predictors: Introduce GlowplugPredictor.

chrome/browser/predictors/resource_prefetch_common.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_PREDICTORS_RESOURCE_PREFETCH_COMMON_H_
 #define CHROME_BROWSER_PREDICTORS_RESOURCE_PREFETCH_COMMON_H_
 
 #include <stddef.h>
 
 #include "base/feature_list.h"
 #include "base/time/time.h"
 #include "components/sessions/core/session_id.h"
 #include "url/gurl.h"
 
 class Profile;
 
 namespace content {
 class WebContents;
 }
 
 namespace predictors {
 
+namespace internal {
+
+bool IsPrefetchingEnabledInternal(Profile* profile, int mode, int mask);
+
+}  // namespace internal
+
 extern const char kSpeculativeResourcePrefetchingFeatureName[];
 extern const char kModeParamName[];
 extern const char kLearningMode[];
 extern const char kExternalPrefetchingMode[];
 extern const char kPrefetchingMode[];
 extern const char kEnableUrlLearningParamName[];
 extern const char kEnableManifestsParamName[];
 extern const char kEnableOriginLearningParamName[];
 extern const base::Feature kSpeculativeResourcePrefetchingFeature;
 
-struct ResourcePrefetchPredictorConfig;
+struct LoadingPredictorConfig;
 
-// Returns true if prefetching is enabled. And will initilize the |config|
-// fields to the appropritate values.
-bool IsSpeculativeResourcePrefetchingEnabled(
-    Profile* profile,
-    ResourcePrefetchPredictorConfig* config);
+// Returns true if prefetching is enabled, and initializes |config|, if not
+// nullptr.
+bool IsSpeculativeResourcePrefetchingEnabled(Profile* profile,
+                                             LoadingPredictorConfig* config);
 
 // Represents the type of key based on which prefetch data is stored.
 enum PrefetchKeyType {
   PREFETCH_KEY_TYPE_HOST,
   PREFETCH_KEY_TYPE_URL
 };
 
-// Indicates what caused the prefetch request.
-enum class PrefetchOrigin { NAVIGATION, EXTERNAL };
-
 // Represents a single navigation for a render frame.
 struct NavigationID {
   NavigationID();
   explicit NavigationID(content::WebContents* web_contents);
   NavigationID(content::WebContents* web_contents,
                const GURL& main_frame_url,
                const base::TimeTicks& creation_time);
   NavigationID(const NavigationID& other);
 
   bool operator<(const NavigationID& rhs) const;
   bool operator==(const NavigationID& rhs) const;
 
   // Returns true iff the tab_id is valid and the Main frame URL is set.
   bool is_valid() const;
 
   SessionID::id_type tab_id;
   GURL main_frame_url;
 
   // NOTE: Even though we store the creation time here, it is not used during
   // comparison of two NavigationIDs because it cannot always be determined
   // correctly.
   base::TimeTicks creation_time;
 };
 
-// Represents the config for the resource prefetch prediction algorithm.
-struct ResourcePrefetchPredictorConfig {
-  // Initializes the config with default values.
-  ResourcePrefetchPredictorConfig();
-  ResourcePrefetchPredictorConfig(const ResourcePrefetchPredictorConfig& other);
-  ~ResourcePrefetchPredictorConfig();
-
-  // The mode the prefetcher is running in. Forms a bit map.
-  enum Mode {
-    LEARNING = 1 << 0,
-    PREFETCHING_FOR_NAVIGATION = 1 << 2,  // Should also turn on LEARNING.
-    PREFETCHING_FOR_EXTERNAL = 1 << 3     // Should also turn on LEARNING.
-  };
-  int mode;
-
-  // Helpers to deal with mode.
-  bool IsLearningEnabled() const;
-  bool IsPrefetchingEnabledForSomeOrigin(Profile* profile) const;
-  bool IsPrefetchingEnabledForOrigin(Profile* profile,
-                                     PrefetchOrigin origin) const;
-
-  bool IsLowConfidenceForTest() const;
-  bool IsHighConfidenceForTest() const;
-  bool IsMoreResourcesEnabledForTest() const;
-  bool IsSmallDBEnabledForTest() const;
-
-  // If a navigation hasn't seen a load complete event in this much time, it
-  // is considered abandoned.
-  size_t max_navigation_lifetime_seconds;
-
-  // Size of LRU caches for the URL and host data.
-  size_t max_urls_to_track;
-  size_t max_hosts_to_track;
-
-  // The number of times we should have seen a visit to this URL in history
-  // to start tracking it. This is to ensure we don't bother with oneoff
-  // entries. For hosts we track each one.
-  size_t min_url_visit_count;
-
-  // The maximum number of resources to store per entry.
-  size_t max_resources_per_entry;
-  // The maximum number of origins to store per entry.
-  size_t max_origins_per_entry;
-  // The number of consecutive misses after which we stop tracking a resource
-  // URL.
-  size_t max_consecutive_misses;
-  // The number of consecutive misses after which we stop tracking a redirect
-  // endpoint.
-  size_t max_redirect_consecutive_misses;
-
-  // The minimum confidence (accuracy of hits) required for a resource to be
-  // prefetched.
-  float min_resource_confidence_to_trigger_prefetch;
-  // The minimum number of times we must have a URL on record to prefetch it.
-  size_t min_resource_hits_to_trigger_prefetch;
-
-  // Maximum number of prefetches that can be inflight for a single navigation.
-  size_t max_prefetches_inflight_per_navigation;
-  // Maximum number of prefetches that can be inflight for a host for a single
-  // navigation.
-  size_t max_prefetches_inflight_per_host_per_navigation;
-  // True iff the predictor could use a url-based database.
-  bool is_url_learning_enabled;
-  // True iff the predictor could use manifests.
-  bool is_manifests_enabled;
-  // True iff origin-based learning is enabled.
-  bool is_origin_learning_enabled;
-};
-
 }  // namespace predictors
 
 #endif  // CHROME_BROWSER_PREDICTORS_RESOURCE_PREFETCH_COMMON_H_