Use substring search to speed up quoted-printable decoder.

diff --git a/v7/src/runtime/mime-codec.scm b/v7/src/runtime/mime-codec.scm
index 2783810b934e895d4aba71be3803ea677dcf4516..32a7d935f108de0803bee82b27b9649ea6a6facc 100644 (file)
--- a/v7/src/runtime/mime-codec.scm
+++ b/v7/src/runtime/mime-codec.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;; $Id: mime-codec.scm,v 14.2 2000/06/08 20:52:23 cph Exp $
+;;; $Id: mime-codec.scm,v 14.3 2000/06/15 15:11:29 cph Exp $
 ;;;
 ;;; Copyright (c) 2000 Massachusetts Institute of Technology
 ;;;
@@ -66,9 +66,9 @@
           (let ((char (string-ref string start))
                 (start (fix:+ start 1)))
             (cond ((not (char-lwsp? char))
-                   (if (char-qp-unencoded? char)
-                       (write-qp-clear context char)
-                       (write-qp-encoded context char))
+                   (if (char-set-member? char-set:qp-encoded char)
+                       (write-qp-encoded context char)
+                       (write-qp-clear context char))
                    (loop start))
                   ((and (eq? type 'PARTIAL)
                         (not (fix:< start end)))
@@ -197,17 +197,19 @@
        (end* (skip-lwsp-backwards string start end)))
 
     (define (loop start)
-      (if (fix:< start end*)
-         (let ((char (string-ref string start))
-               (start (fix:+ start 1)))
-           (if (char=? char #\=)
-               (handle-equals start)
-               (begin
+      (let ((i
+            (substring-find-next-char-in-set string start end*
+                                             char-set:qp-encoded)))
+       (if i
+           (begin
+             (write-substring string start i port)
+             (if (char=? (string-ref string i) #\=)
+                 (handle-equals (fix:+ i 1))
                  ;; RFC 2045 recommends dropping illegal encoded char.
-                 (if (char-qp-unencoded? char)
-                     (write-char char port))
-                 (loop start))))
-         (finish)))
+                 (loop (fix:+ i 1))))
+           (begin
+             (write-substring string start end* port)
+             (finish)))))
 
     (define (handle-equals start)
       (if (fix:< (fix:+ start 1) end*)
@@ -241,8 +243,7 @@
                   (newline port)))
              ((eqv? pending #\=)
               (if (eq? type 'LINE-END)
-                  ;; Soft line break.
-                  unspecific
+                  unspecific           ; Soft line break.
                   ;; Illegal: RFC 2045 recommends leaving as is.
                   (write-char #\= port)))
              ((char? pending)
@@ -283,13 +284,11 @@
          (substring string start end))
       pending))
 
-(define-integrable (char-qp-unencoded? char)
-  (char-set-member? char-set:qp-unencoded char))
-
-(define char-set:qp-unencoded
-  (char-set-union (char-set-difference (ascii-range->char-set #x21 #x7F)
-                                      (char-set #\=))
-                 (char-set #\space #\tab)))
+(define char-set:qp-encoded
+  (char-set-invert
+   (char-set-union (char-set-difference (ascii-range->char-set #x21 #x7F)
+                                       (char-set #\=))
+                  (char-set #\space #\tab))))
 
 (define (char-lwsp? char)
   (or (char=? #\space char)