[Suggestions] Moving suggestions code to a new component

chrome/browser/search/suggestions/suggestions_service.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 CHROME_BROWSER_SEARCH_SUGGESTIONS_SUGGESTIONS_SERVICE_H_
-#define CHROME_BROWSER_SEARCH_SUGGESTIONS_SUGGESTIONS_SERVICE_H_
-
-#include <string>
-#include <vector>
-
-#include "base/basictypes.h"
-#include "base/callback.h"
-#include "base/cancelable_callback.h"
-#include "base/gtest_prod_util.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/memory/weak_ptr.h"
-#include "base/time/time.h"
-#include "chrome/browser/search/suggestions/image_manager.h"
-#include "chrome/browser/search/suggestions/proto/suggestions.pb.h"
-#include "components/keyed_service/core/keyed_service.h"
-#include "net/url_request/url_fetcher_delegate.h"
-#include "ui/gfx/image/image_skia.h"
-#include "url/gurl.h"
-
-namespace net {
-class URLRequestContextGetter;
-}  // namespace net
-
-namespace user_prefs {
-class PrefRegistrySyncable;
-}  // namespace user_prefs
-
-namespace suggestions {
-
-class BlacklistStore;
-class SuggestionsStore;
-
-extern const char kSuggestionsFieldTrialName[];
-extern const char kSuggestionsFieldTrialURLParam[];
-extern const char kSuggestionsFieldTrialCommonParamsParam[];
-extern const char kSuggestionsFieldTrialBlacklistPathParam[];
-extern const char kSuggestionsFieldTrialBlacklistUrlParam[];
-extern const char kSuggestionsFieldTrialStateParam[];
-extern const char kSuggestionsFieldTrialControlParam[];
-extern const char kSuggestionsFieldTrialStateEnabled[];
-
-// An interface to fetch server suggestions asynchronously.
-class SuggestionsService : public KeyedService, public net::URLFetcherDelegate {
- public:
-  typedef base::Callback<void(const SuggestionsProfile&)> ResponseCallback;
-
-  SuggestionsService(net::URLRequestContextGetter* url_request_context,
-                     scoped_ptr<SuggestionsStore> suggestions_store,
-                     scoped_ptr<ImageManager> thumbnail_manager,
-                     scoped_ptr<BlacklistStore> blacklist_store);
-  virtual ~SuggestionsService();
-
-  // Whether this service is enabled.
-  static bool IsEnabled();
-
-  // Whether the user is part of a control group.
-  static bool IsControlGroup();
-
-  // Request suggestions data, which will be passed to |callback|. Initiates a
-  // fetch request unless a pending one exists. To prevent multiple requests,
-  // we place all |callback|s in a queue and update them simultaneously when
-  // fetch request completes. Also posts a task to execute OnRequestTimeout
-  // if the request hasn't completed in a given amount of time.
-  void FetchSuggestionsData(ResponseCallback callback);
-
-  // Similar to FetchSuggestionsData but doesn't post a task to execute
-  // OnDelaySinceFetch.
-  void FetchSuggestionsDataNoTimeout(ResponseCallback callback);
-
-  // Retrieves stored thumbnail for website |url| asynchronously. Calls
-  // |callback| with Bitmap pointer if found, and NULL otherwise.
-  void GetPageThumbnail(
-      const GURL& url,
-      base::Callback<void(const GURL&, const SkBitmap*)> callback);
-
-  // Issue a blacklist request. If there is already a blacklist request
-  // in flight, the new blacklist request is ignored.
-  void BlacklistURL(const GURL& candidate_url,
-                    const ResponseCallback& callback);
-
-  // Determines which URL a blacklist request was for, irrespective of the
-  // request's status. Returns false if |request| is not a blacklist request.
-  static bool GetBlacklistedUrl(const net::URLFetcher& request, GURL* url);
-
-  // Register SuggestionsService related prefs in the Profile prefs.
-  static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
-
- private:
-  FRIEND_TEST_ALL_PREFIXES(SuggestionsServiceTest, BlacklistURLFails);
-  FRIEND_TEST_ALL_PREFIXES(SuggestionsServiceTest, FetchSuggestionsData);
-  FRIEND_TEST_ALL_PREFIXES(SuggestionsServiceTest, UpdateBlacklistDelay);
-
-  // Issue a request.
-  void IssueRequest(const GURL& url);
-
-  // Creates a request to the suggestions service, properly setting headers.
-  net::URLFetcher* CreateSuggestionsRequest(const GURL& url);
-
-  // Called to service the requestors if the issued suggestions request has
-  // not completed in a given amount of time.
-  virtual void OnRequestTimeout();
-
-  // net::URLFetcherDelegate implementation.
-  // Called when fetch request completes. Parses the received suggestions data,
-  // and dispatches them to callbacks stored in queue.
-  virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
-
-  // KeyedService implementation.
-  virtual void Shutdown() OVERRIDE;
-
-  // Load the cached suggestions and service the requestors with them.
-  void ServeFromCache();
-
-  // Apply the local blacklist to |suggestions|, then serve the requestors.
-  void FilterAndServe(SuggestionsProfile* suggestions);
-
-  // Schedule a blacklisting request if the local blacklist isn't empty.
-  // |last_request_successful| is used for exponentially backing off when
-  // requests fail.
-  void ScheduleBlacklistUpload(bool last_request_successful);
-
-  // If the local blacklist isn't empty, pick a URL from it and issue a
-  // blacklist request for it.
-  void UploadOneFromBlacklist();
-
-  // Updates |blacklist_delay_sec_| based on the success of the last request.
-  void UpdateBlacklistDelay(bool last_request_successful);
-
-  // Test seams.
-  int blacklist_delay() const { return blacklist_delay_sec_; }
-  void set_blacklist_delay(int delay) { blacklist_delay_sec_ = delay; }
-
-  // The cache for the suggestions.
-  scoped_ptr<SuggestionsStore> suggestions_store_;
-
-  // The local cache for temporary blacklist, until uploaded to the server.
-  scoped_ptr<BlacklistStore> blacklist_store_;
-
-  // Contains the current suggestions fetch request. Will only have a value
-  // while a request is pending, and will be reset by |OnURLFetchComplete|.
-  scoped_ptr<net::URLFetcher> pending_request_;
-
-  // A closure that is run on a timeout from issuing the suggestions fetch
-  // request, if the request hasn't completed.
-  scoped_ptr<base::CancelableClosure> pending_timeout_closure_;
-
-  // The start time of the previous suggestions request. This is used to measure
-  // the latency of requests. Initially zero.
-  base::TimeTicks last_request_started_time_;
-
-  // The URL to fetch suggestions data from.
-  GURL suggestions_url_;
-
-  // Prefix for building the blacklisting URL.
-  std::string blacklist_url_prefix_;
-
-  // Queue of callbacks. These are flushed when fetch request completes.
-  std::vector<ResponseCallback> waiting_requestors_;
-
-  // Used to obtain server thumbnails, if available.
-  scoped_ptr<ImageManager> thumbnail_manager_;
-
-  net::URLRequestContextGetter* url_request_context_;
-
-  // Delay used when scheduling a blacklisting task.
-  int blacklist_delay_sec_;
-
-  // For callbacks may be run after destruction.
-  base::WeakPtrFactory<SuggestionsService> weak_ptr_factory_;
-
-  // Timeout (in ms) before serving requestors after a fetch suggestions request
-  // has been issued.
-  int request_timeout_ms_;
-
-  DISALLOW_COPY_AND_ASSIGN(SuggestionsService);
-};
-
-}  // namespace suggestions
-
-#endif  // CHROME_BROWSER_SEARCH_SUGGESTIONS_SUGGESTIONS_SERVICE_H_