Separate access token caching logic from signaling connector.

remoting/host/oauth_token_getter.h

+// 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.
+
+#ifndef REMOTING_HOST_OAUTH_TOKEN_GETTER_H_
+#define REMOTING_HOST_OAUTH_TOKEN_GETTER_H_
+
+#include <queue>
+
+#include "base/basictypes.h"
+#include "base/callback.h"
+#include "base/threading/non_thread_safe.h"
+#include "google_apis/gaia/gaia_oauth_client.h"
+
+namespace net {
+class URLRequestContextGetter;
+}  // namespace net
+
+namespace remoting {
+
+// OAuthTokenGetter caches OAuth access tokens and refreshes them as needed.
+class OAuthTokenGetter :
+      public base::NonThreadSafe,
+      public gaia::GaiaOAuthClient::Delegate {
+ public:
+  // Status of the refresh token attempt.
+  enum Status {
+    // Success, credentials in user_email/access_token.
+    SUCCESS,
+    // Network failure (caller may retry).
+    NETWORK_ERROR,
+    // Authentication failure (permanent).
+    AUTH_ERROR,
+  };
+
+  typedef base::Callback<void(Status status,
+                              const std::string& user_email,
+                              const std::string& access_token)> TokenCallback;
+
+  // This structure contains information required to perform
+  // authentication to OAuth2.
+  struct OAuthCredentials {
+    OAuthCredentials(const std::string& login,
+                     const std::string& refresh_token,
+                     bool is_service_account);
+
+    // The user's account name (i.e. their email address).
+    std::string login;
+
+    // Token delegating authority to us to act as the user.
+    std::string refresh_token;
+
+    // Whether these credentials belong to a service account.
+    bool is_service_account;
+  };
+
+  OAuthTokenGetter(
+      scoped_ptr<OAuthCredentials> oauth_credentials,
+      scoped_refptr<net::URLRequestContextGetter> url_request_context_getter);
+  virtual ~OAuthTokenGetter();
+
+  // Call |on_access_token| with an access token, or the failure status.
+  void CallWithToken(const OAuthTokenGetter::TokenCallback& on_access_token);
+
+  // gaia::GaiaOAuthClient::Delegate interface.
+  virtual void OnGetTokensResponse(const std::string& user_email,
+                                   const std::string& access_token,
+                                   int expires_seconds) OVERRIDE;
+  virtual void OnRefreshTokenResponse(const std::string& access_token,
+                                      int expires_in_seconds) OVERRIDE;
+  virtual void OnGetUserEmailResponse(const std::string& user_email) OVERRIDE;
+  virtual void OnOAuthError() OVERRIDE;
+  virtual void OnNetworkError(int response_code) OVERRIDE;
+
+ private:
+  void NotifyCallbacks(Status status,
+                       const std::string& user_email,
+                       const std::string& access_token);
+  void RefreshOAuthToken();
+
+  scoped_ptr<OAuthCredentials> oauth_credentials_;
+  scoped_ptr<gaia::GaiaOAuthClient> gaia_oauth_client_;
+  scoped_refptr<net::URLRequestContextGetter> url_request_context_getter_;
+
+  bool refreshing_oauth_token_;
+  std::string oauth_access_token_;
+  base::Time auth_token_expiry_time_;
+  std::queue<OAuthTokenGetter::TokenCallback> pending_callbacks_;
+
+  DISALLOW_COPY_AND_ASSIGN(OAuthTokenGetter);
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_OAUTH_TOKEN_GETTER_H_