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Commit 107f604f authored by Nick Mathewson's avatar Nick Mathewson :game_die:
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Port over ht.h improvements from Libevent. 

There is a facility (not used now in Tor) to avoid storing the hash
of a given type if it is a fast-to-calculate hash.

There are also a few ancient-openbsd compilation issues fixed here.

The fact that Tor says INLINE while Libevent says inline remains
unaddressed.
parent 1e9400d9
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with 36 additions and 18 deletions
src/common/ht.h
+ 36
− 18
View file @ 107f604f
......@@ -25,19 +25,22 @@
#define HT_INITIALIZER() \
{ NULL, 0, 0, 0, -1 }
#ifdef HT_NO_CACHE_HASH_VALUES
#define HT_ENTRY(type) \
struct { \
struct type *hte_next; \
}
#else
#define HT_ENTRY(type) \
struct { \
struct type *hte_next; \
unsigned hte_hash; \
}
#endif
#define HT_EMPTY(head) \
((head)->hth_n_entries == 0)
/* Helper: alias for the bucket containing 'elm'. */
#define _HT_BUCKET(head, field, elm) \
((head)->hth_table[elm->field.hte_hash % head->hth_table_length])
/* How many elements in 'head'? */
#define HT_SIZE(head) \
((head)->hth_n_entries)
......@@ -98,8 +101,25 @@ ht_string_hash(const char *s)
return h;
}
#ifndef HT_NO_CACHE_HASH_VALUES
#define _HT_SET_HASH(elm, field, hashfn) \
(elm)->field.hte_hash = hashfn(elm)
do { (elm)->field.hte_hash = hashfn(elm); } while (0)
#define _HT_SET_HASHVAL(elm, field, val) \
do { (elm)->field.hte_hash = (val); } while (0)
#define _HT_ELT_HASH(elm, field, hashfn) \
((elm)->field.hte_hash)
#else
#define _HT_SET_HASH(elm, field, hashfn) \
((void)0)
#define _HT_ELT_HASH(elm, field, hashfn) \
(hashfn(elm))
#define _HT_SET_HASHVAL(elm, field, val) \
((void)0)
#endif
/* Helper: alias for the bucket containing 'elm'. */
#define _HT_BUCKET(head, field, elm, hashfn) \
((head)->hth_table[_HT_ELT_HASH(elm,field,hashfn) % head->hth_table_length])
#define HT_FOREACH(x, name, head) \
for ((x) = HT_START(name, head); \
......@@ -126,7 +146,7 @@ ht_string_hash(const char *s)
struct type **p; \
if (!head->hth_table) \
return NULL; \
p = &_HT_BUCKET(head, field, elm); \
p = &_HT_BUCKET(head, field, elm, hashfn); \
while (*p) { \
if (eqfn(*p, elm)) \
return p; \
......@@ -155,7 +175,7 @@ ht_string_hash(const char *s)
name##_HT_GROW(head, head->hth_n_entries+1); \
++head->hth_n_entries; \
_HT_SET_HASH(elm, field, hashfn); \
p = &_HT_BUCKET(head, field, elm); \
p = &_HT_BUCKET(head, field, elm, hashfn); \
elm->field.hte_next = *p; \
*p = elm; \
} \
......@@ -207,7 +227,6 @@ ht_string_hash(const char *s)
void *data) \
{ \
unsigned idx; \
int remove; \
struct type **p, **nextp, *next; \
if (!head->hth_table) \
return; \
......@@ -216,8 +235,7 @@ ht_string_hash(const char *s)
while (*p) { \
nextp = &(*p)->field.hte_next; \
next = *nextp; \
remove = fn(*p, data); \
if (remove) { \
if (fn(*p, data)) { \
--head->hth_n_entries; \
*p = next; \
} else { \
......@@ -251,7 +269,7 @@ ht_string_hash(const char *s)
if ((*elm)->field.hte_next) { \
return &(*elm)->field.hte_next; \
} else { \
unsigned b = ((*elm)->field.hte_hash % head->hth_table_length)+1; \
unsigned b = (_HT_ELT_HASH(*elm, field, hashfn) % head->hth_table_length)+1; \
while (b < head->hth_table_length) { \
if (head->hth_table[b]) \
return &head->hth_table[b]; \
......@@ -263,7 +281,7 @@ ht_string_hash(const char *s)
static INLINE struct type ** \
name##_HT_NEXT_RMV(struct name *head, struct type **elm) \
{ \
unsigned h = (*elm)->field.hte_hash; \
unsigned h = _HT_ELT_HASH(*elm, field, hashfn); \
*elm = (*elm)->field.hte_next; \
--head->hth_n_entries; \
if (*elm) { \
......@@ -320,7 +338,7 @@ ht_string_hash(const char *s)
elm = head->hth_table[b]; \
while (elm) { \
next = elm->field.hte_next; \
b2 = elm->field.hte_hash % new_len; \
b2 = _HT_ELT_HASH(elm, field, hashfn) % new_len; \
elm->field.hte_next = new_table[b2]; \
new_table[b2] = elm; \
elm = next; \
......@@ -338,7 +356,7 @@ ht_string_hash(const char *s)
for (b=0; b < head->hth_table_length; ++b) { \
struct type *e, **pE; \
for (pE = &new_table[b], e = *pE; e != NULL; e = *pE) { \
b2 = e->field.hte_hash % new_len; \
b2 = _HT_ELT_HASH(e, field, hashfn) % new_len; \
if (b2 == b) { \
pE = &e->field.hte_next; \
} else { \
......@@ -390,9 +408,9 @@ ht_string_hash(const char *s)
return 5; \
for (n = i = 0; i < head->hth_table_length; ++i) { \
for (elm = head->hth_table[i]; elm; elm = elm->field.hte_next) { \
if (elm->field.hte_hash != hashfn(elm)) \
if (_HT_ELT_HASH(elm, field, hashfn) != hashfn(elm)) \
return 1000 + i; \
if ((elm->field.hte_hash % head->hth_table_length) != i) \
if ((_HT_ELT_HASH(elm, field, hashfn) % head->hth_table_length) != i) \
return 10000 + i; \
++n; \
} \
......@@ -408,7 +426,7 @@ ht_string_hash(const char *s)
#define _HT_FIND_OR_INSERT(name, field, hashfn, head, eltype, elm, var, y, n) \
{ \
struct name *_##var##_head = head; \
eltype **var; \
struct eltype **var; \
if (!_##var##_head->hth_table || \
_##var##_head->hth_n_entries >= _##var##_head->hth_load_limit) \
name##_HT_GROW(_##var##_head, _##var##_head->hth_n_entries+1); \
......@@ -422,7 +440,7 @@ ht_string_hash(const char *s)
}
#define _HT_FOI_INSERT(field, head, elm, newent, var) \
{ \
newent->field.hte_hash = (elm)->field.hte_hash; \
_HT_SET_HASHVAL(newent, field, (elm)->field.hte_hash); \
newent->field.hte_next = NULL; \
*var = newent; \
++((head)->hth_n_entries); \
......
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