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Make hash_name_lookup able to do case-independent lookups

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Right now nobody uses it, but "index_name_exists()" gets a flag so
you can enable it on a case-by-case basis.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Linus Torvalds
2008-03-21 15:55:19 -07:00
committed by Junio C Hamano
parent df292c791a
commit cd2fef59ed
4 changed files with 52 additions and 6 deletions
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50
name-hash.c
View File

@ -8,12 +8,25 @@
#define NO_THE_INDEX_COMPATIBILITY_MACROS
#include "cache.h"
/*
* This removes bit 5 if bit 6 is set.
*
* That will make US-ASCII characters hash to their upper-case
* equivalent. We could easily do this one whole word at a time,
* but that's for future worries.
*/
static inline unsigned char icase_hash(unsigned char c)
{
return c & ~((c & 0x40) >> 1);
}
static unsigned int hash_name(const char *name, int namelen)
{
unsigned int hash = 0x123;
do {
unsigned char c = *name++;
c = icase_hash(c);
hash = hash*101 + c;
} while (--namelen);
return hash;
@ -54,7 +67,40 @@ void add_name_hash(struct index_state *istate, struct cache_entry *ce)
hash_index_entry(istate, ce);
}
struct cache_entry *index_name_exists(struct index_state *istate, const char *name, int namelen)
static int slow_same_name(const char *name1, int len1, const char *name2, int len2)
{
if (len1 != len2)
return 0;
while (len1) {
unsigned char c1 = *name1++;
unsigned char c2 = *name2++;
len1--;
if (c1 != c2) {
c1 = toupper(c1);
c2 = toupper(c2);
if (c1 != c2)
return 0;
}
}
return 1;
}
static int same_name(const struct cache_entry *ce, const char *name, int namelen, int icase)
{
int len = ce_namelen(ce);
/*
* Always do exact compare, even if we want a case-ignoring comparison;
* we do the quick exact one first, because it will be the common case.
*/
if (len == namelen && !cache_name_compare(name, namelen, ce->name, len))
return 1;
return icase && slow_same_name(name, namelen, ce->name, len);
}
struct cache_entry *index_name_exists(struct index_state *istate, const char *name, int namelen, int icase)
{
unsigned int hash = hash_name(name, namelen);
struct cache_entry *ce;
@ -64,7 +110,7 @@ struct cache_entry *index_name_exists(struct index_state *istate, const char *na
while (ce) {
if (!(ce->ce_flags & CE_UNHASHED)) {
if (!cache_name_compare(name, namelen, ce->name, ce->ce_flags))
if (same_name(ce, name, namelen, icase))
return ce;
}
ce = ce->next;