memcheck_hashtable.h

#ifndef _MEMCHECK_RT_LIST_H
#define _MEMCHECK_RT_LIST_H

#define LIST_POISON1 ((void *) 0x00100100)
#define LIST_POISON2 ((void *) 0x00200200)

/* 2^31 + 2^29 - 2^25 + 2^22 - 2^19 - 2^16 + 1 */
#define GOLDEN_RATIO_PRIME_32 0x9e370001UL

/*  2^63 + 2^61 - 2^57 + 2^54 - 2^51 - 2^18 + 1 */
#define GOLDEN_RATIO_PRIME_64 0x9e37fffffffc0001UL

typedef unsigned int			uint32_t ;
typedef unsigned long long		uint64_t ;

/*
 * Double linked lists with a single pointer list head.
 * Mostly useful for hash tables where the two pointer list head is
 * too wasteful.
 * You lose the ability to access the tail in O(1).
 */

struct hlist_head {
	struct hlist_node *first;
};

struct hlist_node {
	struct hlist_node *next, **pprev;
};

/**
 * container_of - cast a member of a structure out to the containing structure
 * @ptr:	the pointer to the member.
 * @type:	the type of the container struct this is embedded in.
 * @member:	the name of the member within the struct.
 *
 */
#define container_of(ptr, type, member) ({			\
	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
	(type *)( (char *)__mptr - offsetof(type,member) );})

#define HLIST_HEAD_INIT { .first = NULL }
#define HLIST_HEAD(name) struct hlist_head name = {  .first = NULL }
#define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
static inline void INIT_HLIST_NODE(struct hlist_node *h)
{
	h->next = NULL;
	h->pprev = NULL;
}

static inline int hlist_unhashed(const struct hlist_node *h)
{
	return !h->pprev;
}

static inline int hlist_empty(const struct hlist_head *h)
{
	return !h->first;
}

static inline void __hlist_del(struct hlist_node *n)
{
	struct hlist_node *next = n->next;
	struct hlist_node **pprev = n->pprev;
	*pprev = next;
	if (next)
		next->pprev = pprev;
}

static inline void hlist_del(struct hlist_node *n)
{
	__hlist_del(n);
	n->next = LIST_POISON1;
	n->pprev = LIST_POISON2;
}

static inline void hlist_del_init(struct hlist_node *n)
{
	if (!hlist_unhashed(n)) {
		__hlist_del(n);
		INIT_HLIST_NODE(n);
	}
}

static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
{
	struct hlist_node *first = h->first;
	n->next = first;
	if (first)
		first->pprev = &n->next;
	h->first = n;
	n->pprev = &h->first;
}

/* next must be != NULL */
static inline void hlist_add_before(struct hlist_node *n,
					struct hlist_node *next)
{
	n->pprev = next->pprev;
	n->next = next;
	next->pprev = &n->next;
	*(n->pprev) = n;
}

static inline void hlist_add_after(struct hlist_node *n,
					struct hlist_node *next)
{
	next->next = n->next;
	n->next = next;
	next->pprev = &n->next;

	if(next->next)
		next->next->pprev  = &next->next;
}

/* after that we'll appear to be on some hlist and hlist_del will work */
static inline void hlist_add_fake(struct hlist_node *n)
{
	n->pprev = &n->next;
}

/*
 * Move a list from one list head to another. Fixup the pprev
 * reference of the first entry if it exists.
 */
static inline void hlist_move_list(struct hlist_head *old,
				   struct hlist_head *new)
{
	new->first = old->first;
	if (new->first)
		new->first->pprev = &new->first;
	old->first = NULL;
}

#define hlist_entry(ptr, type, member) container_of(ptr,type,member)

#define hlist_for_each(pos, head) \
	for (pos = (head)->first; pos ; pos = pos->next)

#define hlist_for_each_safe(pos, n, head) \
	for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
	     pos = n)

#define hlist_entry_safe(ptr, type, member) \
	({ typeof(ptr) ____ptr = (ptr); \
	   ____ptr ? hlist_entry(____ptr, type, member) : NULL; \
	})

/**
 * hlist_for_each_entry	- iterate over list of given type
 * @pos:	the type * to use as a loop cursor.
 * @head:	the head for your list.
 * @member:	the name of the hlist_node within the struct.
 */
#define hlist_for_each_entry(pos, head, member)				\
	for (pos = hlist_entry_safe((head)->first, typeof(*(pos)), member);\
	     pos;							\
	     pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))

/**
 * hlist_for_each_entry_continue - iterate over a hlist continuing after current point
 * @pos:	the type * to use as a loop cursor.
 * @member:	the name of the hlist_node within the struct.
 */
#define hlist_for_each_entry_continue(pos, member)			\
	for (pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member);\
	     pos;							\
	     pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))

/**
 * hlist_for_each_entry_from - iterate over a hlist continuing from current point
 * @pos:	the type * to use as a loop cursor.
 * @member:	the name of the hlist_node within the struct.
 */
#define hlist_for_each_entry_from(pos, member)				\
	for (; pos;							\
	     pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))

/**
 * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
 * @pos:	the type * to use as a loop cursor.
 * @n:		another &struct hlist_node to use as temporary storage
 * @head:	the head for your list.
 * @member:	the name of the hlist_node within the struct.
 */
#define hlist_for_each_entry_safe(pos, n, head, member) 		\
	for (pos = hlist_entry_safe((head)->first, typeof(*pos), member);\
	     pos && ({ n = pos->member.next; 1; });			\
	     pos = hlist_entry_safe(n, typeof(*pos), member))

#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 ilog2(n)					\
		(n) < 1 ? 0  :				\
		(n) & (1ULL << 63) ? 63 :	\
		(n) & (1ULL << 62) ? 62 :	\
		(n) & (1ULL << 61) ? 61 :	\
		(n) & (1ULL << 60) ? 60 :	\
		(n) & (1ULL << 59) ? 59 :	\
		(n) & (1ULL << 58) ? 58 :	\
		(n) & (1ULL << 57) ? 57 :	\
		(n) & (1ULL << 56) ? 56 :	\
		(n) & (1ULL << 55) ? 55 :	\
		(n) & (1ULL << 54) ? 54 :	\
		(n) & (1ULL << 53) ? 53 :	\
		(n) & (1ULL << 52) ? 52 :	\
		(n) & (1ULL << 51) ? 51 :	\
		(n) & (1ULL << 50) ? 50 :	\
		(n) & (1ULL << 49) ? 49 :	\
		(n) & (1ULL << 48) ? 48 :	\
		(n) & (1ULL << 47) ? 47 :	\
		(n) & (1ULL << 46) ? 46 :	\
		(n) & (1ULL << 45) ? 45 :	\
		(n) & (1ULL << 44) ? 44 :	\
		(n) & (1ULL << 43) ? 43 :	\
		(n) & (1ULL << 42) ? 42 :	\
		(n) & (1ULL << 41) ? 41 :	\
		(n) & (1ULL << 40) ? 40 :	\
		(n) & (1ULL << 39) ? 39 :	\
		(n) & (1ULL << 38) ? 38 :	\
		(n) & (1ULL << 37) ? 37 :	\
		(n) & (1ULL << 36) ? 36 :	\
		(n) & (1ULL << 35) ? 35 :	\
		(n) & (1ULL << 34) ? 34 :	\
		(n) & (1ULL << 33) ? 33 :	\
		(n) & (1ULL << 32) ? 32 :	\
		(n) & (1ULL << 31) ? 31 :	\
		(n) & (1ULL << 30) ? 30 :	\
		(n) & (1ULL << 29) ? 29 :	\
		(n) & (1ULL << 28) ? 28 :	\
		(n) & (1ULL << 27) ? 27 :	\
		(n) & (1ULL << 26) ? 26 :	\
		(n) & (1ULL << 25) ? 25 :	\
		(n) & (1ULL << 24) ? 24 :	\
		(n) & (1ULL << 23) ? 23 :	\
		(n) & (1ULL << 22) ? 22 :	\
		(n) & (1ULL << 21) ? 21 :	\
		(n) & (1ULL << 20) ? 20 :	\
		(n) & (1ULL << 19) ? 19 :	\
		(n) & (1ULL << 18) ? 18 :	\
		(n) & (1ULL << 17) ? 17 :	\
		(n) & (1ULL << 16) ? 16 :	\
		(n) & (1ULL << 15) ? 15 :	\
		(n) & (1ULL << 14) ? 14 :	\
		(n) & (1ULL << 13) ? 13 :	\
		(n) & (1ULL << 12) ? 12 :	\
		(n) & (1ULL << 11) ? 11 :	\
		(n) & (1ULL << 10) ? 10 :	\
		(n) & (1ULL <<  9) ?  9 :	\
		(n) & (1ULL <<  8) ?  8 :	\
		(n) & (1ULL <<  7) ?  7 :	\
		(n) & (1ULL <<  6) ?  6 :	\
		(n) & (1ULL <<  5) ?  5 :	\
		(n) & (1ULL <<  4) ?  4 :	\
		(n) & (1ULL <<  3) ?  3 :	\
		(n) & (1ULL <<  2) ?  2 :	\
		(n) & (1ULL <<  1) ?  1 :	\
		0

#define ARRAY_SIZE(x)	(sizeof(x) / sizeof(x[0]))
#define HASH_SIZE(name) (ARRAY_SIZE(name))
#define HASH_BITS(name) ilog2(HASH_SIZE(name))


/*
 * Prime value was chosen to be roughly 256 + 26.  r5 hash uses 11,
 * so short names (len <= 9) don't even occupy the complete 32bit name
 * space.  A prime >256 ensures short names quickly spread the 32bit
 * name space.  Add about 26 for the estimated amount of information
 * of each character and pick a prime nearby, preferably a bit-sparse
 * one.
 */
static inline uint64_t hash_ptr(void *val, unsigned int bits)
{
	uint64_t hash = (uint64_t)val;

	/*  Sigh, gcc can't optimise this alone like it does for 32 bits. */
	uint64_t n = hash;
	n <<= 18;
	hash -= n;
	n <<= 33;
	hash -= n;
	n <<= 3;
	hash += n;
	n <<= 3;
	hash -= n;
	n <<= 4;
	hash += n;
	n <<= 2;
	hash += n;

	/* High bits are more random, so use them. */
	return hash >> (64 - bits);
}

#define hash_min(val, bits)							\
	(hash_ptr(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_hashed - check whether an object is in any hashtable
 * @node: the &struct hlist_node of the object to be checked
 */
static inline int hash_hashed(struct hlist_node *node)
{
	return !hlist_unhashed(node);
}

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

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

	return 1;
}

/**
 * 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_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_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_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	// _MEMCHECK_RT_LIST_H