From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxxxxxxxx>
Date: Fri, 21 Mar 2008 15:55:19 -0700
Right now nobody uses it, but "index_name_exists()" gets a flag so
you can enable it on a case-by-case basis.
Signed-of-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
---
Oooh.. We actually have some (admittedly stupid) case insensitivity code
starting to appear. So we now hash the names insensitively, and we have
the _capability_ to do case-insensitive lookups, but nobody actually uses
that insensitive lookup capability yet.
But things are now starting to get interesting.
cache.h | 4 ++--
dir.c | 2 +-
name-hash.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++--
unpack-trees.c | 2 +-
4 files changed, 52 insertions(+), 6 deletions(-)
diff --git a/cache.h b/cache.h
index 76d95d2..a9ddaa1 100644
--- a/cache.h
+++ b/cache.h
@@ -264,7 +264,7 @@ static inline void remove_name_hash(struct cache_entry *ce)
#define refresh_cache(flags) refresh_index(&the_index, (flags), NULL, NULL)
#define ce_match_stat(ce, st, options) ie_match_stat(&the_index, (ce), (st), (options))
#define ce_modified(ce, st, options) ie_modified(&the_index, (ce), (st), (options))
-#define cache_name_exists(name, namelen) index_name_exists(&the_index, (name), (namelen))
+#define cache_name_exists(name, namelen, igncase) index_name_exists(&the_index, (name), (namelen), (igncase))
#endif
enum object_type {
@@ -353,7 +353,7 @@ extern int write_index(const struct index_state *, int newfd);
extern int discard_index(struct index_state *);
extern int unmerged_index(const struct index_state *);
extern int verify_path(const char *path);
-extern struct cache_entry *index_name_exists(struct index_state *istate, const char *name, int namelen);
+extern struct cache_entry *index_name_exists(struct index_state *istate, const char *name, int namelen, int igncase);
extern int index_name_pos(const struct index_state *, const char *name, int namelen);
#define ADD_CACHE_OK_TO_ADD 1 /* Ok to add */
#define ADD_CACHE_OK_TO_REPLACE 2 /* Ok to replace file/directory */
diff --git a/dir.c b/dir.c
index edc458e..7362e83 100644
--- a/dir.c
+++ b/dir.c
@@ -371,7 +371,7 @@ static struct dir_entry *dir_entry_new(const char *pathname, int len)
struct dir_entry *dir_add_name(struct dir_struct *dir, const char *pathname, int len)
{
- if (cache_name_exists(pathname, len))
+ if (cache_name_exists(pathname, len, 0))
return NULL;
ALLOC_GROW(dir->entries, dir->nr+1, dir->alloc);
diff --git a/name-hash.c b/name-hash.c
index 2678148..2253870 100644
--- a/name-hash.c
+++ b/name-hash.c
@@ -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 fo 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;
diff --git a/unpack-trees.c b/unpack-trees.c
index ca4c845..bf7d8f6 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -582,7 +582,7 @@ static int verify_absent(struct cache_entry *ce, const char *action,
* delete this path, which is in a subdirectory that
* is being replaced with a blob.
*/
- result = index_name_exists(&o->result, ce->name, ce_namelen(ce));
+ result = index_name_exists(&o->result, ce->name, ce_namelen(ce), 0);
if (result) {
if (result->ce_flags & CE_REMOVE)
return 0;
--
1.5.5.rc0.28.g61a0.dirty
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
