52 lines
885 B
Ruby
52 lines
885 B
Ruby
# Cross-process locking using Redis.
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class DistributedMutex
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attr_accessor :redis
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attr_reader :got_lock
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def initialize(key, redis=nil)
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@key = key
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@redis = redis || $redis
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@got_lock = false
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end
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def try_to_get_lock
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if redis.setnx @key, Time.now.to_i + 60
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redis.expire @key, 60
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@got_lock = true
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else
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begin
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redis.watch @key
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time = redis.get @key
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if time && time.to_i < Time.now.to_i
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@got_lock = redis.multi do
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redis.set @key, Time.now.to_i + 60
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end
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end
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ensure
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redis.unwatch
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end
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end
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end
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def get_lock
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return if @got_lock
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start = Time.now
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while !@got_lock
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try_to_get_lock
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end
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end
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def release_lock
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redis.del @key
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@got_lock = false
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end
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def synchronize
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get_lock
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yield
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ensure
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release_lock
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end
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end
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