Class: SidekiqSmartCache::Redis

Inherits:
Object
  • Object
show all
Defined in:
lib/sidekiq_smart_cache/redis.rb

Instance Method Summary collapse

Constructor Details

#initialize(pool) ⇒ Redis

Returns a new instance of Redis.



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# File 'lib/sidekiq_smart_cache/redis.rb', line 12

def initialize(pool)
  @pool = pool
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name) ⇒ Object 



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# File 'lib/sidekiq_smart_cache/redis.rb', line 39

def method_missing(name, ...)
  @pool.with do |r|
    if COMMANDS.include? name
      retryable = true
      begin
        # log_msg("#{name} #{args}")
        if r.respond_to?(name)
          # old redis gem implements methods including `brpop` and `flusdb`
          r.send(name, ...)
        elsif BLOCKING_COMMANDS.include? name
          # support redis-client semantics
          make_blocking_call(r, name, ...)
        else
          r.call(name.to_s.upcase, ...)
        end
        # stolen from sidekiq - Thanks Mike!
        # Quietly consume this one and return nil
      rescue ERROR_TO_CATCH => ex
        # 2550 Failover can cause the server to become a replica, need
        # to disconnect and reopen the socket to get back to the primary.
        if retryable && ex.message =~ /READONLY/
          r.disconnect!
          retryable = false
          retry
        end
        raise
      end
    else
      super
    end
  end
end

Instance Method Details

#job_completion_key(key) ⇒ Object 



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# File 'lib/sidekiq_smart_cache/redis.rb', line 16

def job_completion_key(key)
  key + '/done'
end

#log_msg(msg) ⇒ Object

WIP all this



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# File 'lib/sidekiq_smart_cache/redis.rb', line 35

def log_msg(msg) # WIP all this
  Rails.logger.info("#{Time.now.iso8601(3)} #{Thread.current[:name]} redis #{msg}")
end

#make_blocking_call(r, name, *args) ⇒ Object 



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# File 'lib/sidekiq_smart_cache/redis.rb', line 72

def make_blocking_call(r, name, *args)
  # The Redis `brpop` implementation seems to allow timeout to be the last argument
  # or a key in a hash `timeout: 5`, so:
  # `r.brpop('key1', 'key2', 5)` - wait five seconds for either queue
  # `r.brpop('key1', 'key2', timeout: 5)` - same
  # `r.brpop('key1', 'key2')` - wait forever on either queue
  timeout = if args.last.is_a?(Hash)
    options = args.pop
    options[:timeout]
  else
    args.pop
  end

  # With RedisClient, the doc is a little thin, but it looks like we want to start with the timeout
  # then the verb, then the array of keys
  # and end with ... a 0?
  blocking_call_args = [timeout, name.to_s.upcase] + args + [0]
  r.blocking_call(*blocking_call_args)
rescue ::RedisClient::TimeoutError
  nil # quietly return nil in this case
end

#send_done_message(key) ⇒ Object 



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# File 'lib/sidekiq_smart_cache/redis.rb', line 20

def send_done_message(key)
  lpush(job_completion_key(key), 'done')
  expire(job_completion_key(key), 1)
end

#wait_for_done_message(key, timeout) ⇒ Object 



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# File 'lib/sidekiq_smart_cache/redis.rb', line 25

def wait_for_done_message(key, timeout)
  return true if defined?(Sidekiq::Testing) && Sidekiq::Testing.inline?

  if brpop(job_completion_key(key), timeout: timeout.to_i)
    # log_msg("got done message for #{key}")
    send_done_message(key) # put it back for any other readers
    true
  end
end