Add plugin helpers for parser and formatter

lib/fluent/plugin_helper.rb

@@ -20,6 +20,8 @@
 require 'fluent/plugin_helper/timer'
 require 'fluent/plugin_helper/child_process'
 require 'fluent/plugin_helper/storage'
+require 'fluent/plugin_helper/parser'
+require 'fluent/plugin_helper/formatter'
 require 'fluent/plugin_helper/retry_state'
 require 'fluent/plugin_helper/compat_parameters'
 

lib/fluent/plugin_helper/formatter.rb

@@ -0,0 +1,141 @@
+#
+# Fluentd
+#
+#    Licensed under the Apache License, Version 2.0 (the "License");
+#    you may not use this file except in compliance with the License.
+#    You may obtain a copy of the License at
+#
+#        http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS,
+#    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#    See the License for the specific language governing permissions and
+#    limitations under the License.
+#
+
+require 'monitor'
+require 'forwardable'
+
+require 'fluent/plugin'
+require 'fluent/plugin/formatter'
+require 'fluent/config/element'
+
+module Fluent
+  module PluginHelper
+    module Formatter
+      def formatter_create(usage: '', type: nil, conf: nil)
+        formatter = @_formatters[usage]
+        return formatter if formatter
+
+        if !type
+          raise ArgumentError, "BUG: both type and conf are not specified" unless conf
+          raise Fluent::ConfigError, "@type is not specified for <format>" unless conf['@type']
+          type = conf['@type']
+        end
+        formatter = Fluent::Plugin.new_formatter(type, parent: self)
+        config = case conf
+                 when Fluent::Config::Element
+                   conf
+                 when Hash
+                   # in code, programmer may use symbols as keys, but Element needs strings
+                   conf = Hash[conf.map{|k,v| [k.to_s, v]}]
+                   Fluent::Config::Element.new('format', usage, conf, [])
+                 when nil
+                   Fluent::Config::Element.new('format', usage, {}, [])
+                 else
+                   raise ArgumentError, "BUG: conf must be a Element, Hash (or unspecified), but '#{conf.class}'"
+                 end
+        formatter.configure(config)
+        if @_formatters_started
+          formatter.start
+        end
+
+        @_formatters[usage] = formatter
+        formatter
+      end
+
+      def self.included(mod)
+        mod.instance_eval do
+          # minimum section definition to instantiate formatter plugin instances
+          config_section :format, required: false, multi: true, param_name: :formatter_configs do
+            config_argument :usage, :string, default: ''
+            config_param    :@type, :string
+          end
+        end
+      end
+
+      attr_reader :_formatters # for tests
+
+      def initialize
+        super
+        @_formatters_started = false
+        @_formatters = {} # usage => formatter
+      end
+
+      def configure(conf)
+        super
+
+        @formatter_configs.each do |section|
+          if @_formatters[section.usage]
+            raise Fluent::ConfigError, "duplicated formatter configured: #{section.usage}"
+          end
+          formatter = Plugin.new_formatter(section[:@type], parent: self)
+          formatter.configure(section.corresponding_config_element)
+          @_formatters[section.usage] = formatter
+        end
+      end
+
+      def start
+        super
+        @_formatters_started = true
+        @_formatters.each_pair do |usage, formatter|
+          formatter.start
+        end
+      end
+
+      def formatter_operate(method_name, &block)
+        @_formatters.each_pair do |usage, formatter|
+          begin
+            formatter.send(method_name)
+            block.call(formatter) if block_given?
+          rescue => e
+            log.error "unexpected error while #{method_name}", usage: usage, formatter: formatter, error: e
+          end
+        end
+      end
+
+      def stop
+        super
+        # timer stops automatically in super
+        formatter_operate(:stop)
+      end
+
+      def before_shutdown
+        formatter_operate(:before_shutdown)
+        super
+      end
+
+      def shutdown
+        formatter_operate(:shutdown)
+        super
+      end
+
+      def after_shutdown
+        formatter_operate(:after_shutdown)
+        super
+      end
+
+      def close
+        formatter_operate(:close)
+        super
+      end
+
+      def terminate
+        formatter_operate(:terminate)
+        @_formatters = {}
+        super
+      end
+    end
+  end
+end

lib/fluent/plugin_helper/parser.rb

@@ -0,0 +1,141 @@
+#
+# Fluentd
+#
+#    Licensed under the Apache License, Version 2.0 (the "License");
+#    you may not use this file except in compliance with the License.
+#    You may obtain a copy of the License at
+#
+#        http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS,
+#    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#    See the License for the specific language governing permissions and
+#    limitations under the License.
+#
+
+require 'monitor'
+require 'forwardable'
+
+require 'fluent/plugin'
+require 'fluent/plugin/parser'
+require 'fluent/config/element'
+
+module Fluent
+  module PluginHelper
+    module Parser
+      def parser_create(usage: '', type: nil, conf: nil)
+        parser = @_parsers[usage]
+        return parser if parser
+
+        if !type
+          raise ArgumentError, "BUG: both type and conf are not specified" unless conf
+          raise Fluent::ConfigError, "@type is not specified for <parse>" unless conf['@type']
+          type = conf['@type']
+        end
+        parser = Fluent::Plugin.new_parser(type, parent: self)
+        config = case conf
+                 when Fluent::Config::Element
+                   conf
+                 when Hash
+                   # in code, programmer may use symbols as keys, but Element needs strings
+                   conf = Hash[conf.map{|k,v| [k.to_s, v]}]
+                   Fluent::Config::Element.new('parse', usage, conf, [])
+                 when nil
+                   Fluent::Config::Element.new('parse', usage, {}, [])
+                 else
+                   raise ArgumentError, "BUG: conf must be a Element, Hash (or unspecified), but '#{conf.class}'"
+                 end
+        parser.configure(config)
+        if @_parsers_started
+          parser.start
+        end
+
+        @_parsers[usage] = parser
+        parser
+      end
+
+      def self.included(mod)
+        mod.instance_eval do
+          # minimum section definition to instantiate parser plugin instances
+          config_section :parse, required: false, multi: true, param_name: :parser_configs do
+            config_argument :usage, :string, default: ''
+            config_param    :@type, :string
+          end
+        end
+      end
+
+      attr_reader :_parsers # for tests
+
+      def initialize
+        super
+        @_parsers_started = false
+        @_parsers = {} # usage => parser
+      end
+
+      def configure(conf)
+        super
+
+        @parser_configs.each do |section|
+          if @_parsers[section.usage]
+            raise Fluent::ConfigError, "duplicated parsers configured: #{section.usage}"
+          end
+          parser = Plugin.new_parser(section[:@type], parent: self)
+          parser.configure(section.corresponding_config_element)
+          @_parsers[section.usage] = parser
+        end
+      end
+
+      def start
+        super
+        @_parsers_started = true
+        @_parsers.each_pair do |usage, parser|
+          parser.start
+        end
+      end
+
+      def parser_operate(method_name, &block)
+        @_parsers.each_pair do |usage, parser|
+          begin
+            parser.send(method_name)
+            block.call(parser) if block_given?
+          rescue => e
+            log.error "unexpected error while #{method_name}", usage: usage, parser: parser, error: e
+          end
+        end
+      end
+
+      def stop
+        super
+        # timer stops automatically in super
+        parser_operate(:stop)
+      end
+
+      def before_shutdown
+        parser_operate(:before_shutdown)
+        super
+      end
+
+      def shutdown
+        parser_operate(:shutdown)
+        super
+      end
+
+      def after_shutdown
+        parser_operate(:after_shutdown)
+        super
+      end
+
+      def close
+        parser_operate(:close)
+        super
+      end
+
+      def terminate
+        parser_operate(:terminate)
+        @_parsers = {}
+        super
+      end
+    end
+  end
+end