DESCRIPTION:
Queues store and forward messages. Queues can be configured in the server or created at runtime. Queues must be attached to at least one exchange in order to receive messages from publishers.
| Class | Bunny::Queue09 |
| In: |
lib/bunny/queue09.rb
|
| Parent: | Qrack::Queue |
Queues store and forward messages. Queues can be configured in the server or created at runtime. Queues must be attached to at least one exchange in order to receive messages from publishers.
# File lib/bunny/queue09.rb, line 14
14: def initialize(client, name, opts = {})
15: # check connection to server
16: raise Bunny::ConnectionError, 'Not connected to server' if client.status == :not_connected
17:
18: @client = client
19: @opts = opts
20: @delivery_tag = nil
21:
22: # Queues without a given name are named by the server and are generally
23: # bound to the process that created them.
24: if !name
25: opts = {
26: :passive => false,
27: :durable => false,
28: :exclusive => true,
29: :auto_delete => true,
30: :deprecated_ticket => 0
31: }.merge(opts)
32: end
33:
34: # ignore the :nowait option if passed, otherwise program will hang waiting for a
35: # response that will not be sent by the server
36: opts.delete(:nowait)
37:
38: client.send_frame(
39: Qrack::Protocol09::Queue::Declare.new({ :queue => name || '', :nowait => false, :deprecated_ticket => 0 }.merge(opts))
40: )
41:
42: method = client.next_method
43:
44: client.check_response(method, Qrack::Protocol09::Queue::DeclareOk, "Error declaring queue #{name}")
45:
46: @name = method.queue
47: client.queues[@name] = self
48: end
Acknowledges one or more messages delivered via the Deliver or Get-Ok methods. The client can ask to confirm a single message or a set of messages up to and including a specific message.
# File lib/bunny/queue09.rb, line 67
67: def ack(opts={})
68: # Set delivery tag
69: if delivery_tag.nil? and opts[:delivery_tag].nil?
70: raise Bunny::AcknowledgementError, "No delivery tag received"
71: else
72: self.delivery_tag = opts[:delivery_tag] if delivery_tag.nil?
73: end
74:
75: client.send_frame(
76: Qrack::Protocol09::Basic::Ack.new({:delivery_tag => delivery_tag, :multiple => false}.merge(opts))
77: )
78:
79: # reset delivery tag
80: self.delivery_tag = nil
81: end
Binds a queue to an exchange. Until a queue is bound it will not receive any messages. Queues are bound to the direct exchange ’’ by default. If error occurs, a Bunny::ProtocolError is raised.
:bind_ok if successful.
# File lib/bunny/queue09.rb, line 100
100: def bind(exchange, opts = {})
101: exchange = exchange.respond_to?(:name) ? exchange.name : exchange
102:
103: # ignore the :nowait option if passed, otherwise program will hang waiting for a
104: # response that will not be sent by the server
105: opts.delete(:nowait)
106:
107: client.send_frame(
108: Qrack::Protocol09::Queue::Bind.new({ :queue => name,
109: :exchange => exchange,
110: :routing_key => opts.delete(:key),
111: :nowait => false,
112: :deprecated_ticket => 0 }.merge(opts))
113: )
114:
115: method = client.next_method
116:
117: client.check_response(method, Qrack::Protocol09::Queue::BindOk,
118: "Error binding queue: #{name} to exchange: #{exchange}")
119:
120: # return message
121: :bind_ok
122: end
Requests that a queue is deleted from broker/server. When a queue is deleted any pending messages are sent to a dead-letter queue if this is defined in the server configuration. Removes reference from queues if successful. If an error occurs raises Bunny::ProtocolError.
:delete_ok if successful
# File lib/bunny/queue09.rb, line 147
147: def delete(opts = {})
148: # ignore the :nowait option if passed, otherwise program will hang waiting for a
149: # response that will not be sent by the server
150: opts.delete(:nowait)
151:
152: client.send_frame(
153: Qrack::Protocol09::Queue::Delete.new({ :queue => name, :nowait => false, :deprecated_ticket => 0 }.merge(opts))
154: )
155:
156: method = client.next_method
157:
158: client.check_response(method, Qrack::Protocol09::Queue::DeleteOk, "Error deleting queue #{name}")
159:
160: client.queues.delete(name)
161:
162: # return confirmation
163: :delete_ok
164: end
Gets a message from a queue in a synchronous way. If error occurs, raises Bunny::ProtocolError.
Hash {:header, :payload, :delivery_details}. :delivery_details is a hash {:consumer_tag, :delivery_tag, :redelivered, :exchange, :routing_key}.
If the queue is empty the returned hash will contain the values -
:header => nil :payload => :queue_empty :delivery_details => nil
N.B. If a block is provided then the hash will be passed into the block and the return value will be nil.
# File lib/bunny/queue09.rb, line 195
195: def pop(opts = {}, &blk)
196:
197: # do we want to have to provide an acknowledgement?
198: ack = opts.delete(:ack)
199:
200: client.send_frame(
201: Qrack::Protocol09::Basic::Get.new({ :queue => name,
202: :consumer_tag => name,
203: :no_ack => !ack,
204: :nowait => true,
205: :deprecated_ticket => 0 }.merge(opts))
206: )
207:
208: method = client.next_method
209:
210: if method.is_a?(Qrack::Protocol09::Basic::GetEmpty) then
211: queue_empty = true
212: elsif !method.is_a?(Qrack::Protocol09::Basic::GetOk)
213: raise Bunny::ProtocolError, "Error getting message from queue #{name}"
214: end
215:
216: if !queue_empty
217: # get delivery tag to use for acknowledge
218: self.delivery_tag = method.delivery_tag if ack
219:
220: header = client.next_payload
221:
222: # If maximum frame size is smaller than message payload body then message
223: # will have a message header and several message bodies
224: msg = ''
225: while msg.length < header.size
226: msg += client.next_payload
227: end
228:
229: msg_hash = {:header => header, :payload => msg, :delivery_details => method.arguments}
230:
231: else
232: msg_hash = {:header => nil, :payload => :queue_empty, :delivery_details => nil}
233: end
234:
235: # Pass message hash to block or return message hash
236: blk ? blk.call(msg_hash) : msg_hash
237:
238: end
Removes all messages from a queue. It does not cancel consumers. Purged messages are deleted without any formal "undo" mechanism. If an error occurs raises Bunny::ProtocolError.
:purge_ok if successful
# File lib/bunny/queue09.rb, line 256
256: def purge(opts = {})
257: # ignore the :nowait option if passed, otherwise program will hang waiting for a
258: # response that will not be sent by the server
259: opts.delete(:nowait)
260:
261: client.send_frame(
262: Qrack::Protocol09::Queue::Purge.new({ :queue => name, :nowait => false, :deprecated_ticket => 0 }.merge(opts))
263: )
264:
265: method = client.next_method
266:
267: client.check_response(method, Qrack::Protocol09::Queue::PurgeOk, "Error purging queue #{name}")
268:
269: # return confirmation
270: :purge_ok
271:
272: end
Returns hash {:message_count, :consumer_count}.
# File lib/bunny/queue09.rb, line 282
282: def status
283: client.send_frame(
284: Qrack::Protocol09::Queue::Declare.new({ :queue => name, :passive => true, :deprecated_ticket => 0 })
285: )
286: method = client.next_method
287: {:message_count => method.message_count, :consumer_count => method.consumer_count}
288: end
# File lib/bunny/queue09.rb, line 290
290: def subscribe(opts = {}, &blk)
291: # Create subscription
292: s = Bunny::Subscription09.new(client, self, opts)
293: s.start(&blk)
294:
295: # Reset when subscription finished
296: @subscription = nil
297: end
Removes a queue binding from an exchange. If error occurs, a Bunny::ProtocolError is raised.
:unbind_ok if successful.
# File lib/bunny/queue09.rb, line 316
316: def unbind(exchange, opts = {})
317: exchange = exchange.respond_to?(:name) ? exchange.name : exchange
318:
319: # ignore the :nowait option if passed, otherwise program will hang waiting for a
320: # response that will not be sent by the server
321: opts.delete(:nowait)
322:
323: client.send_frame(
324: Qrack::Protocol09::Queue::Unbind.new({ :queue => name,
325: :exchange => exchange,
326: :routing_key => opts.delete(:key),
327: :nowait => false,
328: :deprecated_ticket => 0 }.merge(opts)
329: )
330: )
331:
332: method = client.next_method
333:
334: client.check_response(method, Qrack::Protocol09::Queue::UnbindOk, "Error unbinding queue #{name}")
335:
336: # return message
337: :unbind_ok
338: end
Cancels a consumer. This does not affect already delivered messages, but it does mean the server will not send any more messages for that consumer.
:unsubscribe_ok if successful
# File lib/bunny/queue09.rb, line 358
358: def unsubscribe(opts = {})
359: # Default consumer_tag from subscription if not passed in
360: consumer_tag = subscription ? subscription.consumer_tag : opts[:consumer_tag]
361:
362: # Must have consumer tag to tell server what to unsubscribe
363: raise Bunny::UnsubscribeError,
364: "No consumer tag received" if !consumer_tag
365:
366: # Cancel consumer
367: client.send_frame( Qrack::Protocol09::Basic::Cancel.new(:consumer_tag => consumer_tag,
368: :nowait => false))
369:
370: method = client.next_method
371:
372: client.check_response(method, Qrack::Protocol09::Basic::CancelOk,
373: "Error unsubscribing from queue #{name}")
374:
375: # Reset subscription
376: @subscription = nil
377:
378: # Return confirmation
379: :unsubscribe_ok
380:
381: end