diff options
Diffstat (limited to 'include/qemu/qht.h')
| -rw-r--r-- | include/qemu/qht.h | 32 |
1 files changed, 25 insertions, 7 deletions
diff --git a/include/qemu/qht.h b/include/qemu/qht.h index 531aa95325..1fb9116fa0 100644 --- a/include/qemu/qht.h +++ b/include/qemu/qht.h @@ -11,8 +11,11 @@ #include "qemu/thread.h" #include "qemu/qdist.h" +typedef bool (*qht_cmp_func_t)(const void *a, const void *b); + struct qht { struct qht_map *map; + qht_cmp_func_t cmp; QemuMutex lock; /* serializes setters of ht->map */ unsigned int mode; }; @@ -47,10 +50,12 @@ typedef void (*qht_iter_func_t)(struct qht *ht, void *p, uint32_t h, void *up); /** * qht_init - Initialize a QHT * @ht: QHT to be initialized + * @cmp: default comparison function. Cannot be NULL. * @n_elems: number of entries the hash table should be optimized for. * @mode: bitmask with OR'ed QHT_MODE_* */ -void qht_init(struct qht *ht, size_t n_elems, unsigned int mode); +void qht_init(struct qht *ht, qht_cmp_func_t cmp, size_t n_elems, + unsigned int mode); /** * qht_destroy - destroy a previously initialized QHT @@ -65,6 +70,7 @@ void qht_destroy(struct qht *ht); * @ht: QHT to insert to * @p: pointer to be inserted * @hash: hash corresponding to @p + * @existing: address where the pointer to an existing entry can be copied to * * Attempting to insert a NULL @p is a bug. * Inserting the same pointer @p with different @hash values is a bug. @@ -73,16 +79,18 @@ void qht_destroy(struct qht *ht); * inserted into the hash table. * * Returns true on success. - * Returns false if the @p-@hash pair already exists in the hash table. + * Returns false if there is an existing entry in the table that is equivalent + * (i.e. ht->cmp matches and the hash is the same) to @p-@h. If @existing + * is !NULL, a pointer to this existing entry is copied to it. */ -bool qht_insert(struct qht *ht, void *p, uint32_t hash); +bool qht_insert(struct qht *ht, void *p, uint32_t hash, void **existing); /** - * qht_lookup - Look up a pointer in a QHT + * qht_lookup_custom - Look up a pointer using a custom comparison function. * @ht: QHT to be looked up - * @func: function to compare existing pointers against @userp * @userp: pointer to pass to @func * @hash: hash of the pointer to be looked up + * @func: function to compare existing pointers against @userp * * Needs to be called under an RCU read-critical section. * @@ -94,8 +102,18 @@ bool qht_insert(struct qht *ht, void *p, uint32_t hash); * Returns the corresponding pointer when a match is found. * Returns NULL otherwise. */ -void *qht_lookup(struct qht *ht, qht_lookup_func_t func, const void *userp, - uint32_t hash); +void *qht_lookup_custom(struct qht *ht, const void *userp, uint32_t hash, + qht_lookup_func_t func); + +/** + * qht_lookup - Look up a pointer in a QHT + * @ht: QHT to be looked up + * @userp: pointer to pass to the comparison function + * @hash: hash of the pointer to be looked up + * + * Calls qht_lookup_custom() using @ht's default comparison function. + */ +void *qht_lookup(struct qht *ht, const void *userp, uint32_t hash); /** * qht_remove - remove a pointer from the hash table |