1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
|
# 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
# https://www.ruby-doc.org/core/classes/Object.html#M000337). However, you can
# configure your own digest method via which responds to #hexdigest (see
# https://ruby-doc.org/stdlib/libdoc/openssl/rdoc/OpenSSL/Digest.html):
#
# I18n.cache_key_digest = OpenSSL::Digest::SHA256.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
|
