cc/tiles/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_TILES_TILE_PRIORITY_H_
   6 #define CC_TILES_TILE_PRIORITY_H_
   7
   8 #include <algorithm>
   9 #include <limits>
  10 #include <string>
  11
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/trace_event/trace_event_argument.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   LAST_TREE = 1
  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   void AsValueInto(base::trace_event::TracedValue* dict) const;
  55
  56   bool IsHigherPriorityThan(const TilePriority& other) const {
  57     return priority_bin < other.priority_bin ||
  58            (priority_bin == other.priority_bin &&
  59             distance_to_visible < other.distance_to_visible);
  60   }
  61
  62   TileResolution resolution;
  63   PriorityBin priority_bin;
  64   float distance_to_visible;
  65 };
  66
  67 std::string TilePriorityBinToString(TilePriority::PriorityBin bin);
  68
  69 enum TileMemoryLimitPolicy {
  70   // Nothing. This mode is used when visible is set to false.
  71   ALLOW_NOTHING = 0,
  72
  73   // You might be made visible, but you're not being interacted with.
  74   ALLOW_ABSOLUTE_MINIMUM = 1,  // Tall.
  75
  76   // You're being interacted with, but we're low on memory.
  77   ALLOW_PREPAINT_ONLY = 2,  // Grande.
  78
  79   // You're the only thing in town. Go crazy.
  80   ALLOW_ANYTHING = 3  // Venti.
  81 };
  82 std::string TileMemoryLimitPolicyToString(TileMemoryLimitPolicy policy);
  83
  84 enum TreePriority {
  85   SAME_PRIORITY_FOR_BOTH_TREES,
  86   SMOOTHNESS_TAKES_PRIORITY,
  87   NEW_CONTENT_TAKES_PRIORITY,
  88   LAST_TREE_PRIORITY = NEW_CONTENT_TAKES_PRIORITY
  89   // Be sure to update TreePriorityAsValue when adding new fields.
  90 };
  91 std::string TreePriorityToString(TreePriority prio);
  92
  93 class GlobalStateThatImpactsTilePriority {
  94  public:
  95   GlobalStateThatImpactsTilePriority()
  96       : memory_limit_policy(ALLOW_NOTHING),
  97         soft_memory_limit_in_bytes(0),
  98         hard_memory_limit_in_bytes(0),
  99         num_resources_limit(0),
 100         tree_priority(SAME_PRIORITY_FOR_BOTH_TREES) {}
 101
 102   TileMemoryLimitPolicy memory_limit_policy;
 103
 104   size_t soft_memory_limit_in_bytes;
 105   size_t hard_memory_limit_in_bytes;
 106   size_t num_resources_limit;
 107
 108   TreePriority tree_priority;
 109
 110   bool operator==(const GlobalStateThatImpactsTilePriority& other) const {
 111     return memory_limit_policy == other.memory_limit_policy &&
 112            soft_memory_limit_in_bytes == other.soft_memory_limit_in_bytes &&
 113            hard_memory_limit_in_bytes == other.hard_memory_limit_in_bytes &&
 114            num_resources_limit == other.num_resources_limit &&
 115            tree_priority == other.tree_priority;
 116   }
 117   bool operator!=(const GlobalStateThatImpactsTilePriority& other) const {
 118     return !(*this == other);
 119   }
 120
 121   void AsValueInto(base::trace_event::TracedValue* dict) const;
 122 };
 123
 124 }  // namespace cc
 125
 126 #endif  // CC_TILES_TILE_PRIORITY_H_