The zaqar.storage.redis.messages module

class MessageController(*args, **kwargs)

Bases: zaqar.storage.base.Message, zaqar.storage.redis.scripting.Mixin

Implements message resource operations using Redis.

Messages are scoped by project + queue.

Redis Data Structures:

1. Message id’s list (Redis sorted set)

   Each queue in the system has a set of message ids currently in the queue. The list is sorted based on a ranking which is incremented atomically using the counter(MESSAGE_RANK_COUNTER_SUFFIX) also stored in the database for every queue.

   Key: <project_id>.<queue_name>.messages

2. Index of message ID lists (Redis sorted set)

   This is a sorted set that facilitates discovery of all the message ID lists. This is necessary when performing garbage collection on the IDs contained within these lists.

   Key: msgset_index

3. Messages(Redis Hash):

   Scoped by the UUID of the message, the redis datastructure has the following information.

   Name	Field
   id	id
   ttl	t
   expires	e
   body	b
   claim	c
   claim expiry time	c.e
   client uuid	u
   created time	cr

4. Messages rank counter (Redis Hash):

   Key: <project_id>.<queue_name>.rank_counter

bulk_delete(*args, **kwargs)

bulk_get(*args, **kwargs)

delete(*args, **kwargs)

first(*args, **kwargs)

gc(*args, **kwargs)

Garbage-collect expired message data.

Not all message data can be automatically expired. This method cleans up the remainder.

Returns:Number of messages removed

get(*args, **kwargs)

list(*args, **kwargs)

pop(*args, **kwargs)

post(*args, **kwargs)

script_names = [‘index_messages’]

class MessageQueueHandler(driver, control_driver)

Bases: object

create(*args, **kwargs)

delete(*args, **kwargs)

stats(*args, **kwargs)