From b2168c5a2a37be1e9937659c499bb30be1db286e Mon Sep 17 00:00:00 2001
From: akr <akr@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Sun, 6 Jan 2008 16:38:04 +0000
Subject: [PATCH] * string.c (coderange_scan): optimize ASCII-8BIT string.  
 (rb_enc_str_buf_cat): don't call coderange_scan if possible.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@14915 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog |  5 +++++
 string.c  | 31 ++++++++++++++++++++++++++-----
 2 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index ff88c49f1b..80425f8542 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Jan  7 01:36:49 2008  Tanaka Akira  <akr@fsij.org>
+
+	* string.c (coderange_scan): optimize ASCII-8BIT string.
+	  (rb_enc_str_buf_cat): don't call coderange_scan if possible.
+
 Mon Jan  7 01:05:45 2008  Tanaka Akira  <akr@fsij.org>
 
 	* lib/erb.rb (ERB::Revision): cut off locale dependent string in Date
diff --git a/string.c b/string.c
index 6679ff44fb..c9d0fa3eef 100644
--- a/string.c
+++ b/string.c
@@ -119,6 +119,17 @@ coderange_scan(const char *p, long len, rb_encoding *enc)
     const char *e = p + len;
     int cr;
 
+    if (rb_enc_to_index(enc) == 0) {
+        /* enc is ASCII-8BIT.  ASCII-8BIT string never be broken. */
+        while (p < e) {
+            if (!ISASCII((unsigned char)*p)) {
+                return ENC_CODERANGE_VALID;
+            }
+            p++;
+        }
+        return ENC_CODERANGE_7BIT;
+    }
+
     cr = rb_enc_asciicompat(enc) ? ENC_CODERANGE_7BIT : ENC_CODERANGE_VALID;
     while (p < e) {
         int ret = rb_enc_precise_mbclen(p, e, enc);
@@ -1056,12 +1067,22 @@ rb_enc_str_buf_cat(VALUE str, const char *ptr, long len, rb_encoding *ptr_enc)
     int ptr_a8 = rb_enc_to_index(ptr_enc) == 0;
 
     str_cr = ENC_CODERANGE(str);
-    ptr_cr = coderange_scan(ptr, len, ptr_enc);
 
-    if (str_cr == ENC_CODERANGE_UNKNOWN) {
-        if (str_a8 ? !ptr_a8
-                   : (str_enc != ptr_enc && ptr_cr != ENC_CODERANGE_7BIT)) {
-            str_cr = rb_enc_str_coderange(str);
+    if (str_enc == ptr_enc) {
+        if (str_cr == ENC_CODERANGE_UNKNOWN ||
+            (ptr_a8 && str_cr != ENC_CODERANGE_7BIT)) {
+            ptr_cr = ENC_CODERANGE_UNKNOWN;
+        }
+        else {
+            ptr_cr = coderange_scan(ptr, len, ptr_enc);
+        }
+    }
+    else {
+        ptr_cr = coderange_scan(ptr, len, ptr_enc);
+        if (str_cr == ENC_CODERANGE_UNKNOWN) {
+            if (str_a8 || ptr_cr != ENC_CODERANGE_7BIT) {
+                str_cr = rb_enc_str_coderange(str);
+            }
         }
     }