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