racket/collects/web-server/private/response.ss
Jay McCarthy 0214f207e7 Streamlining a few feautures
svn: r6773
2007-06-29 20:21:59 +00:00

216 lines
9.6 KiB
Scheme

(module response mzscheme
(require (lib "contract.ss")
(lib "port.ss")
(lib "list.ss")
(lib "plt-match.ss")
(lib "xml.ss" "xml")
"connection-manager.ss"
"../private/request-structs.ss"
"../private/response-structs.ss"
"util.ss")
(provide/contract
[rename ext:output-response output-response (connection? response? . -> . void)]
[rename ext:output-response/method output-response/method (connection? response? symbol? . -> . void)]
[rename ext:output-file output-file (connection? path? symbol? bytes? integer? integer? . -> . void)])
;; Table 1. head responses:
; ------------------------------------------------------------------------------
; |method | close? | x-fer coding || response actions
; |-----------------------------------------------------------------------------
; |-----------------------------------------------------------------------------
; |head | #t | chunked || 1. Output the headers only.
; |-------------------------------|| 2. Add the special connection-close header.
; |head | #t | not-chunked ||
; |-----------------------------------------------------------------------------
; |head | #f | chunked || 1. Output the headers only.
; |-------------------------------|| 2. Don't add the connection-close header.
; |head | #f | not-chunked ||
; |-----------------------------------------------------------------------------
;; Table 2. get responses:
; ------------------------------------------------------------------------------
; |method | x-fer-coding | close? || response actions
; |-----------------------------------------------------------------------------
; |-----------------------------------------------------------------------------
; | get | chunked | #t || 1. Output headers as above.
; | | | || 2. Generate trivial chunked response.
; |-----------------------------------------------------------------------------
; | get | chunked | #f || 1. Output headers as above.
; | | | || 2. Generate chunks as per RFC 2616 sec. 3.6
; |-----------------------------------------------------------------------------
; | get | not chunked | #t || 1. Output headers as above.
; |-------------------------------|| 2. Generate usual non-chunked response.
; | get | not chunked | #f ||
; |-----------------------------------------------------------------------------
;; Notes:
;; 1. close? is a boolean which corresponds roughly to the protocol version.
;; #t |-> 1.0 and #f |-> 1.1. See function close-connection? in
;; private/request.ss
;;
;; 2. In the case of a chunked response when close? = #f, then the response
;; must be compliant with http 1.0. In this case the chunked response is
;; simply turned into a non-chunked one.
(define (output-response conn resp)
(output-response/method conn resp 'get))
; XXX Check method in response
(define (output-response/method conn resp meth)
(define bresp (response->response/basic (connection-close? conn) resp))
(output-headers+response/basic conn bresp)
(unless (eq? meth 'head)
(output-response/basic conn bresp)))
(define (response->response/basic close? resp)
(cond
[(response/full? resp)
(make-response/full
(response/basic-code resp)
(response/basic-message resp)
(response/basic-seconds resp)
(response/basic-mime resp)
(list* (make-header #"Content-Length" (string->bytes/utf-8 (number->string (response/full->size resp))))
(response/basic-headers resp))
(response/full-body resp))]
[(response/incremental? resp)
(if close?
resp
(make-response/incremental
(response/basic-code resp)
(response/basic-message resp)
(response/basic-seconds resp)
(response/basic-mime resp)
(list* (make-header #"Transfer-Encoding" #"chunked")
(response/basic-headers resp))
(response/incremental-generator resp)))]
[(and (pair? resp) (bytes? (car resp)))
(response->response/basic
close?
(make-response/full 200 "Okay" (current-seconds) (car resp) empty
(cdr resp)))]
[else
(response->response/basic
close?
(make-response/full 200 "Okay" (current-seconds) TEXT/HTML-MIME-TYPE empty
(list (xexpr->string resp))))]))
;; Write the headers portion of a response to an output port.
;; NOTE: According to RFC 2145 the server should write HTTP/1.1
;; header for *all* clients.
(define (output-headers+response/basic conn bresp)
(define o-port (connection-o-port conn))
(fprintf o-port "HTTP/1.1 ~a ~a\r\n" (response/basic-code bresp) (response/basic-message bresp))
(for-each (match-lambda
[(struct header (field value))
(fprintf o-port "~a: ~a\r\n" field value)])
(list* (make-header #"Date" (string->bytes/utf-8 (seconds->gmt-string (current-seconds))))
(make-header #"Last-Modified" (string->bytes/utf-8 (seconds->gmt-string (response/basic-seconds bresp))))
(make-header #"Server" #"PLT Scheme")
(make-header #"Content-Type" (response/basic-mime bresp))
(append (if (connection-close? conn)
(list (make-header #"Connection" #"close"))
empty)
(response/basic-headers bresp))))
(fprintf o-port "\r\n"))
(define (output-response/basic conn bresp)
(define o-port (connection-o-port conn))
(match bresp
[(? response/full?)
(for-each
(lambda (str) (display str o-port))
(response/full-body bresp))]
[(? response/incremental?)
(if (connection-close? conn)
((response/incremental-generator bresp)
(lambda chunks
(for-each (lambda (chunk) (display chunk o-port)) chunks)))
(begin
((response/incremental-generator bresp)
(lambda chunks
(fprintf o-port "~x\r\n"
(apply + 0 (map data-length chunks)))
(for-each (lambda (chunk) (display chunk o-port)) chunks)
(fprintf o-port "\r\n")))
; one \r\n ends the last (empty) chunk and the second \r\n ends the (non-existant) trailers
(fprintf o-port "0\r\n\r\n")))]))
(define (data-length x)
(if (string? x)
(data-length (string->bytes/utf-8 x))
(bytes-length x)))
; seconds->gmt-string : Nat -> String
; format is rfc1123 compliant according to rfc2068 (http/1.1)
(define (seconds->gmt-string s)
(let* ([local-date (seconds->date s)]
[date (seconds->date (- s
(date-time-zone-offset local-date)
(if (date-dst? local-date) 3600 0)))])
(format "~a, ~a ~a ~a ~a:~a:~a GMT"
(vector-ref DAYS (date-week-day date))
(two-digits (date-day date))
(vector-ref MONTHS (sub1 (date-month date)))
(date-year date)
(two-digits (date-hour date))
(two-digits (date-minute date))
(two-digits (date-second date)))))
; two-digits : num -> str
(define (two-digits n)
(let ([str (number->string n)])
(if (< n 10) (string-append "0" str) str)))
(define MONTHS
#("Jan" "Feb" "Mar" "Apr" "May" "Jun" "Jul" "Aug" "Sep" "Oct" "Nov" "Dec"))
(define DAYS
#("Sun" "Mon" "Tue" "Wed" "Thu" "Fri" "Sat"))
(define (ext:wrap f)
(lambda (conn . args)
(with-handlers ([exn? (lambda (exn)
(kill-connection! conn)
(raise exn))])
(apply f conn args)
(flush-output (connection-o-port conn)))))
(define ext:output-response
(ext:wrap output-response))
;; response/full->size: response/full -> number
(define (response/full->size resp)
(apply + (map data-length (response/full-body resp))))
;; output-file: connection path symbol bytes integer integer -> void
(define (output-file conn file-path method mime-type
start end-or-inf)
(define total-len (file-size file-path))
(define end (if (equal? +inf.0 end-or-inf)
total-len
end-or-inf))
(define len (- end start))
(define bresp
(make-response/basic 206 "Okay" (file-or-directory-modify-seconds file-path) mime-type
(list (make-header #"Content-Length" (string->bytes/utf-8 (number->string len)))
; XXX Remove on non-gets?
(make-header #"Content-Range" (string->bytes/utf-8 (format "bytes ~a-~a/~a" start end total-len))))))
(output-headers+response/basic conn bresp)
(when (eq? method 'get)
; XXX Move out?
(adjust-connection-timeout! conn len) ; Give it one second per byte.
(with-handlers ([void (lambda (e) (network-error 'output-file/partial (exn-message e)))])
(call-with-input-file file-path
(lambda (i-port)
(define _ (file-position i-port start))
(define i-port/end (make-limited-input-port i-port end #t))
(copy-port i-port/end (connection-o-port conn))
(close-input-port i-port/end))))))
(define ext:output-file
(ext:wrap output-file))
(define ext:output-response/method
(ext:wrap output-response/method)))