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-rw-r--r--source3/lib/util_str.c79
1 files changed, 72 insertions, 7 deletions
diff --git a/source3/lib/util_str.c b/source3/lib/util_str.c
index 8ef4ddade6..5157de0d91 100644
--- a/source3/lib/util_str.c
+++ b/source3/lib/util_str.c
@@ -1,8 +1,10 @@
/*
Unix SMB/CIFS implementation.
Samba utility functions
+
Copyright (C) Andrew Tridgell 1992-2001
Copyright (C) Simo Sorce 2001-2002
+ Copyright (C) Martin Pool 2003
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@@ -22,6 +24,11 @@
#include "includes.h"
/**
+ * @file
+ * @brief String utilities.
+ **/
+
+/**
* Get the next token from a string, return False if none found.
* Handles double-quotes.
*
@@ -140,21 +147,79 @@ char **toktocliplist(int *ctok, const char *sep)
}
/**
- Case insensitive string compararison.
-**/
-
+ * Case insensitive string compararison.
+ *
+ * iconv does not directly give us a way to compare strings in
+ * arbitrary unix character sets -- all we can is convert and then
+ * compare. This is expensive.
+ *
+ * As an optimization, we do a first pass that considers only the
+ * prefix of the strings that is entirely 7-bit. Within this, we
+ * check whether they have the same value.
+ *
+ * Hopefully this will often give the answer without needing to copy.
+ * In particular it should speed comparisons to literal ascii strings
+ * or comparisons of strings that are "obviously" different.
+ *
+ * If we find a non-ascii character we fall back to converting via
+ * iconv.
+ *
+ * This should never be slower than convering the whole thing, and
+ * often faster.
+ *
+ * A different optimization would be to compare for bitwise equality
+ * in the binary encoding. (It would be possible thought hairy to do
+ * both simultaneously.) But in that case if they turn out to be
+ * different, we'd need to restart the whole thing.
+ *
+ * Even better is to implement strcasecmp for each encoding and use a
+ * function pointer.
+ **/
int StrCaseCmp(const char *s, const char *t)
{
+
+ const char * ps, * pt;
pstring buf1, buf2;
- unix_strupper(s, strlen(s)+1, buf1, sizeof(buf1));
- unix_strupper(t, strlen(t)+1, buf2, sizeof(buf2));
- return strcmp(buf1,buf2);
+
+ for (ps = s, pt = t; ; ps++, pt++) {
+ char us, ut;
+
+ if (!*ps && !*pt)
+ return 0; /* both ended */
+ else if (!*ps)
+ return -1; /* s is a prefix */
+ else if (!*pt)
+ return +1; /* t is a prefix */
+ else if ((*ps & 0x80) || (*pt & 0x80))
+ /* not ascii anymore, do it the hard way from here on in */
+ break;
+
+ us = toupper(*ps);
+ ut = toupper(*pt);
+ if (us == ut)
+ continue;
+ else if (us < ut)
+ return -1;
+ else if (us > ut)
+ return +1;
+ }
+
+ /* TODO: Don't do this with a fixed-length buffer. This could
+ * still be much more efficient. */
+ /* TODO: Hardcode a char-by-char comparison for UTF-8, which
+ * can be much faster. */
+ /* TODO: Test case for this! */
+
+ unix_strupper(ps, strlen(ps)+1, buf1, sizeof(buf1));
+ unix_strupper(pt, strlen(pt)+1, buf2, sizeof(buf2));
+
+ return strcmp(buf1, buf2);
}
+
/**
Case insensitive string compararison, length limited.
**/
-
int StrnCaseCmp(const char *s, const char *t, size_t n)
{
pstring buf1, buf2;