racket/collects/web-server/dispatch-log.ss
2005-12-02 16:30:23 +00:00

64 lines
2.6 KiB
Scheme

(module dispatch-log mzscheme
(require (lib "url.ss" "net")
(lib "date.ss")
(lib "async-channel.ss")
(lib "plt-match.ss"))
(require "dispatch.ss"
"servlet-helpers.ss")
(provide interface-version
gen-dispatcher)
(define interface-version 'v1)
(define (gen-dispatcher log-format log-path)
(if log-path
(case log-format
[(parenthesized-default)
(let ([log-message (gen-log-message log-format log-path)])
(lambda (conn req)
(let ([host (get-host (request-uri req) (request-headers req))])
(log-message (request-host-ip req)
(request-client-ip req)
(request-method req)
(request-uri req)
host)
(next-dispatcher))))]
[else
(lambda (conn req) (next-dispatcher))])
(lambda (conn req)
(next-dispatcher))))
; gen-log-message : sym str -> str str sym url str -> str
; XXX: check apache log configuration formats
; other server's include the original request line,
; including the major and minor HTTP version numbers
; to produce a string that is displayed into the log file
; This is a kill-safe wait-less abstraction
(define (gen-log-message log-format log-path)
(let* ([log-ch (make-async-channel)]
[log-thread
(thread/suspend-to-kill
(lambda ()
(let loop ([log-p #f])
(with-handlers ([exn? (lambda (e) (loop #f))])
(if (not (and log-p (file-exists? log-path)))
(begin
(unless (eq? log-p #f)
(close-output-port log-p))
(let ([new-log-p (open-output-file log-path 'append)])
(file-stream-buffer-mode new-log-p 'line)
(loop new-log-p)))
(sync
(handle-evt
log-ch
(match-lambda
[(list host-ip client-ip method uri host)
(display
(format "~s~n"
(list 'from client-ip 'to host-ip 'for (url->string uri) 'at
(date->string (seconds->date (current-seconds)) #t)))
log-p)
(loop log-p)]))))))))])
(lambda args
(thread-resume log-thread)
(async-channel-put log-ch args)
(void)))))