Changeset 0db0df2 in mainline for kernel/genarch/src/mm

Timestamp:

2025-04-07T17:53:53Z (3 months ago)

Author:

Jiří Zárevúcky <zarevucky.jiri@…>

Branches:

master

Children:

45226285, 93de384

Parents:

8f8818ac

git-author:

Jiří Zárevúcky <zarevucky.jiri@…> (2025-04-07 16:41:57)

git-committer:

Jiří Zárevúcky <zarevucky.jiri@…> (2025-04-07 17:53:53)

Message:

Hash table improvements

Implement hash_table_foreach macro, analogous to list_foreach.

Remove superfluous argument to hash_table_find_next().
(If the user needs to recheck the part of the list already
checked by hash_table_find(), they can just rerun that function.)

Add hash argument to hash_table_ops_t::key_equal.
The big change here is that users with big keys can store the hash
value alongside key in their entries, and for the low low cost of
sizeof(size_t) bytes eliminate a bunch of expensive key comparisons.

Also added a hash function for strings and arbitrary data.
Found this one by asking ChatGPT, because the latency of accesses
to my book collection is currently a couple of hours.

+ Some drive-by unused #include removal.

File:

• kernel/genarch/src/mm/page_ht.c (modified) (2 diffs)

kernel/genarch/src/mm/page_ht.c

@@ -55 +55 @@
 static size_t ht_hash(const ht_link_t *);
 static size_t ht_key_hash(const void *);
-static bool ht_key_equal(const void *, const ht_link_t *);
+static bool ht_key_equal(const void *, size_t, const ht_link_t *);
 static void ht_remove_callback(ht_link_t *);
 
@@ -119 +119 @@
 
 /** Return true if the key is equal to the item's lookup key. */
-bool ht_key_equal(const void *arg, const ht_link_t *item)
+bool ht_key_equal(const void *arg, size_t hash, const ht_link_t *item)
 {
         const uintptr_t *key = arg;