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
13namespace content {
14
15namespace {
16
17FileSystemDispatcher* GetFileSystemDispatcher() {
18  return ChildThread::current() ?
19      ChildThread::current()->file_system_dispatcher() : NULL;
20}
21
22}  // namespace
23
24typedef FileSystemDispatcher::StatusCallback StatusCallback;
25typedef FileSystemDispatcher::WriteCallback WriteCallback;
26
27// This instance may be created outside main thread but runs mainly
28// on main thread.
29class WebFileWriterImpl::WriterBridge
30    : public base::RefCountedThreadSafe<WriterBridge> {
31 public:
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
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
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
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
72  base::WaitableEvent* waitable_event() {
73    return waitable_event_.get();
74  }
75
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>;
84  virtual ~WriterBridge() {}
85
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
93  void DidFinish(base::File::Error status) {
94    PostTaskToWorker(base::Bind(status_callback_, status));
95  }
96
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
121WebFileWriterImpl::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
130WebFileWriterImpl::~WebFileWriterImpl() {
131}
132
133void 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
139void 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
147void WebFileWriterImpl::DoCancel() {
148  RunOnMainThread(base::Bind(&WriterBridge::Cancel, bridge_,
149      base::Bind(&WebFileWriterImpl::DidFinish, AsWeakPtr())));
150}
151
152void 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