Client-to-server messages in GCMNetworkChannel

sync/notifier/gcm_network_channel.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 "google_apis/gaia/google_service_auth_error.h"
+#include "net/http/http_status_code.h"
+#include "net/url_request/url_fetcher.h"
+#include "net/url_request/url_request_status.h"
 #include "sync/notifier/gcm_network_channel.h"
+#include "sync/notifier/gcm_network_channel_delegate.h"
 
 namespace syncer {
 
-GCMNetworkChannel::GCMNetworkChannel() {
+GCMNetworkChannel::GCMNetworkChannel(
+    scoped_refptr<net::URLRequestContextGetter> request_context_getter,
+    scoped_ptr<GCMNetworkChannelDelegate> delegate)
+    : request_context_getter_(request_context_getter),
+      delegate_(delegate.Pass()),
+      weak_factory_(this) {
+  delegate_->Register(base::Bind(&GCMNetworkChannel::OnRegisterComplete,
+      weak_factory_.GetWeakPtr()));
 }
 
 GCMNetworkChannel::~GCMNetworkChannel() {
 }
 
-void GCMNetworkChannel::SendEncodedMessage(const std::string& encoded_message) {
+void GCMNetworkChannel::UpdateCredentials(const std::string& email,
+    const std::string& token) {
+  // Do nothing. We get access token by requesting it for every message.
 }
 
-void GCMNetworkChannel::UpdateCredentials(const std::string& email,
-    const std::string& token) {
+void GCMNetworkChannel::OnRegisterComplete(const std::string& registration_id,

[rlarocque, 2014/01/16 18:52:48]

nit: either put this parameter on the next line, or indent the next parameter up
to the '('.

[pavely, 2014/01/17 00:44:39]

Done.

+    gcm::GCMClient::Result result) {
+  if (result == gcm::GCMClient::SUCCESS) {
+    DCHECK(!registration_id.empty());
+    DVLOG(2) << "Got registration_id";
+    registration_id_ = registration_id;
+    if (!encoded_message_.empty())
+      RequestAccessToken();
+  } else {
+    DVLOG(2) << "Register failed";
+    // TODO(pavely): Don't know what to do if registration fails. Let's not do
+    // anything for now.
+  }
+}
+
+void GCMNetworkChannel::SendEncodedMessage(const std::string& encoded_message) {
+  DCHECK(!encoded_message.empty());
+  DVLOG(2) << "SendEncodedMessage";
+  encoded_message_ = encoded_message;
+
+  if (!registration_id_.empty()) {
+    RequestAccessToken();
+  }
+}
+
+void GCMNetworkChannel::RequestAccessToken() {
+  delegate_->RequestToken(base::Bind(&GCMNetworkChannel::OnGetTokenComplete,
+      weak_factory_.GetWeakPtr()));

[rlarocque, 2014/01/16 18:52:48]

another indentation nit: I think the second line should be aligned with the '('
that follows the 'Bind'.

[pavely, 2014/01/17 00:44:39]

Done.

+}
+
+void GCMNetworkChannel::OnGetTokenComplete(
+    const GoogleServiceAuthError& error, const std::string& token) {
+  if (encoded_message_.empty()) {
+    // Nothing to do.
+    return;
+  }
+
+  if (!(error == GoogleServiceAuthError::AuthErrorNone())) {
+    // Requesting access token failed. Persistent errors will be reported by
+    // token service. Just drop this request, cacheinvalidations will retry
+    // sending message and at that time we'll retry requesting access token.
+    DVLOG(1) << "RequestAccessToken failed: " << error.ToString();
+    return;
+  }
+  DCHECK(!token.empty());
+  // Save access token in case POST fails and we need to invalidate it.
+  access_token_ = token;
+
+  DVLOG(2) << "Got access token, sending message";
+
+  fetcher_.reset(net::URLFetcher::Create(BuildUrl(), net::URLFetcher::POST,
+      this));

[rlarocque, 2014/01/16 18:52:48]

more nits: I recommend indenting the 'this' parameter or moving all the
parameters to the 'Create(' call onto this line.

The relevant style guideline rule is here:
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Functi...

[pavely, 2014/01/17 00:44:39]

Done.

+  fetcher_->SetRequestContext(request_context_getter_);
+  std::string auth_header;

[rlarocque, 2014/01/16 18:52:48]

I think it's slightly better to declare and initialize the string at the same
time.  As a bonus, you could declare the string 'const' if you did this.

[pavely, 2014/01/17 00:44:39]

Done.

+  auth_header = "Authorization: Bearer " + access_token_;
+  fetcher_->AddExtraRequestHeader(auth_header);
+  fetcher_->SetUploadData("application/x-protobuffer", encoded_message_);
+  fetcher_->Start();
+  // Clear message to prevent accidentally resending it in the future.
+  encoded_message_.clear();
+}
+
+void GCMNetworkChannel::OnURLFetchComplete(const net::URLFetcher* source) {
+  DCHECK_EQ(fetcher_, source);
+  // Free fetcher at the end of function.
+  scoped_ptr<net::URLFetcher> fetcher = fetcher_.Pass();
+
+  net::URLRequestStatus status = fetcher->GetStatus();
+  if (!status.is_success()) {
+    DVLOG(1) << "URLFetcher failure";
+    return;
+  }
+
+  if (fetcher->GetResponseCode() == net::HTTP_UNAUTHORIZED) {
+    DVLOG(1) << "URLFetcher failure: HTTP_UNAUTHORIZED";
+    delegate_->InvalidateToken(access_token_);
+    return;
+  }
+  DVLOG(2) << "URLFetcher success";
+}
+
+GURL GCMNetworkChannel::BuildUrl() {
+  DCHECK(!registration_id_.empty());
+  // Prepare NetworkEndpointId using registration_id
+  // Serialize NetworkEndpointId into byte array and base64 encode.
+  // Format url using encoded NetworkEndpointId.
+  // TODO(pavely): implement all of the above.
+  return GURL("http://invalid.url.com");
 }
 
 }  // namespace syncer