chrome/browser/predictors/resource_prefetch_common.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_BROWSER_PREDICTORS_RESOURCE_PREFETCH_COMMON_H_
   6 #define CHROME_BROWSER_PREDICTORS_RESOURCE_PREFETCH_COMMON_H_
   7
   8 #include "base/time/time.h"
   9 #include "url/gurl.h"
  10
  11 class Profile;
  12
  13 namespace content {
  14 class WebContents;
  15 }
  16
  17 namespace predictors {
  18
  19 struct ResourcePrefetchPredictorConfig;
  20
  21 // Returns true if prefetching is enabled. And will initilize the |config|
  22 // fields to the appropritate values.
  23 bool IsSpeculativeResourcePrefetchingEnabled(
  24     Profile* profile,
  25     ResourcePrefetchPredictorConfig* config);
  26
  27 // Represents the type of key based on which prefetch data is stored.
  28 enum PrefetchKeyType {
  29   PREFETCH_KEY_TYPE_HOST,
  30   PREFETCH_KEY_TYPE_URL
  31 };
  32
  33 // Represents a single navigation for a render frame.
  34 struct NavigationID {
  35   // TODO(shishir): Maybe take process_id, frame_id and url as input in
  36   // constructor.
  37   NavigationID();
  38   NavigationID(const NavigationID& other);
  39   explicit NavigationID(content::WebContents* web_contents);
  40   bool operator<(const NavigationID& rhs) const;
  41   bool operator==(const NavigationID& rhs) const;
  42
  43   bool IsSameRenderer(const NavigationID& other) const;
  44
  45   // Returns true iff the render_process_id_, render_frame_id_ and
  46   // frame_url_ has been set correctly.
  47   bool is_valid() const;
  48
  49   int render_process_id;
  50   int render_frame_id;
  51   GURL main_frame_url;
  52
  53   // NOTE: Even though we store the creation time here, it is not used during
  54   // comparison of two NavigationIDs because it cannot always be determined
  55   // correctly.
  56   base::TimeTicks creation_time;
  57 };
  58
  59 // Represents the config for the resource prefetch prediction algorithm. It is
  60 // useful for running experiments.
  61 struct ResourcePrefetchPredictorConfig {
  62   // Initializes the config with default values.
  63   ResourcePrefetchPredictorConfig();
  64   ~ResourcePrefetchPredictorConfig();
  65
  66   // The mode the prefetcher is running in. Forms a bit map.
  67   enum Mode {
  68     URL_LEARNING    = 1 << 0,
  69     HOST_LEARNING   = 1 << 1,
  70     URL_PREFETCHING = 1 << 2,  // Should also turn on URL_LEARNING.
  71     HOST_PRFETCHING = 1 << 3   // Should also turn on HOST_LEARNING.
  72   };
  73   int mode;
  74
  75   // Helpers to deal with mode.
  76   bool IsLearningEnabled() const;
  77   bool IsPrefetchingEnabled(Profile* profile) const;
  78   bool IsURLLearningEnabled() const;
  79   bool IsHostLearningEnabled() const;
  80   bool IsURLPrefetchingEnabled(Profile* profile) const;
  81   bool IsHostPrefetchingEnabled(Profile* profile) const;
  82
  83   bool IsLowConfidenceForTest() const;
  84   bool IsHighConfidenceForTest() const;
  85   bool IsMoreResourcesEnabledForTest() const;
  86   bool IsSmallDBEnabledForTest() const;
  87
  88   // If a navigation hasn't seen a load complete event in this much time, it
  89   // is considered abandoned.
  90   size_t max_navigation_lifetime_seconds;
  91
  92   // Size of LRU caches for the URL and host data.
  93   size_t max_urls_to_track;
  94   size_t max_hosts_to_track;
  95
  96   // The number of times we should have seen a visit to this URL in history
  97   // to start tracking it. This is to ensure we don't bother with oneoff
  98   // entries. For hosts we track each one.
  99   size_t min_url_visit_count;
 100
 101   // The maximum number of resources to store per entry.
 102   size_t max_resources_per_entry;
 103   // The number of consecutive misses after we stop tracking a resource URL.
 104   size_t max_consecutive_misses;
 105
 106   // The minimum confidence (accuracy of hits) required for a resource to be
 107   // prefetched.
 108   float min_resource_confidence_to_trigger_prefetch;
 109   // The minimum number of times we must have a URL on record to prefetch it.
 110   size_t min_resource_hits_to_trigger_prefetch;
 111
 112   // Maximum number of prefetches that can be inflight for a single navigation.
 113   size_t max_prefetches_inflight_per_navigation;
 114   // Maximum number of prefetches that can be inflight for a host for a single
 115   // navigation.
 116   size_t max_prefetches_inflight_per_host_per_navigation;
 117 };
 118
 119 }  // namespace predictors
 120
 121 #endif  // CHROME_BROWSER_PREDICTORS_RESOURCE_PREFETCH_COMMON_H_