# File actionpack/lib/action_dispatch/http/cache.rb, line 71
def cache_control_directives
  @cache_control_directives ||= CacheControlDirectives.new(get_header("HTTP_CACHE_CONTROL"))
end

# File actionpack/lib/action_dispatch/http/cache.rb, line 36
def etag_matches?(etag)
  if etag
    validators = if_none_match_etags
    validators.include?(etag) || validators.include?("*")
  end
end

# File actionpack/lib/action_dispatch/http/cache.rb, line 49
def fresh?(response)
  if Request.strict_freshness
    if if_none_match
      etag_matches?(response.etag)
    elsif if_modified_since
      not_modified?(response.last_modified)
    else
      false
    end
  else
    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

# File actionpack/lib/action_dispatch/http/cache.rb, line 14
def if_modified_since
  if since = get_header(HTTP_IF_MODIFIED_SINCE)
    # `If-Modified-Since` carries an HTTP-date, which per RFC 9110 may be in
    # any of the three legal formats (IMF-fixdate, RFC 850, or asctime).
    # `Time.httpdate` accepts all three; it also matches how the response side
    # parses `Last-Modified`/`Date`. `Time.rfc2822` only accepted IMF-fixdate.
    Time.httpdate(since) rescue nil
  end
end

# File actionpack/lib/action_dispatch/http/cache.rb, line 24
def if_none_match
  get_header HTTP_IF_NONE_MATCH
end

# File actionpack/lib/action_dispatch/http/cache.rb, line 28
def if_none_match_etags
  if_none_match ? if_none_match.split(",").each(&:strip!) : []
end

# File actionpack/lib/action_dispatch/http/cache.rb, line 32
def not_modified?(modified_at)
  if_modified_since && modified_at && if_modified_since >= modified_at
end