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# 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::Proton
# The receiving endpoint.
#
# @see Sender
#
class Receiver < Link
# @private
PROTON_METHOD_PREFIX = "pn_link"
# @private
include Util::Wrapper
# Open {Receiver} link
#
# @overload open_receiver(address)
# @param address [String] address of the source to receive from
# @overload open_receiver(opts)
# @param opts [Hash] Receiver options, see {Receiver#open}
# @option opts [Integer] :credit_window automatically maintain this much credit
# for messages to be pre-fetched while the current message is processed.
# @option opts [Boolean] :auto_accept if true, deliveries that are not settled by
# the application in {MessagingHandler#on_message} are automatically accepted.
# @option opts [Boolean] :dynamic (false) dynamic property for source {Terminus#dynamic}
# @option opts [String,Hash] :source source address or source options, see {Terminus#apply}
# @option opts [String,Hash] :target target address or target options, see {Terminus#apply}
# @option opts [String] :name (generated) unique name for the link.
def open(opts=nil)
opts ||= {}
opts = { :source => opts } if opts.is_a? String
@credit_window = opts.fetch(:credit_window, 10)
@auto_accept = opts.fetch(:auto_accept, true)
source.apply(opts[:source])
target.apply(opts[:target])
source.dynamic = !!opts[:dynamic]
super()
self
end
# @return [Integer] credit window, see {#open}
attr_reader :credit_window
# @return [Boolean] auto_accept flag, see {#open}
attr_reader :auto_accept
# @!attribute drain
#
# The drain mode.
#
# If a receiver is in drain mode, then the sending endpoint of a link must
# immediately use up all available credit on the link. If this is not
# possible, the excess credit must be returned by invoking #drained.
#
# Only the receiving endpoint can set the drain mode.
#
# @return [Boolean] True if drain mode is set.
#
proton_set_get :drain
# @!attribute [r] draining?
#
# Returns if a link is currently draining.
#
# A link is defined to be draining when drain mode is set to true and
# the sender still has excess credit.
#
# @return [Boolean] True if the receiver is currently draining.
#
proton_caller :draining?
# Grants credit for incoming deliveries.
#
# @param n [Integer] The amount to increment the link credit.
#
def flow(n)
Cproton.pn_link_flow(@impl, n)
end
# Allows receiving up to the specified limit of data from the remote
# endpoint.
#
# Note that large messages can be streamed across the network, so just
# because there is no data to read does not imply the message is complete.
#
# To ensure the entirety of the message data has been read, either call
# #receive until nil is returned, or verify that #partial? is false and
# Delivery#pending is 0.
#
# @param limit [Integer] The maximum bytes to receive.
#
# @return [Integer, nil] The number of bytes received, or nil if the end of
# the stream was reached.
#
# @see Deliver#pending To see how much buffer space is needed.
#
# @raise [LinkError] If an error occurs.
#
def receive(limit)
(n, bytes) = Cproton.pn_link_recv(@impl, limit)
return nil if n == Qpid::Proton::Error::EOS
raise LinkError.new("[#{n}]: #{Cproton.pn_link_error(@impl)}") if n < 0
return bytes
end
end
end
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