DevTools: add backend for discovering connected ADB devices.

chrome/browser/devtools/devtools_adb_bridge.cc

+// Copyright (c) 2013 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/devtools/devtools_adb_bridge.h"
+
+#include <algorithm>
+#include <utility>
+
+#include "base/bind.h"
+#include "base/compiler_specific.h"
+#include "base/logging.h"
+#include "base/message_loop_proxy.h"
+#include "base/stringprintf.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/threading/thread.h"
+#include "chrome/browser/devtools/adb_client_socket.h"
+#include "content/public/browser/browser_thread.h"
+#include "net/base/io_buffer.h"
+#include "net/url_request/url_request_context_getter.h"
+
+using content::BrowserThread;
+
+namespace {
+
+static const char* kDevToolsAdbBridgeThreadName = "Chrome_DevToolsADBThread";
+const int kAdbPort = 5037;
+const int kBufferSize = 16 * 1024;
+
+}  // namespace
+
+struct DevToolsAdbBridge::RequestInfo {
+  Callback callback;
+  scoped_refptr<net::IOBuffer> buffer;
+  std::string data;
+};
+
+// static
+DevToolsAdbBridge* DevToolsAdbBridge::Start(Profile* profile) {
+  return new DevToolsAdbBridge(profile);
+}
+
+void DevToolsAdbBridge::Stop() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  if (!thread_.get())
+    return;
+  BrowserThread::PostTaskAndReply(
+      BrowserThread::FILE, FROM_HERE,
+      base::Bind(&DevToolsAdbBridge::StopHandlerOnFileThread, this),
+      base::Bind(&DevToolsAdbBridge::ResetHandlerAndReleaseOnUIThread, this));
+}
+
+void DevToolsAdbBridge::Query(
+    const std::string query,
+    const Callback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  // There is a race condition in case Query immediately follows start. We
+  // consider it Ok since query is polling anyways.
+  if (!thread_.get()) {
+    callback.Run("ADB is not yet connected", std::string());
+    return;
+  }
+  thread_->message_loop()->PostTask(
+      FROM_HERE,
+      base::Bind(&DevToolsAdbBridge::QueryOnHandlerThread,
+                 this, query, callback));
+}
+
+void DevToolsAdbBridge::Fetch(
+    const std::string url,
+    const Callback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  thread_->message_loop()->PostTask(
+      FROM_HERE,
+      base::Bind(&DevToolsAdbBridge::FetchOnHandlerThread,
+                 this, url, callback));
+}
+
+DevToolsAdbBridge::DevToolsAdbBridge(Profile* profile)
+    : profile_(profile) {
+  // Balanced in ResetThreadAndRelease().
+  AddRef();
+
+  thread_.reset(new base::Thread(kDevToolsAdbBridgeThreadName));
+  BrowserThread::PostTask(
+      BrowserThread::FILE, FROM_HERE,
+      base::Bind(&DevToolsAdbBridge::StartHandlerOnFileThread, this));
+}
+
+DevToolsAdbBridge::~DevToolsAdbBridge() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  // Stop() must be called prior to destruction.
+  DCHECK(thread_.get() == NULL);
+}
+
+void DevToolsAdbBridge::StartHandlerOnFileThread() {
+  base::Thread::Options options;
+  options.message_loop_type = MessageLoop::TYPE_IO;
+  if (!thread_->StartWithOptions(options)) {
+    BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(&DevToolsAdbBridge::ResetHandlerOnUIThread, this));
+    return;
+  }
+
+  thread_->message_loop()->PostTask(
+      FROM_HERE,
+      base::Bind(&DevToolsAdbBridge::InitOnHandlerThread, this));
+}
+
+// Runs on FILE thread to make sure that it is serialized against
+// {Start|Stop}HandlerThread and to allow calling pthread_join.
+void DevToolsAdbBridge::StopHandlerOnFileThread() {
+  if (!thread_->message_loop())
+    return;
+  thread_->message_loop()->PostTask(
+      FROM_HERE,
+      base::Bind(&DevToolsAdbBridge::TeardownOnHandlerThread, this));
+  // Thread::Stop joins the thread.
+  thread_->Stop();
+}
+
+void DevToolsAdbBridge::ResetHandlerAndReleaseOnUIThread() {
+  ResetHandlerOnUIThread();
+  Release();
+}
+
+void DevToolsAdbBridge::ResetHandlerOnUIThread() {
+  thread_.reset();
+}
+
+void DevToolsAdbBridge::InitOnHandlerThread() {
+}
+
+void DevToolsAdbBridge::QueryOnHandlerThread(
+    const std::string query,
+    const Callback& callback) {
+  ADBClientSocket::Query(
+      kAdbPort, query,
+      base::Bind(&DevToolsAdbBridge::QueryResponseOnHandlerThread,
+                 base::Unretained(this), callback));
+}
+
+void DevToolsAdbBridge::FetchOnHandlerThread(
+    const std::string url,
+    const Callback& callback) {
+  net::URLRequestContext* context =
+      profile_->GetRequestContext()->GetURLRequestContext();
+  net::URLRequest* request = new net::URLRequest(GURL(url), this, context);
+  RequestInfo info;
+  info.callback = callback;
+  info.buffer = new net::IOBuffer(kBufferSize);
+  info.data = "";
+  request_info_[request] = info;
+  request->Start();
+}
+
+void DevToolsAdbBridge::QueryResponseOnHandlerThread(
+    const Callback& callback,
+    const std::string& error,
+    const std::string& response) {
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(&DevToolsAdbBridge::RespondOnUIThread, this,
+          callback, error, response));
+}
+
+void DevToolsAdbBridge::TeardownOnHandlerThread() {
+}
+
+void DevToolsAdbBridge::RespondOnUIThread(
+    const Callback& callback,
+    const std::string& error,
+    const std::string& response) {
+  callback.Run(error, response);
+}
+
+// Called on the handler thread.
+void DevToolsAdbBridge::OnResponseStarted(net::URLRequest* request) {
+  int bytes_read = 0;
+  // Some servers may treat HEAD requests as GET requests.  To free up the
+  // network connection as soon as possible, signal that the request has
+  // completed immediately, without trying to read any data back (all we care
+  // about is the response code and headers, which we already have).
+  net::IOBuffer* buffer = request_info_[request].buffer.get();
+  if (request->status().is_success())
+    request->Read(buffer, kBufferSize, &bytes_read);
+  OnReadCompleted(request, bytes_read);
+}
+
+// Called on the handler thread.
+void DevToolsAdbBridge::OnReadCompleted(net::URLRequest* request,
+                                        int bytes_read) {
+  net::IOBuffer* buffer = request_info_[request].buffer.get();
+  do {
+    if (!request->status().is_success() || bytes_read <= 0)
+      break;
+    request_info_[request].data =
+        request_info_[request].data + std::string(buffer->data(), bytes_read);
+  } while (request->Read(buffer, kBufferSize, &bytes_read));
+
+  // See comments re: HEAD requests in OnResponseStarted().
+  if (!request->status().is_io_pending()) {
+    BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(&DevToolsAdbBridge::RespondOnUIThread, this,
+            request_info_[request].callback, "", request_info_[request].data));
+    request_info_.erase(request);
+    delete request;
+  }
+}