Class: Google::Protobuf::LegacyObjectCache

Inherits:
Object
  • Object
show all
Defined in:
lib/google/protobuf/object_cache.rb

Instance Method Summary collapse

Constructor Details

#initialize ⇒ LegacyObjectCache

Returns a new instance of LegacyObjectCache.



42
43
44
45
46
 
# File 'lib/google/protobuf/object_cache.rb', line 42

def initialize
  @secondary_map = {}
  @map = ObjectSpace::WeakMap.new
  @mutex = Mutex.new
end

Instance Method Details

#get(key) ⇒ Object 



48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
 
# File 'lib/google/protobuf/object_cache.rb', line 48

def get(key)
  value = if secondary_key = @secondary_map[key]
    @map[secondary_key]
  else
    @mutex.synchronize do
      @map[(@secondary_map[key] ||= Object.new)]
    end
  end

  # GC if we could remove at least 2000 entries or 20% of the table size
  # (whichever is greater).  Since the cost of the GC pass is O(N), we
  # want to make sure that we condition this on overall table size, to
  # avoid O(N^2) CPU costs.
  cutoff = (@secondary_map.size * 0.2).ceil
  cutoff = 2_000 if cutoff < 2_000
  if (@secondary_map.size - @map.size) > cutoff
    purge
  end

  value
end

#try_add(key, value) ⇒ Object 



70
71
72
73
74
75
76
77
78
79
80
81
 
# File 'lib/google/protobuf/object_cache.rb', line 70

def try_add(key, value)
  if secondary_key = @secondary_map[key]
    if old_value = @map[secondary_key]
      return old_value
    end
  end

  @mutex.synchronize do
    secondary_key ||= (@secondary_map[key] ||= Object.new)
    @map[secondary_key] ||= value
  end
end