Adding the Copresence RpcHandler and HttpPost helper.

components/copresence/rpc/http_post.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 "components/copresence/rpc/http_post.h"
+
+// TODO(ckehoe): Support third-party protobufs too.
+#include <google/protobuf/message_lite.h>
+
+#include "base/bind.h"
+#include "google_apis/google_api_keys.h"
+#include "net/base/load_flags.h"
+#include "net/base/url_util.h"
+#include "net/http/http_status_code.h"
+#include "net/url_request/url_fetcher.h"
+#include "net/url_request/url_request_context_getter.h"
+
+namespace copresence {
+
+// TODO(ckehoe): Come up with a better fix for Chromium.
+#ifdef GOOGLE_CHROME_BUILD
+namespace {
+
+const char kApiKeyField[] = "key";
+
+}  // namespace
+#endif
+
+const char HttpPost::kTracingTokenField[] = "trace";
+
+HttpPost::HttpPost(net::URLRequestContextGetter* url_context_getter,
+                   const std::string& server_host,
+                   const std::string& rpc_name,
+                   const std::string& tracing_token,
+                   const google::protobuf::MessageLite& request_proto) {
+  // Create the base URL to call.
+  GURL url(server_host + "/" + rpc_name);
+
+  // Add the Chrome API key.
+  // TODO(ckehoe): Replace this with an app-specific key once the
+  //               server API supports it. Also fix the Chromium case.
+#ifdef GOOGLE_CHROME_BUILD
+  DCHECK(google_apis::HasKeysConfigured());
+  url = net::AppendQueryParameter(url, kApiKeyField, google_apis::GetAPIKey());
+#endif
+
+  // Add the tracing token, if specified.
+  if (!tracing_token.empty()) {
+    url = net::AppendQueryParameter(
+        url, kTracingTokenField, "token:" + tracing_token);
+  }
+
+  // Serialize the proto for transmission.
+  std::string request_data;
+  bool serialize_success = request_proto.SerializeToString(&request_data);
+  DCHECK(serialize_success);
+
+  // Configure and send the request.
+  url_fetcher_.reset(net::URLFetcher::Create(
+      kUrlFetcherId, url, net::URLFetcher::POST, this));
+  url_fetcher_->SetRequestContext(url_context_getter);
+  url_fetcher_->SetLoadFlags(net::LOAD_BYPASS_CACHE |
+                             net::LOAD_DISABLE_CACHE |
+                             net::LOAD_DO_NOT_SAVE_COOKIES |
+                             net::LOAD_DO_NOT_SEND_COOKIES |
+                             net::LOAD_DO_NOT_SEND_AUTH_DATA);
+  url_fetcher_->SetUploadData("application/x-protobuf", request_data);
+}
+
+HttpPost::~HttpPost() {}
+
+void HttpPost::Start(const ResponseCallback& response_callback) {
+  response_callback_ = response_callback;
+  url_fetcher_->Start();
+}
+
+void HttpPost::OnURLFetchComplete(const net::URLFetcher* source) {
+  DCHECK_EQ(url_fetcher_.get(), source);
+
+  // Gather response info.
+  std::string response;
+  source->GetResponseAsString(&response);
+  int response_code = source->GetResponseCode();
+
+  // Log any errors.
+  if (response_code < 0) {
+    LOG(WARNING) << "Couldn't contact the Copresence server at "
+                 << source->GetURL();
+  } else if (response_code != net::HTTP_OK) {
+    LOG(WARNING) << "Copresence request got HTTP response code "
+                 << response_code << ". Response:\n" << response;
+  }
+
+  // Return the response.
+  response_callback_.Run(response_code, response);
+}
+
+}  // namespace copresence