| #-- |
| # Licensed to the Apache Software Foundation (ASF) under one |
| # or more contributor license agreements. See the NOTICE file |
| # distributed with this work for additional information |
| # regarding copyright ownership. The ASF licenses this file |
| # to you 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. |
| #++ |
| |
| module Qpid |
| |
| module Messaging |
| |
| # +Receiver+ is the entity through which messages are received. |
| # |
| # An instance of +Receiver+ can only be created using an active (i.e., not |
| # previously closed) Session. See Qpid::Messaging::Session.create_receiver |
| # for more details. |
| # |
| # ==== Example |
| # |
| # # create a connection and a session |
| # conn = Qpid::Messaging::Connection.new :url => "mybroker:5762" |
| # conn.open |
| # session = conn.create_session |
| # |
| # # create a receiver that listens on the "updates" topic of "alerts" |
| # receiver = session.create_receiver "alerts/updates" |
| # |
| # # wait for an incoming message and process it |
| # incoming = receiver.get Qpid::Messaging::Duration::FOREVER |
| # process(incoming) |
| # |
| class Receiver |
| |
| def initialize(session, receiver_impl) # :nodoc: |
| @session = session |
| @receiver_impl = receiver_impl |
| end |
| |
| def receiver_impl # :nodoc: |
| @receiver_impl |
| end |
| |
| # Retrieves a message from the local queue, or waits for up to |
| # the duration specified for one to become available. |
| # |
| # If no message is received within the specified time then a |
| # MessagingException is raised. |
| # |
| # ==== Options |
| # |
| # * duration - the timeout to wait |
| # |
| # ==== Examples |
| # |
| # # retrieves a message, also handles exceptions raised on no messages |
| # begin |
| # # checks for a message, returning immediately |
| # msg = recv.get Qpid::Messaging::Duration::IMMEDIATE |
| # puts "Received this message: #{message.content}" |
| # rescue |
| # puts "No messages available. |
| # end |
| # |
| def get(duration = Qpid::Messaging::Duration::FOREVER) |
| message_impl = @receiver_impl.get duration.duration_impl |
| create_message_wrapper message_impl unless message_impl.nil? |
| end |
| |
| # Retrieves a message from the receiver's subscription, or waits |
| # for up to the duration specified for one to become available. |
| # |
| # If no message is fetched within the specified time then a |
| # MessagingException is raised. |
| # |
| # ==== Options |
| # |
| # * duration - the timeout to wait (def. Duration::FOREVER) |
| # |
| # ==== Examples |
| # |
| # # retrieves a message, also handles exceptions raised on no messages |
| # begin |
| # # checks for a message, times out after one second |
| # msg = recv.fetch Qpid::Messaging::Duration::SECOND |
| # puts "Fetched this message: #{message.content}" |
| # rescue |
| # puts "No messages available. |
| # end |
| # |
| def fetch(duration = Qpid::Messaging::Duration::FOREVER) |
| message_impl = @receiver_impl.fetch duration.duration_impl |
| create_message_wrapper message_impl unless message_impl.nil? |
| end |
| |
| # Sets the capacity. |
| # |
| # The capacity of a +Receiver+ is the number of Messages that can be |
| # pre-fetched from the broker and held locally. If capacity is 0 then |
| # messages will never be pre-fetched and all messages must instead be |
| # retrieved using #fetch. |
| # |
| # ==== Options |
| # |
| # * capacity - the capacity |
| # |
| # ==== Examples |
| # |
| # # create a receiver and give it a capacity of 50 |
| # recv = session.create_receiver "alerts/minor" |
| # recv.capacity = 50 |
| # |
| def capacity=(capacity); @receiver_impl.setCapacity capacity; end |
| |
| # Returns the capacity. |
| def capacity; @receiver_impl.getCapacity; end |
| |
| # Returns the number of messages locally held. |
| # |
| # The available is always 0 <= available <= capacity. |
| # |
| # If the #capacity is set to 0 then available will always be 0. |
| # |
| # ==== Examples |
| # |
| # # output the number of messages waiting while processing |
| # loop do |
| # puts "There are #{recv.available} messages pending..." |
| # # wait forever (the default) for the next message |
| # msg = recv.get |
| # # process the message |
| # dispatch_message msg |
| # end |
| # |
| def available; @receiver_impl.getAvailable; end |
| |
| # Returns the number of messages that have been received and acknowledged |
| # but whose acknowledgements have not been confirmed by the sender. |
| def unsettled; @receiver_impl.getUnsettled; end |
| |
| # Closes this +Receiver+. |
| # |
| # This does not affect the owning Session or Connection. |
| def close; @receiver_impl.close; end |
| |
| # Returns whether the +Receiver+ is closed. |
| def closed?; @receiver_impl.isClosed; end |
| |
| # Returns the name of this +Receiver+. |
| def name; @receiver_impl.getName; end |
| |
| # Returns the owning Session for this +Receiver+. |
| def session; @session; end |
| |
| private |
| |
| def create_message_wrapper message_impl # :nodoc: |
| Qpid::Messaging::Message.new(:impl => message_impl) |
| end |
| |
| end |
| |
| end |
| |
| end |
| |