[linux-block.git] / tools / perf / util / hashmap.h

/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */

/*
 * Generic non-thread safe hash map implementation.
 *
 * Copyright (c) 2019 Facebook
 */
#ifndef __LIBBPF_HASHMAP_H
#define __LIBBPF_HASHMAP_H

#include <stdbool.h>
#include <stddef.h>
#include <limits.h>

static inline size_t hash_bits(size_t h, int bits)
{
	/* shuffle bits and return requested number of upper bits */
	if (bits == 0)
		return 0;

#if (__SIZEOF_SIZE_T__ == __SIZEOF_LONG_LONG__)
	/* LP64 case */
	return (h * 11400714819323198485llu) >> (__SIZEOF_LONG_LONG__ * 8 - bits);
#elif (__SIZEOF_SIZE_T__ <= __SIZEOF_LONG__)
	return (h * 2654435769lu) >> (__SIZEOF_LONG__ * 8 - bits);
#else
#	error "Unsupported size_t size"
#endif
}

/* generic C-string hashing function */
static inline size_t str_hash(const char *s)
{
	size_t h = 0;

	while (*s) {
		h = h * 31 + *s;
		s++;
	}
	return h;
}

typedef size_t (*hashmap_hash_fn)(long key, void *ctx);
typedef bool (*hashmap_equal_fn)(long key1, long key2, void *ctx);

/*
 * Hashmap interface is polymorphic, keys and values could be either
 * long-sized integers or pointers, this is achieved as follows:
 * - interface functions that operate on keys and values are hidden
 *   behind auxiliary macros, e.g. hashmap_insert <-> hashmap__insert;
 * - these auxiliary macros cast the key and value parameters as
 *   long or long *, so the user does not have to specify the casts explicitly;
 * - for pointer parameters (e.g. old_key) the size of the pointed
 *   type is verified by hashmap_cast_ptr using _Static_assert;
 * - when iterating using hashmap__for_each_* forms
 *   hasmap_entry->key should be used for integer keys and
 *   hasmap_entry->pkey should be used for pointer keys,
 *   same goes for values.
 */
struct hashmap_entry {
	union {
		long key;
		const void *pkey;
	};
	union {
		long value;
		void *pvalue;
	};
	struct hashmap_entry *next;
};

struct hashmap {
	hashmap_hash_fn hash_fn;
	hashmap_equal_fn equal_fn;
	void *ctx;

	struct hashmap_entry **buckets;
	size_t cap;
	size_t cap_bits;
	size_t sz;
};

#define HASHMAP_INIT(hash_fn, equal_fn, ctx) {	\
	.hash_fn = (hash_fn),			\
	.equal_fn = (equal_fn),			\
	.ctx = (ctx),				\
	.buckets = NULL,			\
	.cap = 0,				\
	.cap_bits = 0,				\
	.sz = 0,				\
}

void hashmap__init(struct hashmap *map, hashmap_hash_fn hash_fn,
		   hashmap_equal_fn equal_fn, void *ctx);
struct hashmap *hashmap__new(hashmap_hash_fn hash_fn,
			     hashmap_equal_fn equal_fn,
			     void *ctx);
void hashmap__clear(struct hashmap *map);
void hashmap__free(struct hashmap *map);

size_t hashmap__size(const struct hashmap *map);
size_t hashmap__capacity(const struct hashmap *map);

/*
 * Hashmap insertion strategy:
 * - HASHMAP_ADD - only add key/value if key doesn't exist yet;
 * - HASHMAP_SET - add key/value pair if key doesn't exist yet; otherwise,
 *   update value;
 * - HASHMAP_UPDATE - update value, if key already exists; otherwise, do
 *   nothing and return -ENOENT;
 * - HASHMAP_APPEND - always add key/value pair, even if key already exists.
 *   This turns hashmap into a multimap by allowing multiple values to be
 *   associated with the same key. Most useful read API for such hashmap is
 *   hashmap__for_each_key_entry() iteration. If hashmap__find() is still
 *   used, it will return last inserted key/value entry (first in a bucket
 *   chain).
 */
enum hashmap_insert_strategy {
	HASHMAP_ADD,
	HASHMAP_SET,
	HASHMAP_UPDATE,
	HASHMAP_APPEND,
};

#define hashmap_cast_ptr(p) ({								\
	_Static_assert((p) == NULL || sizeof(*(p)) == sizeof(long),			\
		       #p " pointee should be a long-sized integer or a pointer");	\
	(long *)(p);									\
})

/*
 * hashmap__insert() adds key/value entry w/ various semantics, depending on
 * provided strategy value. If a given key/value pair replaced already
 * existing key/value pair, both old key and old value will be returned
 * through old_key and old_value to allow calling code do proper memory
 * management.
 */
int hashmap_insert(struct hashmap *map, long key, long value,
		   enum hashmap_insert_strategy strategy,
		   long *old_key, long *old_value);

#define hashmap__insert(map, key, value, strategy, old_key, old_value) \
	hashmap_insert((map), (long)(key), (long)(value), (strategy),  \
		       hashmap_cast_ptr(old_key),		       \
		       hashmap_cast_ptr(old_value))

#define hashmap__add(map, key, value) \
	hashmap__insert((map), (key), (value), HASHMAP_ADD, NULL, NULL)

#define hashmap__set(map, key, value, old_key, old_value) \
	hashmap__insert((map), (key), (value), HASHMAP_SET, (old_key), (old_value))

#define hashmap__update(map, key, value, old_key, old_value) \
	hashmap__insert((map), (key), (value), HASHMAP_UPDATE, (old_key), (old_value))

#define hashmap__append(map, key, value) \
	hashmap__insert((map), (key), (value), HASHMAP_APPEND, NULL, NULL)

bool hashmap_delete(struct hashmap *map, long key, long *old_key, long *old_value);

#define hashmap__delete(map, key, old_key, old_value)		       \
	hashmap_delete((map), (long)(key),			       \
		       hashmap_cast_ptr(old_key),		       \
		       hashmap_cast_ptr(old_value))

bool hashmap_find(const struct hashmap *map, long key, long *value);

#define hashmap__find(map, key, value) \
	hashmap_find((map), (long)(key), hashmap_cast_ptr(value))

/*
 * hashmap__for_each_entry - iterate over all entries in hashmap
 * @map: hashmap to iterate
 * @cur: struct hashmap_entry * used as a loop cursor
 * @bkt: integer used as a bucket loop cursor
 */
#define hashmap__for_each_entry(map, cur, bkt)				    \
	for (bkt = 0; bkt < map->cap; bkt++)				    \
		for (cur = map->buckets[bkt]; cur; cur = cur->next)

/*
 * hashmap__for_each_entry_safe - iterate over all entries in hashmap, safe
 * against removals
 * @map: hashmap to iterate
 * @cur: struct hashmap_entry * used as a loop cursor
 * @tmp: struct hashmap_entry * used as a temporary next cursor storage
 * @bkt: integer used as a bucket loop cursor
 */
#define hashmap__for_each_entry_safe(map, cur, tmp, bkt)		    \
	for (bkt = 0; bkt < map->cap; bkt++)				    \
		for (cur = map->buckets[bkt];				    \
		     cur && ({tmp = cur->next; true; });		    \
		     cur = tmp)

/*
 * hashmap__for_each_key_entry - iterate over entries associated with given key
 * @map: hashmap to iterate
 * @cur: struct hashmap_entry * used as a loop cursor
 * @key: key to iterate entries for
 */
#define hashmap__for_each_key_entry(map, cur, _key)			    \
	for (cur = map->buckets						    \
		     ? map->buckets[hash_bits(map->hash_fn((_key), map->ctx), map->cap_bits)] \
		     : NULL;						    \
	     cur;							    \
	     cur = cur->next)						    \
		if (map->equal_fn(cur->key, (_key), map->ctx))

#define hashmap__for_each_key_entry_safe(map, cur, tmp, _key)		    \
	for (cur = map->buckets						    \
		     ? map->buckets[hash_bits(map->hash_fn((_key), map->ctx), map->cap_bits)] \
		     : NULL;						    \
	     cur && ({ tmp = cur->next; true; });			    \
	     cur = tmp)							    \
		if (map->equal_fn(cur->key, (_key), map->ctx))

#endif /* __LIBBPF_HASHMAP_H */
Commit	Line	Data
eee19501 IR	1	/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
	2
	3	/*
	4	* Generic non-thread safe hash map implementation.
	5	*
	6	* Copyright (c) 2019 Facebook
	7	*/
	8	#ifndef __LIBBPF_HASHMAP_H
	9	#define __LIBBPF_HASHMAP_H
	10
	11	#include <stdbool.h>
	12	#include <stddef.h>
	13	#include <limits.h>
eee19501 IR	14
	15	static inline size_t hash_bits(size_t h, int bits)
	16	{
	17	/* shuffle bits and return requested number of upper bits */
3b13eaf0 ACM	18	if (bits == 0)
	19	return 0;
	20
94fddb7a ACM	21	#if (__SIZEOF_SIZE_T__ == __SIZEOF_LONG_LONG__)
	22	/* LP64 case */
	23	return (h * 11400714819323198485llu) >> (__SIZEOF_LONG_LONG__ * 8 - bits);
	24	#elif (__SIZEOF_SIZE_T__ <= __SIZEOF_LONG__)
	25	return (h * 2654435769lu) >> (__SIZEOF_LONG__ * 8 - bits);
	26	#else
	27	# error "Unsupported size_t size"
	28	#endif
eee19501 IR	29	}
eee19501 IR	30
e555b4b8 ACM	31	/* generic C-string hashing function */
	32	static inline size_t str_hash(const char *s)
	33	{
	34	size_t h = 0;
	35
	36	while (*s) {
	37	h = h * 31 + *s;
	38	s++;
	39	}
	40	return h;
	41	}
	42
c302378b EZ	43	typedef size_t (hashmap_hash_fn)(long key, void ctx);
c302378b EZ	44	typedef bool (hashmap_equal_fn)(long key1, long key2, void ctx);
eee19501	45
c302378b EZ	46	/*
	47	* Hashmap interface is polymorphic, keys and values could be either
	48	* long-sized integers or pointers, this is achieved as follows:
	49	* - interface functions that operate on keys and values are hidden
	50	* behind auxiliary macros, e.g. hashmap_insert <-> hashmap__insert;
	51	* - these auxiliary macros cast the key and value parameters as
	52	* long or long *, so the user does not have to specify the casts explicitly;
	53	* - for pointer parameters (e.g. old_key) the size of the pointed
	54	* type is verified by hashmap_cast_ptr using _Static_assert;
	55	* - when iterating using hashmap__for_each_* forms
	56	* hasmap_entry->key should be used for integer keys and
	57	* hasmap_entry->pkey should be used for pointer keys,
	58	* same goes for values.
	59	*/
eee19501	60	struct hashmap_entry {
c302378b EZ	61	union {
	62	long key;
	63	const void *pkey;
	64	};
	65	union {
	66	long value;
	67	void *pvalue;
	68	};
eee19501 IR	69	struct hashmap_entry *next;
	70	};
	71
	72	struct hashmap {
	73	hashmap_hash_fn hash_fn;
	74	hashmap_equal_fn equal_fn;
	75	void *ctx;
	76
	77	struct hashmap_entry **buckets;
	78	size_t cap;
	79	size_t cap_bits;
	80	size_t sz;
	81	};
	82
	83	#define HASHMAP_INIT(hash_fn, equal_fn, ctx) { \
	84	.hash_fn = (hash_fn), \
	85	.equal_fn = (equal_fn), \
	86	.ctx = (ctx), \
	87	.buckets = NULL, \
	88	.cap = 0, \
	89	.cap_bits = 0, \
	90	.sz = 0, \
	91	}
	92
	93	void hashmap__init(struct hashmap *map, hashmap_hash_fn hash_fn,
	94	hashmap_equal_fn equal_fn, void *ctx);
	95	struct hashmap *hashmap__new(hashmap_hash_fn hash_fn,
	96	hashmap_equal_fn equal_fn,
	97	void *ctx);
	98	void hashmap__clear(struct hashmap *map);
	99	void hashmap__free(struct hashmap *map);
	100
	101	size_t hashmap__size(const struct hashmap *map);
	102	size_t hashmap__capacity(const struct hashmap *map);
	103
	104	/*
	105	* Hashmap insertion strategy:
	106	* - HASHMAP_ADD - only add key/value if key doesn't exist yet;
	107	* - HASHMAP_SET - add key/value pair if key doesn't exist yet; otherwise,
	108	* update value;
	109	* - HASHMAP_UPDATE - update value, if key already exists; otherwise, do
	110	* nothing and return -ENOENT;
	111	* - HASHMAP_APPEND - always add key/value pair, even if key already exists.
	112	* This turns hashmap into a multimap by allowing multiple values to be
	113	* associated with the same key. Most useful read API for such hashmap is
	114	* hashmap__for_each_key_entry() iteration. If hashmap__find() is still
	115	* used, it will return last inserted key/value entry (first in a bucket
	116	* chain).
	117	*/
	118	enum hashmap_insert_strategy {
	119	HASHMAP_ADD,
	120	HASHMAP_SET,
	121	HASHMAP_UPDATE,
	122	HASHMAP_APPEND,
	123	};
	124
c302378b EZ	125	#define hashmap_cast_ptr(p) ({ \
	126	_Static_assert((p) == NULL \|\| sizeof(*(p)) == sizeof(long), \
	127	#p " pointee should be a long-sized integer or a pointer"); \
	128	(long *)(p); \
	129	})
	130
eee19501 IR	131	/*
	132	* hashmap__insert() adds key/value entry w/ various semantics, depending on
	133	* provided strategy value. If a given key/value pair replaced already
	134	* existing key/value pair, both old key and old value will be returned
	135	* through old_key and old_value to allow calling code do proper memory
	136	* management.
	137	*/
c302378b EZ	138	int hashmap_insert(struct hashmap *map, long key, long value,
	139	enum hashmap_insert_strategy strategy,
	140	long old_key, long old_value);
eee19501	141
c302378b EZ	142	#define hashmap__insert(map, key, value, strategy, old_key, old_value) \
	143	hashmap_insert((map), (long)(key), (long)(value), (strategy), \
	144	hashmap_cast_ptr(old_key), \
	145	hashmap_cast_ptr(old_value))
eee19501	146
c302378b EZ	147	#define hashmap__add(map, key, value) \
c302378b EZ	148	hashmap__insert((map), (key), (value), HASHMAP_ADD, NULL, NULL)
eee19501	149
c302378b EZ	150	#define hashmap__set(map, key, value, old_key, old_value) \
c302378b EZ	151	hashmap__insert((map), (key), (value), HASHMAP_SET, (old_key), (old_value))
eee19501	152
c302378b EZ	153	#define hashmap__update(map, key, value, old_key, old_value) \
	154	hashmap__insert((map), (key), (value), HASHMAP_UPDATE, (old_key), (old_value))
	155
	156	#define hashmap__append(map, key, value) \
	157	hashmap__insert((map), (key), (value), HASHMAP_APPEND, NULL, NULL)
	158
	159	bool hashmap_delete(struct hashmap map, long key, long old_key, long *old_value);
	160
	161	#define hashmap__delete(map, key, old_key, old_value) \
	162	hashmap_delete((map), (long)(key), \
	163	hashmap_cast_ptr(old_key), \
	164	hashmap_cast_ptr(old_value))
eee19501	165
c302378b	166	bool hashmap_find(const struct hashmap map, long key, long value);
eee19501	167
c302378b EZ	168	#define hashmap__find(map, key, value) \
c302378b EZ	169	hashmap_find((map), (long)(key), hashmap_cast_ptr(value))
eee19501 IR	170
	171	/*
	172	* hashmap__for_each_entry - iterate over all entries in hashmap
	173	* @map: hashmap to iterate
	174	* @cur: struct hashmap_entry * used as a loop cursor
	175	* @bkt: integer used as a bucket loop cursor
	176	*/
	177	#define hashmap__for_each_entry(map, cur, bkt) \
	178	for (bkt = 0; bkt < map->cap; bkt++) \
	179	for (cur = map->buckets[bkt]; cur; cur = cur->next)
	180
	181	/*
	182	* hashmap__for_each_entry_safe - iterate over all entries in hashmap, safe
	183	* against removals
	184	* @map: hashmap to iterate
	185	* @cur: struct hashmap_entry * used as a loop cursor
	186	* @tmp: struct hashmap_entry * used as a temporary next cursor storage
	187	* @bkt: integer used as a bucket loop cursor
	188	*/
	189	#define hashmap__for_each_entry_safe(map, cur, tmp, bkt) \
	190	for (bkt = 0; bkt < map->cap; bkt++) \
	191	for (cur = map->buckets[bkt]; \
	192	cur && ({tmp = cur->next; true; }); \
	193	cur = tmp)
	194
	195	/*
	196	* hashmap__for_each_key_entry - iterate over entries associated with given key
	197	* @map: hashmap to iterate
	198	* @cur: struct hashmap_entry * used as a loop cursor
	199	* @key: key to iterate entries for
	200	*/
	201	#define hashmap__for_each_key_entry(map, cur, _key) \
3b13eaf0 ACM	202	for (cur = map->buckets \
	203	? map->buckets[hash_bits(map->hash_fn((_key), map->ctx), map->cap_bits)] \
	204	: NULL; \
eee19501 IR	205	cur; \
	206	cur = cur->next) \
	207	if (map->equal_fn(cur->key, (_key), map->ctx))
	208
	209	#define hashmap__for_each_key_entry_safe(map, cur, tmp, _key) \
3b13eaf0 ACM	210	for (cur = map->buckets \
	211	? map->buckets[hash_bits(map->hash_fn((_key), map->ctx), map->cap_bits)] \
	212	: NULL; \
eee19501 IR	213	cur && ({ tmp = cur->next; true; }); \
	214	cur = tmp) \
	215	if (map->equal_fn(cur->key, (_key), map->ctx))
	216
	217	#endif /* __LIBBPF_HASHMAP_H */