Class: Rodauth::OAuth::TtlStore

Inherits:
Object
  • Object
show all
Defined in:
lib/rodauth/oauth/ttl_store.rb

Overview

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.

Constant Summary collapse

DEFAULT_TTL =

default TTL is one day

60 * 60 * 24

Instance Method Summary collapse

Constructor Details

#initialize ⇒ TtlStore

Returns a new instance of TtlStore.



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# File 'lib/rodauth/oauth/ttl_store.rb', line 14

def initialize
  @store_mutex = Mutex.new
  @store = {}
end

Instance Method Details

#[](key) ⇒ Object 



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# File 'lib/rodauth/oauth/ttl_store.rb', line 19

def [](key)
  lookup(key, now)
end

#set(key, &block) ⇒ Object 



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# File 'lib/rodauth/oauth/ttl_store.rb', line 23

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

#uncache(key) ⇒ Object 



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# File 'lib/rodauth/oauth/ttl_store.rb', line 43

def uncache(key)
  @store_mutex.synchronize do
    @store.delete(key)
  end
end