racket/collects/handin-server/private/config.rkt
2010-09-13 02:35:22 -04:00

124 lines
5.5 KiB
Racket

#lang racket/base
(require racket/file)
;; This module should be invoked when we're in the server directory
(provide server-dir)
(define server-dir
(let ([dir (or (getenv "PLT_HANDINSERVER_DIR") (current-directory))])
(if (directory-exists? dir)
dir
(error 'config "handin server directory does not exist: ~e" dir))))
(define config-file (path->complete-path "config.rktd" server-dir))
(define poll-freq 2000.0) ; poll at most once every two seconds
(define last-poll #f)
(define last-filetime #f)
(define raw-config #f)
(define config-cache #f)
(provide get-conf)
(define (get-conf key)
(unless (and raw-config
(< (- (current-inexact-milliseconds) last-poll) poll-freq))
(set! last-poll (current-inexact-milliseconds))
(let ([filetime (file-or-directory-modify-seconds config-file)])
(unless (and filetime (equal? filetime last-filetime))
(set! last-filetime filetime)
(with-handlers
([void (lambda (e)
(raise-user-error 'get-conf "could not read conf (~a): ~a"
config-file (exn-message e)))])
(when raw-config
;; can't use log-line from logger, since it makes a cycle,
;; but make sure it's written in one shot; in any case, don't
;; write anything if this is the first read, since the logger
;; is not initialized yet (and if there's an error at this
;; stage, the server will exit)
(fprintf (current-error-port)
(format "reloading configuration from ~a\n"
config-file)))
(let ([c (with-input-from-file config-file read)])
(if (and (list? c)
(andmap (lambda (x)
(and (pair? x) (symbol? (car x))))
c))
(set! raw-config c)
(error "malformed configuration file content"))))
(set! config-cache (make-hasheq)))))
(hash-ref config-cache key
(lambda ()
(let*-values ([(default translate) (config-default+translate key)]
;; translate = #f => this is a computed value
[(v) (if translate
(translate (cond [(assq key raw-config) => cadr]
[else default]))
default)])
(hash-set! config-cache key v)
v))))
(define (id x) x)
(define (rx s) (if (regexp? s) s (regexp s)))
(define (path p) (path->complete-path p server-dir))
(define (path/false p) (and p (path p)))
(define (path-list l) (map path l))
(define (config-default+translate which)
(case which
[(active-dirs) (values '() path-list )]
[(inactive-dirs) (values '() path-list )]
[(port-number) (values 7979 id )]
[(use-https) (values #t id )]
[(hook-file) (values #f path/false )]
[(session-timeout) (values 300 id )]
[(session-memory-limit) (values 40000000 id )]
[(default-file-name) (values "handin.rkt" id )]
[(max-upload) (values 500000 id )]
[(max-upload-keep) (values 9 id )]
[(user-regexp) (values #rx"^[a-z][a-z0-9]+$" rx )]
[(user-desc) (values "alphanumeric string" id )]
[(username-case-sensitive) (values #f id )]
[(allow-new-users) (values #f id )]
[(allow-change-info) (values #f id )]
[(master-password) (values #f id )]
[(log-output) (values #t id )]
[(log-file) (values "log" path/false )]
[(web-log-file) (values #f path/false )]
[(extra-fields)
(values '(("Full Name" #f #f)
("ID#" #f #f)
("Email" #rx"^[^@<>\"`',]+@[a-zA-Z0-9_.-]+[.][a-zA-Z]+$"
"a valid email address"))
id)]
;; computed from the above (mark by translate = #f)
[(all-dirs)
(values (append (get-conf 'active-dirs) (get-conf 'inactive-dirs)) #f)]
[(names-dirs) ; see below
(values (paths->map (get-conf 'all-dirs)) #f)]
[(user-fields)
(values (filter (lambda (f) (not (eq? '- (cadr f))))
(get-conf 'extra-fields))
#f)]
[else (error 'get-conf "unknown configuration entry: ~s" which)]))
;; This is used below to map names to submission directory paths and back
;; returns a (list-of (either (list name path) (list path name)))
(define (paths->map dirs)
(define (path->name dir)
(unless (directory-exists? dir)
(if (file-exists? dir)
(error 'get-conf "directory entry points at a file: ~e" dir)
(make-directory* dir)))
(let-values ([(_1 name _2) (split-path dir)])
(path-element->string name)))
(let ([names (map path->name dirs)])
(append (map list names dirs) (map list dirs names))))
;; Translates an assignment name to a directory path or back
(provide assignment<->dir)
(define (assignment<->dir a/d)
(cond [(assoc a/d (get-conf 'names-dirs)) => cadr]
[else (error 'assignment<->dir "internal error: ~e" a/d)]))