Files
git/name-hash.c
Joshua Jensen eeecf0bc5b Add case insensitivity support for directories when using git status
When using a case preserving but case insensitive file system, directory
case can differ but still refer to the same physical directory.  git
status reports the directory with the alternate case as an Untracked
file.  (That is, when mydir/filea.txt is added to the repository and
then the directory on disk is renamed from mydir/ to MyDir/, git status
shows MyDir/ as being untracked.)

Support has been added in name-hash.c for hashing directories with a
terminating slash into the name hash. When index_name_exists() is called
with a directory (a name with a terminating slash), the name is not
found via the normal cache_name_compare() call, but it is found in the
slow_same_name() function.

Additionally, in dir.c, directory_exists_in_index_icase() allows newly
added directories deeper in the directory chain to be identified.

Ultimately, it would be better if the file list was read in case
insensitive alphabetical order from disk, but this change seems to
suffice for now.

The end result is the directory is looked up in a case insensitive
manner and does not show in the Untracked files list.

Signed-off-by: Joshua Jensen <jjensen@workspacewhiz.com>
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-08-16 13:30:15 -07:00

120 lines
2.5 KiB
C

/*
* name-hash.c
*
* Hashing names in the index state
*
* Copyright (C) 2008 Linus Torvalds
*/
#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;
}
static void hash_index_entry(struct index_state *istate, struct cache_entry *ce)
{
void **pos;
unsigned int hash;
if (ce->ce_flags & CE_HASHED)
return;
ce->ce_flags |= CE_HASHED;
ce->next = NULL;
hash = hash_name(ce->name, ce_namelen(ce));
pos = insert_hash(hash, ce, &istate->name_hash);
if (pos) {
ce->next = *pos;
*pos = ce;
}
}
static void lazy_init_name_hash(struct index_state *istate)
{
int nr;
if (istate->name_hash_initialized)
return;
for (nr = 0; nr < istate->cache_nr; nr++)
hash_index_entry(istate, istate->cache[nr]);
istate->name_hash_initialized = 1;
}
void add_name_hash(struct index_state *istate, struct cache_entry *ce)
{
ce->ce_flags &= ~CE_UNHASHED;
if (istate->name_hash_initialized)
hash_index_entry(istate, ce);
}
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;
lazy_init_name_hash(istate);
ce = lookup_hash(hash, &istate->name_hash);
while (ce) {
if (!(ce->ce_flags & CE_UNHASHED)) {
if (same_name(ce, name, namelen, icase))
return ce;
}
ce = ce->next;
}
return NULL;
}