Thread (11 messages) flat view 11 messages, 2 authors, 2016-06-15
STALE3720d

Revision v1 of 2 in this series.

Revisions (2)
  1. v1 current
  2. v2 [diff vs current]

[PATCH 8/8] wildmatch: advance faster in <asterisk> + <literal> patterns

From: Nguyễn Thái Ngọc Duy <hidden>
Date: 2016-06-15 22:55:35
Subsystem: the rest · Maintainer: Linus Torvalds

compat, '*/*/*' on linux-2.6.git file list 2000 times, before:
wildmatch 7s 985049us
fnmatch   2s 735541us or 34.26% faster

and after:
wildmatch 4s 492549us
fnmatch   0s 888263us or 19.77% slower

Signed-off-by: Nguyễn Thái Ngọc Duy <redacted>
---
 wildmatch.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
diff --git a/wildmatch.c b/wildmatch.c
index 3794c4d..68b02e4 100644
--- a/wildmatch.c
+++ b/wildmatch.c
@@ -132,6 +132,27 @@ static int dowild(const uchar *p, const uchar *text, unsigned int flags)
 			while (1) {
 				if (t_ch == '\0')
 					break;
+				/*
+				 * Try to advance faster when an asterisk is
+				 * followed by a literal. We know in this case
+				 * that the the string before the literal
+				 * must belong to "*".
+				 */
+				if (!is_glob_special(*p)) {
+					p_ch = *p;
+					if ((flags & WM_CASEFOLD) && ISUPPER(p_ch))
+						p_ch = tolower(p_ch);
+					while ((t_ch = *text) != '\0' &&
+					       (!(flags & WM_PATHNAME) || t_ch != '/')) {
+						if ((flags & WM_CASEFOLD) && ISUPPER(t_ch))
+							t_ch = tolower(t_ch);
+						if (t_ch == p_ch)
+							break;
+						text++;
+					}
+					if (t_ch != p_ch)
+						return WM_NOMATCH;
+				}
 				if ((matched = dowild(p, text,  flags)) != WM_NOMATCH) {
 					if (!special || matched != WM_ABORT_TO_STARSTAR)
 						return matched;
-- 
1.8.0.rc2.23.g1fb49df
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