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
14using webkit_glue::WorkerTaskRunner;
15
16namespace content {
17
18namespace {
19
20FileSystemDispatcher* GetFileSystemDispatcher() {
21  return ChildThread::current() ?
22      ChildThread::current()->file_system_dispatcher() : NULL;
23}
24
25}  // namespace
26
27typedef FileSystemDispatcher::StatusCallback StatusCallback;
28typedef FileSystemDispatcher::WriteCallback WriteCallback;
29
30// This instance may be created outside main thread but runs mainly
31// on main thread.
32class WebFileWriterImpl::WriterBridge
33    : public base::RefCountedThreadSafe<WriterBridge> {
34 public:
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
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
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
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
75  base::WaitableEvent* waitable_event() {
76    return waitable_event_.get();
77  }
78
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>;
87  virtual ~WriterBridge() {}
88
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
96  void DidFinish(base::PlatformFileError status) {
97    PostTaskToWorker(base::Bind(status_callback_, status));
98  }
99
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
124WebFileWriterImpl::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
133WebFileWriterImpl::~WebFileWriterImpl() {
134}
135
136void 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
142void 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
150void WebFileWriterImpl::DoCancel() {
151  RunOnMainThread(base::Bind(&WriterBridge::Cancel, bridge_,
152      base::Bind(&WebFileWriterImpl::DidFinish, AsWeakPtr())));
153}
154
155void 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