hash: allow caching of hash value

src/apk_blob.h

@@ -41,6 +41,7 @@ int apk_blob_spn(apk_blob_t blob, const char *accept, apk_blob_t *l, apk_blob_t
 int apk_blob_cspn(apk_blob_t blob, const char *reject, apk_blob_t *l, apk_blob_t *r);
 int apk_blob_split(apk_blob_t blob, apk_blob_t split, apk_blob_t *l, apk_blob_t *r);
 int apk_blob_rsplit(apk_blob_t blob, char split, apk_blob_t *l, apk_blob_t *r);
+unsigned long apk_blob_hash_seed(apk_blob_t, unsigned long seed);
 unsigned long apk_blob_hash(apk_blob_t str);
 int apk_blob_compare(apk_blob_t a, apk_blob_t b);
 unsigned int apk_blob_parse_uint(apk_blob_t *b, int radix);

src/apk_database.h

@@ -38,6 +38,7 @@ struct apk_db_file {
 struct apk_db_dir {
 	apk_hash_node hash_node;
 
+	unsigned int hash;
 	struct hlist_head files;
 	struct apk_db_dir *parent;
 

src/apk_hash.h

@@ -4,7 +4,7 @@
  * Copyright (C) 2008 Timo Teräs <timo.teras@iki.fi>
  * All rights reserved.
  *
- * This program is free software; you can redistribute it and/or modify it 
+ * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published
  * by the Free Software Foundation. See http://www.gnu.org/ for details.
  */
@@ -48,8 +48,36 @@ void apk_hash_init(struct apk_hash *h, const struct apk_hash_ops *ops,
 void apk_hash_free(struct apk_hash *h);
 
 int apk_hash_foreach(struct apk_hash *h, apk_hash_enumerator_f e, void *ctx);
-apk_hash_item apk_hash_get(struct apk_hash *h, apk_blob_t key);
-void apk_hash_insert(struct apk_hash *h, apk_hash_item item);
-void apk_hash_delete(struct apk_hash *h, apk_blob_t key);
+apk_hash_item apk_hash_get_hashed(struct apk_hash *h, apk_blob_t key, unsigned long hash);
+void apk_hash_insert_hashed(struct apk_hash *h, apk_hash_item item, unsigned long hash);
+void apk_hash_delete_hashed(struct apk_hash *h, apk_blob_t key, unsigned long hash);
+
+static inline unsigned long apk_hash_from_key(struct apk_hash *h, apk_blob_t key)
+{
+	return h->ops->hash_key(key);
+}
+
+static inline unsigned long apk_hash_from_item(struct apk_hash *h, apk_hash_item item)
+{
+	if (h->ops->hash_item != NULL)
+		return h->ops->hash_item(item);
+	return apk_hash_from_key(h, h->ops->get_key(item));
+}
+
+static inline apk_hash_item apk_hash_get(struct apk_hash *h, apk_blob_t key)
+{
+	return apk_hash_get_hashed(h, key, apk_hash_from_key(h, key));
+}
+
+
+static inline void apk_hash_insert(struct apk_hash *h, apk_hash_item item)
+{
+	return apk_hash_insert_hashed(h, item, apk_hash_from_item(h, item));
+}
+
+static inline void apk_hash_delete(struct apk_hash *h, apk_blob_t key)
+{
+	return apk_hash_delete_hashed(h, key, apk_hash_from_key(h, key));
+}
 
 #endif

src/blob.c

@@ -98,9 +98,9 @@ int apk_blob_split(apk_blob_t blob, apk_blob_t split, apk_blob_t *l, apk_blob_t
 	}
 }
 
-unsigned long apk_blob_hash(apk_blob_t blob)
+unsigned long apk_blob_hash_seed(apk_blob_t blob, unsigned long seed)
 {
-	unsigned long hash = 5381;
+	unsigned long hash = seed;
 	int i;
 
         for (i = 0; i < blob.len; i++)
@@ -109,6 +109,11 @@ unsigned long apk_blob_hash(apk_blob_t blob)
 	return hash;
 }
 
+unsigned long apk_blob_hash(apk_blob_t blob)
+{
+	return apk_blob_hash_seed(blob, 5381);
+}
+
 int apk_blob_compare(apk_blob_t a, apk_blob_t b)
 {
 	if (a.len == b.len)

src/database.c

@@ -101,6 +101,7 @@ static const struct apk_hash_ops dir_hash_ops = {
 };
 
 struct apk_db_file_hash_key {
+	unsigned long dirhash;
 	apk_blob_t dirname;
 	apk_blob_t filename;
 };
@@ -109,16 +110,14 @@ static unsigned long apk_db_file_hash_key(apk_blob_t _key)
 {
 	struct apk_db_file_hash_key *key = (struct apk_db_file_hash_key *) _key.ptr;
 
-	return apk_blob_hash(key->dirname) ^
-	       apk_blob_hash(key->filename);
+	return apk_blob_hash_seed(key->filename, key->dirhash);
 }
 
 static unsigned long apk_db_file_hash_item(apk_hash_item item)
 {
 	struct apk_db_file *dbf = (struct apk_db_file *) item;
 
-	return apk_blob_hash(APK_BLOB_STR(dbf->diri->dir->dirname)) ^
-	       apk_blob_hash(APK_BLOB_STR(dbf->filename));
+	return apk_blob_hash_seed(APK_BLOB_STR(dbf->filename), dbf->diri->dir->hash);
 }
 
 static int apk_db_file_compare_item(apk_hash_item item, apk_blob_t _key)
@@ -127,6 +126,9 @@ static int apk_db_file_compare_item(apk_hash_item item, apk_blob_t _key)
 	struct apk_db_file_hash_key *key = (struct apk_db_file_hash_key *) _key.ptr;
 	int r;
 
+	if (key->dirhash != dbf->diri->dir->hash)
+		return key->dirhash - dbf->diri->dir->hash;
+
 	r = apk_blob_compare(key->dirname, APK_BLOB_STR(dbf->diri->dir->dirname));
 	if (r != 0)
 		return r;
@@ -150,8 +152,9 @@ struct apk_name *apk_db_query_name(struct apk_database *db, apk_blob_t name)
 struct apk_name *apk_db_get_name(struct apk_database *db, apk_blob_t name)
 {
 	struct apk_name *pn;
+	unsigned long hash = apk_hash_from_key(&db->available.names, name);
 
-	pn = apk_db_query_name(db, name);
+	pn = (struct apk_name *) apk_hash_get_hashed(&db->available.names, name, hash);
 	if (pn != NULL)
 		return pn;
 
@@ -161,7 +164,7 @@ struct apk_name *apk_db_get_name(struct apk_database *db, apk_blob_t name)
 
 	pn->name = apk_blob_cstr(name);
 	pn->id = db->name_id++;
-	apk_hash_insert(&db->available.names, pn);
+	apk_hash_insert_hashed(&db->available.names, pn, hash);
 
 	return pn;
 }
@@ -195,12 +198,13 @@ static struct apk_db_dir *apk_db_dir_get(struct apk_database *db,
 {
 	struct apk_db_dir *dir;
 	apk_blob_t bparent;
+	unsigned long hash = apk_hash_from_key(&db->installed.dirs, name);
 	int i;
 
 	if (name.len && name.ptr[name.len-1] == '/')
 		name.len--;
 
-	dir = apk_db_dir_query(db, name);
+	dir = (struct apk_db_dir *) apk_hash_get_hashed(&db->installed.dirs, name, hash);
 	if (dir != NULL)
 		return apk_db_dir_ref(dir);
 
@@ -210,7 +214,8 @@ static struct apk_db_dir *apk_db_dir_get(struct apk_database *db,
 	dir->refs = 1;
 	memcpy(dir->dirname, name.ptr, name.len);
 	dir->dirname[name.len] = 0;
-	apk_hash_insert(&db->installed.dirs, dir);
+	dir->hash = apk_blob_hash(APK_BLOB_STR(dir->dirname));
+	apk_hash_insert_hashed(&db->installed.dirs, dir, hash);
 
 	if (name.len == 0)
 		dir->parent = NULL;
@@ -286,6 +291,7 @@ struct apk_db_file *apk_db_file_query(struct apk_database *db,
 	struct apk_db_file_hash_key key;
 
 	key = (struct apk_db_file_hash_key) {
+		.dirhash = apk_blob_hash(dir),
 		.dirname = dir,
 		.filename = name,
 	};

src/hash.c

@@ -4,7 +4,7 @@
  * Copyright (C) 2008 Timo Teräs <timo.teras@iki.fi>
  * All rights reserved.
  *
- * This program is free software; you can redistribute it and/or modify it 
+ * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published
  * by the Free Software Foundation. See http://www.gnu.org/ for details.
  */
@@ -43,15 +43,14 @@ int apk_hash_foreach(struct apk_hash *h, apk_hash_enumerator_f e, void *ctx)
 	return 0;
 }
 
-apk_hash_item apk_hash_get(struct apk_hash *h, apk_blob_t key)
+apk_hash_item apk_hash_get_hashed(struct apk_hash *h, apk_blob_t key, unsigned long hash)
 {
 	ptrdiff_t offset = h->ops->node_offset;
-	unsigned long hash;
 	apk_hash_node *pos;
 	apk_hash_item item;
 	apk_blob_t itemkey;
 
-	hash = h->ops->hash_key(key) % h->buckets->num;
+	hash %= h->buckets->num;
 	if (h->ops->compare_item != NULL) {
 		hlist_for_each(pos, &h->buckets->item[hash]) {
 			item = ((void *) pos) - offset;
@@ -70,30 +69,24 @@ apk_hash_item apk_hash_get(struct apk_hash *h, apk_blob_t key)
 	return NULL;
 }
 
-void apk_hash_insert(struct apk_hash *h, apk_hash_item item)
+void apk_hash_insert_hashed(struct apk_hash *h, apk_hash_item item, unsigned long hash)
 {
-	unsigned long hash;
 	apk_hash_node *node;
 
-	if (h->ops->hash_item == NULL)
-		hash = h->ops->hash_key(h->ops->get_key(item));
-	else
-		hash = h->ops->hash_item(item);
 	hash %= h->buckets->num;
 	node = (apk_hash_node *) (item + h->ops->node_offset);
 	hlist_add_head(node, &h->buckets->item[hash]);
 	h->num_items++;
 }
 
-void apk_hash_delete(struct apk_hash *h, apk_blob_t key)
+void apk_hash_delete_hashed(struct apk_hash *h, apk_blob_t key, unsigned long hash)
 {
 	ptrdiff_t offset = h->ops->node_offset;
-	unsigned long hash;
 	apk_hash_node *pos;
 	apk_hash_item item;
 	apk_blob_t itemkey;
 
-	hash = h->ops->hash_key(key) % h->buckets->num;
+	hash %= h->buckets->num;
 	if (h->ops->compare_item != NULL) {
 		hlist_for_each(pos, &h->buckets->item[hash]) {
 			item = ((void *) pos) - offset;