in_gc_stat: Add use_symbol_keys parameter

lib/fluent/plugin/in_gc_stat.rb

@@ -24,13 +24,22 @@ class GCStatInput < Fluent::Plugin::Input
 
     def initialize
       super
+      @key_map = nil
     end
 
     config_param :emit_interval, :time, default: 60
+    config_param :use_symbol_keys, :bool, default: true
     config_param :tag, :string
 
     def configure(conf)
       super
+
+      unless @use_symbol_keys
+        @key_map = {}
+        GC.stat.each_key { |key|
+          @key_map[key] = key.to_s
+        }
+      end
     end
 
     def multi_workers_ready?
@@ -50,6 +59,13 @@ def shutdown
     def on_timer
       now = Fluent::EventTime.now
       record = GC.stat
+      unless @use_symbol_keys
+        new_record = {}
+        record.each_pair { |k, v|
+          new_record[@key_map[k]] = v
+        }
+        record = new_record
+      end
       router.emit(@tag, now, record)
     end
   end

test/plugin/test_in_gc_stat.rb

@@ -22,9 +22,14 @@ def test_configure
     assert_equal("t1", d.instance.tag)
   end
 
-  def test_emit
+  def setup_gc_stat
     stat = GC.stat
     stub(GC).stat { stat }
+    stat
+  end
+
+  def test_emit
+    stat = setup_gc_stat
 
     d = create_driver
     d.run(expect_emits: 2)
@@ -36,4 +41,22 @@ def test_emit
       assert(events[i][1].is_a?(Fluent::EventTime))
     }
   end
+
+  def test_emit_with_use_symbol_keys_false
+    stat = setup_gc_stat
+    result = {}
+    stat.each_pair { |k, v|
+      result[k.to_s] = v
+    }
+
+    d = create_driver(CONFIG + "use_symbol_keys false")
+    d.run(expect_emits: 2)
+
+    events = d.events
+    assert(events.length > 0)
+    events.each_index {|i|
+      assert_equal(result, events[i][2])
+      assert(events[i][1].is_a?(Fluent::EventTime))
+    }
+  end
 end