54 lines
1.0 KiB
Ruby
54 lines
1.0 KiB
Ruby
require_dependency 'rate_limiter/limit_exceeded'
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require_dependency 'rate_limiter/on_create_record'
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# A redis backed rate limiter.
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class RateLimiter
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# We don't observe rate limits in test mode
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def self.disabled?
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Rails.env.test?
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end
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def initialize(user, key, max, secs)
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@user = user
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@key = "rate-limit:#{@user.id}:#{key}"
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@max = max
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@secs = secs
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end
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def clear!
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$redis.del(@key)
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end
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def can_perform?
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return true if RateLimiter.disabled?
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return true if @user.staff?
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result = $redis.get(@key)
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return true if result.blank?
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return true if result.to_i < @max
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false
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end
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def performed!
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return if RateLimiter.disabled?
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return if @user.staff?
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result = $redis.incr(@key).to_i
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$redis.expire(@key, @secs) if result == 1
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if result > @max
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# In case we go over, clamp it to the maximum
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$redis.decr(@key)
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raise LimitExceeded.new($redis.ttl(@key))
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end
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end
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def rollback!
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return if RateLimiter.disabled?
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$redis.decr(@key)
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end
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end
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