/usr/lib/ruby/vendor_ruby/action_controller/metal/conditional_get.rb is in ruby-actionpack 2:4.2.6-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 | require 'active_support/core_ext/hash/keys'
module ActionController
module ConditionalGet
extend ActiveSupport::Concern
include RackDelegation
include Head
included do
class_attribute :etaggers
self.etaggers = []
end
module ClassMethods
# Allows you to consider additional controller-wide information when generating an ETag.
# For example, if you serve pages tailored depending on who's logged in at the moment, you
# may want to add the current user id to be part of the ETag to prevent authorized displaying
# of cached pages.
#
# class InvoicesController < ApplicationController
# etag { current_user.try :id }
#
# def show
# # Etag will differ even for the same invoice when it's viewed by a different current_user
# @invoice = Invoice.find(params[:id])
# fresh_when(@invoice)
# end
# end
def etag(&etagger)
self.etaggers += [etagger]
end
end
# Sets the +etag+, +last_modified+, or both on the response and renders a
# <tt>304 Not Modified</tt> response if the request is already fresh.
#
# === Parameters:
#
# * <tt>:etag</tt>.
# * <tt>:last_modified</tt>.
# * <tt>:public</tt> By default the Cache-Control header is private, set this to
# +true+ if you want your application to be cachable by other devices (proxy caches).
# * <tt>:template</tt> By default, the template digest for the current
# controller/action is included in ETags. If the action renders a
# different template, you can include its digest instead. If the action
# doesn't render a template at all, you can pass <tt>template: false</tt>
# to skip any attempt to check for a template digest.
#
# === Example:
#
# def show
# @article = Article.find(params[:id])
# fresh_when(etag: @article, last_modified: @article.created_at, public: true)
# end
#
# This will render the show template if the request isn't sending a matching ETag or
# If-Modified-Since header and just a <tt>304 Not Modified</tt> response if there's a match.
#
# You can also just pass a record where +last_modified+ will be set by calling
# +updated_at+ and the +etag+ by passing the object itself.
#
# def show
# @article = Article.find(params[:id])
# fresh_when(@article)
# end
#
# When passing a record, you can still set whether the public header:
#
# def show
# @article = Article.find(params[:id])
# fresh_when(@article, public: true)
# end
#
# When rendering a different template than the default controller/action
# style, you can indicate which digest to include in the ETag:
#
# before_action { fresh_when @article, template: 'widgets/show' }
#
def fresh_when(record_or_options, additional_options = {})
if record_or_options.is_a? Hash
options = record_or_options
options.assert_valid_keys(:etag, :last_modified, :public, :template)
else
record = record_or_options
options = { etag: record, last_modified: record.try(:updated_at) }.merge!(additional_options)
end
response.etag = combine_etags(options) if options[:etag] || options[:template]
response.last_modified = options[:last_modified] if options[:last_modified]
response.cache_control[:public] = true if options[:public]
head :not_modified if request.fresh?(response)
end
# Sets the +etag+ and/or +last_modified+ on the response and checks it against
# the client request. If the request doesn't match the options provided, the
# request is considered stale and should be generated from scratch. Otherwise,
# it's fresh and we don't need to generate anything and a reply of <tt>304 Not Modified</tt> is sent.
#
# === Parameters:
#
# * <tt>:etag</tt>.
# * <tt>:last_modified</tt>.
# * <tt>:public</tt> By default the Cache-Control header is private, set this to
# +true+ if you want your application to be cachable by other devices (proxy caches).
# * <tt>:template</tt> By default, the template digest for the current
# controller/action is included in ETags. If the action renders a
# different template, you can include its digest instead. If the action
# doesn't render a template at all, you can pass <tt>template: false</tt>
# to skip any attempt to check for a template digest.
#
# === Example:
#
# def show
# @article = Article.find(params[:id])
#
# if stale?(etag: @article, last_modified: @article.created_at)
# @statistics = @article.really_expensive_call
# respond_to do |format|
# # all the supported formats
# end
# end
# end
#
# You can also just pass a record where +last_modified+ will be set by calling
# +updated_at+ and the +etag+ by passing the object itself.
#
# def show
# @article = Article.find(params[:id])
#
# if stale?(@article)
# @statistics = @article.really_expensive_call
# respond_to do |format|
# # all the supported formats
# end
# end
# end
#
# When passing a record, you can still set whether the public header:
#
# def show
# @article = Article.find(params[:id])
#
# if stale?(@article, public: true)
# @statistics = @article.really_expensive_call
# respond_to do |format|
# # all the supported formats
# end
# end
# end
#
# When rendering a different template than the default controller/action
# style, you can indicate which digest to include in the ETag:
#
# def show
# super if stale? @article, template: 'widgets/show'
# end
#
def stale?(record_or_options, additional_options = {})
fresh_when(record_or_options, additional_options)
!request.fresh?(response)
end
# Sets a HTTP 1.1 Cache-Control header. Defaults to issuing a +private+
# instruction, so that intermediate caches must not cache the response.
#
# expires_in 20.minutes
# expires_in 3.hours, public: true
# expires_in 3.hours, public: true, must_revalidate: true
#
# This method will overwrite an existing Cache-Control header.
# See http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html for more possibilities.
#
# The method will also ensure a HTTP Date header for client compatibility.
def expires_in(seconds, options = {})
response.cache_control.merge!(
:max_age => seconds,
:public => options.delete(:public),
:must_revalidate => options.delete(:must_revalidate)
)
options.delete(:private)
response.cache_control[:extras] = options.map {|k,v| "#{k}=#{v}"}
response.date = Time.now unless response.date?
end
# Sets a HTTP 1.1 Cache-Control header of <tt>no-cache</tt> so no caching should
# occur by the browser or intermediate caches (like caching proxy servers).
def expires_now
response.cache_control.replace(:no_cache => true)
end
private
def combine_etags(options)
etags = etaggers.map { |etagger| instance_exec(options, &etagger) }.compact
etags.unshift options[:etag]
end
end
end
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