From e5332f1aa9226a0934ae616828e1dbf603d50d91 Mon Sep 17 00:00:00 2001
From: Richard Nyberg <rnyberg@murmeldjur.se>
Date: Fri, 6 Feb 2009 20:03:56 +0100
Subject: [PATCH] Hashtable tweaks.
o Added ability to set the ratio items:buckets.
o One can remove items while iterating.
o _htbl_tov now allocates the result array, _htbl_fillv acts as the old
_htbl_tov did.
---
misc/hashtable.c | 86 +++++++++++++++++++++++++++++++++++++-----------
misc/hashtable.h | 36 +++++++++++++-------
2 files changed, 92 insertions(+), 30 deletions(-)
diff --git a/misc/hashtable.c b/misc/hashtable.c
index b124749..519af5f 100644
--- a/misc/hashtable.c
+++ b/misc/hashtable.c
@@ -11,13 +11,14 @@ struct _htbl {
size_t size;
size_t keyoff;
size_t chainoff;
+ float ratio;
};
#define KEYP(tbl, o) ((void *)(o) + (tbl)->keyoff)
#define CHAINP(tbl, o) *(struct _any **)((void *)(o) + (tbl)->chainoff)
struct _htbl *
-_htbl_create(int (*eq)(const void *, const void *),
+_htbl_create(float ratio, int (*eq)(const void *, const void *),
uint32_t (*hash)(const void *), size_t keyoff, size_t chainoff)
{
struct _htbl *tbl = calloc(1, sizeof(*tbl));
@@ -25,6 +26,7 @@ _htbl_create(int (*eq)(const void *, const void *),
return NULL;
tbl->size = 0;
tbl->buckcnt = 1;
+ tbl->ratio = ratio;
tbl->keyoff = keyoff;
tbl->chainoff = chainoff;
tbl->hash = hash;
@@ -94,7 +96,7 @@ _htbl_insert(struct _htbl *tbl, struct _any *o)
{
bucket_insert(tbl, o);
tbl->size++;
- if (tbl->size > tbl->buckcnt * 4 / 5)
+ if (tbl->size > tbl->buckcnt * tbl->ratio)
_htbl_grow(tbl);
}
@@ -113,23 +115,20 @@ struct _any *
_htbl_remove(struct _htbl *tbl, const void *key)
{
size_t bi = tbl->hash(key) % tbl->buckcnt;
- struct _any *p = NULL, *o = tbl->buckets[bi];
+ struct _any **p = &tbl->buckets[bi], *o = tbl->buckets[bi];
while (o != NULL && !tbl->eq(KEYP(tbl, o), key)) {
- p = o;
- o = CHAINP(tbl, o);
+ p = &CHAINP(tbl, o);
+ o = *p;
}
if (o != NULL) {
- if (p == NULL)
- tbl->buckets[bi] = CHAINP(tbl, o);
- else
- CHAINP(tbl, p) = CHAINP(tbl, o);
+ *p = CHAINP(tbl, o);
tbl->size--;
}
return o;
}
void
-_htbl_tov(struct _htbl *tbl, struct _any **v)
+_htbl_fillv(struct _htbl *tbl, struct _any **v)
{
size_t vi = 0;
size_t bi = 0;
@@ -145,32 +144,81 @@ _htbl_tov(struct _htbl *tbl, struct _any **v)
}
}
+struct _any **
+_htbl_tov(struct _htbl *tbl)
+{
+ struct _any **v = malloc(sizeof(*v));
+ if (v != NULL)
+ _htbl_fillv(tbl, v);
+ return v;
+}
+
size_t
_htbl_size(struct _htbl *tbl)
{
return tbl->size;
}
-void
-_htbl_iter_init(struct _htbl *tbl, struct htbl_iter *it)
+static void
+iter_next_bucket(struct htbl_iter *it)
{
+ while (it->tbl->buckets[it->bi] == NULL)
+ it->bi++;
+ it->obj = it->tbl->buckets[it->bi];
+ it->ptr = &it->tbl->buckets[it->bi];
+}
+
+struct _any *
+_htbl_iter_first(struct _htbl *tbl, struct htbl_iter *it)
+{
+ if (tbl->size == 0)
+ return NULL;
+
it->tbl = tbl;
+ it->cnt = 1;
it->bi = 0;
- it->cnt = 0;
- it->obj = NULL;
+ iter_next_bucket(it);
+ return it->obj;
}
struct _any *
_htbl_iter_next(struct htbl_iter *it)
{
+ struct _any *tmp;
if (it->cnt == it->tbl->size)
return NULL;
- it->obj = it->cnt == 0 ?
- it->tbl->buckets[it->bi] : CHAINP(it->tbl, it->obj);
- while (it->obj == NULL) {
+
+ it->cnt++;
+ if ((tmp = CHAINP(it->tbl, it->obj)) != NULL) {
+ it->ptr = &CHAINP(it->tbl, it->obj);
+ it->obj = tmp;
+ } else {
it->bi++;
- it->obj = it->tbl->buckets[it->bi];
+ iter_next_bucket(it);
+ }
+ return it->obj;
+}
+
+#include <stdio.h>
+
+struct _any *
+_htbl_iter_del(struct htbl_iter *it)
+{
+ struct _any *tmp;
+
+ it->tbl->size--;
+ if (it->cnt > it->tbl->size) {
+ *it->ptr = NULL;
+ return NULL;
+ }
+
+ if ((tmp = CHAINP(it->tbl, it->obj)) != NULL) {
+ *it->ptr = tmp;
+ it->obj = tmp;
+ } else {
+ *it->ptr = NULL;
+ it->bi++;
+ iter_next_bucket(it);
}
- it->cnt++;
return it->obj;
}
diff --git a/misc/hashtable.h b/misc/hashtable.h
index 84a8e0b..adc4229 100644
--- a/misc/hashtable.h
+++ b/misc/hashtable.h
@@ -5,30 +5,34 @@ struct htbl_iter {
struct _htbl *tbl;
size_t bi;
size_t cnt;
+ struct _any **ptr;
struct _any *obj;
};
-struct _htbl *_htbl_create(int (*equal)(const void *, const void *),
+struct _htbl *_htbl_create(float ratio,
+ int (*equal)(const void *, const void *),
uint32_t (*hash)(const void *), size_t keyoff, size_t chainoff);
void _htbl_free(struct _htbl *tbl);
void _htbl_insert(struct _htbl *tbl, struct _any *o);
struct _any *_htbl_remove(struct _htbl *tbl, const void *key);
struct _any *_htbl_find(struct _htbl *tbl, const void *key);
-void _htbl_tov(struct _htbl *tb, struct _any **v);
+void _htbl_fillv(struct _htbl *tbl, struct _any **v);
+struct _any **_htbl_tov(struct _htbl *tbl);
size_t _htbl_size(struct _htbl *tbl);
-void _htbl_iter_init(struct _htbl *tbl, struct htbl_iter *it);
+struct _any *_htbl_iter_first(struct _htbl *tbl, struct htbl_iter *it);
struct _any *_htbl_iter_next(struct htbl_iter *it);
+struct _any *_htbl_iter_del(struct htbl_iter *it);
#define HTBL_ENTRY(name) struct _any *name
#define HTBL_TYPE(name, type, ktype, kname, cname) \
__attribute__((always_inline)) static inline struct name * \
-name##_create(int (*equal)(const void *, const void *), \
+name##_create(float ratio, int (*equal)(const void *, const void *), \
uint32_t (*hash)(const void *)) \
{ \
return (struct name *) \
- _htbl_create(equal, hash, offsetof(struct type, kname), \
- offsetof(struct type, cname)); \
+ _htbl_create(ratio, equal, hash, offsetof(struct type, kname), \
+ offsetof(struct type, cname)); \
} \
\
__attribute__((always_inline)) static inline struct type * \
@@ -54,10 +58,15 @@ name##_insert(struct name *tbl, struct type *o) \
{ \
_htbl_insert((struct _htbl *)tbl, (struct _any *)o); \
} \
+__attribute__((always_inline)) static inline struct type ** \
+name##_tov(struct name *tbl) \
+{ \
+ return (struct type **) _htbl_tov((struct _htbl *)tbl); \
+} \
__attribute__((always_inline)) static inline void \
-name##_tov(struct name *tbl, struct type **v) \
+name##_fillv(struct name *tbl, struct type **v) \
{ \
- _htbl_tov((struct _htbl *)tbl, (struct _any **)v); \
+ _htbl_fillv((struct _htbl *)tbl, (struct _any **)v); \
} \
\
__attribute__((always_inline)) static inline size_t \
@@ -66,13 +75,18 @@ name##_size(struct name *tbl) \
return _htbl_size((struct _htbl *)tbl); \
} \
\
-__attribute__((always_inline)) static inline void \
-name##_iter_init(struct name *tbl, struct htbl_iter *it) \
+__attribute__((always_inline)) static inline struct type * \
+name##_iter_first(struct name *tbl, struct htbl_iter *it) \
{ \
- _htbl_iter_init((struct _htbl *)tbl, it); \
+ return (struct type *)_htbl_iter_first((struct _htbl *)tbl, it); \
} \
\
__attribute__((always_inline)) static inline struct type * \
+name##_iter_del(struct htbl_iter *it) \
+{ \
+ return (struct type *)_htbl_iter_del(it); \
+} \
+__attribute__((always_inline)) static inline struct type * \
name##_iter_next(struct htbl_iter *it) \
{ \
return (struct type *)_htbl_iter_next(it); \