cc/resources/tile_priority.h

   1 // Copyright 2012 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 CC_RESOURCES_TILE_PRIORITY_H_
   6 #define CC_RESOURCES_TILE_PRIORITY_H_
   7
   8 #include <algorithm>
   9 #include <limits>
  10 #include <string>
  11
  12 #include "base/debug/trace_event_argument.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "cc/base/cc_export.h"
  15
  16 namespace base {
  17 class Value;
  18 }
  19
  20 namespace cc {
  21
  22 enum WhichTree {
  23   // Note: these must be 0 and 1 because we index with them in various places,
  24   // e.g. in Tile::priority_.
  25   ACTIVE_TREE = 0,
  26   PENDING_TREE = 1,
  27   NUM_TREES = 2
  28   // Be sure to update WhichTreeAsValue when adding new fields.
  29 };
  30 scoped_ptr<base::Value> WhichTreeAsValue(WhichTree tree);
  31
  32 enum TileResolution {
  33   LOW_RESOLUTION = 0 ,
  34   HIGH_RESOLUTION = 1,
  35   NON_IDEAL_RESOLUTION = 2,
  36 };
  37 std::string TileResolutionToString(TileResolution resolution);
  38
  39 struct CC_EXPORT TilePriority {
  40   enum PriorityBin { NOW, SOON, EVENTUALLY };
  41
  42   TilePriority()
  43       : resolution(NON_IDEAL_RESOLUTION),
  44         priority_bin(EVENTUALLY),
  45         distance_to_visible(std::numeric_limits<float>::infinity()) {}
  46
  47   TilePriority(TileResolution resolution,
  48                PriorityBin bin,
  49                float distance_to_visible)
  50       : resolution(resolution),
  51         priority_bin(bin),
  52         distance_to_visible(distance_to_visible) {}
  53
  54   TilePriority(const TilePriority& active, const TilePriority& pending) {
  55     if (active.resolution == HIGH_RESOLUTION ||
  56         pending.resolution == HIGH_RESOLUTION)
  57       resolution = HIGH_RESOLUTION;
  58     else if (active.resolution == LOW_RESOLUTION ||
  59              pending.resolution == LOW_RESOLUTION)
  60       resolution = LOW_RESOLUTION;
  61     else
  62       resolution = NON_IDEAL_RESOLUTION;
  63
  64     if (active.priority_bin < pending.priority_bin) {
  65       priority_bin = active.priority_bin;
  66       distance_to_visible = active.distance_to_visible;
  67     } else if (active.priority_bin > pending.priority_bin) {
  68       priority_bin = pending.priority_bin;
  69       distance_to_visible = pending.distance_to_visible;
  70     } else {
  71       priority_bin = active.priority_bin;
  72       distance_to_visible =
  73           std::min(active.distance_to_visible, pending.distance_to_visible);
  74     }
  75   }
  76
  77   void AsValueInto(base::debug::TracedValue* dict) const;
  78
  79   bool operator ==(const TilePriority& other) const {
  80     return resolution == other.resolution &&
  81            priority_bin == other.priority_bin &&
  82            distance_to_visible == other.distance_to_visible;
  83   }
  84
  85   bool operator !=(const TilePriority& other) const {
  86     return !(*this == other);
  87   }
  88
  89   bool IsHigherPriorityThan(const TilePriority& other) const {
  90     return priority_bin < other.priority_bin ||
  91            (priority_bin == other.priority_bin &&
  92             distance_to_visible < other.distance_to_visible);
  93   }
  94
  95   TileResolution resolution;
  96   PriorityBin priority_bin;
  97   float distance_to_visible;
  98 };
  99
 100 std::string TilePriorityBinToString(TilePriority::PriorityBin bin);
 101
 102 enum TileMemoryLimitPolicy {
 103   // Nothing. This mode is used when visible is set to false.
 104   ALLOW_NOTHING = 0,
 105
 106   // You might be made visible, but you're not being interacted with.
 107   ALLOW_ABSOLUTE_MINIMUM = 1,  // Tall.
 108
 109   // You're being interacted with, but we're low on memory.
 110   ALLOW_PREPAINT_ONLY = 2,  // Grande.
 111
 112   // You're the only thing in town. Go crazy.
 113   ALLOW_ANYTHING = 3  // Venti.
 114 };
 115 std::string TileMemoryLimitPolicyToString(TileMemoryLimitPolicy policy);
 116
 117 enum TreePriority {
 118   SAME_PRIORITY_FOR_BOTH_TREES,
 119   SMOOTHNESS_TAKES_PRIORITY,
 120   NEW_CONTENT_TAKES_PRIORITY,
 121   NUM_TREE_PRIORITIES
 122   // Be sure to update TreePriorityAsValue when adding new fields.
 123 };
 124 std::string TreePriorityToString(TreePriority prio);
 125
 126 class GlobalStateThatImpactsTilePriority {
 127  public:
 128   GlobalStateThatImpactsTilePriority()
 129       : memory_limit_policy(ALLOW_NOTHING),
 130         soft_memory_limit_in_bytes(0),
 131         hard_memory_limit_in_bytes(0),
 132         num_resources_limit(0),
 133         tree_priority(SAME_PRIORITY_FOR_BOTH_TREES) {}
 134
 135   TileMemoryLimitPolicy memory_limit_policy;
 136
 137   size_t soft_memory_limit_in_bytes;
 138   size_t hard_memory_limit_in_bytes;
 139   size_t num_resources_limit;
 140
 141   TreePriority tree_priority;
 142
 143   bool operator==(const GlobalStateThatImpactsTilePriority& other) const {
 144     return memory_limit_policy == other.memory_limit_policy &&
 145            soft_memory_limit_in_bytes == other.soft_memory_limit_in_bytes &&
 146            hard_memory_limit_in_bytes == other.hard_memory_limit_in_bytes &&
 147            num_resources_limit == other.num_resources_limit &&
 148            tree_priority == other.tree_priority;
 149   }
 150   bool operator!=(const GlobalStateThatImpactsTilePriority& other) const {
 151     return !(*this == other);
 152   }
 153
 154   void AsValueInto(base::debug::TracedValue* dict) const;
 155 };
 156
 157 }  // namespace cc
 158
 159 #endif  // CC_RESOURCES_TILE_PRIORITY_H_