streams as http-body's; read chunked transfer-encoding

smol-http/http-msg.rkt

@@ -9,10 +9,12 @@
 
          http-body?
          empty-http-body
-         write-http-body)
+         write-http-body
+         in-http-body-chunks)
 
 (require racket/match
          racket/port
+         racket/stream
          "./util.rkt")
 
 (module+ test
@@ -126,17 +128,33 @@
 
 (define (http-body? x)
   (or (eq? x #f)
-      (bytes? x)))
+      (bytes? x)
+      (stream? x)))
 
 (define empty-http-body #f)
 
+;; (write-http-body bdy [port]) -> void?
+;; bdy : http-body?
+;; port : output-port?
+(define (write-http-body bdy [port (current-output-port)])
+  (match bdy
+    [#f (void)]
+    [(? bytes? bs) (write-bytes bs port)]
+    [(? stream? bss) (error 'write-http-body "chunked is not implemented sorry. ;(")]))
+
+;; (in-http-body-chunks bdy) -> (streamof bytes)
+;; bdy : http-body?
+(define (in-http-body-chunks bdy)
+  (match bdy
+    [#f '()]
+    [(? bytes? bs) (list bs)]
+    [(? stream? bss) bss]))
+
 (define (http-body-additional-headers bdy)
   (match bdy
     [#f '()]
-    [(? bytes? bs) `([content-length . ,(bytes-length bs)])]))
-
-(define (write-http-body bdy [port (current-output-port)])
-  (when bdy (write-bytes bdy port)))
+    [(? bytes? bs) `([content-length . ,(bytes-length bs)])]
+    [(? stream?) '([transfer-encoding . #"chunked"])]))
 
 ;; ---------------------------------------------------------------------------------------
 ;; Parsing
@@ -189,15 +207,21 @@
 ;; tenc, clen : (or/c #f bytes?)
 ;; port : input-port?
 (define (read-http-body tenc clen [port (current-input-port)])
-  (define len (and clen (string->number (bytes->string/utf-8 clen))))
+  (define len (and clen (string->int (bytes->string/utf-8 clen))))
   (cond
     [(equal? tenc #"chunked") (read-chunked-stream port)]
     [(number? len) (read-bytes len port)]
     [(and (not tenc) (not len)) #f]
     [else (raise-read-http-error "read-http-body: not sure how to read HTTP body")]))
 
+;; input-port? -> [streamof bytes?]
 (define (read-chunked-stream port)
-  ('...))
+  (define len (string->number (read-crlf-line port)))
+  (define data (read-bytes len port))
+  (match-define #"\r\n" (read-bytes 2 port))
+  (if (zero? len)
+      empty-stream
+      (stream-cons data (read-chunked-stream port))))
 
 ;; ==========================================
 
@@ -221,6 +245,17 @@
                                                              [content-length . 5]))
                                         #"hello"))
 
+  (let* ([p (open-input-bytes (bytes-append #"HTTP/1.1 200 OK\r\n"
+                                            #"Transfer-Encoding: chunked\r\n"
+                                            #"\r\n"
+                                            #"5\r\nhello\r\n"
+                                            #"2\r\n, \r\n"
+                                            #"6\r\nworld!\r\n"
+                                            #"0\r\n\r\n"))]
+         [msg (read-http-msg p)])
+    (check-equal? (for/list ([bs (in-http-body-chunks (http-msg-body msg))]) bs)
+                  '(#"hello" #", " #"world!")))
+
   ;; "write --> read" works
   (let-values ([(in out) (make-pipe)])
     (thread (λ () (write-http-msg ex-req-/ out)))

smol-http/main.rkt

@@ -2,6 +2,8 @@
 (require "./util.rkt"
          "./http-msg.rkt")
 (provide (all-from-out "./http-msg.rkt")
-         (except-out (all-from-out "./util.rkt") ->bytes))
+         http-request-method?
+         http-response-code?
+         http-response-code-name)
 
 (module+ test)

smol-http/util.rkt

@@ -2,7 +2,8 @@
 (provide http-request-method?
          http-response-code?
          http-response-code-name
-         ->bytes)
+         ->bytes
+         string->int)
 
 (module+ test (require rackunit))
 
@@ -33,6 +34,10 @@
       x
       (string->bytes/utf-8 (format "~a" x))))
 
+(define (string->int s)
+  (define n (string->number s))
+  (and (exact-integer? n) n))
+
 (module+ test
   (let ([b #"hello"]) (check-eq? (->bytes b) b))
   (check-equal? (->bytes 5) #"5"))