39 lines
1.3 KiB
Ruby
39 lines
1.3 KiB
Ruby
# frozen_string_literal: true
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module Gitlab
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# This module provides helper methods which are intregrated with GitLab::ExclusiveLease
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module ExclusiveLeaseHelpers
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FailedToObtainLockError = Class.new(StandardError)
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##
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# This helper method blocks a process/thread until the other process cancel the obrainted lease key.
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#
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# Note: It's basically discouraged to use this method in the unicorn's thread,
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# because it holds the connection until all `retries` is consumed.
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# This could potentially eat up all connection pools.
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def in_lock(key, ttl: 1.minute, retries: 10, sleep_sec: 0.01.seconds)
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raise ArgumentError, 'Key needs to be specified' unless key
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lease = Gitlab::ExclusiveLease.new(key, timeout: ttl)
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retried = false
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max_attempts = 1 + retries
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until uuid = lease.try_obtain
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# Keep trying until we obtain the lease. To prevent hammering Redis too
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# much we'll wait for a bit.
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attempt_number = max_attempts - retries
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delay = sleep_sec.respond_to?(:call) ? sleep_sec.call(attempt_number) : sleep_sec
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sleep(delay)
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(retries -= 1) < 0 ? break : retried ||= true
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end
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raise FailedToObtainLockError, 'Failed to obtain a lock' unless uuid
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yield(retried)
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ensure
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Gitlab::ExclusiveLease.cancel(key, uuid)
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end
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end
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end
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