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| 1 // Copyright (c) 2011 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 // This is the browser side of the cache manager, it tracks the activity of the | |
| 6 // render processes and allocates available memory cache resources. | |
| 7 | |
| 8 #ifndef CHROME_BROWSER_RENDERER_HOST_WEB_CACHE_MANAGER_H_ | |
| 9 #define CHROME_BROWSER_RENDERER_HOST_WEB_CACHE_MANAGER_H_ | |
| 10 | |
| 11 #include <list> | |
| 12 #include <map> | |
| 13 #include <set> | |
| 14 | |
| 15 #include "base/basictypes.h" | |
| 16 #include "base/compiler_specific.h" | |
| 17 #include "base/gtest_prod_util.h" | |
| 18 #include "base/memory/weak_ptr.h" | |
| 19 #include "base/time/time.h" | |
| 20 #include "content/public/browser/notification_observer.h" | |
| 21 #include "content/public/browser/notification_registrar.h" | |
| 22 #include "third_party/WebKit/public/web/WebCache.h" | |
| 23 | |
| 24 template<typename Type> | |
| 25 struct DefaultSingletonTraits; | |
| 26 class PrefRegistrySimple; | |
| 27 | |
| 28 class WebCacheManager : public content::NotificationObserver { | |
| 29 friend class WebCacheManagerTest; | |
| 30 FRIEND_TEST_ALL_PREFIXES(WebCacheManagerBrowserTest, CrashOnceOnly); | |
| 31 | |
| 32 public: | |
| 33 static void RegisterPrefs(PrefRegistrySimple* registry); | |
| 34 | |
| 35 // Gets the singleton WebCacheManager object. The first time this method | |
| 36 // is called, a WebCacheManager object is constructed and returned. | |
| 37 // Subsequent calls will return the same object. | |
| 38 static WebCacheManager* GetInstance(); | |
| 39 | |
| 40 // When a render process is created, it registers itself with the cache | |
| 41 // manager host, causing the renderer to be allocated cache resources. | |
| 42 void Add(int renderer_id); | |
| 43 | |
| 44 // When a render process ends, it removes itself from the cache manager host, | |
| 45 // freeing the manager to assign its cache resources to other renderers. | |
| 46 void Remove(int renderer_id); | |
| 47 | |
| 48 // The cache manager assigns more cache resources to active renderer. When a | |
| 49 // renderer is active, it should inform the cache manager to receive more | |
| 50 // cache resources. | |
| 51 // | |
| 52 // When a renderer moves from being inactive to being active, the cache | |
| 53 // manager may decide to adjust its resource allocation, but it will delay | |
| 54 // the recalculation, allowing ObserveActivity to return quickly. | |
| 55 void ObserveActivity(int renderer_id); | |
| 56 | |
| 57 // Periodically, renderers should inform the cache manager of their current | |
| 58 // statistics. The more up-to-date the cache manager's statistics, the | |
| 59 // better it can allocate cache resources. | |
| 60 void ObserveStats( | |
| 61 int renderer_id, const blink::WebCache::UsageStats& stats); | |
| 62 | |
| 63 // The global limit on the number of bytes in all the in-memory caches. | |
| 64 size_t global_size_limit() const { return global_size_limit_; } | |
| 65 | |
| 66 // Sets the global size limit, forcing a recalculation of cache allocations. | |
| 67 void SetGlobalSizeLimit(size_t bytes); | |
| 68 | |
| 69 // Clears all in-memory caches. | |
| 70 void ClearCache(); | |
| 71 | |
| 72 // Clears all in-memory caches when a tab is reloaded or the user navigates | |
| 73 // to a different website. | |
| 74 void ClearCacheOnNavigation(); | |
| 75 | |
| 76 // content::NotificationObserver implementation: | |
| 77 virtual void Observe(int type, | |
| 78 const content::NotificationSource& source, | |
| 79 const content::NotificationDetails& details) OVERRIDE; | |
| 80 | |
| 81 // Gets the default global size limit. This interrogates system metrics to | |
| 82 // tune the default size to the current system. | |
| 83 static size_t GetDefaultGlobalSizeLimit(); | |
| 84 | |
| 85 protected: | |
| 86 // The amount of idle time before we consider a tab to be "inactive" | |
| 87 static const int kRendererInactiveThresholdMinutes = 5; | |
| 88 | |
| 89 // Keep track of some renderer information. | |
| 90 struct RendererInfo : blink::WebCache::UsageStats { | |
| 91 // The access time for this renderer. | |
| 92 base::Time access; | |
| 93 }; | |
| 94 | |
| 95 typedef std::map<int, RendererInfo> StatsMap; | |
| 96 | |
| 97 // An allocation is the number of bytes a specific renderer should use for | |
| 98 // its cache. | |
| 99 typedef std::pair<int,size_t> Allocation; | |
| 100 | |
| 101 // An allocation strategy is a list of allocations specifying the resources | |
| 102 // each renderer is permitted to consume for its cache. | |
| 103 typedef std::list<Allocation> AllocationStrategy; | |
| 104 | |
| 105 // This class is a singleton. Do not instantiate directly. | |
| 106 WebCacheManager(); | |
| 107 friend struct DefaultSingletonTraits<WebCacheManager>; | |
| 108 | |
| 109 virtual ~WebCacheManager(); | |
| 110 | |
| 111 // Recomputes the allocation of cache resources among the renderers. Also | |
| 112 // informs the renderers of their new allocation. | |
| 113 void ReviseAllocationStrategy(); | |
| 114 | |
| 115 // Schedules a call to ReviseAllocationStrategy after a short delay. | |
| 116 void ReviseAllocationStrategyLater(); | |
| 117 | |
| 118 // The various tactics used as part of an allocation strategy. To decide | |
| 119 // how many resources a given renderer should be allocated, we consider its | |
| 120 // usage statistics. Each tactic specifies the function that maps usage | |
| 121 // statistics to resource allocations. | |
| 122 // | |
| 123 // Determining a resource allocation strategy amounts to picking a tactic | |
| 124 // for each renderer and checking that the total memory required fits within | |
| 125 // our |global_size_limit_|. | |
| 126 enum AllocationTactic { | |
| 127 // Ignore cache statistics and divide resources equally among the given | |
| 128 // set of caches. | |
| 129 DIVIDE_EVENLY, | |
| 130 | |
| 131 // Allow each renderer to keep its current set of cached resources, with | |
| 132 // some extra allocation to store new objects. | |
| 133 KEEP_CURRENT_WITH_HEADROOM, | |
| 134 | |
| 135 // Allow each renderer to keep its current set of cached resources. | |
| 136 KEEP_CURRENT, | |
| 137 | |
| 138 // Allow each renderer to keep cache resources it believes are currently | |
| 139 // being used, with some extra allocation to store new objects. | |
| 140 KEEP_LIVE_WITH_HEADROOM, | |
| 141 | |
| 142 // Allow each renderer to keep cache resources it believes are currently | |
| 143 // being used, but instruct the renderer to discard all other data. | |
| 144 KEEP_LIVE, | |
| 145 }; | |
| 146 | |
| 147 // Helper functions for devising an allocation strategy | |
| 148 | |
| 149 // Add up all the stats from the given set of renderers and place the result | |
| 150 // in |stats|. | |
| 151 void GatherStats(const std::set<int>& renderers, | |
| 152 blink::WebCache::UsageStats* stats); | |
| 153 | |
| 154 // Get the amount of memory that would be required to implement |tactic| | |
| 155 // using the specified allocation tactic. This function defines the | |
| 156 // semantics for each of the tactics. | |
| 157 static size_t GetSize(AllocationTactic tactic, | |
| 158 const blink::WebCache::UsageStats& stats); | |
| 159 | |
| 160 // Attempt to use the specified tactics to compute an allocation strategy | |
| 161 // and place the result in |strategy|. |active_stats| and |inactive_stats| | |
| 162 // are the aggregate statistics for |active_renderers_| and | |
| 163 // |inactive_renderers_|, respectively. | |
| 164 // | |
| 165 // Returns |true| on success and |false| on failure. Does not modify | |
| 166 // |strategy| on failure. | |
| 167 bool AttemptTactic(AllocationTactic active_tactic, | |
| 168 const blink::WebCache::UsageStats& active_stats, | |
| 169 AllocationTactic inactive_tactic, | |
| 170 const blink::WebCache::UsageStats& inactive_stats, | |
| 171 AllocationStrategy* strategy); | |
| 172 | |
| 173 // For each renderer in |renderers|, computes its allocation according to | |
| 174 // |tactic| and add the result to |strategy|. Any |extra_bytes_to_allocate| | |
| 175 // is divided evenly among the renderers. | |
| 176 void AddToStrategy(const std::set<int>& renderers, | |
| 177 AllocationTactic tactic, | |
| 178 size_t extra_bytes_to_allocate, | |
| 179 AllocationStrategy* strategy); | |
| 180 | |
| 181 // Enact an allocation strategy by informing the renderers of their | |
| 182 // allocations according to |strategy|. | |
| 183 void EnactStrategy(const AllocationStrategy& strategy); | |
| 184 | |
| 185 enum ClearCacheOccasion { | |
| 186 // Instructs to clear the cache instantly. | |
| 187 INSTANTLY, | |
| 188 // Instructs to clear the cache when a navigation takes place (this | |
| 189 // includes reloading a tab). | |
| 190 ON_NAVIGATION | |
| 191 }; | |
| 192 | |
| 193 // Inform all |renderers| to clear their cache. | |
| 194 void ClearRendererCache(const std::set<int>& renderers, | |
| 195 ClearCacheOccasion occation); | |
| 196 | |
| 197 // Check to see if any active renderers have fallen inactive. | |
| 198 void FindInactiveRenderers(); | |
| 199 | |
| 200 // The global size limit for all in-memory caches. | |
| 201 size_t global_size_limit_; | |
| 202 | |
| 203 // Maps every renderer_id our most recent copy of its statistics. | |
| 204 StatsMap stats_; | |
| 205 | |
| 206 // Every renderer we think is still around is in one of these two sets. | |
| 207 // | |
| 208 // Active renderers are those renderers that have been active more recently | |
| 209 // than they have been inactive. | |
| 210 std::set<int> active_renderers_; | |
| 211 // Inactive renderers are those renderers that have been inactive more | |
| 212 // recently than they have been active. | |
| 213 std::set<int> inactive_renderers_; | |
| 214 | |
| 215 base::WeakPtrFactory<WebCacheManager> weak_factory_; | |
| 216 | |
| 217 content::NotificationRegistrar registrar_; | |
| 218 | |
| 219 DISALLOW_COPY_AND_ASSIGN(WebCacheManager); | |
| 220 }; | |
| 221 | |
| 222 #endif // CHROME_BROWSER_RENDERER_HOST_WEB_CACHE_MANAGER_H_ | |
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Chromium Code Reviews
Issue 528363002:
Move webCacheManager to //components. (Closed)
Base URL: https://chromium.googlesource.com/chromium/src.git@master