DevTools: add backend for discovering connected ADB devices.

chrome/browser/devtools/protocol_http_request.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/protocol_http_request.h"
+
+#include "base/threading/thread.h"
+#include "chrome/browser/profiles/profile.h"
+#include "content/public/browser/browser_thread.h"
+#include "net/base/io_buffer.h"
+#include "net/url_request/url_request.h"
+#include "net/url_request/url_request_context_getter.h"
+
+using content::BrowserThread;
+
+namespace {
+
+const int kBufferSize = 16 * 1024;
+
+}  // namespace
+
+ProtocolHttpRequest::ProtocolHttpRequest(
+    Profile* profile,
+    const std::string& url,
+    const Callback& callback)
+    : request_context_(profile->GetRequestContext()),
+      url_(url),
+      callback_(callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  if (!url_.is_valid()) {
+    error_ = "Invalid URL: " + url_.possibly_invalid_spec();
+    RespondOnUIThread();
+    return;
+  }
+
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&ProtocolHttpRequest::Start, base::Unretained(this)));
+}
+
+ProtocolHttpRequest::~ProtocolHttpRequest() {
+}
+
+void ProtocolHttpRequest::Start() {
+  request_ = new net::URLRequest(url_, this,
+      request_context_->GetURLRequestContext());
+  io_buffer_ = new net::IOBuffer(kBufferSize);
+  request_->Start();
+}
+
+void ProtocolHttpRequest::OnResponseStarted(net::URLRequest* request) {
+  if (!request->status().is_success())
+    error_ = "HTTP 404";
+  int bytes_read = 0;
+  if (request->status().is_success())
+    request->Read(io_buffer_.get(), kBufferSize, &bytes_read);
+  OnReadCompleted(request, bytes_read);
+}
+
+void ProtocolHttpRequest::OnReadCompleted(net::URLRequest* request,
+                                          int bytes_read) {
+  do {
+    if (!request->status().is_success() || bytes_read <= 0)
+      break;
+    data_ += std::string(io_buffer_->data(), bytes_read);
+  } while (request->Read(io_buffer_, kBufferSize, &bytes_read));
+
+  if (!request->status().is_io_pending()) {
+    BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(&ProtocolHttpRequest::RespondOnUIThread,
+                   base::Unretained(this)));
+    delete request;
+  }
+}
+
+void ProtocolHttpRequest::RespondOnUIThread() {
+  callback_.Run(error_, data_);
+  delete this;
+}