racket/collects/web-server/private/util.ss
2007-01-17 01:18:50 +00:00

176 lines
6.9 KiB
Scheme

(module util mzscheme
(require (lib "contract.ss")
(lib "string.ss")
(lib "list.ss")
(lib "url.ss" "net")
(lib "plt-match.ss")
(lib "uri-codec.ss" "net"))
(require "../request-structs.ss")
;; valid-port? : any/c -> boolean?
(define (valid-port? p)
(and (integer? p) (exact? p) (<= 1 p 65535)))
;; ripped this off from url-unit.ss
(define (url-path->string strs)
(apply string-append
(apply append
(map (lambda (s) (list "/" (maybe-join-params s)))
strs))))
;; needs to unquote things!
(define (maybe-join-params s)
(if (string? s)
s
(let ([s (path/param-path s)])
(if (string? s)
s
(case s
[(same) "."]
[(up) ".."]
[else (error 'maybe-join-params
"bad value from path/param-path: ~e" s)])))))
;; decompse-request : request -> uri * symbol * string
(define (decompose-request req)
(let* ([uri (request-uri req)]
[method (request-method req)]
[path (uri-decode (url-path->string (url-path uri)))])
(values uri method path)))
;; network-error: symbol string . values -> void
;; throws a formatted exn:fail:network
(define (network-error src fmt . args)
(raise (make-exn:fail:network (format "~a: ~a" src (apply format fmt args))
(current-continuation-marks))))
;; build-path-unless-absolute : path-string? path-string? -> path?
(define (build-path-unless-absolute base path)
(if (absolute-path? path)
(build-path path)
(build-path base path)))
;; exn->string : (or/c exn any) -> string
(define (exn->string exn)
(if (exn? exn)
(parameterize ([current-error-port (open-output-string)])
((error-display-handler) (exn-message exn) exn)
(get-output-string (current-error-port)))
(format "~s\n" exn)))
; lowercase-symbol! : (or/c string bytes) -> symbol
(define (lowercase-symbol! s)
(let ([s (if (bytes? s)
(bytes->string/utf-8 s)
s)])
(string-lowercase! s)
(string->symbol s)))
; prefix? : str -> str -> bool
; more here - consider moving this to mzlib's string.ss
;; Notes: (GregP)
;; 1. What's the significance of char # 255 ???
;; 2. 255 isn't an ascii character. ascii is 7-bit
;; 3. OK f this. It is only used in three places, some of them
;; will involve bytes while the others may involve strings. So
;; I will just use regular expressions and get on with life.
(define (prefix?-old prefix)
(let* ([len (string-length prefix)]
[last (string-ref prefix (sub1 len))]
[ascii (char->integer last)])
(if (= 255 ascii)
; something could be done about this - ab255 -> ac
; and all 255's eliminates upper range check
(error 'prefix? "prefix can't end in the largest character")
(let ([next (string-append (substring prefix 0 (sub1 len))
(string (integer->char (add1 ascii))))])
(lambda (x)
(and (string<=? prefix x) (string<? x next)))))))
(define (directory-part path)
(let-values ([(base name must-be-dir) (split-path path)])
(cond
[(eq? 'relative base) (current-directory)]
[(not base) (error 'directory-part "~a is a top-level directory" path)]
[(path? base) base])))
; more here - ".." should probably raise an error instead of disappearing.
; XXX: This is terrible. should re-write.
(define (url-path->path base p)
(let ([path-elems (regexp-split #rx"/" p)])
;;; Hardcoded, bad, and wrong
(if (or (string=? (car path-elems) "servlets")
(and (string=? (car path-elems) "")
(string=? (cadr path-elems) "servlets")))
;; Servlets can have extra stuff after them
(let ([build-path
(lambda (b p)
(if (string=? p "")
b
(build-path b p)))])
(let loop ([p-e (if (string=? (car path-elems) "")
(cddr path-elems)
(cdr path-elems))]
[f (build-path base
(if (string=? (car path-elems) "")
(cadr path-elems)
(car path-elems)))])
(cond
[(null? p-e)
f]
[(directory-exists? f)
(loop (cdr p-e) (build-path f (car p-e)))]
[(file-exists? f)
f]
[else
f]))) ;; Don't worry about e.g. links for now
(apply build-path base
(reverse!
(foldl (lambda (x acc)
(cond
[(string=? x "") acc]
[(string=? x ".") acc]
[(string=? x "..") (if (pair? acc) (cdr acc) acc)]
[else (cons x acc)]))
null
(regexp-split #rx"/" p)))))))
; to convert a platform dependent path into a listof path parts such that
; (forall x (equal? (path->list x) (path->list (apply build-path (path->list x)))))
(define (path->list p)
(let loop ([p p] [acc null])
(let-values ([(base name must-be-dir?) (split-path p)])
(let ([new-acc (cons name acc)])
(cond
[(string? base) (loop base new-acc)]
[else ; conflate 'relative and #f
new-acc])))))
; this is used by launchers
; extract-flag : sym (listof (cons sym alpha)) alpha -> alpha
; XXX remove
(define (extract-flag name flags default)
(let ([x (assq name flags)])
(if x
(cdr x)
default)))
; hash-table-empty? : hash-table -> bool
(define (hash-table-empty? table)
(zero? (hash-table-count table)))
(provide/contract
[url-path->string ((listof (or/c string? path/param?)) . -> . string?)]
[extract-flag (symbol? (listof (cons/c symbol? any/c)) any/c . -> . any/c)]
[hash-table-empty? (any/c . -> . boolean?)]
[valid-port? (any/c . -> . boolean?)]
[decompose-request ((request?) . ->* . (url? symbol? string?))]
[network-error ((symbol? string?) (listof any/c) . ->* . (void))]
[path->list (path? . -> . (cons/c (or/c path? (symbols 'up 'same))
(listof (or/c path? (symbols 'up 'same)))))]
[url-path->path ((or/c (symbols 'up 'same) path?) string? . -> . path?)]
[directory-part (path? . -> . path?)]
[lowercase-symbol! ((or/c string? bytes?) . -> . symbol?)]
[exn->string ((or/c exn? any/c) . -> . string?)]
[build-path-unless-absolute (path-string? path-string? . -> . path?)]))