RightAws::SqsGen2Interface

Right::Aws::SqsGen2Interface - RightScale's low-level Amazon SQS interface for API version 2008-01-01 and later. For explanations of the semantics of each call, please refer to Amazon's documentation at developer.amazonwebservices.com/connect/kbcategory.jspa?categoryID=31

This class provides a procedural interface to SQS. Conceptually it is mostly a pass-through interface to SQS and its API is very similar to the bare SQS API. For a somewhat higher-level and object-oriented interface, see RightAws::SqsGen2.

Public Class Methods

api() click to toggle source
# File lib/sqs/right_sqs_gen2_interface.rb, line 58
def self.api 
  @@api
end
bench_sqs() click to toggle source
# File lib/sqs/right_sqs_gen2_interface.rb, line 53
def self.bench_sqs
  @@bench.service
end
bench_xml() click to toggle source
# File lib/sqs/right_sqs_gen2_interface.rb, line 50
def self.bench_xml
  @@bench.xml
end
new(aws_access_key_id=nil, aws_secret_access_key=nil, params={}) click to toggle source

Creates a new SqsInterface instance. This instance is limited to operations on SQS objects created with Amazon's 2008-01-01 API version. This interface will not work on objects created with prior API versions. See Amazon's article "Migrating to Amazon SQS API version 2008-01-01" at: developer.amazonwebservices.com/connect/entry.jspa?externalID=1148

sqs = RightAws::SqsGen2Interface.new('1E3GDYEOGFJPIT75KDT40','hgTHt68JY07JKUY08ftHYtERkjgtfERn57DFE379', {:multi_thread => true, :logger => Logger.new('/tmp/x.log')})

Params is a hash:

{:server       => 'queue.amazonaws.com' # Amazon service host: 'queue.amazonaws.com' (default)
 :port         => 443                   # Amazon service port: 80 or 443 (default)
 :multi_thread => true|false            # Multi-threaded (connection per each thread): true or false (default)
 :signature_version => '0'              # The signature version : '0' or '1'(default)
 :logger       => Logger Object}        # Logger instance: logs to STDOUT if omitted }
# File lib/sqs/right_sqs_gen2_interface.rb, line 78
def initialize(aws_access_key_id=nil, aws_secret_access_key=nil, params={})
  init({ :name             => 'SQS', 
         :default_host     => ENV['SQS_URL'] ? URI.parse(ENV['SQS_URL']).host   : DEFAULT_HOST, 
         :default_port     => ENV['SQS_URL'] ? URI.parse(ENV['SQS_URL']).port   : DEFAULT_PORT, 
         :default_protocol => ENV['SQS_URL'] ? URI.parse(ENV['SQS_URL']).scheme : DEFAULT_PROTOCOL }, 
       aws_access_key_id     || ENV['AWS_ACCESS_KEY_ID'], 
       aws_secret_access_key || ENV['AWS_SECRET_ACCESS_KEY'], 
       params)
end
queue_name_by_url(queue_url) click to toggle source

Returns short queue name by url.

RightSqs.queue_name_by_url('http://queue.amazonaws.com/ZZ7XXXYYYBINS/my_awesome_queue') #=> 'my_awesome_queue'
# File lib/sqs/right_sqs_gen2_interface.rb, line 301
def self.queue_name_by_url(queue_url)
  queue_url[/[^\/]*$/]
rescue
  on_exception
end

Public Instance Methods

clear_queue(queue_url) click to toggle source

Removes all visible messages from queue. Return true or an exception.

sqs.clear_queue('http://queue.amazonaws.com/ZZ7XXXYYYBINS/my_awesome_queue') #=> true
# File lib/sqs/right_sqs_gen2_interface.rb, line 331
def clear_queue(queue_url)
  while (pop_messages(queue_url, 10).length > 0) ; end   # delete all messages in queue
  true
rescue
  on_exception
end
create_queue(queue_name, default_visibility_timeout=nil) click to toggle source

Creates a new queue, returning its URI.

sqs.create_queue('my_awesome_queue') #=> 'http://queue.amazonaws.com/ZZ7XXXYYYBINS/my_awesome_queue'
# File lib/sqs/right_sqs_gen2_interface.rb, line 153
def create_queue(queue_name, default_visibility_timeout=nil)
  req_hash = generate_request('CreateQueue', 'QueueName' => queue_name,
                              'DefaultVisibilityTimeout' => default_visibility_timeout || DEFAULT_VISIBILITY_TIMEOUT )
  request_info(req_hash, SqsCreateQueueParser.new(:logger => @logger))
rescue
  on_exception
end
delete_message(queue_url, receipt_handle) click to toggle source

Deletes message from queue. Returns true or an exception. Amazon returns true on deletion of non-existent messages. You must use the receipt handle for a message to delete it, not the message ID.

From the SQS Developer Guide: "It is possible you will receive a message even after you have deleted it. This might happen on rare occasions if one of the servers storing a copy of the message is unavailable when you request to delete the message. The copy remains on the server and might be returned to you again on a subsequent receive request. You should create your system to be idempotent so that receiving a particular message more than once is not a problem. "

sqs.delete_message('http://queue.amazonaws.com/ZZ7XXXYYYBINS/my_awesome_queue', 'Euvo62/1nlIet...ao03hd9Sa0w==') #=> true
# File lib/sqs/right_sqs_gen2_interface.rb, line 276
def delete_message(queue_url, receipt_handle)
  req_hash = generate_request('DeleteMessage', 'ReceiptHandle' => receipt_handle, :queue_url  => queue_url)
  request_info(req_hash, SqsStatusParser.new(:logger => @logger))
rescue
  on_exception
end
delete_queue(queue_url) click to toggle source

Deletes queue. Any messages in the queue are permanently lost. Returns true or an exception. Queue deletion can take up to 60 s to propagate through SQS. Thus, after a deletion, subsequent list_queues calls may still show the deleted queue. It is not unusual within the 60 s window to see the deleted queue absent from one list_queues call but present in the subsequent one. Deletion is eventual.

sqs.delete_queue('http://queue.amazonaws.com/ZZ7XXXYYYBINS/my_awesome_queue_2') #=> true
# File lib/sqs/right_sqs_gen2_interface.rb, line 185
def delete_queue(queue_url)
  req_hash = generate_request('DeleteQueue', :queue_url      => queue_url)
  request_info(req_hash, SqsStatusParser.new(:logger => @logger))
rescue
  on_exception
end
get_queue_attributes(queue_url, attribute='All') click to toggle source

Retrieves the queue attribute(s). Returns a hash of attribute(s) or an exception.

sqs.get_queue_attributes('http://queue.amazonaws.com/ZZ7XXXYYYBINS/my_awesome_queue') 
#=> {"ApproximateNumberOfMessages"=>"0", "VisibilityTimeout"=>"30"}
# File lib/sqs/right_sqs_gen2_interface.rb, line 197
def get_queue_attributes(queue_url, attribute='All')
  req_hash = generate_request('GetQueueAttributes', 'AttributeName' => attribute, :queue_url  => queue_url)
  request_info(req_hash, SqsGetQueueAttributesParser.new(:logger => @logger))
rescue
  on_exception
end
get_queue_length(queue_url) click to toggle source

Returns approximate number of messages in queue.

sqs.get_queue_length('http://queue.amazonaws.com/ZZ7XXXYYYBINS/my_awesome_queue') #=> 3
# File lib/sqs/right_sqs_gen2_interface.rb, line 321
def get_queue_length(queue_url)
  get_queue_attributes(queue_url)['ApproximateNumberOfMessages'].to_i
rescue
  on_exception
end
list_queues(queue_name_prefix=nil) click to toggle source

Lists all queues owned by this user that have names beginning with queue_name_prefix. If queue_name_prefix is omitted then retrieves a list of all queues. Queue creation is an eventual operation and created queues may not show up in immediately subsequent list_queues calls.

sqs.create_queue('my_awesome_queue')
sqs.create_queue('my_awesome_queue_2')
sqs.list_queues('my_awesome') #=> ['http://queue.amazonaws.com/ZZ7XXXYYYBINS/my_awesome_queue','http://queue.amazonaws.com/ZZ7XXXYYYBINS/my_awesome_queue_2']
# File lib/sqs/right_sqs_gen2_interface.rb, line 169
def list_queues(queue_name_prefix=nil)
  req_hash = generate_request('ListQueues', 'QueueNamePrefix' => queue_name_prefix)
  request_info(req_hash, SqsListQueuesParser.new(:logger => @logger))
rescue
  on_exception
end
pop_message(queue_url) click to toggle source

Pops (retrieves and deletes) first accessible message from queue. Returns the message in format {:id=>'message_id', :body=>'message_body'} or nil.

sqs.pop_message('http://queue.amazonaws.com/ZZ7XXXYYYBINS/my_awesome_queue') #=>
  {:id=>"12345678904GEZX9746N|0N9ED344VK5Z3SV1DTM0|1RVYH4X3TJ0987654321", :body=>"message_1"}
# File lib/sqs/right_sqs_gen2_interface.rb, line 359
def pop_message(queue_url)
  messages = pop_messages(queue_url)
  messages.blank? ? nil : messages[0]
rescue
  on_exception
end
pop_messages(queue_url, number_of_messages=1) click to toggle source

Pops (retrieves and deletes) up to 'number_of_messages' from queue. Returns an array of retrieved messages in format: [{:id=>'message_id', :body=>'message_body'}].

sqs.pop_messages('http://queue.amazonaws.com/ZZ7XXXYYYBINS/my_awesome_queue', 3) #=>
[{"ReceiptHandle"=>"Euvo62/...+Zw==", "MD5OfBody"=>"16af2...81e3", "Body"=>"Goodbyte World!", 
"MessageId"=>"MEZI...JSWDE="}, {...}, ... , {...} ]
# File lib/sqs/right_sqs_gen2_interface.rb, line 344
def pop_messages(queue_url, number_of_messages=1)
  messages = receive_message(queue_url, number_of_messages)
  messages.each do |message|
    delete_message(queue_url, message['ReceiptHandle'])
  end
  messages
rescue
  on_exception
end
push_message(queue_url, message) click to toggle source

Same as send_message

Alias for: send_message
queue_name_by_url(queue_url) click to toggle source

Returns short queue name by url.

sqs.queue_name_by_url('http://queue.amazonaws.com/ZZ7XXXYYYBINS/my_awesome_queue') #=> 'my_awesome_queue'
# File lib/sqs/right_sqs_gen2_interface.rb, line 311
def queue_name_by_url(queue_url)
  self.class.queue_name_by_url(queue_url)
rescue
  on_exception
end
queue_url_by_name(queue_name) click to toggle source

Given the queue's short name, this call returns the queue URL or nil if queue is not found

sqs.queue_url_by_name('my_awesome_queue') #=> 'http://queue.amazonaws.com/ZZ7XXXYYYBINS/my_awesome_queue'
# File lib/sqs/right_sqs_gen2_interface.rb, line 286
def queue_url_by_name(queue_name)
  return queue_name if queue_name.include?('/')
  queue_urls = list_queues(queue_name)
  queue_urls.each do |queue_url|
    return queue_url if queue_name_by_url(queue_url) == queue_name
  end
  nil
rescue
  on_exception
end
receive_message(queue_url, max_number_of_messages=1, visibility_timeout=nil) click to toggle source

Retrieves a list of messages from queue. Returns an array of hashes in format: {:id=>'message_id', body=>'message_body'}

sqs.receive_message('http://queue.amazonaws.com/ZZ7XXXYYYBINS/my_awesome_queue',10, 5) #=>
 [{"ReceiptHandle"=>"Euvo62...kw==", "MD5OfBody"=>"16af2171b5b83cfa35ce254966ba81e3", 
   "Body"=>"Goodbyte World!", "MessageId"=>"MUM4WlAyR...pYOTA="}, ..., {}]

Normally this call returns fewer messages than the maximum specified, even if they are available.

# File lib/sqs/right_sqs_gen2_interface.rb, line 233
def receive_message(queue_url, max_number_of_messages=1, visibility_timeout=nil)
  return [] if max_number_of_messages == 0
  req_hash = generate_post_request('ReceiveMessage', 'MaxNumberOfMessages'  => max_number_of_messages, 'VisibilityTimeout' => visibility_timeout,
                                   :queue_url          => queue_url )
  request_info(req_hash, SqsReceiveMessageParser.new(:logger => @logger))
rescue
  on_exception
end
send_message(queue_url, message) click to toggle source

Sends a new message to a queue. Message size is limited to 8 KB. If successful, this call returns a hash containing key/value pairs for "MessageId" and "MD5OfMessageBody":

sqs.send_message('http://queue.amazonaws.com/ZZ7XXXYYYBINS/my_awesome_queue', 'message_1') #=> "1234567890...0987654321"
=> {"MessageId"=>"MEs4M0JKNlRCRTBBSENaMjROTk58QVFRNzNEREhDVFlFOVJDQ1JKNjF8UTdBRllCUlJUMjhKMUI1WDJSWDE=", "MD5OfMessageBody"=>"16af2171b5b83cfa35ce254966ba81e3"}

On failure, send_message raises an exception.

# File lib/sqs/right_sqs_gen2_interface.rb, line 252
def send_message(queue_url, message)
  req_hash = generate_post_request('SendMessage', :message  => message, :queue_url => queue_url)
  request_info(req_hash, SqsSendMessagesParser.new(:logger => @logger))
rescue
  on_exception
end
Also aliased as: push_message
set_queue_attributes(queue_url, attribute, value) click to toggle source

Sets queue attribute. Returns true or an exception.

sqs.set_queue_attributes('http://queue.amazonaws.com/ZZ7XXXYYYBINS/my_awesome_queue', "VisibilityTimeout", 10) #=> true

From the SQS Dev Guide: "Currently, you can set only the VisibilityTimeout attribute for a queue... When you change a queue's attributes, the change can take up to 60 seconds to propagate throughout the SQS system."

NB: Attribute values may not be immediately available to other queries for some time after an update. See the SQS documentation for semantics, but in general propagation can take up to 60 s.

# File lib/sqs/right_sqs_gen2_interface.rb, line 217
def set_queue_attributes(queue_url, attribute, value)
  req_hash = generate_request('SetQueueAttributes', 'Attribute.Name'  => attribute, 'Attribute.Value' => value, :queue_url  => queue_url)
  request_info(req_hash, SqsStatusParser.new(:logger => @logger))
rescue
  on_exception
end

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