blob: d2404e63c5526866e2477a900c6d634a7ab0f9ac (
plain) (
blame)
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
|
module ActionDispatch
module Http
module Cache
module Request
def if_modified_since
if since = env['HTTP_IF_MODIFIED_SINCE']
Time.rfc2822(since) rescue nil
end
end
def if_none_match
env['HTTP_IF_NONE_MATCH']
end
def not_modified?(modified_at)
if_modified_since && modified_at && if_modified_since >= modified_at
end
def etag_matches?(etag)
if_none_match && if_none_match == etag
end
# Check response freshness (Last-Modified and ETag) against request
# If-Modified-Since and If-None-Match conditions. If both headers are
# supplied, both must match, or the request is not considered fresh.
def fresh?(response)
last_modified = if_modified_since
etag = if_none_match
return false unless last_modified || etag
success = true
success &&= not_modified?(response.last_modified) if last_modified
success &&= etag_matches?(response.etag) if etag
success
end
end
module Response
attr_reader :cache_control
def initialize(*)
status, header, body = super
@cache_control = {}
@etag = self["ETag"]
if cache_control = self["Cache-Control"]
cache_control.split(/,\s*/).each do |segment|
first, last = segment.split("=")
last ||= true
@cache_control[first.to_sym] = last
end
end
end
def last_modified
if last = headers['Last-Modified']
Time.httpdate(last)
end
end
def last_modified?
headers.include?('Last-Modified')
end
def last_modified=(utc_time)
headers['Last-Modified'] = utc_time.httpdate
end
def etag
@etag
end
def etag?
@etag
end
def etag=(etag)
key = ActiveSupport::Cache.expand_cache_key(etag)
@etag = self["ETag"] = %("#{Digest::MD5.hexdigest(key)}")
end
private
def handle_conditional_get!
if etag? || last_modified? || !@cache_control.empty?
set_conditional_cache_control!
elsif nonempty_ok_response?
self.etag = @body
if request && request.etag_matches?(etag)
self.status = 304
self.body = []
end
set_conditional_cache_control!
else
headers["Cache-Control"] = "no-cache"
end
end
def nonempty_ok_response?
@status == 200 && string_body?
end
def string_body?
!@blank && @body.respond_to?(:all?) && @body.all? { |part| part.is_a?(String) }
end
DEFAULT_CACHE_CONTROL = "max-age=0, private, must-revalidate"
def set_conditional_cache_control!
control = @cache_control
return if self["Cache-Control"].present?
if control.empty?
headers["Cache-Control"] = DEFAULT_CACHE_CONTROL
elsif @cache_control[:no_cache]
headers["Cache-Control"] = "no-cache"
else
extras = control[:extras]
max_age = control[:max_age]
options = []
options << "max-age=#{max_age.to_i}" if max_age
options << (control[:public] ? "public" : "private")
options << "must-revalidate" if control[:must_revalidate]
options.concat(extras) if extras
headers["Cache-Control"] = options.join(", ")
end
end
end
end
end
end
|
