diff options
| author | Mike Blumenkrantz <michael.blumenkrantz@gmail.com> | 2021-01-12 14:49:48 -0500 |
|---|---|---|
| committer | Marge Bot <eric+marge@anholt.net> | 2021-04-07 22:57:27 +0000 |
| commit | 31e546a762b7ed4c73d7207868ace87fcc01f063 (patch) | |
| tree | 3d7b07f0298e7b65ce7c847aa9bd94c239ee818d /src/util/hash_table.h | |
| parent | 759cc914501fa13d0093cfe8a9b0fc32e36bfb5c (diff) | |
util/hash_table: add macro for destructively iterating entries
a common usage for hash tables is for tracking exactly one instance of a pointer
for a given period of time, after which the table's entries are purged and it
is reused
this macro enables the purge phase of such usage to reset the table to a
pristine state, avoiding future rehashing due to ballooning of deleted entries
Reviewed-by: Adam Jackson <ajax@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8498>
Diffstat (limited to 'src/util/hash_table.h')
| -rw-r--r-- | src/util/hash_table.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/src/util/hash_table.h b/src/util/hash_table.h index 9281b917318..ff3b3bef576 100644 --- a/src/util/hash_table.h +++ b/src/util/hash_table.h @@ -103,6 +103,8 @@ void _mesa_hash_table_remove_key(struct hash_table *ht, struct hash_entry *_mesa_hash_table_next_entry(struct hash_table *ht, struct hash_entry *entry); +struct hash_entry *_mesa_hash_table_next_entry_unsafe(const struct hash_table *ht, + struct hash_entry *entry); struct hash_entry * _mesa_hash_table_random_entry(struct hash_table *ht, bool (*predicate)(struct hash_entry *entry)); @@ -136,6 +138,15 @@ _mesa_hash_table_reserve(struct hash_table *ht, unsigned size); for (struct hash_entry *entry = _mesa_hash_table_next_entry(ht, NULL); \ entry != NULL; \ entry = _mesa_hash_table_next_entry(ht, entry)) +/** + * This foreach function destroys the table as it iterates. + * It is not safe to use when inserting or removing entries. + */ +#define hash_table_foreach_remove(ht, entry) \ + for (struct hash_entry *entry = _mesa_hash_table_next_entry_unsafe(ht, NULL); \ + (ht)->entries; \ + entry->hash = 0, entry->key = (void*)NULL, entry->data = NULL, \ + (ht)->entries--, entry = _mesa_hash_table_next_entry_unsafe(ht, entry)) static inline void hash_table_call_foreach(struct hash_table *ht, |