Class: Karafka::TimeTrackers::Poll

Inherits:
Base
  • Object
show all
Defined in:
lib/karafka/time_trackers/poll.rb

Overview

Object used to keep track of time we’ve used running certain operations. Polling is running in a single thread, thus we do not have to worry about this being thread-safe.

Examples:

Keep track of sleeping and stop after 3 seconds of 0.1 sleep intervals

time_poll = Poll.new(3000)
time_poll.start

until time_poll.exceeded?
  time_poll.start
  puts "I have #{time_poll.remaining.to_i}ms remaining to sleep..."
  sleep(0.1)
  time_poll.checkpoint
end

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(total_time) ⇒ TimeTracker

Returns time poll instance.

Parameters:

  • total_time (Integer) —

    amount of milliseconds before we exceed the given time limit



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# File 'lib/karafka/time_trackers/poll.rb', line 23

def initialize(total_time)
  @remaining = total_time
  @attempts = 0
  super()
end

Instance Attribute Details

#attempts ⇒ Object (readonly)

Returns the value of attribute attempts.



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# File 'lib/karafka/time_trackers/poll.rb', line 19

def attempts
  @attempts
end

#remaining ⇒ Object (readonly)

Returns the value of attribute remaining.



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# File 'lib/karafka/time_trackers/poll.rb', line 19

def remaining
  @remaining
end

Instance Method Details

#backoff ⇒ Object

Sleeps for amount of time matching attempt, so we sleep more with each attempt in case of a retry.



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# File 'lib/karafka/time_trackers/poll.rb', line 53

def backoff
  # backoff should not be included in the remaining time computation, otherwise it runs
  # shortly, never back-offing beyond a small number because of the sleep
  @remaining += backoff_interval
  # Sleep requires seconds not ms
  sleep(backoff_interval / 1_000.0)
end

#checkpoint ⇒ Object

Stops time tracking of a given piece of code and updates the remaining time.



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# File 'lib/karafka/time_trackers/poll.rb', line 41

def checkpoint
  @remaining -= (monotonic_now - @started_at)
end

#exceeded? ⇒ Boolean

Returns did we exceed the time limit.

Returns:

  • (Boolean) —

    did we exceed the time limit



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# File 'lib/karafka/time_trackers/poll.rb', line 30

def exceeded?
  @remaining <= 0
end

#retryable? ⇒ Boolean

Returns If anything went wrong, can we retry after a backoff period or not (do we have enough time).

Returns:

  • (Boolean) —

    If anything went wrong, can we retry after a backoff period or not (do we have enough time)



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# File 'lib/karafka/time_trackers/poll.rb', line 47

def retryable?
  remaining > backoff_interval
end

#start ⇒ Object

Starts time tracking.



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# File 'lib/karafka/time_trackers/poll.rb', line 35

def start
  @attempts += 1
  @started_at = monotonic_now
end