diff options
Diffstat (limited to 'src')
-rw-r--r-- | src/search/hsearch.c | 103 |
1 files changed, 73 insertions, 30 deletions
diff --git a/src/search/hsearch.c b/src/search/hsearch.c index 6fe5ced0..88edb263 100644 --- a/src/search/hsearch.c +++ b/src/search/hsearch.c @@ -1,6 +1,8 @@ +#define _GNU_SOURCE #include <stdlib.h> #include <string.h> #include <search.h> +#include "libc.h" /* open addressing hash table with 2^n table size @@ -19,9 +21,17 @@ struct elem { size_t hash; }; -static size_t mask; -static size_t used; -static struct elem *tab; +struct __tab { + struct elem *elems; + size_t mask; + size_t used; +}; + +static struct hsearch_data htab; + +int __hcreate_r(size_t, struct hsearch_data *); +void __hdestroy_r(struct hsearch_data *); +int __hsearch_r(ENTRY, ACTION, ENTRY **, struct hsearch_data *); static size_t keyhash(char *k) { @@ -33,29 +43,29 @@ static size_t keyhash(char *k) return h; } -static int resize(size_t nel) +static int resize(size_t nel, struct hsearch_data *htab) { size_t newsize; size_t i, j; struct elem *e, *newe; - struct elem *oldtab = tab; - struct elem *oldend = tab + mask + 1; + struct elem *oldtab = htab->__tab->elems; + struct elem *oldend = htab->__tab->elems + htab->__tab->mask + 1; if (nel > MAXSIZE) nel = MAXSIZE; for (newsize = MINSIZE; newsize < nel; newsize *= 2); - tab = calloc(newsize, sizeof *tab); - if (!tab) { - tab = oldtab; + htab->__tab->elems = calloc(newsize, sizeof *htab->__tab->elems); + if (!htab->__tab->elems) { + htab->__tab->elems = oldtab; return 0; } - mask = newsize - 1; + htab->__tab->mask = newsize - 1; if (!oldtab) return 1; for (e = oldtab; e < oldend; e++) if (e->item.key) { for (i=e->hash,j=1; ; i+=j++) { - newe = tab + (i & mask); + newe = htab->__tab->elems + (i & htab->__tab->mask); if (!newe->item.key) break; } @@ -67,27 +77,21 @@ static int resize(size_t nel) int hcreate(size_t nel) { - mask = 0; - used = 0; - tab = 0; - return resize(nel); + return __hcreate_r(nel, &htab); } void hdestroy(void) { - free(tab); - tab = 0; - mask = 0; - used = 0; + __hdestroy_r(&htab); } -static struct elem *lookup(char *key, size_t hash) +static struct elem *lookup(char *key, size_t hash, struct hsearch_data *htab) { size_t i, j; struct elem *e; for (i=hash,j=1; ; i+=j++) { - e = tab + (i & mask); + e = htab->__tab->elems + (i & htab->__tab->mask); if (!e->item.key || (e->hash==hash && strcmp(e->item.key, key)==0)) break; @@ -97,22 +101,61 @@ static struct elem *lookup(char *key, size_t hash) ENTRY *hsearch(ENTRY item, ACTION action) { + ENTRY *e; + + __hsearch_r(item, action, &e, &htab); + return e; +} + +int __hcreate_r(size_t nel, struct hsearch_data *htab) +{ + int r; + + htab->__tab = calloc(1, sizeof *htab->__tab); + if (!htab->__tab) + return 0; + r = resize(nel, htab); + if (r == 0) { + free(htab->__tab); + htab->__tab = 0; + } + return r; +} +weak_alias(__hcreate_r, hcreate_r); + +void __hdestroy_r(struct hsearch_data *htab) +{ + if (htab->__tab) free(htab->__tab->elems); + free(htab->__tab); + htab->__tab = 0; +} +weak_alias(__hdestroy_r, hdestroy_r); + +int __hsearch_r(ENTRY item, ACTION action, ENTRY **retval, struct hsearch_data *htab) +{ size_t hash = keyhash(item.key); - struct elem *e = lookup(item.key, hash); + struct elem *e = lookup(item.key, hash, htab); - if (e->item.key) - return &e->item; - if (action == FIND) + if (e->item.key) { + *retval = &e->item; + return 1; + } + if (action == FIND) { + *retval = 0; return 0; + } e->item = item; e->hash = hash; - if (++used > mask - mask/4) { - if (!resize(2*used)) { - used--; + if (++htab->__tab->used > htab->__tab->mask - htab->__tab->mask/4) { + if (!resize(2*htab->__tab->used, htab)) { + htab->__tab->used--; e->item.key = 0; + *retval = 0; return 0; } - e = lookup(item.key, hash); + e = lookup(item.key, hash, htab); } - return &e->item; + *retval = &e->item; + return 1; } +weak_alias(__hsearch_r, hsearch_r); |