racket/collects/web-server/connection-manager.ss
2005-05-27 18:56:37 +00:00

49 lines
1.8 KiB
Scheme

;; this is an trivial implementation of the connection-manger interface that
;; uses timeouts instead of a queued-model.
;; the queued-model is also fully implemented but won't be used at this time.
(module connection-manager mzscheme
(require "timer.ss"
(lib "contract.ss"))
(define-struct connection (timer i-port o-port custodian close?)
(make-inspector))
(provide/contract
[struct connection
([timer timer?]
[i-port input-port?] [o-port output-port?] [custodian custodian?]
[close? boolean?])]
[start-connection-manager (custodian? . -> . void)]
[new-connection (number? input-port? output-port? custodian? boolean? . -> . connection?)]
[kill-connection! (connection? . -> . void)]
[adjust-connection-timeout! (connection? number? . -> . void)])
;; start-connection-manager: custodian -> void
;; does nothing
(define start-connection-manager void)
;; new-connection: number i-port o-port custodian -> connection
;; ask the connection manager for a new connection
(define (new-connection time-to-live i-port o-port cust close?)
(make-connection
(start-timer time-to-live
(lambda ()
(close-output-port o-port)
(close-input-port i-port)
(custodian-shutdown-all cust)))
i-port o-port cust close?))
;; kill-connection!: connection -> void
;; kill this connection
(define (kill-connection! conn-demned)
(close-output-port (connection-o-port conn-demned))
(close-input-port (connection-i-port conn-demned))
(custodian-shutdown-all (connection-custodian conn-demned)))
;; adjust-connection-timeout!: connection number -> void
;; change the expiration time for this connection
(define (adjust-connection-timeout! conn time)
(reset-timer (connection-timer conn) time))
)