lib/rufus/lru.rb in rufus-lru-1.0.4 vs lib/rufus/lru.rb in rufus-lru-1.0.5

@@ -20,15 +20,17 @@
 # THE SOFTWARE.
 #
 # "made in Japan"
 #++
 
+require 'thread'
 
+
 module Rufus
 module Lru
 
-  VERSION = '1.0.4'
+  VERSION = '1.0.5'
 
   #
   # A Hash that has a max size. After the maxsize has been reached, the
   # least recently used entries (LRU hence), will be discared to make
   # room for the new entries.
@@ -44,11 +46,12 @@
   #
   #   h[:newer] = "b"
   #
   #   puts h.inspect # >> {:newer=>"b", 3=>"aaa", 4=>"aaaa"}
   #
-  # Nota bene: this class is not threadsafe.
+  # Nota bene: this class is not thread-safe. If you need something thread-safe,
+  # use Rufus::Lru::SynchronizedHash.
   #
   class Hash < ::Hash
 
     attr_reader :maxsize
     attr_reader :lru_keys
@@ -139,11 +142,36 @@
       while size >= @maxsize
         delete(@lru_keys.delete_at(0))
       end
     end
   end
+
+  #
+  # A thread-safe version of the lru hash.
+  #
+  class SynchronizedHash < Hash
+
+    def initialize(maxsize)
+
+      super
+      @mutex = Mutex.new
+    end
+
+    def [](key)
+
+      @mutex.synchronize { super }
+    end
+
+    def []=(key, value)
+
+      @mutex.synchronize { super }
+    end
+  end
 end
 end
 
-class LruHash < Rufus::Lru::Hash
-end
+
+#
+# The original LruHash class, kept for backward compatibility.
+#
+class LruHash < Rufus::Lru::Hash; end