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module Rack
# Rack::URLMap takes a hash mapping urls or paths to apps, and
# dispatches accordingly. Support for HTTP/1.1 host names exists if
# the URLs start with <tt>http://</tt> or <tt>https://</tt>.
#
# URLMap modifies the SCRIPT_NAME and PATH_INFO such that the part
# relevant for dispatch is in the SCRIPT_NAME, and the rest in the
# PATH_INFO. This should be taken care of when you need to
# reconstruct the URL in order to create links.
#
# URLMap dispatches in such a way that the longest paths are tried
# first, since they are most specific.
class URLMap
NEGATIVE_INFINITY = -1.0 / 0.0
INFINITY = 1.0 / 0.0
def initialize(map = {})
remap(map)
end
def remap(map)
@mapping = map.map { |location, app|
if location =~ %r{\Ahttps?://(.*?)(/.*)}
host, location = $1, $2
else
host = nil
end
unless location[0] == ?/
raise ArgumentError, "paths need to start with /"
end
location = location.chomp('/')
match = Regexp.new("^#{Regexp.quote(location).gsub('/', '/+')}(.*)", nil, 'n')
[host, location, match, app]
}.sort_by do |(host, location, _, _)|
[host ? -host.size : INFINITY, -location.size]
end
end
def call(env)
path = env[PATH_INFO]
script_name = env[SCRIPT_NAME]
http_host = env[HTTP_HOST]
server_name = env[SERVER_NAME]
server_port = env[SERVER_PORT]
is_same_server = casecmp?(http_host, server_name) ||
casecmp?(http_host, "#{server_name}:#{server_port}")
@mapping.each do |host, location, match, app|
unless casecmp?(http_host, host) \
|| casecmp?(server_name, host) \
|| (!host && is_same_server)
next
end
next unless m = match.match(path.to_s)
rest = m[1]
next unless !rest || rest.empty? || rest[0] == ?/
env[SCRIPT_NAME] = (script_name + location)
env[PATH_INFO] = rest
return app.call(env)
end
[404, {CONTENT_TYPE => "text/plain", "X-Cascade" => "pass"}, ["Not Found: #{path}"]]
ensure
env[PATH_INFO] = path
env[SCRIPT_NAME] = script_name
end
private
def casecmp?(v1, v2)
# if both nil, or they're the same string
return true if v1 == v2
# if either are nil... (but they're not the same)
return false if v1.nil?
return false if v2.nil?
# otherwise check they're not case-insensitive the same
v1.casecmp(v2).zero?
end
end
end