209 lines
6.6 KiB
C
209 lines
6.6 KiB
C
/*
|
|
* 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 DEFINE_READ_MOSTLY_HASHTABLE(name, bits) \
|
|
struct hlist_head name[1 << (bits)] __read_mostly = \
|
|
{ [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
|
|
* @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, obj, member) \
|
|
for ((bkt) = 0, obj = NULL; obj == NULL && (bkt) < HASH_SIZE(name);\
|
|
(bkt)++)\
|
|
hlist_for_each_entry(obj, &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
|
|
* @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, obj, member) \
|
|
for ((bkt) = 0, obj = NULL; obj == NULL && (bkt) < HASH_SIZE(name);\
|
|
(bkt)++)\
|
|
hlist_for_each_entry_rcu(obj, &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
|
|
* @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, tmp, obj, member) \
|
|
for ((bkt) = 0, obj = NULL; obj == NULL && (bkt) < HASH_SIZE(name);\
|
|
(bkt)++)\
|
|
hlist_for_each_entry_safe(obj, 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
|
|
* @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, member, key) \
|
|
hlist_for_each_entry(obj, &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
|
|
* @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, member, key) \
|
|
hlist_for_each_entry_rcu(obj, &name[hash_min(key, HASH_BITS(name))],\
|
|
member)
|
|
|
|
/**
|
|
* hash_for_each_possible_rcu_notrace - 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
|
|
* @member: the name of the hlist_node within the struct
|
|
* @key: the key of the objects to iterate over
|
|
*
|
|
* This is the same as hash_for_each_possible_rcu() except that it does
|
|
* not do any RCU debugging or tracing.
|
|
*/
|
|
#define hash_for_each_possible_rcu_notrace(name, obj, member, key) \
|
|
hlist_for_each_entry_rcu_notrace(obj, \
|
|
&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
|
|
* @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, tmp, member, key) \
|
|
hlist_for_each_entry_safe(obj, tmp,\
|
|
&name[hash_min(key, HASH_BITS(name))], member)
|
|
|
|
|
|
#endif
|