Sha256: 3bf8ee3b8b1c31b7c6434142004984c40ea3bbc9286c1436b20b49712184b250
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Versions: 4
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Stored size: 1.54 KB
Contents
# frozen_string_literal: true
#
# The TTL store is a data structure which keeps data by a key, and with a time-to-live.
# It is specifically designed for data which is static, i.e. for a certain key in a
# sufficiently large span, the value will be the same.
#
# Because of that, synchronizations around reads do not exist, while write synchronizations
# will be short-circuited by a read.
#
class Rodauth::OAuth::TtlStore
DEFAULT_TTL = 60 * 60 * 24 # default TTL is one day
def initialize
@store_mutex = Mutex.new
@store = {}
end
def [](key)
lookup(key, now)
end
def set(key, &block)
@store_mutex.synchronize do
# short circuit
return @store[key][:payload] if @store[key] && @store[key][:ttl] < now
end
payload, ttl = block.call
return payload unless ttl
@store_mutex.synchronize do
# given that the block call triggers network, and two requests for the same key be processed
# at the same time, this ensures the first one wins.
return @store[key][:payload] if @store[key] && @store[key][:ttl] < now
@store[key] = { payload: payload, ttl: ttl || (now + DEFAULT_TTL) }
end
@store[key][:payload]
end
def uncache(key)
@store_mutex.synchronize do
@store.delete(key)
end
end
private
def now
Process.clock_gettime(Process::CLOCK_MONOTONIC)
end
# do not use directly!
def lookup(key, ttl)
return unless @store.key?(key)
value = @store[key]
return if value.empty?
return unless value[:ttl] > ttl
value[:payload]
end
end
Version data entries
4 entries across 4 versions & 1 rubygems