Support DB#increment.

lib/kyotocabinet.rb

@@ -108,6 +108,11 @@ def get(key)
     end
     alias_method :[], :get
 
+    alias_method :_increment, :increment
+    def increment(key, num=0, orig=0)
+      self._increment(key, num, orig)
+    end
+
     alias_method :_set, :set
     def set(k, v)
       self._set(k.to_java_bytes, v.to_s.to_java_bytes)

spec/kyotocabinet_spec.rb

@@ -16,10 +16,25 @@ module KyotoCabinet
         @db = DB.new
         @db.open("%", KyotoCabinet::DB::OWRITER | KyotoCabinet::DB::OCREATE)
         @db["hello"] = "world"
+        @db["int_a"] = [0].pack("Q>")
       end
 
-      it "returns nil from get properly" do
-        @db.get("foo").should be_nil
+      describe "#get" do
+        it "returns nil properly" do
+          @db.get("foo").should be_nil
+        end
+      end
+
+      describe "#increment" do
+        it "creates a value with one arg" do
+          @db.increment("int_z")
+          @db["int_z"].should_not be_nil
+        end
+
+        it "increments with two args" do
+          @db.increment("int_a", 1)
+          @db["int_a"].unpack("Q>")[0].should == 1
+        end
       end
 
       after(:each) do