[deliverable/linux.git] / include / linux / hashtable.h

/*
 * Statically sized hash table implementation
 * (C) 2012  Sasha Levin <levinsasha928@gmail.com>
 */

#ifndef _LINUX_HASHTABLE_H
#define _LINUX_HASHTABLE_H

#include <linux/list.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/hash.h>
#include <linux/rculist.h>

#define DEFINE_HASHTABLE(name, bits)						\
	struct hlist_head name[1 << (bits)] =					\
			{ [0 ... ((1 << (bits)) - 1)] = HLIST_HEAD_INIT }

#define DECLARE_HASHTABLE(name, bits)                                   	\
	struct hlist_head name[1 << (bits)]

#define HASH_SIZE(name) (ARRAY_SIZE(name))
#define HASH_BITS(name) ilog2(HASH_SIZE(name))

/* Use hash_32 when possible to allow for fast 32bit hashing in 64bit kernels. */
#define hash_min(val, bits)							\
	(sizeof(val) <= 4 ? hash_32(val, bits) : hash_long(val, bits))

static inline void __hash_init(struct hlist_head *ht, unsigned int sz)
{
	unsigned int i;

	for (i = 0; i < sz; i++)
		INIT_HLIST_HEAD(&ht[i]);
}

/**
 * hash_init - initialize a hash table
 * @hashtable: hashtable to be initialized
 *
 * Calculates the size of the hashtable from the given parameter, otherwise
 * same as hash_init_size.
 *
 * This has to be a macro since HASH_BITS() will not work on pointers since
 * it calculates the size during preprocessing.
 */
#define hash_init(hashtable) __hash_init(hashtable, HASH_SIZE(hashtable))

/**
 * hash_add - add an object to a hashtable
 * @hashtable: hashtable to add to
 * @node: the &struct hlist_node of the object to be added
 * @key: the key of the object to be added
 */
#define hash_add(hashtable, node, key)						\
	hlist_add_head(node, &hashtable[hash_min(key, HASH_BITS(hashtable))])

/**
 * hash_add_rcu - add an object to a rcu enabled hashtable
 * @hashtable: hashtable to add to
 * @node: the &struct hlist_node of the object to be added
 * @key: the key of the object to be added
 */
#define hash_add_rcu(hashtable, node, key)					\
	hlist_add_head_rcu(node, &hashtable[hash_min(key, HASH_BITS(hashtable))])

/**
 * hash_hashed - check whether an object is in any hashtable
 * @node: the &struct hlist_node of the object to be checked
 */
static inline bool hash_hashed(struct hlist_node *node)
{
	return !hlist_unhashed(node);
}

static inline bool __hash_empty(struct hlist_head *ht, unsigned int sz)
{
	unsigned int i;

	for (i = 0; i < sz; i++)
		if (!hlist_empty(&ht[i]))
			return false;

	return true;
}

/**
 * hash_empty - check whether a hashtable is empty
 * @hashtable: hashtable to check
 *
 * This has to be a macro since HASH_BITS() will not work on pointers since
 * it calculates the size during preprocessing.
 */
#define hash_empty(hashtable) __hash_empty(hashtable, HASH_SIZE(hashtable))

/**
 * hash_del - remove an object from a hashtable
 * @node: &struct hlist_node of the object to remove
 */
static inline void hash_del(struct hlist_node *node)
{
	hlist_del_init(node);
}

/**
 * hash_del_rcu - remove an object from a rcu enabled hashtable
 * @node: &struct hlist_node of the object to remove
 */
static inline void hash_del_rcu(struct hlist_node *node)
{
	hlist_del_init_rcu(node);
}

/**
 * hash_for_each - iterate over a hashtable
 * @name: hashtable to iterate
 * @bkt: integer to use as bucket loop cursor
 * @node: the &struct list_head to use as a loop cursor for each entry
 * @obj: the type * to use as a loop cursor for each entry
 * @member: the name of the hlist_node within the struct
 */
#define hash_for_each(name, bkt, node, obj, member)				\
	for ((bkt) = 0, node = NULL; node == NULL && (bkt) < HASH_SIZE(name); (bkt)++)\
		hlist_for_each_entry(obj, node, &name[bkt], member)

/**
 * hash_for_each_rcu - iterate over a rcu enabled hashtable
 * @name: hashtable to iterate
 * @bkt: integer to use as bucket loop cursor
 * @node: the &struct list_head to use as a loop cursor for each entry
 * @obj: the type * to use as a loop cursor for each entry
 * @member: the name of the hlist_node within the struct
 */
#define hash_for_each_rcu(name, bkt, node, obj, member)				\
	for ((bkt) = 0, node = NULL; node == NULL && (bkt) < HASH_SIZE(name); (bkt)++)\
		hlist_for_each_entry_rcu(obj, node, &name[bkt], member)

/**
 * hash_for_each_safe - iterate over a hashtable safe against removal of
 * hash entry
 * @name: hashtable to iterate
 * @bkt: integer to use as bucket loop cursor
 * @node: the &struct list_head to use as a loop cursor for each entry
 * @tmp: a &struct used for temporary storage
 * @obj: the type * to use as a loop cursor for each entry
 * @member: the name of the hlist_node within the struct
 */
#define hash_for_each_safe(name, bkt, node, tmp, obj, member)			\
	for ((bkt) = 0, node = NULL; node == NULL && (bkt) < HASH_SIZE(name); (bkt)++)\
		hlist_for_each_entry_safe(obj, node, tmp, &name[bkt], member)

/**
 * hash_for_each_possible - iterate over all possible objects hashing to the
 * same bucket
 * @name: hashtable to iterate
 * @obj: the type * to use as a loop cursor for each entry
 * @node: the &struct list_head to use as a loop cursor for each entry
 * @member: the name of the hlist_node within the struct
 * @key: the key of the objects to iterate over
 */
#define hash_for_each_possible(name, obj, node, member, key)			\
	hlist_for_each_entry(obj, node,	&name[hash_min(key, HASH_BITS(name))], member)

/**
 * hash_for_each_possible_rcu - iterate over all possible objects hashing to the
 * same bucket in an rcu enabled hashtable
 * in a rcu enabled hashtable
 * @name: hashtable to iterate
 * @obj: the type * to use as a loop cursor for each entry
 * @node: the &struct list_head to use as a loop cursor for each entry
 * @member: the name of the hlist_node within the struct
 * @key: the key of the objects to iterate over
 */
#define hash_for_each_possible_rcu(name, obj, node, member, key)		\
	hlist_for_each_entry_rcu(obj, node, &name[hash_min(key, HASH_BITS(name))], member)

/**
 * hash_for_each_possible_safe - iterate over all possible objects hashing to the
 * same bucket safe against removals
 * @name: hashtable to iterate
 * @obj: the type * to use as a loop cursor for each entry
 * @node: the &struct list_head to use as a loop cursor for each entry
 * @tmp: a &struct used for temporary storage
 * @member: the name of the hlist_node within the struct
 * @key: the key of the objects to iterate over
 */
#define hash_for_each_possible_safe(name, obj, node, tmp, member, key)		\
	hlist_for_each_entry_safe(obj, node, tmp,				\
		&name[hash_min(key, HASH_BITS(name))], member)


#endif
Commit	Line	Data
d9b482c8 SL	1	/*
	2	* Statically sized hash table implementation
	3	* (C) 2012 Sasha Levin <levinsasha928@gmail.com>
	4	*/
	5
	6	#ifndef _LINUX_HASHTABLE_H
	7	#define _LINUX_HASHTABLE_H
	8
	9	#include <linux/list.h>
	10	#include <linux/types.h>
	11	#include <linux/kernel.h>
	12	#include <linux/hash.h>
	13	#include <linux/rculist.h>
	14
	15	#define DEFINE_HASHTABLE(name, bits) \
	16	struct hlist_head name[1 << (bits)] = \
	17	{ [0 ... ((1 << (bits)) - 1)] = HLIST_HEAD_INIT }
	18
	19	#define DECLARE_HASHTABLE(name, bits) \
	20	struct hlist_head name[1 << (bits)]
	21
	22	#define HASH_SIZE(name) (ARRAY_SIZE(name))
	23	#define HASH_BITS(name) ilog2(HASH_SIZE(name))
	24
	25	/* Use hash_32 when possible to allow for fast 32bit hashing in 64bit kernels. */
	26	#define hash_min(val, bits) \
	27	(sizeof(val) <= 4 ? hash_32(val, bits) : hash_long(val, bits))
	28
	29	static inline void __hash_init(struct hlist_head *ht, unsigned int sz)
	30	{
	31	unsigned int i;
	32
	33	for (i = 0; i < sz; i++)
	34	INIT_HLIST_HEAD(&ht[i]);
	35	}
	36
	37	/**
	38	* hash_init - initialize a hash table
	39	* @hashtable: hashtable to be initialized
	40	*
	41	* Calculates the size of the hashtable from the given parameter, otherwise
	42	* same as hash_init_size.
	43	*
	44	* This has to be a macro since HASH_BITS() will not work on pointers since
	45	* it calculates the size during preprocessing.
	46	*/
	47	#define hash_init(hashtable) __hash_init(hashtable, HASH_SIZE(hashtable))
	48
	49	/**
	50	* hash_add - add an object to a hashtable
	51	* @hashtable: hashtable to add to
	52	* @node: the &struct hlist_node of the object to be added
	53	* @key: the key of the object to be added
	54	*/
	55	#define hash_add(hashtable, node, key) \
	56	hlist_add_head(node, &hashtable[hash_min(key, HASH_BITS(hashtable))])
	57
	58	/**
	59	* hash_add_rcu - add an object to a rcu enabled hashtable
	60	* @hashtable: hashtable to add to
	61	* @node: the &struct hlist_node of the object to be added
	62	* @key: the key of the object to be added
	63	*/
	64	#define hash_add_rcu(hashtable, node, key) \
65	hlist_add_head_rcu(node, &hashtable[hash_min(key, HASH_BITS(hashtable))])
66
67	/**
68	* hash_hashed - check whether an object is in any hashtable
69	* @node: the &struct hlist_node of the object to be checked
70	*/
71	static inline bool hash_hashed(struct hlist_node *node)
72	{
73	return !hlist_unhashed(node);
74	}
75
76	static inline bool __hash_empty(struct hlist_head *ht, unsigned int sz)
77	{
78	unsigned int i;
79
80	for (i = 0; i < sz; i++)
81	if (!hlist_empty(&ht[i]))
82	return false;
83
84	return true;
85	}
86
87	/**
88	* hash_empty - check whether a hashtable is empty
89	* @hashtable: hashtable to check
90	*
91	* This has to be a macro since HASH_BITS() will not work on pointers since
92	* it calculates the size during preprocessing.
93	*/
94	#define hash_empty(hashtable) __hash_empty(hashtable, HASH_SIZE(hashtable))
95
96	/**
97	* hash_del - remove an object from a hashtable
98	* @node: &struct hlist_node of the object to remove
99	*/
100	static inline void hash_del(struct hlist_node *node)
101	{
102	hlist_del_init(node);
103	}
104
105	/**
106	* hash_del_rcu - remove an object from a rcu enabled hashtable
107	* @node: &struct hlist_node of the object to remove
108	*/
109	static inline void hash_del_rcu(struct hlist_node *node)
110	{
111	hlist_del_init_rcu(node);
112	}
113
114	/**
115	* hash_for_each - iterate over a hashtable
116	* @name: hashtable to iterate
117	* @bkt: integer to use as bucket loop cursor
118	* @node: the &struct list_head to use as a loop cursor for each entry
119	* @obj: the type * to use as a loop cursor for each entry
120	* @member: the name of the hlist_node within the struct
121	*/
122	#define hash_for_each(name, bkt, node, obj, member) \
123	for ((bkt) = 0, node = NULL; node == NULL && (bkt) < HASH_SIZE(name); (bkt)++)\
124	hlist_for_each_entry(obj, node, &name[bkt], member)
125
126	/**
127	* hash_for_each_rcu - iterate over a rcu enabled hashtable
128	* @name: hashtable to iterate
129	* @bkt: integer to use as bucket loop cursor
130	* @node: the &struct list_head to use as a loop cursor for each entry
131	* @obj: the type * to use as a loop cursor for each entry
132	* @member: the name of the hlist_node within the struct
133	*/
134	#define hash_for_each_rcu(name, bkt, node, obj, member) \
135	for ((bkt) = 0, node = NULL; node == NULL && (bkt) < HASH_SIZE(name); (bkt)++)\
136	hlist_for_each_entry_rcu(obj, node, &name[bkt], member)
137
138	/**
139	* hash_for_each_safe - iterate over a hashtable safe against removal of
140	* hash entry
141	* @name: hashtable to iterate
142	* @bkt: integer to use as bucket loop cursor
143	* @node: the &struct list_head to use as a loop cursor for each entry
144	* @tmp: a &struct used for temporary storage
145	* @obj: the type * to use as a loop cursor for each entry
146	* @member: the name of the hlist_node within the struct
147	*/
148	#define hash_for_each_safe(name, bkt, node, tmp, obj, member) \
149	for ((bkt) = 0, node = NULL; node == NULL && (bkt) < HASH_SIZE(name); (bkt)++)\
150	hlist_for_each_entry_safe(obj, node, tmp, &name[bkt], member)
151
152	/**
153	* hash_for_each_possible - iterate over all possible objects hashing to the
154	* same bucket
155	* @name: hashtable to iterate
156	* @obj: the type * to use as a loop cursor for each entry
157	* @node: the &struct list_head to use as a loop cursor for each entry
158	* @member: the name of the hlist_node within the struct
159	* @key: the key of the objects to iterate over
160	*/
161	#define hash_for_each_possible(name, obj, node, member, key) \
162	hlist_for_each_entry(obj, node, &name[hash_min(key, HASH_BITS(name))], member)
163
164	/**
165	* hash_for_each_possible_rcu - iterate over all possible objects hashing to the
166	* same bucket in an rcu enabled hashtable
167	* in a rcu enabled hashtable
168	* @name: hashtable to iterate
169	* @obj: the type * to use as a loop cursor for each entry
170	* @node: the &struct list_head to use as a loop cursor for each entry
171	* @member: the name of the hlist_node within the struct
172	* @key: the key of the objects to iterate over
173	*/
174	#define hash_for_each_possible_rcu(name, obj, node, member, key) \
175	hlist_for_each_entry_rcu(obj, node, &name[hash_min(key, HASH_BITS(name))], member)
176
177	/**
178	* hash_for_each_possible_safe - iterate over all possible objects hashing to the
179	* same bucket safe against removals
180	* @name: hashtable to iterate
181	* @obj: the type * to use as a loop cursor for each entry
182	* @node: the &struct list_head to use as a loop cursor for each entry
183	* @tmp: a &struct used for temporary storage
184	* @member: the name of the hlist_node within the struct
185	* @key: the key of the objects to iterate over
186	*/
187	#define hash_for_each_possible_safe(name, obj, node, tmp, member, key) \
188	hlist_for_each_entry_safe(obj, node, tmp, \
189	&name[hash_min(key, HASH_BITS(name))], member)
190
191
192	#endif