blob: 428e62dc6bc970b0bf02f698699cf960cbb2b391 (
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
|
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
def cache_control
@cache_control ||= {}
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 = %("#{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
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
|
