/
key_value.rb
177 lines (155 loc) · 4.9 KB
/
key_value.rb
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require 'i18n/backend/base'
module I18n
begin
require 'oj'
class JSON
class << self
def encode(value)
Oj::Rails.encode(value)
end
def decode(value)
Oj.load(value)
end
end
end
rescue LoadError
require 'active_support/json'
JSON = ActiveSupport::JSON
end
module Backend
# This is a basic backend for key value stores. It receives on
# initialization the store, which should respond to three methods:
#
# * store#[](key) - Used to get a value
# * store#[]=(key, value) - Used to set a value
# * store#keys - Used to get all keys
#
# Since these stores only supports string, all values are converted
# to JSON before being stored, allowing it to also store booleans,
# hashes and arrays. However, this store does not support Procs.
#
# As the ActiveRecord backend, Symbols are just supported when loading
# translations from the filesystem or through explicit store translations.
#
# Also, avoid calling I18n.available_locales since it's a somehow
# expensive operation in most stores.
#
# == Example
#
# To setup I18n to use TokyoCabinet in memory is quite straightforward:
#
# require 'rufus/tokyo/cabinet' # gem install rufus-tokyo
# I18n.backend = I18n::Backend::KeyValue.new(Rufus::Tokyo::Cabinet.new('*'))
#
# == Performance
#
# You may make this backend even faster by including the Memoize module.
# However, notice that you should properly clear the cache if you change
# values directly in the key-store.
#
# == Subtrees
#
# In most backends, you are allowed to retrieve part of a translation tree:
#
# I18n.backend.store_translations :en, :foo => { :bar => :baz }
# I18n.t "foo" #=> { :bar => :baz }
#
# This backend supports this feature by default, but it slows down the storage
# of new data considerably and makes hard to delete entries. That said, you are
# allowed to disable the storage of subtrees on initialization:
#
# I18n::Backend::KeyValue.new(@store, false)
#
# This is useful if you are using a KeyValue backend chained to a Simple backend.
class KeyValue
module Implementation
attr_accessor :store
include Base, Flatten
def initialize(store, subtrees=true)
@store, @subtrees = store, subtrees
end
def store_translations(locale, data, options = {})
escape = options.fetch(:escape, true)
flatten_translations(locale, data, escape, @subtrees).each do |key, value|
key = "#{locale}.#{key}"
case value
when Hash
if @subtrees && (old_value = @store[key])
old_value = JSON.decode(old_value)
value = old_value.deep_symbolize_keys.deep_merge!(value) if old_value.is_a?(Hash)
end
when Proc
raise "Key-value stores cannot handle procs"
end
@store[key] = JSON.encode(value) unless value.is_a?(Symbol)
end
end
def available_locales
locales = @store.keys.map { |k| k =~ /\./; $` }
locales.uniq!
locales.compact!
locales.map! { |k| k.to_sym }
locales
end
protected
def subtrees?
@subtrees
end
def lookup(locale, key, scope = [], options = {})
key = normalize_flat_keys(locale, key, scope, options[:separator])
value = @store["#{locale}.#{key}"]
value = JSON.decode(value) if value
if value.is_a?(Hash)
value.deep_symbolize_keys
elsif !value.nil?
value
elsif !@subtrees
SubtreeProxy.new("#{locale}.#{key}", @store)
end
end
def pluralize(locale, entry, count)
if subtrees?
super
else
key = pluralization_key(entry, count)
entry[key]
end
end
end
class SubtreeProxy
def initialize(master_key, store)
@master_key = master_key
@store = store
@subtree = nil
end
def has_key?(key)
@subtree && @subtree.has_key?(key) || self[key]
end
def [](key)
unless @subtree && value = @subtree[key]
value = @store["#{@master_key}.#{key}"]
if value
value = JSON.decode(value)
(@subtree ||= {})[key] = value
end
end
value
end
def is_a?(klass)
Hash == klass || super
end
alias :kind_of? :is_a?
def instance_of?(klass)
Hash == klass || super
end
def nil?
@subtree.nil?
end
def inspect
@subtree.inspect
end
end
include Implementation
end
end
end