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"
+
+#include <google/protobuf/message_lite.h>
+
+#include "base/bind.h"
+#include "base/command_line.h"
+#include "chrome/common/chrome_switches.h"
+#include "content/public/browser/browser_context.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 {
+
+namespace {
+
+const char kDefaultCopresenceServer[] =
+    "https://www.googleapis.com/copresence/v2/copresence";
+const char kTracingTokenField[] = "trace";
+const char kApiKeyField[] = "key";
+
+}  // namespace
+
+// Send a request to the Copresence server.

[Daniel Erat, 2014/08/06 00:44:46]

put comments like these in the header instead of the implementation

[Charlie, 2014/08/06 19:32:18]

Done.

+// After calling the callback, this object will delete itself.
+HttpPost::HttpPost(net::URLRequestContextGetter* url_context_getter,
+                   const std::string& rpc_name,
+                   scoped_ptr<google::protobuf::MessageLite> request_proto,
+                   const ResponseCallback& response_callback)
+                   : response_callback_(response_callback) {
+  // Create the base URL to call.
+  CommandLine* command_line = CommandLine::ForCurrentProcess();
+  const std::string copresence_server_url =
+      command_line->HasSwitch(switches::kCopresenceServer) ?
+      command_line->GetSwitchValueASCII(switches::kCopresenceServer) :
+      kDefaultCopresenceServer;
+  GURL url(copresence_server_url + "/" + rpc_name);
+
+  // Add the Chrome API key.
+  DCHECK(google_apis::HasKeysConfigured());
+  url = net::AppendQueryParameter(url, kApiKeyField, google_apis::GetAPIKey());
+
+  // Add the tracing token, if specified.
+  if (command_line->HasSwitch(switches::kCopresenceTracingToken)) {
+    url = net::AppendQueryParameter(
+        url,
+        kTracingTokenField,
+        "token:" + command_line->GetSwitchValueASCII(
+            switches::kCopresenceTracingToken));
+  }
+
+  // Serialize the proto for transmission.
+  std::string request_data;
+  DCHECK(request_proto->SerializeToString(&request_data));
+
+  // 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);
+  url_fetcher_->Start();
+}
+
+HttpPost::~HttpPost() {}
+
+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(ERROR) << "Couldn't contact the Copresence server at "
+               << source->GetURL();
+  } else if (response_code != net::HTTP_OK) {
+    LOG(ERROR) << "Copresence request got HTTP response code " << response_code
+               << ". Response:\n" << response;
+  }
+
+  // Return the response.
+  response_callback_.Run(response_code, response);
+  delete this;

[Daniel Erat, 2014/08/06 00:44:46]

i'm not sure whether it's safe to leak these if they're still running when
chrome exits

[Charlie, 2014/08/06 19:32:18]

Ok. Can you clarify how you'd like us to handle this? Should the HttpPost stay
in the scope of the caller, and we pass a WeakPtr to the URLFetcher? 

On 2014/08/06 00:44:46, Daniel Erat wrote:

[Daniel Erat, 2014/08/06 21:35:17]

i'm not entirely sure whether this is a problem, but it might cause failures in
the memcheck or asan bots. if you can get away with doing this, it's definitely
simpler than the alternative of yeah, passing weak pointers and keeping this
class owned by some other class that deletes all of its outstanding requests on
destruction while also getting notified when requests finish to avoid
double-frees. :-(

here's an old change where i had to do something similar and took the more
complicated approach: https://chromiumcodereview.appspot.com/10818017

GDataContactsService::DownloadContacts() creates a new DownloadContactsRequest
and registers it. OnRequestComplete() is called when the request is done, and
~GDataContactsService() cancels and deletes all of the outstanding requests.

[Charlie, 2014/08/06 22:36:23]

Thanks. Added a note to the header file.

+}
+
+}  // namespace copresence