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Reintroduce cache with tests

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1 parent cafed35 commit f767ac22fa213df754e160c59189d28ed4f95568 @sgrif sgrif committed Nov 19, 2014
@@ -3,13 +3,15 @@ module Type
class HashLookupTypeMap < TypeMap # :nodoc:
delegate :key?, to: :@mapping
- def fetch(type, *args, &block)
- @mapping.fetch(type, block).call(type, *args)
- end
-
def alias_type(type, alias_type)
register_type(type) { |_, *args| lookup(alias_type, *args) }
end
+
+ private
+
+ def perform_fetch(type, *args, &block)
+ @mapping.fetch(type, block).call(type, *args)
+ end
end
end
end
@@ -3,26 +3,22 @@ module Type
class TypeMap # :nodoc:
def initialize
@mapping = {}
+ @cache = Hash.new do |h, key|
+ h[key] = {}
+ end
end
def lookup(lookup_key, *args)
fetch(lookup_key, *args) { default_value }
end
- def fetch(lookup_key, *args)
- matching_pair = @mapping.reverse_each.detect do |key, _|
- key === lookup_key
- end
-
- if matching_pair
- matching_pair.last.call(lookup_key, *args)
- else
- yield lookup_key, *args
- end
+ def fetch(lookup_key, *args, &block)
+ @cache[lookup_key][args] ||= perform_fetch(lookup_key, *args, &block)
end
def register_type(key, value = nil, &block)
raise ::ArgumentError unless value || block
+ @cache.clear
if block
@mapping[key] = block
@@ -44,6 +40,18 @@ def clear
private
+ def perform_fetch(lookup_key, *args)
+ matching_pair = @mapping.reverse_each.detect do |key, _|
+ key === lookup_key
+ end
+
+ if matching_pair
+ matching_pair.last.call(lookup_key, *args)
+ else
+ yield lookup_key, *args
+ end
+ end
+
def default_value
@default_value ||= Value.new
end
@@ -139,6 +139,38 @@ def test_fetch_yields_args
assert_equal "foo-1-2-3", mapping.fetch("foo", 1, 2, 3) { |*args| args.join("-") }
assert_equal "bar-1-2-3", mapping.fetch("bar", 1, 2, 3) { |*args| args.join("-") }
end
+
+ def test_fetch_memoizes
+ mapping = TypeMap.new
+
+ looked_up = false
+ mapping.register_type(1) do
+ fail if looked_up
+ looked_up = true
+ "string"
+ end
+
+ assert_equal "string", mapping.fetch(1)
+ assert_equal "string", mapping.fetch(1)
+ end
+
+ def test_fetch_memoizes_on_args
+ mapping = TypeMap.new
+ mapping.register_type("foo") { |*args| args.join("-") }
+
+ assert_equal "foo-1-2-3", mapping.fetch("foo", 1, 2, 3) { |*args| args.join("-") }
+ assert_equal "foo-2-3-4", mapping.fetch("foo", 2, 3, 4) { |*args| args.join("-") }
+ end
+
+ def test_register_clears_cache
+ mapping = TypeMap.new
+
+ mapping.register_type(1, "string")
+ mapping.lookup(1)
+ mapping.register_type(1, "int")
+
+ assert_equal "int", mapping.lookup(1)
+ end
end
end
end

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