Add suspend option to in dummy plugin

lib/fluent/plugin/in_dummy.rb

@@ -26,13 +26,16 @@ class DummyInput < Input
     helpers :thread, :storage
 
     BIN_NUM = 10
+    DEFAULT_STORAGE_TYPE = 'local'
 
     desc "The value is the tag assigned to the generated events."
     config_param :tag, :string
     desc "It configures how many events to generate per second."
     config_param :rate, :integer, default: 1
     desc "If specified, each generated event has an auto-incremented key field."
     config_param :auto_increment_key, :string, default: nil
+    desc "The boolean to suspend-and-resume incremental value after restart"
+    config_param :suspend, :bool, default: false
     desc "The dummy data to be generated. An array of JSON hashes or a single JSON hash."
     config_param :dummy, default: [{"message"=>"dummy"}] do |val|
       begin
@@ -58,12 +61,16 @@ def initialize
     def configure(conf)
       super
       @dummy_index = 0
+      config = conf.elements.select{|e| e.name == 'storage' }.first
+      @storage = storage_create(usage: 'suspend', conf: config, default_type: DEFAULT_STORAGE_TYPE)
     end
 
     def start
       super
 
-      @storage = storage_create(type: 'local')
+      @storage.put(:increment_value, 0) unless @storage.get(:increment_value)
+      @storage.put(:dummy_index, 0) unless @storage.get(:dummy_index)
+
       if @auto_increment_key && !@storage.get(:auto_increment_value)
         @storage.put(:auto_increment_value, -1)
       end
@@ -100,7 +107,7 @@ def generate
       d = @dummy[@dummy_index]
       unless d
         @dummy_index = 0
-        d = @dummy[0]
+        d = @dummy[@dummy_index]
       end
       @dummy_index += 1
       if @auto_increment_key

lib/fluent/plugin/storage_local.rb

@@ -58,7 +58,7 @@ def configure(conf)
               raise Fluent::ConfigError, "Unexpected error: failed to read data from plugin storage file: '#{@path}'"
             end
           else
-            raise Fluent::ConfigError, "Directory is not writable for plugin storage file '#{@path}'" unless File.writable?(@path)
+            raise Fluent::ConfigError, "Directory is not writable for plugin storage file '#{dir}'" unless File.writable?(dir)
           end
         end
       end

test/plugin/test_in_dummy.rb

@@ -1,6 +1,7 @@
 require_relative '../helper'
 require 'fluent/test/driver/input'
 require 'fluent/plugin/in_dummy'
+require 'fileutils'
 
 class DummyTest < Test::Unit::TestCase
   def setup
@@ -90,4 +91,98 @@ def create_driver(conf)
       end
     end
   end
+
+  TEST_PLUGIN_STORAGE_PATH = File.join( File.dirname(File.dirname(__FILE__)), 'tmp', 'in_dummy', 'store' )
+  FileUtils.mkdir_p TEST_PLUGIN_STORAGE_PATH
+
+  sub_test_case "doesn't suspend internal counters in default" do
+    config1 = {
+      'tag' => 'dummy',
+      'rate' => '2',
+      'dummy' => '[{"x": 1, "y": "1"}, {"x": 2, "y": "2"}, {"x": 3, "y": "3"}]',
+      'auto_increment_key' => 'id',
+      'suspend' => false,
+    }
+    conf1 = config_element('ROOT', '', config1, [])
+    test "value of auto increment key is not suspended after stop-and-start" do
+      assert !File.exist?(File.join(TEST_PLUGIN_STORAGE_PATH, 'json', 'test-01.json'))
+
+      d1 = create_driver(conf1)
+      d1.run(timeout: 0.5) do
+        d1.instance.emit(4)
+      end
+
+      first_id1 = d1.events.first[2]['id']
+      assert_equal 0, first_id1
+
+      last_id1 = d1.events.last[2]['id']
+      assert { last_id1 > 0 }
+
+      assert !File.exist?(File.join(TEST_PLUGIN_STORAGE_PATH, 'json', 'test-01.json'))
+
+      d2 = create_driver(conf1)
+      d2.run(timeout: 0.5) do
+        d2.instance.emit(4)
+      end
+
+      first_id2 = d2.events.first[2]['id']
+      assert_equal 0, first_id2
+
+      assert !File.exist?(File.join(TEST_PLUGIN_STORAGE_PATH, 'json', 'test-01.json'))
+    end
+  end
+
+  sub_test_case "suspend internal counters if suspend is true" do
+    setup do
+      FileUtils.rm_rf(TEST_PLUGIN_STORAGE_PATH)
+      FileUtils.mkdir_p(File.join(TEST_PLUGIN_STORAGE_PATH, 'json'))
+      FileUtils.chmod_R(0755, File.join(TEST_PLUGIN_STORAGE_PATH, 'json'))
+    end
+
+    config2 = {
+      '@id' => 'test-02',
+      'tag' => 'dummy',
+      'rate' => '2',
+      'dummy' => '[{"x": 1, "y": "1"}, {"x": 2, "y": "2"}, {"x": 3, "y": "3"}]',
+      'auto_increment_key' => 'id',
+      'suspend' => true,
+    }
+    conf2 = config_element('ROOT', '', config2, [
+              config_element(
+                'storage', '',
+                {'@type' => 'local',
+                 '@id' => 'test-02',
+                 'path' => File.join(TEST_PLUGIN_STORAGE_PATH,
+                                     'json', 'test-02.json'),
+                 'persistent' => true,
+                })
+            ])
+    test "value of auto increment key is suspended after stop-and-start" do
+      assert !File.exist?(File.join(TEST_PLUGIN_STORAGE_PATH, 'json', 'test-02.json'))
+
+      d1 = create_driver(conf2)
+      d1.run(timeout: 0.5) do
+        d1.instance.emit(4)
+      end
+
+      first_id1 = d1.events.first[2]['id']
+      assert_equal 0, first_id1
+
+      last_id1 = d1.events.last[2]['id']
+      assert { last_id1 > 0 }
+
+      assert File.exist?(File.join(TEST_PLUGIN_STORAGE_PATH, 'json', 'test-02.json'))
+
+      d2 = create_driver(conf2)
+      d2.run(timeout: 0.5) do
+        d2.instance.emit(4)
+      end
+      d2.events
+
+      first_id2 = d2.events.first[2]['id']
+      assert_equal last_id1 + 1, first_id2
+
+      assert File.exist?(File.join(TEST_PLUGIN_STORAGE_PATH, 'json', 'test-02.json'))
+    end
+  end
 end