ruby-dev

前田です。

>>>>> In [ruby-dev:3773]
>>>>> "前田" == MAEDA Shugo <shugo@aianet.ne.jp> san wrote:

前田> pack.cのencodes()は、ループの中で毎回str_cat()を呼ぶために、
前田> 何度もreallocするせいで少し遅いような気がするのですが、どうでしょう。

バッファリングするようにしたらかなり速くなりました:-)

$ time /usr/local/bin/ruby -e '[open("ruby").read].pack("m")'
real    0m3.651s
user    0m2.400s
sys     0m1.250s
$ time ./ruby -e '[open("ruby").read].pack("m")'

real    0m0.891s
user    0m0.750s
sys     0m0.140s

パッチを添付します。
あと、文字列の範囲外のメモリにアクセスしないように変更してあります。


-- 
前田 修吾 (mailto:shugo@aianet.ne.jp)

Attachments (1)

pack.c.diff (1.69 KB, text/x-diff)

--- pack.c.orig	Wed Dec  9 16:47:44 1998
+++ pack.c	Wed Dec  9 19:08:37 1998
@@ -513,38 +513,41 @@
     int len;
     int type;
 {
-    char hunk[4];
+    char *buff = ALLOCA_N(char, len * 4 / 3 + 6);
+    int i = 0;
     char *p, *pend;
     char *trans = type == 'u' ? uu_table : b64_table;
     int padding;
 
     if (type == 'u') {
-	*hunk = len + ' ';
-	str_cat(str, hunk, 1);
+	buff[i++] = len + ' ';
 	padding = '`';
     }
     else {
 	padding = '=';
     }
-    while (len > 0) {
-	hunk[0] = trans[077 & (*s >> 2)];
-	hunk[1] = trans[077 & (((*s << 4) & 060) | ((s[1] >> 4) & 017))];
-	hunk[2] = trans[077 & (((s[1] << 2) & 074) | ((s[2] >> 6) & 03))];
-	hunk[3] = trans[077 & s[2]];
-	str_cat(str, hunk, 4);
+    while (len >= 3) {
+	buff[i++] = trans[077 & (*s >> 2)];
+	buff[i++] = trans[077 & (((*s << 4) & 060) | ((s[1] >> 4) & 017))];
+	buff[i++] = trans[077 & (((s[1] << 2) & 074) | ((s[2] >> 6) & 03))];
+	buff[i++] = trans[077 & s[2]];
 	s += 3;
 	len -= 3;
     }
-    p = RSTRING(str)->ptr;
-    pend = RSTRING(str)->ptr + RSTRING(str)->len;
-    if (len == -1) {
-	pend[-1] = padding;
+    if (len == 2) {
+	buff[i++] = trans[077 & (*s >> 2)];
+	buff[i++] = trans[077 & (((*s << 4) & 060) | ((s[1] >> 4) & 017))];
+	buff[i++] = trans[077 & (((s[1] << 2) & 074) | (('\0' >> 6) & 03))];
+	buff[i++] = padding;
     }
-    else if (len == -2) {
-	pend[-2] = padding;
-	pend[-1] = padding;
+    else if (len == 1) {
+	buff[i++] = trans[077 & (*s >> 2)];
+	buff[i++] = trans[077 & (((*s << 4) & 060) | (('\0' >> 4) & 017))];
+	buff[i++] = padding;
+	buff[i++] = padding;
     }
-    str_cat(str, "\n", 1);
+    buff[i++] = '\n';
+    str_cat(str, buff, i);
 }
 
 static char hex_table[] = "0123456789ABCDEF";

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[#3726] str_new — ttate@...

[#3731] Re: [ruby-list:11138] Re: 拡張モジュールの Makefile — Motoyuki Kasahara <m-kasahr@...>

[#3733] Re: about ext/{tk,tcltklib}/Makefile — WATANABE Hirofumi <watanabe@...>

[#3747] constants (or class vriable?) — Wakou Aoyama <wakou@...>

[#3749] Error message in dln.c(Win32) — WATANABE Hirofumi <watanabe@...>

[#3773] pack("M")/unpack("M") — shugo@... (MAEDA Shugo)

[#3794] port NetBSD/ alpha 1.3I — SHIROYAMA Takayuki <psi@...>

[#3808] 予告 : ruby 1.1d0 release is coming soon. — matz@... (Yukihiro Matsumoto)

[#3826] ruby 1.1d0 released — matz@... (Yukihiro Matsumoto)

[#3827] Method Defining Method — Shin-ichro Hara <sinara@...>

[#3836] "make test" is something wrong (ruby-1.1d0) — ttate@...

[#3846] Re: ruby 1.1d0 released — 助田 雅紀 <masaki.suketa@...>

[#3848] instruby.rb (patch for 1.1d0) — ttate@...

[#3849] Re: ruby 1.1d0 released — SHIROYAMA Takayuki <psi@...>

[#3851] tkutil patch (for 1.1d0) — ttate@...

[#3857] [patch] enum.c — shugo@... (MAEDA Shugo)

[#3859] missing/setenv.c in 1.1d0 — Inaba Hiroto <inaba@...>

[#3862] 1.1d0 new here document — Wakou Aoyama <wakou@...>

[#3864] make bug? ruby-1.1d0 — Yutaka Matsumoto <ymatsu@...>

[#3873] (?: ) does not work? — shugo@... (MAEDA Shugo)

[#3881] I want to catch all jump — shugo@... (Shugo Maeda)

[#3882] subscribe — Koji Oda <oda@...1.qnes.nec.co.jp>

[#3894] ruby 1.1d1 released — matz@... (Yukihiro Matsumoto)

[#3899] interpreter reinitialization — shugo@... (Shugo Maeda)

[#3950] Re: version number — 助田 雅紀 <masaki.suketa@...>

[#3962] ruby 1.3(!) released — matz@... (Yukihiro Matsumoto)

[#3966] [BUG] exception in safe level 4 — shugo@... (Shugo Maeda)

[#3983] compile error in gc.c — Fukuda Masaki <fukuda@...>

[#3986] Re: [ruby-list:11444] ruby 1.2 released — Hiroshi Igarashi <igarashi@...>

[#3997] [BUG] "#{}" while 1 — gotoken@... (GOTO Kentaro)

[#4002] config.guess — Koji Arai <JCA02266@...>

[#4005] [BUG] ruby 1.3(98/12/24) [i686-linux] at rb_gc_mark() — Ryo HAYASAKA <hayasaka@...>

[#4015] Integer proper methods — gotoken@... (GOTO Kentaro)

[#4030] module Precision — gotoken@... (GOTO Kentaro)

[#4032] [Req] make-symbol? — shugo@... (Shugo Maeda)

[#4035] about philos.rb — ttate@...

[#4041] static — gotoken@... (GOTO Kentaro)

[ruby-dev:3786] pack("m")

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[#3846] Re: ruby 1.1d0 released — 助田　雅紀 <masaki.suketa@...>

[#3950] Re: version number — 助田　雅紀 <masaki.suketa@...>