eval-server/eval-server.sld

100 lines
3.7 KiB
Scheme

(define-library (eval-server)
(import (srfi 1)
(srfi 13)
(srfi 98)
(scheme base)
(scheme write)
(only (chicken blob) blob->string)
(only (srfi 4) u8vector->blob)
(spiffy)
(intarweb)
(uri-common)
(tar))
(begin
(define implementations
'(("gauche" '("gosh" "-r" "7"))))
(define implementation-name first)
(define (respond-with-error status string)
(send-response status: status body: string))
(define (bytevector->string bytes)
(blob->string (u8vector->blob bytes)))
(define (tar-for-each proc)
(let loop ()
(let ((entry (read-tar-entry)))
(unless (eof-object? entry)
(proc entry)
(loop)))))
(define (handle-the-scheme-implementation impl)
(let ((cmdline #f)
(environ #f)
(cwd (string->utf8 "/"))
(fd0 #f))
(parameterize ((current-input-port (request-port (current-request))))
(tar-for-each
(lambda (entry)
(let ((name (tar-entry-name entry)))
(write name)(newline)
(cond ((equal? "proc/self/cmdline" name)
(set! cmdline (read-tar-entry-bytes)))
((equal? "proc/self/environ" name)
(set! stdin (read-tar-entry-bytes)))
((equal? "proc/self/cwd" name)
(set! stdin (read-tar-entry-bytes)))
((equal? "proc/self/fd/0" name)
(set! stdin (read-tar-entry-bytes)))
((string-prefix? "proc/self/fd/" name)
(error "Bad file descriptor on input"))
((or (equal? "proc" name) (string-prefix? "proc/" name))
(error "Bad /proc entry on input")))))))
(send-response
status: 'ok
body: (bytevector->string
(let ((bytes (string->utf8
(string-append "Hello "
(implementation-name impl)))))
(bytevector-append
(bytevector-append
(make-tar-header-for-regular-file "proc/self/fd/1" bytes)
bytes
(make-tar-padding bytes))
(make-tar-eof)))))))
(define (handle-scheme-implementation)
(let ((path (uri-path (request-uri (current-request))))
(head (request-headers (current-request))))
(write (header-value 'content-type head))(newline)
(write (header-value 'accept head))(newline)
(if (not (and (tar-content-type? (header-value 'content-type head))
(tar-content-type? (header-value 'accept head))))
(respond-with-error 'bad-request "Not tar files")
(let* ((impl-name (second path))
(impl (assoc impl-name implementations)))
(if (not impl)
(respond-with-error 'not-found
"No such Scheme implementation")
(handle-the-scheme-implementation impl))))))
(define (handle-request continue)
(let ((path (uri-path (request-uri (current-request)))))
(write path)(newline)
(if (and (= 2 (length path))
(eq? '/ (first path))
(string? (second path)))
(handle-scheme-implementation)
(continue))))
(define (main)
(vhost-map `(("localhost" . ,handle-request)))
(server-port
(string->number (or (get-environment-variable "PORT")
(error "No PORT"))))
(start-server))
(main)))