rf-web/vendor/bundle/gems/i18n-1.7.0/lib/i18n/backend/cache.rb

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2019-10-21 08:18:17 +00:00
# frozen_string_literal: true
# This module allows you to easily cache all responses from the backend - thus
# speeding up the I18n aspects of your application quite a bit.
#
# To enable caching you can simply include the Cache module to the Simple
# backend - or whatever other backend you are using:
#
# I18n::Backend::Simple.send(:include, I18n::Backend::Cache)
#
# You will also need to set a cache store implementation that you want to use:
#
# I18n.cache_store = ActiveSupport::Cache.lookup_store(:memory_store)
#
# You can use any cache implementation you want that provides the same API as
# ActiveSupport::Cache (only the methods #fetch and #write are being used).
#
# The cache_key implementation by default assumes you pass values that return
# a valid key from #hash (see
# http://www.ruby-doc.org/core/classes/Object.html#M000337). However, you can
# configure your own digest method via which responds to #hexdigest (see
# http://ruby-doc.org/stdlib/libdoc/digest/rdoc/index.html):
#
# I18n.cache_key_digest = Digest::MD5.new
#
# If you use a lambda as a default value in your translation like this:
#
# I18n.t(:"date.order", :default => lambda {[:month, :day, :year]})
#
# Then you will always have a cache miss, because each time this method
# is called the lambda will have a different hash value. If you know
# the result of the lambda is a constant as in the example above, then
# to cache this you can make the lambda a constant, like this:
#
# DEFAULT_DATE_ORDER = lambda {[:month, :day, :year]}
# ...
# I18n.t(:"date.order", :default => DEFAULT_DATE_ORDER)
#
# If the lambda may result in different values for each call then consider
# also using the Memoize backend.
#
module I18n
class << self
@@cache_store = nil
@@cache_namespace = nil
@@cache_key_digest = nil
def cache_store
@@cache_store
end
def cache_store=(store)
@@cache_store = store
end
def cache_namespace
@@cache_namespace
end
def cache_namespace=(namespace)
@@cache_namespace = namespace
end
def cache_key_digest
@@cache_key_digest
end
def cache_key_digest=(key_digest)
@@cache_key_digest = key_digest
end
def perform_caching?
!cache_store.nil?
end
end
module Backend
# TODO Should the cache be cleared if new translations are stored?
module Cache
def translate(locale, key, options = EMPTY_HASH)
I18n.perform_caching? ? fetch(cache_key(locale, key, options)) { super } : super
end
protected
def fetch(cache_key, &block)
result = _fetch(cache_key, &block)
throw(:exception, result) if result.is_a?(MissingTranslation)
result = result.dup if result.frozen? rescue result
result
end
def _fetch(cache_key, &block)
result = I18n.cache_store.read(cache_key)
return result unless result.nil?
result = catch(:exception, &block)
I18n.cache_store.write(cache_key, result) unless result.is_a?(Proc)
result
end
def cache_key(locale, key, options)
# This assumes that only simple, native Ruby values are passed to I18n.translate.
"i18n/#{I18n.cache_namespace}/#{locale}/#{digest_item(key)}/#{digest_item(options)}"
end
private
def digest_item(key)
I18n.cache_key_digest ? I18n.cache_key_digest.hexdigest(key.to_s) : key.to_s.hash
end
end
end
end