chrome.bluetooth API improvements.

chrome/browser/extensions/api/bluetooth/bluetooth_socket_event_dispatcher.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/extensions/api/bluetooth/bluetooth_socket_event_dispatcher.h"
+
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/extensions/api/bluetooth/bluetooth_api_socket.h"
+#include "chrome/common/extensions/api/bluetooth.h"
+#include "extensions/browser/event_router.h"
+#include "extensions/browser/extension_system.h"
+#include "net/base/io_buffer.h"
+#include "net/base/net_errors.h"
+
+namespace {
+
+namespace bluetooth = extensions::api::bluetooth;
+using extensions::BluetoothApiSocket;
+
+int kDefaultBufferSize = 4096;
+
+bluetooth::ReceiveError MapErrorReason(BluetoothApiSocket::ErrorReason value) {
+  switch (value) {
+    case BluetoothApiSocket::kDisconnected:
+      return bluetooth::RECEIVE_ERROR_DISCONNECTED;
+    case BluetoothApiSocket::kIOPending:
+    // kIOPending is not relevant to apps, as BluetoothSocketEventDispatcher
+    // handles this specific error.
+    // fallthrough
+    default:
+      return bluetooth::RECEIVE_ERROR_SYSTEM_ERROR;
+  }
+}
+
+}  // namespace
+
+namespace extensions {
+namespace api {
+
+using content::BrowserThread;
+
+BluetoothSocketEventDispatcher::BluetoothSocketEventDispatcher(
+    content::BrowserContext* context,
+    scoped_refptr<SocketData> socket_data)
+    : thread_id_(BluetoothApiSocket::kThreadId),
+      browser_context_id_(context),
+      socket_data_(socket_data) {}
+
+BluetoothSocketEventDispatcher::~BluetoothSocketEventDispatcher() {}
+
+BluetoothSocketEventDispatcher::ReceiveParams::ReceiveParams() {}
+
+BluetoothSocketEventDispatcher::ReceiveParams::~ReceiveParams() {}
+
+void BluetoothSocketEventDispatcher::OnSocketResume(
+    const std::string& extension_id,
+    int socket_id) {
+  DCHECK(BrowserThread::CurrentlyOn(thread_id_));
+
+  ReceiveParams params;
+  params.extension_id = extension_id;
+  params.socket_id = socket_id;
+  StartReceive(params);
+}
+
+void BluetoothSocketEventDispatcher::StartReceive(const ReceiveParams& params) {
+  DCHECK(BrowserThread::CurrentlyOn(thread_id_));
+
+  BluetoothApiSocket* socket =
+      socket_data_->Get(params.extension_id, params.socket_id);
+  if (!socket) {
+    // This can happen if the socket is closed while our callback is active.
+    return;
+  }
+  DCHECK(params.extension_id == socket->owner_extension_id())
+      << "Socket has wrong owner.";
+
+  // Don't start another read if the socket has been paused.
+  if (socket->paused())
+    return;
+
+  int buffer_size = socket->buffer_size();
+  if (buffer_size <= 0)
+    buffer_size = kDefaultBufferSize;
+  socket->Receive(
+      buffer_size,
+      base::Bind(
+          &BluetoothSocketEventDispatcher::ReceiveCallback, this, params),
+      base::Bind(
+          &BluetoothSocketEventDispatcher::ReceiveErrorCallback, this, params));
+}
+
+void BluetoothSocketEventDispatcher::ReceiveCallback(
+    const ReceiveParams& params,
+    int bytes_read,
+    scoped_refptr<net::IOBuffer> io_buffer) {
+  DCHECK(BrowserThread::CurrentlyOn(thread_id_));
+
+  // Dispatch "onReceive" event.
+  bluetooth::ReceiveInfo receive_info;
+  receive_info.socket_id = params.socket_id;
+  receive_info.data = std::string(io_buffer->data(), bytes_read);
+  scoped_ptr<base::ListValue> args = bluetooth::OnReceive::Create(receive_info);
+  scoped_ptr<Event> event(
+      new Event(bluetooth::OnReceive::kEventName, args.Pass()));
+  PostEvent(params, event.Pass());
+
+  // Post a task to delay the read until the socket is available, as
+  // calling StartReceive at this point would error with ERR_IO_PENDING.
+  BrowserThread::PostTask(
+      thread_id_,
+      FROM_HERE,
+      base::Bind(&BluetoothSocketEventDispatcher::StartReceive, this, params));
+}
+
+void BluetoothSocketEventDispatcher::ReceiveErrorCallback(
+    const ReceiveParams& params,
+    BluetoothApiSocket::ErrorReason error_reason,
+    const std::string& error) {
+  DCHECK(BrowserThread::CurrentlyOn(thread_id_));
+
+  if (error_reason == BluetoothApiSocket::kIOPending) {
+    // This happens when resuming a socket which already had an active "read"
+    // callback. We can safely ignore this error, as the application should not
+    // care.
+    return;
+  }
+
+  // Dispatch "onReceiveError" event but don't start another read to avoid
+  // potential infinite reads if we have a persistent network error.
+  bluetooth::ReceiveErrorInfo receive_error_info;
+  receive_error_info.socket_id = params.socket_id;
+  receive_error_info.error_message = error;
+  receive_error_info.error = MapErrorReason(error_reason);
+  scoped_ptr<base::ListValue> args =
+      bluetooth::OnReceiveError::Create(receive_error_info);
+  scoped_ptr<Event> event(
+      new Event(bluetooth::OnReceiveError::kEventName, args.Pass()));
+  PostEvent(params, event.Pass());
+
+  // Since we got an error, the socket is now "paused" until the application
+  // "resumes" it.
+  BluetoothApiSocket* socket =
+      socket_data_->Get(params.extension_id, params.socket_id);
+  if (socket) {
+    socket->set_paused(true);
+  }
+}
+
+void BluetoothSocketEventDispatcher::PostEvent(const ReceiveParams& params,
+                                               scoped_ptr<Event> event) {
+  DCHECK(BrowserThread::CurrentlyOn(thread_id_));
+
+  BrowserThread::PostTask(
+      BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(&BluetoothSocketEventDispatcher::DispatchEvent,
+                 this,
+                 params.extension_id,
+                 base::Passed(event.Pass())));
+}
+
+void BluetoothSocketEventDispatcher::DispatchEvent(
+    const std::string& extension_id,
+    scoped_ptr<Event> event) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  content::BrowserContext* context =
+      reinterpret_cast<content::BrowserContext*>(browser_context_id_);
+  if (!extensions::ExtensionsBrowserClient::Get()->IsValidContext(context))
+    return;
+
+  EventRouter* router = ExtensionSystem::Get(context)->event_router();
+  if (router)
+    router->DispatchEventToExtension(extension_id, event.Pass());
+}
+
+}  // namespace api
+}  // namespace extensions