Add 'handler_forward' plugin.

lib/droonga/plugin/handler_forward.rb

@@ -0,0 +1,69 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2013 droonga project
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License version 2.1 as published by the Free Software Foundation.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+require "droonga/handler"
+
+module Droonga
+  class MergeHandler < Droonga::Handler
+    Droonga::HandlerPlugin.register("forward", self)
+
+    CONFIG_FILE_PATH = 'config.json'
+
+    def handlable?(command)
+      true
+    end
+
+    def handle(command, request, *arguments)
+      destination = get_destination
+      post(request,
+           "to" => destination, "type" => command, "arguments" => arguments)
+    rescue => exception
+      if $log
+        $log.error "error while handling #{command}",
+          request: request,
+          arguments: arguments,
+          exception: exception
+        $log.error_backtrace
+      end
+    end
+
+    def get_destination
+      loop do
+        refresh_config
+        if @config && @config["forward"]
+          path = @context.database.path
+          destination = @config["forward"][path]
+          return destination unless destination.nil? || destination.empty?
+          sleep 5
+        end
+      end
+    end
+
+    def refresh_config
+      unless File.exists?(CONFIG_FILE_PATH)
+        @config = nil
+        return
+      end
+      mtime = File.mtime(CONFIG_FILE_PATH)
+      return if @config_mtime == mtime
+      open(CONFIG_FILE_PATH) do |file|
+        @config = JSON.parse(file.read)
+      end
+      @config_mtime = mtime
+    end
+  end
+end