diff options
Diffstat (limited to 'src/common/ht.h')
| -rw-r--r-- | src/common/ht.h | 101 |
1 files changed, 60 insertions, 41 deletions
diff --git a/src/common/ht.h b/src/common/ht.h index 0850c0709..25156c416 100644 --- a/src/common/ht.h +++ b/src/common/ht.h @@ -1,6 +1,6 @@ /* Copyright (c) 2002, Christopher Clark. * Copyright (c) 2005-2006, Nick Mathewson. - * Copyright (c) 2007-2011, The Tor Project, Inc. */ + * Copyright (c) 2007-2012, The Tor Project, Inc. */ /* See license at end. */ /* Based on ideas by Christopher Clark and interfaces from Niels Provos. */ @@ -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 +101,26 @@ ht_string_hash(const char *s) return h; } -#define _HT_SET_HASH(elm, field, hashfn) \ - (elm)->field.hte_hash = hashfn(elm) +#ifndef HT_NO_CACHE_HASH_VALUES +#define HT_SET_HASH_(elm, field, hashfn) \ + 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); \ @@ -109,7 +130,7 @@ ht_string_hash(const char *s) #define HT_PROTOTYPE(name, type, field, hashfn, eqfn) \ int name##_HT_GROW(struct name *ht, unsigned min_capacity); \ void name##_HT_CLEAR(struct name *ht); \ - int _##name##_HT_REP_IS_BAD(const struct name *ht); \ + int name##_HT_REP_IS_BAD_(const struct name *ht); \ static INLINE void \ name##_HT_INIT(struct name *head) { \ head->hth_table_length = 0; \ @@ -121,12 +142,12 @@ ht_string_hash(const char *s) /* Helper: returns a pointer to the right location in the table \ * 'head' to find or insert the element 'elm'. */ \ static INLINE struct type ** \ - _##name##_HT_FIND_P(struct name *head, struct type *elm) \ + name##_HT_FIND_P_(struct name *head, struct type *elm) \ { \ 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; \ @@ -141,8 +162,8 @@ ht_string_hash(const char *s) { \ struct type **p; \ struct name *h = (struct name *) head; \ - _HT_SET_HASH(elm, field, hashfn); \ - p = _##name##_HT_FIND_P(h, elm); \ + HT_SET_HASH_(elm, field, hashfn); \ + p = name##_HT_FIND_P_(h, elm); \ return p ? *p : NULL; \ } \ /* Insert the element 'elm' into the table 'head'. Do not call this \ @@ -154,8 +175,8 @@ ht_string_hash(const char *s) if (!head->hth_table || head->hth_n_entries >= head->hth_load_limit) \ 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); \ + HT_SET_HASH_(elm, field, hashfn); \ + p = &HT_BUCKET_(head, field, elm, hashfn); \ elm->field.hte_next = *p; \ *p = elm; \ } \ @@ -168,8 +189,8 @@ ht_string_hash(const char *s) struct type **p, *r; \ if (!head->hth_table || head->hth_n_entries >= head->hth_load_limit) \ name##_HT_GROW(head, head->hth_n_entries+1); \ - _HT_SET_HASH(elm, field, hashfn); \ - p = _##name##_HT_FIND_P(head, elm); \ + HT_SET_HASH_(elm, field, hashfn); \ + p = name##_HT_FIND_P_(head, elm); \ r = *p; \ *p = elm; \ if (r && (r!=elm)) { \ @@ -187,8 +208,8 @@ ht_string_hash(const char *s) name##_HT_REMOVE(struct name *head, struct type *elm) \ { \ struct type **p, *r; \ - _HT_SET_HASH(elm, field, hashfn); \ - p = _##name##_HT_FIND_P(head,elm); \ + HT_SET_HASH_(elm, field, hashfn); \ + p = name##_HT_FIND_P_(head,elm); \ if (!p || !*p) \ return NULL; \ r = *p; \ @@ -207,7 +228,6 @@ ht_string_hash(const char *s) void *data) \ { \ unsigned idx; \ - int remove; \ struct type **p, **nextp, *next; \ if (!head->hth_table) \ return; \ @@ -216,8 +236,7 @@ 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 +270,8 @@ 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 +283,7 @@ 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 +340,7 @@ 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 +358,7 @@ 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 { \ @@ -368,7 +388,7 @@ ht_string_hash(const char *s) /* Debugging helper: return false iff the representation of 'head' is \ * internally consistent. */ \ int \ - _##name##_HT_REP_IS_BAD(const struct name *head) \ + name##_HT_REP_IS_BAD_(const struct name *head) \ { \ unsigned n, i; \ struct type *elm; \ @@ -390,9 +410,9 @@ 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; \ } \ @@ -405,24 +425,24 @@ ht_string_hash(const char *s) /** Implements an over-optimized "find and insert if absent" block; * not meant for direct usage by typical code, or usage outside the critical * path.*/ -#define _HT_FIND_OR_INSERT(name, field, hashfn, head, eltype, elm, var, y, n) \ +#define HT_FIND_OR_INSERT_(name, field, hashfn, head, eltype, elm, var, y, n) \ { \ - struct name *_##var##_head = head; \ - 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); \ - _HT_SET_HASH((elm), field, hashfn); \ - var = _##name##_HT_FIND_P(_##var##_head, (elm)); \ + struct name *var##_head_ = head; \ + 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); \ + HT_SET_HASH_((elm), field, hashfn); \ + var = name##_HT_FIND_P_(var##_head_, (elm)); \ if (*var) { \ y; \ } else { \ n; \ } \ } -#define _HT_FOI_INSERT(field, head, elm, newent, var) \ +#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); \ @@ -431,9 +451,8 @@ ht_string_hash(const char *s) /* * Copyright 2005, Nick Mathewson. Implementation logic is adapted from code * by Christopher Clark, retrofit to allow drop-in memory management, and to - * use the same interface as Niels Provos's HT_H. I'm not sure whether this - * is a derived work any more, but whether it is or not, the license below - * applies. + * use the same interface as Niels Provos's tree.h. This is probably still + * a derived work, so the original license below still applies. * * Copyright (c) 2002, Christopher Clark * All rights reserved. |