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# AUTHOR: blink <blinketje@gmail.com>; blink#ruby-lang@irc.freenode.net
# bugrep: Andreas Zehnder
require 'time'
require 'rack/request'
require 'rack/response'
module Rack
module Session
module Abstract
# ID sets up a basic framework for implementing an id based sessioning
# service. Cookies sent to the client for maintaining sessions will only
# contain an id reference. Only #get_session and #set_session are
# required to be overwritten.
#
# All parameters are optional.
# * :key determines the name of the cookie, by default it is
# 'rack.session'
# * :path, :domain, :expire_after, :secure, and :httponly set the related
# cookie options as by Rack::Response#add_cookie
# * :defer will not set a cookie in the response.
# * :renew (implementation dependent) will prompt the generation of a new
# session id, and migration of data to be referenced at the new id. If
# :defer is set, it will be overridden and the cookie will be set.
# * :sidbits sets the number of bits in length that a generated session
# id will be.
#
# These options can be set on a per request basis, at the location of
# env['rack.session.options']. Additionally the id of the session can be
# found within the options hash at the key :id. It is highly not
# recommended to change its value.
#
# Is Rack::Utils::Context compatible.
class ID
DEFAULT_OPTIONS = {
:path => '/',
:domain => nil,
:expire_after => nil,
:secure => false,
:httponly => true,
:defer => false,
:renew => false,
:sidbits => 128
}
attr_reader :key, :default_options
def initialize(app, options={})
@app = app
@key = options[:key] || "rack.session"
@default_options = self.class::DEFAULT_OPTIONS.merge(options)
end
def call(env)
context(env)
end
def context(env, app=@app)
load_session(env)
status, headers, body = app.call(env)
commit_session(env, status, headers, body)
end
private
# Generate a new session id using Ruby #rand. The size of the
# session id is controlled by the :sidbits option.
# Monkey patch this to use custom methods for session id generation.
def generate_sid
"%0#{@default_options[:sidbits] / 4}x" %
rand(2**@default_options[:sidbits] - 1)
end
# Extracts the session id from provided cookies and passes it and the
# environment to #get_session. It then sets the resulting session into
# 'rack.session', and places options and session metadata into
# 'rack.session.options'.
def load_session(env)
request = Rack::Request.new(env)
session_id = request.cookies[@key]
begin
session_id, session = get_session(env, session_id)
env['rack.session'] = session
rescue
env['rack.session'] = Hash.new
end
env['rack.session.options'] = @default_options.
merge(:id => session_id)
end
# Acquires the session from the environment and the session id from
# the session options and passes them to #set_session. If successful
# and the :defer option is not true, a cookie will be added to the
# response with the session's id.
def commit_session(env, status, headers, body)
session = env['rack.session']
options = env['rack.session.options']
session_id = options[:id]
if not session_id = set_session(env, session_id, session, options)
env["rack.errors"].puts("Warning! #{self.class.name} failed to save session. Content dropped.")
[status, headers, body]
elsif options[:defer] and not options[:renew]
env["rack.errors"].puts("Defering cookie for #{session_id}") if $VERBOSE
[status, headers, body]
else
cookie = Hash.new
cookie[:value] = session_id
cookie[:expires] = Time.now + options[:expire_after] unless options[:expire_after].nil?
response = Rack::Response.new(body, status, headers)
response.set_cookie(@key, cookie.merge(options))
response.to_a
end
end
# All thread safety and session retrival proceedures should occur here.
# Should return [session_id, session].
# If nil is provided as the session id, generation of a new valid id
# should occur within.
def get_session(env, sid)
raise '#get_session not implemented.'
end
# All thread safety and session storage proceedures should occur here.
# Should return true or false dependant on whether or not the session
# was saved or not.
def set_session(env, sid, session, options)
raise '#set_session not implemented.'
end
end
end
end
end
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