# File lib/serverside/http/caching.rb, line 5
 5:     def cache(opts)
 6:       # check cache-control
 7:       remove_cache_control
 8:       if cache_control = opts[:cache_control]
 9:         add_header(CACHE_CONTROL, cache_control)
10:       end
11:       
12:       # add an expires header
13:       if expires = opts[:expires] || (opts[:ttl] && (Time.now + opts[:ttl]))
14:         add_header(EXPIRES, expires.httpdate)
15:       end
16:     end

    # File lib/serverside/http/caching.rb, line 49
49:     def etag_match(etag)
50:       return false unless @request
51:       matches = @request.headers[IF_NONE_MATCH]
52:       if matches
53:         matches.split(COMMA).each do |e|
54:           return true if e.strip == etag
55:         end
56:       end
57:       false
58:     end

    # File lib/serverside/http/caching.rb, line 62
62:     def modified_match(last_modified)
63:       return false unless @request
64:       if modified_since = @request.headers[IF_MODIFIED_SINCE]
65:         last_modified.to_i == Time.parse(modified_since).to_i
66:       else
67:         false
68:       end
69:     rescue => e
70:       raise BadRequestError, "Invalid value in If-Modified-Since header"
71:     end

    # File lib/serverside/http/caching.rb, line 82
82:     def remove_cache_control
83:       @headers.reject! {|h| h =~ /^#{CACHE_CONTROL}/}
84:     end

    # File lib/serverside/http/caching.rb, line 74
74:     def set_cache_control(directive)
75:       add_header(CACHE_CONTROL, directive)
76:     end

    # File lib/serverside/http/caching.rb, line 78
78:     def set_no_cache
79:       set_cache_control(NO_CACHE)
80:     end

    # File lib/serverside/http/caching.rb, line 21
21:     def validate_cache(opts, &block)
22:       valid_cache = false
23:       
24:       # check etag
25:       if etag = opts[:etag]
26:         etag = "\"#{etag}\""
27:         add_header(ETAG, etag) if etag
28:         valid_cache = etag_match(etag)
29:       end
30:       
31:       # check last_modified
32:       if last_modified = opts[:last_modified]
33:         add_header(LAST_MODIFIED, last_modified.httpdate)
34:         valid_cache ||= modified_match(last_modified)
35:       end
36:       
37:       # set cache-related headers
38:       cache(opts)
39:       
40:       # if not modified, we have a 304 response. Otherwise we yield to the
41:       # supplied block.
42:       valid_cache ? (@status = STATUS_NOT_MODIFIED) : yield(self)
43:     end