diff options
Diffstat (limited to 'activesupport')
-rw-r--r-- | activesupport/lib/active_support/weak_hash.rb | 41 | ||||
-rw-r--r-- | activesupport/test/weak_hash_test.rb | 33 |
2 files changed, 74 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/weak_hash.rb b/activesupport/lib/active_support/weak_hash.rb new file mode 100644 index 0000000000..d6096e606e --- /dev/null +++ b/activesupport/lib/active_support/weak_hash.rb @@ -0,0 +1,41 @@ +module ActiveSupport + if defined?(RUBY_ENGINE) && RUBY_ENGINE == 'jruby' + WeakHash = ::Weakling::WeakHash + else + class WeakHash + def initialize(cache = Hash.new) + @cache = cache + @key_map = {} + @rev_cache = Hash.new{|h,k| h[k] = {}} + @reclaim_value = lambda do |value_id| + if value = @rev_cache.delete(value_id) + value.each_key{|key| @cache.delete key} + end + end + end + + def [](key) + value_id = @cache[key] + value_id && ObjectSpace._id2ref(value_id) + rescue RangeError + nil + end + + def []=(key, value) + @rev_cache[value.object_id][key] = true + @cache[key] = value.object_id + @key_map[key.object_id] = key + + ObjectSpace.define_finalizer(value, @reclaim_value) + end + + def clear + @cache.clear + end + + def delete(key) + @cache.delete(key) + end + end + end +end diff --git a/activesupport/test/weak_hash_test.rb b/activesupport/test/weak_hash_test.rb new file mode 100644 index 0000000000..7d1620dc34 --- /dev/null +++ b/activesupport/test/weak_hash_test.rb @@ -0,0 +1,33 @@ +require 'abstract_unit' +require 'active_support/weak_hash' + +class WeakHashTest < ActiveSupport::TestCase + + def setup + @weak_hash = ActiveSupport::WeakHash.new + @str = "A"; + @obj = Object.new + end + + test "allows us to assign value, and return assigned value" do + a = @str; b = @obj + assert_equal @weak_hash[a] = b, b + end + + test "should allow us to assign and read value" do + a = @str; b = @obj + assert_equal @weak_hash[a] = b, b + assert_equal @weak_hash[a], b + end + + test "should use object_id to identify objects" do + a = Object.new + @weak_hash[a] = "b" + assert_nil @weak_hash[a.dup] + end + + test "should find objects that have same hash" do + @weak_hash["a"] = "b" + assert_equal "b", @weak_hash["a"] + end +end |