/*
* Copyright (c) 2018 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
#ifndef _CUCKOO_HASHTABLE_H_
#define _CUCKOO_HASHTABLE_H_
#ifdef BSD_KERNEL_PRIVATE
SYSCTL_DECL(_kern_skywalk_libcuckoo);
/*
* Cuckoo Hash Table
*
* Cuckoo_hashtable is resizable, multi-reader/multi-write thread safe.
*/
#define CUCKOO_HASHTABLE_ENTRIES_MAX (1<<24)
/*
* Cuckoo_node is embedded in the object associated by cuckoo_hashtable,
* so cuckoo_hashtable doesn't need to store key/value pair. This is designed
* due to the fact that typical user of a hashtable would anyway have the key
* stored elsewhere (most often in the looked-up object).
*
* The cuckoo_hashtabl_node forms a singly linked list of objects that have
* exactly the same hash value (not just hash bucket collision). This is the
* result of not storing full length key in the table. So the caller has to
* traverse the list to add or find the correct object.
*
*/
struct cuckoo_node {
struct cuckoo_node *next;
};
#ifndef container_of
#define container_of(ptr, type, member) \
((type*)(((uintptr_t)ptr) - offsetof(type, member)))
#endif
struct cuckoo_hashtable;
typedef int (*cuckoo_obj_cmp_func)(struct cuckoo_node *node, void *key);
typedef uint32_t (*cuckoo_obj_refcount_func)(struct cuckoo_node *);
typedef void (*cuckoo_obj_retain_func)(struct cuckoo_node *);
typedef void (*cuckoo_obj_release_func)(struct cuckoo_node *);
struct cuckoo_hashtable_params {
size_t cht_capacity;
cuckoo_obj_cmp_func cht_obj_cmp;
cuckoo_obj_retain_func cht_obj_retain;
cuckoo_obj_release_func cht_obj_release;
};
__BEGIN_DECLS
struct cuckoo_hashtable * cuckoo_hashtable_create(
struct cuckoo_hashtable_params *p);
void cuckoo_hashtable_free(struct cuckoo_hashtable *ht);
size_t cuckoo_hashtable_entries(struct cuckoo_hashtable *h);
size_t cuckoo_hashtable_capacity(struct cuckoo_hashtable *h);
uint32_t cuckoo_hashtable_load_factor(struct cuckoo_hashtable *h);
size_t cuckoo_hashtable_memory_footprint(struct cuckoo_hashtable *h);
void cuckoo_hashtable_try_shrink(struct cuckoo_hashtable *h);
int cuckoo_hashtable_add_with_hash(struct cuckoo_hashtable *h, struct cuckoo_node *node,
uint32_t key);
int cuckoo_hashtable_del(struct cuckoo_hashtable *h, struct cuckoo_node *node,
uint32_t key);
struct cuckoo_node *cuckoo_hashtable_find_with_hash(struct cuckoo_hashtable *h,
void *key, uint32_t hv);
/*
* There is no guarantee that keys concurrently operated would be returned by
* walk function. But walk function won't return invalid key/node pairs.
*/
void cuckoo_hashtable_foreach(struct cuckoo_hashtable *ht,
void (^handler)(struct cuckoo_node *node, uint32_t hv));
#if (DEVELOPMENT || DEBUG)
void cht_test_init(void);
void cht_test_fini(void);
int cuckoo_hashtable_health_check(struct cuckoo_hashtable *h);
void cuckoo_hashtable_dump(struct cuckoo_hashtable *h);
#endif /* !DEVELOPMENT && !DEBUG */
__END_DECLS
#endif /* BSD_KERNEL_PRIVATE */
#endif /* !_CUCKOO_HASHTABLE_H_ */