diff options
| -rw-r--r-- | source3/lib/util_str.c | 79 |
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; |