Class: Kraps::RedisQueue

Inherits:
Object
  • Object
show all
Defined in:
lib/kraps/redis_queue.rb

Constant Summary collapse

VISIBILITY_TIMEOUT = 
60

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(redis:, token:, namespace:, ttl:) ⇒ RedisQueue

Returns a new instance of RedisQueue.



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# File 'lib/kraps/redis_queue.rb', line 7

def initialize(redis:, token:, namespace:, ttl:)
  @redis = redis
  @token = token
  @namespace = namespace
  @ttl = ttl
end

Instance Attribute Details

#token ⇒ Object (readonly)

Returns the value of attribute token.



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# File 'lib/kraps/redis_queue.rb', line 5

def token
  @token
end

Instance Method Details

#dequeue ⇒ Object 



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# File 'lib/kraps/redis_queue.rb', line 42

def dequeue
  @dequeue_script ||= <<~SCRIPT
    local queue_key, pending_key, status_key, ttl, visibility_timeout = ARGV[1], ARGV[2], ARGV[3], tonumber(ARGV[4]), tonumber(ARGV[5])

    local zitem = redis.call('zrange', pending_key, 0, 0, 'WITHSCORES')
    local job = zitem[1]

    if not zitem[2] or tonumber(zitem[2]) > tonumber(redis.call('time')[1]) then
      job = redis.call('lpop', queue_key)
    end

    redis.call('expire', queue_key, ttl)
    redis.call('expire', pending_key, ttl)
    redis.call('expire', status_key, ttl)

    if not job then return nil end

    redis.call('zadd', pending_key, tonumber(redis.call('time')[1]) + visibility_timeout, job)
    redis.call('expire', pending_key, ttl)

    return job
  SCRIPT

  job = @redis.eval(@dequeue_script, argv: [redis_queue_key, redis_pending_key, redis_status_key, @ttl, VISIBILITY_TIMEOUT])

  unless job
    yield(nil)
    return
  end

  keep_alive(job) do
    yield(JSON.parse(job)) if job
  end

  @remove_script ||= <<~SCRIPT
    local queue_key, pending_key, status_key, ttl, job = ARGV[1], ARGV[2], ARGV[3], tonumber(ARGV[4]), ARGV[5]

    redis.call('zrem', pending_key, job)

    redis.call('expire', queue_key, ttl)
    redis.call('expire', pending_key, ttl)
    redis.call('expire', status_key, ttl)
  SCRIPT

  @redis.eval(@remove_script, argv: [redis_queue_key, redis_pending_key, redis_status_key, @ttl, job])
end

#enqueue(payload) ⇒ Object 



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# File 'lib/kraps/redis_queue.rb', line 28

def enqueue(payload)
  @enqueue_script ||= <<~SCRIPT
    local queue_key, pending_key, status_key, ttl, job = ARGV[1], ARGV[2], ARGV[3], tonumber(ARGV[4]), ARGV[5]

    redis.call('rpush', queue_key, job)

    redis.call('expire', queue_key, ttl)
    redis.call('expire', pending_key, ttl)
    redis.call('expire', status_key, ttl)
  SCRIPT

  @redis.eval(@enqueue_script, argv: [redis_queue_key, redis_pending_key, redis_status_key, @ttl, JSON.generate(payload)])
end

#size ⇒ Object 



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# File 'lib/kraps/redis_queue.rb', line 14

def size
  @size_script ||= <<~SCRIPT
    local queue_key, pending_key, status_key, ttl, job = ARGV[1], ARGV[2], ARGV[3], tonumber(ARGV[4]), ARGV[5]

    redis.call('expire', queue_key, ttl)
    redis.call('expire', pending_key, ttl)
    redis.call('expire', status_key, ttl)

    return redis.call('llen', queue_key) + redis.call('zcard', pending_key)
  SCRIPT

  @redis.eval(@size_script, argv: [redis_queue_key, redis_pending_key, redis_status_key, @ttl])
end

#stop ⇒ Object 



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# File 'lib/kraps/redis_queue.rb', line 89

def stop
  @stop_script ||= <<~SCRIPT
    local queue_key, pending_key, status_key, ttl = ARGV[1], ARGV[2], ARGV[3], tonumber(ARGV[4])

    redis.call('hset', status_key, 'stopped', 1)

    redis.call('expire', queue_key, ttl)
    redis.call('expire', pending_key, ttl)
    redis.call('expire', status_key, ttl)
  SCRIPT

  @redis.eval(@stop_script, argv: [redis_queue_key, redis_pending_key, redis_status_key, @ttl])
end

#stopped? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/kraps/redis_queue.rb', line 103

def stopped?
  @stopped_script ||= <<~SCRIPT
    local queue_key, pending_key, status_key, ttl = ARGV[1], ARGV[2], ARGV[3], tonumber(ARGV[4])

    redis.call('expire', queue_key, ttl)
    redis.call('expire', pending_key, ttl)
    redis.call('expire', status_key, ttl)

    return redis.call('hget', status_key, 'stopped')
  SCRIPT

  @redis.eval(@stopped_script, argv: [redis_queue_key, redis_pending_key, redis_status_key, @ttl]).to_i == 1
end