Index: components/password_manager/core/browser/affiliation_fetch_throttler.h |
diff --git a/components/password_manager/core/browser/affiliation_fetch_throttler.h b/components/password_manager/core/browser/affiliation_fetch_throttler.h |
new file mode 100644 |
index 0000000000000000000000000000000000000000..f4b75444aa9b24c9b125ea6ea402c67ea41e2d1b |
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+++ b/components/password_manager/core/browser/affiliation_fetch_throttler.h |
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+// Copyright 2015 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 COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_AFFILIATION_FETCH_THROTTLER_H_ |
+#define COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_AFFILIATION_FETCH_THROTTLER_H_ |
+ |
+#include "base/gtest_prod_util.h" |
+#include "base/macros.h" |
+#include "base/memory/ref_counted.h" |
+#include "base/memory/scoped_ptr.h" |
+#include "base/memory/weak_ptr.h" |
+#include "net/base/backoff_entry.h" |
+#include "net/base/network_change_notifier.h" |
+ |
+namespace base { |
+class TickClock; |
+class SingleThreadTaskRunner; |
+} // namespace base |
+ |
+namespace password_manager { |
+ |
+class AffiliationFetchThrottlerDelegate; |
+ |
+// Implements the throttling logic that the AffiliationBackend will use when it |
+// needs to issue requests over the network to fetch affiliation information. |
+// |
+// This class manages only the scheduling of the requests. It is up to the |
+// consumer (the AffiliationBackend) to actually assemble and send the requests, |
+// to report back about their success or failure, and to retry them if desired. |
+// The process goes like this: |
+// 1.) The consumer calls SignalNetworkRequestNeeded(). |
+// 2.) Once appropriate, OnCanSendNetworkRequest() is called on the delegate. |
+// 3.) The consumer sends the request, and waits until it completes. |
+// 4.) The consumer calls InformOfNetworkRequestComplete(). |
+// Note that only a single request at a time is supported. |
+// |
+// If the request fails in Step 3, the consumer should not automatically retry |
+// it. Instead it should always proceed to Step 4, and then -- if retrying the |
+// request is desired -- proceed immediately to Step 1. That is, it should act |
+// as if another request was needed right away. |
+// |
+// Essentially, this class implements exponential backoff in case of network and |
+// server errors with the additional constraint that no requests will be issued |
+// in the first place while there is known to be no network connectivity. This |
+// prevents the exponential backoff delay from growing huge during long offline |
+// periods, so that requests will not be held back for too long after |
+// connectivity is restored. |
+class AffiliationFetchThrottler |
+ : public net::NetworkChangeNotifier::ConnectionTypeObserver { |
+ public: |
+ // Creates an instance that will use |tick_clock| as its tick source, and will |
+ // post to |task_runner| to call the |delegate|'s OnSendNetworkRequest(). The |
+ // |delegate| should outlive the throttler. |
+ AffiliationFetchThrottler( |
+ AffiliationFetchThrottlerDelegate* delegate, |
+ const scoped_refptr<base::SingleThreadTaskRunner>& task_runner, |
+ scoped_ptr<base::TickClock> tick_clock); |
+ ~AffiliationFetchThrottler() override; |
+ |
+ // Signals to the throttling logic that a network request is needed, and that |
+ // OnCanSendNetworkRequest() should be called as soon as the request can be |
+ // sent. OnCanSendNetworkRequest() will always be called asynchronously. |
+ // |
+ // Calls to this method will be ignored when a request is already known to be |
+ // needed or while a request is in flight. To signal that another request will |
+ // be needed right away after the current one, call this method after calling |
+ // InformOfNetworkRequestComplete(). |
+ void SignalNetworkRequestNeeded(); |
+ |
+ // Informs the back-off logic that the in-flight network request has been |
+ // completed, either with |success| or not. |
+ void InformOfNetworkRequestComplete(bool success); |
+ |
+ private: |
+ FRIEND_TEST_ALL_PREFIXES(AffiliationFetchThrottlerTest, FailedRequests); |
+ FRIEND_TEST_ALL_PREFIXES(AffiliationFetchThrottlerTest, |
+ GracePeriodAfterConnectivityIsRestored); |
+ FRIEND_TEST_ALL_PREFIXES(AffiliationFetchThrottlerTest, |
+ GracePeriodAfterConnectivityIsRestored2); |
+ FRIEND_TEST_ALL_PREFIXES(AffiliationFetchThrottlerTest, |
+ GracePeriodAfterConnectivityIsRestored3); |
+ FRIEND_TEST_ALL_PREFIXES(AffiliationFetchThrottlerTest, |
+ ConnectivityLostDuringBackoff); |
+ FRIEND_TEST_ALL_PREFIXES(AffiliationFetchThrottlerTest, |
+ ConnectivityLostAndRestoredDuringBackoff); |
+ FRIEND_TEST_ALL_PREFIXES(AffiliationFetchThrottlerTest, FlakyConnectivity); |
+ FRIEND_TEST_ALL_PREFIXES(AffiliationFetchThrottlerTest, |
+ ConnectivityLostDuringRequest); |
+ FRIEND_TEST_ALL_PREFIXES(AffiliationFetchThrottlerTest, |
+ ConnectivityLostAndRestoredDuringRequest); |
+ FRIEND_TEST_ALL_PREFIXES(AffiliationFetchThrottlerTest, |
+ ConnectivityLostAndRestoredDuringRequest2); |
+ |
+ enum State { IDLE, FETCH_NEEDED, FETCH_IN_FLIGHT }; |
+ |
+ // Exponential backoff parameters in case of network and server errors |
+ static const net::BackoffEntry::Policy kBackoffPolicy; |
+ |
+ // Minimum delay before sending the first request once network connectivity is |
+ // restored. The fuzzing factor in |kBackoffParameters.jitter_factor| applies. |
+ static const int64_t kGracePeriodAfterReconnectMs; |
+ |
+ // Ensures that OnBackoffDelayExpiredCallback() is scheduled to be called back |
+ // once the |exponential_backoff_| delay expires. |
+ void EnsureCallbackIsScheduled(); |
+ |
+ // Called back when the |exponential_backoff_| delay expires. |
+ void OnBackoffDelayExpiredCallback(); |
+ |
+ // net::NetworkChangeNotifier::ConnectionTypeObserver: |
+ void OnConnectionTypeChanged( |
+ net::NetworkChangeNotifier::ConnectionType type) override; |
+ |
+ AffiliationFetchThrottlerDelegate* delegate_; |
+ scoped_refptr<base::SingleThreadTaskRunner> task_runner_; |
+ State state_; |
+ bool has_network_connectivity_; |
+ bool is_fetch_scheduled_; |
+ scoped_ptr<base::TickClock> tick_clock_; |
+ scoped_ptr<net::BackoffEntry> exponential_backoff_; |
+ |
+ base::WeakPtrFactory<AffiliationFetchThrottler> weak_ptr_factory_; |
+ |
+ DISALLOW_COPY_AND_ASSIGN(AffiliationFetchThrottler); |
+}; |
+ |
+} // namespace password_manager |
+ |
+#endif // COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_AFFILIATION_FETCH_THROTTLER_H_ |