44                 const StatusCallback& status_callback) {
45     status_callback_ = status_callback;
46     if (!GetFileSystemDispatcher())
47       return;
48     ChildThread::current()->file_system_dispatcher()->Truncate(
49         path, offset, &request_id_,
50         base::Bind(&WriterBridge::DidFinish, this));
51   }
52 
Write(const GURL & path,const std::string & id,int64 offset,const WriteCallback & write_callback,const StatusCallback & error_callback)53   void Write(const GURL& path, const std::string& id, int64 offset,
54              const WriteCallback& write_callback,
55              const StatusCallback& error_callback) {
56     write_callback_ = write_callback;
57     status_callback_ = error_callback;
58     if (!GetFileSystemDispatcher())
59       return;
60     ChildThread::current()->file_system_dispatcher()->Write(
61         path, id, offset, &request_id_,
62         base::Bind(&WriterBridge::DidWrite, this),
63         base::Bind(&WriterBridge::DidFinish, this));
64   }
65 
Cancel(const StatusCallback & status_callback)66   void Cancel(const StatusCallback& status_callback) {
67     status_callback_ = status_callback;
68     if (!GetFileSystemDispatcher())
69       return;
70     ChildThread::current()->file_system_dispatcher()->Cancel(
71         request_id_,
72         base::Bind(&WriterBridge::DidFinish, this));
73   }
74 
waitable_event()75   base::WaitableEvent* waitable_event() {
76     return waitable_event_.get();
77   }
78 
WaitAndRun()79   void WaitAndRun() {
80     waitable_event_->Wait();
81     DCHECK(!results_closure_.is_null());
82     results_closure_.Run();
83   }
84 
85  private:
86   friend class base::RefCountedThreadSafe<WriterBridge>;
~WriterBridge()87   virtual ~WriterBridge() {}
88 
DidWrite(int64 bytes,bool complete)89   void DidWrite(int64 bytes, bool complete) {
90     written_bytes_ += bytes;
91     if (waitable_event_ && !complete)
92       return;
93     PostTaskToWorker(base::Bind(write_callback_, written_bytes_, complete));
94   }
95 
DidFinish(base::PlatformFileError status)96   void DidFinish(base::PlatformFileError status) {
97     PostTaskToWorker(base::Bind(status_callback_, status));
98   }
99 
PostTaskToWorker(const base::Closure & closure)100   void PostTaskToWorker(const base::Closure& closure) {
101     written_bytes_ = 0;
102     if (!thread_id_) {
103       DCHECK(!waitable_event_);
104       closure.Run();
105       return;
106     }
107     if (waitable_event_) {
108       results_closure_ = closure;
109       waitable_event_->Signal();
110       return;
111     }
112     WorkerTaskRunner::Instance()->PostTask(thread_id_, closure);
113   }
114 
115   StatusCallback status_callback_;
116   WriteCallback write_callback_;
117   int request_id_;
118   int thread_id_;
119   int written_bytes_;
120   scoped_ptr<base::WaitableEvent> waitable_event_;
121   base::Closure results_closure_;
122 };
123 
WebFileWriterImpl(const GURL & path,blink::WebFileWriterClient * client,Type type,base::MessageLoopProxy * main_thread_loop)124 WebFileWriterImpl::WebFileWriterImpl(
125      const GURL& path, blink::WebFileWriterClient* client,
126      Type type,
127      base::MessageLoopProxy* main_thread_loop)
128   : WebFileWriterBase(path, client),
129     main_thread_loop_(main_thread_loop),
130     bridge_(new WriterBridge(type)) {
131 }
132 
~WebFileWriterImpl()133 WebFileWriterImpl::~WebFileWriterImpl() {
134 }
135 
DoTruncate(const GURL & path,int64 offset)136 void WebFileWriterImpl::DoTruncate(const GURL& path, int64 offset) {
137   RunOnMainThread(base::Bind(&WriterBridge::Truncate, bridge_,
138       path, offset,
139       base::Bind(&WebFileWriterImpl::DidFinish, AsWeakPtr())));
140 }
141 
DoWrite(const GURL & path,const std::string & blob_id,int64 offset)142 void WebFileWriterImpl::DoWrite(
143     const GURL& path, const std::string& blob_id, int64 offset) {
144   RunOnMainThread(base::Bind(&WriterBridge::Write, bridge_,
145       path, blob_id, offset,
146       base::Bind(&WebFileWriterImpl::DidWrite, AsWeakPtr()),
147       base::Bind(&WebFileWriterImpl::DidFinish, AsWeakPtr())));
148 }
149 
DoCancel()150 void WebFileWriterImpl::DoCancel() {
151   RunOnMainThread(base::Bind(&WriterBridge::Cancel, bridge_,
152       base::Bind(&WebFileWriterImpl::DidFinish, AsWeakPtr())));
153 }
154 
RunOnMainThread(const base::Closure & closure)155 void WebFileWriterImpl::RunOnMainThread(const base::Closure& closure) {
156   if (main_thread_loop_->RunsTasksOnCurrentThread()) {
157     DCHECK(!bridge_->waitable_event());
158     closure.Run();
159     return;
160   }
161   main_thread_loop_->PostTask(FROM_HERE, closure);
162   if (bridge_->waitable_event())
163     bridge_->WaitAndRun();
164 }
165 
166 }  // namespace content
167