#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)
+struct dir_entry {
+ struct hashmap_entry ent;
+ struct dir_entry *parent;
+ struct cache_entry *ce;
+ int nr;
+ unsigned int namelen;
+};
+
+static int dir_entry_cmp(const struct dir_entry *e1,
+ const struct dir_entry *e2, const char *name)
{
- return c & ~((c & 0x40) >> 1);
+ return e1->namelen != e2->namelen || strncasecmp(e1->ce->name,
+ name ? name : e2->ce->name, e1->namelen);
}
-static unsigned int hash_name(const char *name, int namelen)
+static struct dir_entry *find_dir_entry(struct index_state *istate,
+ const char *name, unsigned int namelen)
{
- unsigned int hash = 0x123;
-
- while (namelen--) {
- unsigned char c = *name++;
- c = icase_hash(c);
- hash = hash*101 + c;
- }
- return hash;
+ struct dir_entry key;
+ hashmap_entry_init(&key, memihash(name, namelen));
+ key.namelen = namelen;
+ return hashmap_get(&istate->dir_hash, &key, name);
}
-static void hash_index_entry_directories(struct index_state *istate, struct cache_entry *ce)
+static struct dir_entry *hash_dir_entry(struct index_state *istate,
+ struct cache_entry *ce, int namelen)
{
/*
* Throw each directory component in the hash for quick lookup
- * during a git status. Directory components are stored with their
+ * during a git status. Directory components are stored without their
* closing slash. Despite submodules being a directory, they never
- * reach this point, because they are stored without a closing slash
- * in the cache.
+ * reach this point, because they are stored
+ * in index_state.name_hash (as ordinary cache_entries).
*
- * Note that the cache_entry stored with the directory does not
- * represent the directory itself. It is a pointer to an existing
- * filename, and its only purpose is to represent existence of the
- * directory in the cache. It is very possible multiple directory
- * hash entries may point to the same cache_entry.
+ * Note that the cache_entry stored with the dir_entry merely
+ * supplies the name of the directory (up to dir_entry.namelen). We
+ * track the number of 'active' files in a directory in dir_entry.nr,
+ * so we can tell if the directory is still relevant, e.g. for git
+ * status. However, if cache_entries are removed, we cannot pinpoint
+ * an exact cache_entry that's still active. It is very possible that
+ * multiple dir_entries point to the same cache_entry.
*/
- unsigned int hash;
- void **pos;
+ struct dir_entry *dir;
+
+ /* get length of parent directory */
+ while (namelen > 0 && !is_dir_sep(ce->name[namelen - 1]))
+ namelen--;
+ if (namelen <= 0)
+ return NULL;
+ namelen--;
+
+ /* lookup existing entry for that directory */
+ dir = find_dir_entry(istate, ce->name, namelen);
+ if (!dir) {
+ /* not found, create it and add to hash table */
+ dir = xcalloc(1, sizeof(struct dir_entry));
+ hashmap_entry_init(dir, memihash(ce->name, namelen));
+ dir->namelen = namelen;
+ dir->ce = ce;
+ hashmap_add(&istate->dir_hash, dir);
+
+ /* recursively add missing parent directories */
+ dir->parent = hash_dir_entry(istate, ce, namelen);
+ }
+ return dir;
+}
- const char *ptr = ce->name;
- while (*ptr) {
- while (*ptr && *ptr != '/')
- ++ptr;
- if (*ptr == '/') {
- ++ptr;
- hash = hash_name(ce->name, ptr - ce->name);
- pos = insert_hash(hash, ce, &istate->name_hash);
- if (pos) {
- ce->dir_next = *pos;
- *pos = ce;
- }
- }
+static void add_dir_entry(struct index_state *istate, struct cache_entry *ce)
+{
+ /* Add reference to the directory entry (and parents if 0). */
+ struct dir_entry *dir = hash_dir_entry(istate, ce, ce_namelen(ce));
+ while (dir && !(dir->nr++))
+ dir = dir->parent;
+}
+
+static void remove_dir_entry(struct index_state *istate, struct cache_entry *ce)
+{
+ /*
+ * Release reference to the directory entry. If 0, remove and continue
+ * with parent directory.
+ */
+ struct dir_entry *dir = hash_dir_entry(istate, ce, ce_namelen(ce));
+ while (dir && !(--dir->nr)) {
+ struct dir_entry *parent = dir->parent;
+ hashmap_remove(&istate->dir_hash, dir, NULL);
+ free(dir);
+ dir = parent;
}
}
if (ce->ce_flags & CE_HASHED)
return;
ce->ce_flags |= CE_HASHED;
- ce->next = ce->dir_next = NULL;
- hash = hash_name(ce->name, ce_namelen(ce));
+ ce->next = NULL;
+ hash = memihash(ce->name, ce_namelen(ce));
pos = insert_hash(hash, ce, &istate->name_hash);
if (pos) {
ce->next = *pos;
*pos = ce;
}
- if (ignore_case)
- hash_index_entry_directories(istate, ce);
+ if (ignore_case && !(ce->ce_flags & CE_UNHASHED))
+ add_dir_entry(istate, ce);
}
static void lazy_init_name_hash(struct index_state *istate)
return;
if (istate->cache_nr)
preallocate_hash(&istate->name_hash, istate->cache_nr);
+ hashmap_init(&istate->dir_hash, (hashmap_cmp_fn) dir_entry_cmp, 0);
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)
{
+ /* if already hashed, add reference to directory entries */
+ if (ignore_case && (ce->ce_flags & CE_STATE_MASK) == CE_STATE_MASK)
+ add_dir_entry(istate, ce);
+
ce->ce_flags &= ~CE_UNHASHED;
if (istate->name_hash_initialized)
hash_index_entry(istate, ce);
}
+/*
+ * We don't actually *remove* it, we can just mark it invalid so that
+ * we won't find it in lookups.
+ *
+ * Not only would we have to search the lists (simple enough), but
+ * we'd also have to rehash other hash buckets in case this makes the
+ * hash bucket empty (common). So it's much better to just mark
+ * it.
+ */
+void remove_name_hash(struct index_state *istate, struct cache_entry *ce)
+{
+ /* if already hashed, release reference to directory entries */
+ if (ignore_case && (ce->ce_flags & CE_STATE_MASK) == CE_HASHED)
+ remove_dir_entry(istate, ce);
+
+ ce->ce_flags |= CE_UNHASHED;
+}
+
static int slow_same_name(const char *name1, int len1, const char *name2, int len2)
{
if (len1 != len2)
if (!icase)
return 0;
- /*
- * If the entry we're comparing is a filename (no trailing slash), then compare
- * the lengths exactly.
- */
- if (name[namelen - 1] != '/')
- return slow_same_name(name, namelen, ce->name, len);
+ return slow_same_name(name, namelen, ce->name, len);
+}
+
+struct cache_entry *index_dir_exists(struct index_state *istate, const char *name, int namelen)
+{
+ struct cache_entry *ce;
+ struct dir_entry *dir;
+
+ lazy_init_name_hash(istate);
+ dir = find_dir_entry(istate, name, namelen);
+ if (dir && dir->nr)
+ return dir->ce;
/*
- * For a directory, we point to an arbitrary cache_entry filename. Just
- * make sure the directory portion matches.
+ * It might be a submodule. Unlike plain directories, which are stored
+ * in the dir-hash, submodules are stored in the name-hash, so check
+ * there, as well.
*/
- return slow_same_name(name, namelen, ce->name, namelen < len ? namelen : len);
+ ce = index_file_exists(istate, name, namelen, 1);
+ if (ce && S_ISGITLINK(ce->ce_mode))
+ return ce;
+
+ return NULL;
}
-struct cache_entry *index_name_exists(struct index_state *istate, const char *name, int namelen, int icase)
+struct cache_entry *index_file_exists(struct index_state *istate, const char *name, int namelen, int icase)
{
- unsigned int hash = hash_name(name, namelen);
+ unsigned int hash = memihash(name, namelen);
struct cache_entry *ce;
lazy_init_name_hash(istate);
if (same_name(ce, name, namelen, icase))
return ce;
}
- if (icase && name[namelen - 1] == '/')
- ce = ce->dir_next;
- else
- ce = ce->next;
- }
-
- /*
- * Might be a submodule. Despite submodules being directories,
- * they are stored in the name hash without a closing slash.
- * When ignore_case is 1, directories are stored in the name hash
- * with their closing slash.
- *
- * The side effect of this storage technique is we have need to
- * remove the slash from name and perform the lookup again without
- * the slash. If a match is made, S_ISGITLINK(ce->mode) will be
- * true.
- */
- if (icase && name[namelen - 1] == '/') {
- ce = index_name_exists(istate, name, namelen - 1, icase);
- if (ce && S_ISGITLINK(ce->ce_mode))
- return ce;
+ ce = ce->next;
}
return NULL;
}
+
+struct cache_entry *index_name_exists(struct index_state *istate, const char *name, int namelen, int icase)
+{
+ if (namelen > 0 && name[namelen - 1] == '/')
+ return index_dir_exists(istate, name, namelen - 1);
+ return index_file_exists(istate, name, namelen, icase);
+}
+
+void free_name_hash(struct index_state *istate)
+{
+ if (!istate->name_hash_initialized)
+ return;
+ istate->name_hash_initialized = 0;
+
+ free_hash(&istate->name_hash);
+ hashmap_free(&istate->dir_hash, 1);
+}