diff options
Diffstat (limited to 'locale/locfile-hash.c')
-rw-r--r-- | locale/locfile-hash.c | 254 |
1 files changed, 0 insertions, 254 deletions
diff --git a/locale/locfile-hash.c b/locale/locfile-hash.c deleted file mode 100644 index d977822664..0000000000 --- a/locale/locfile-hash.c +++ /dev/null @@ -1,254 +0,0 @@ -/* Copyright (C) 1995 Free Software Foundation, Inc. - -The GNU C Library is free software; you can redistribute it and/or -modify it under the terms of the GNU Library General Public License as -published by the Free Software Foundation; either version 2 of the -License, or (at your option) any later version. - -The GNU C Library is distributed in the hope that it will be useful, -but WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU -Library General Public License for more details. - -You should have received a copy of the GNU Library General Public -License along with the GNU C Library; see the file COPYING.LIB. If -not, write to the Free Software Foundation, Inc., 675 Mass Ave, -Cambridge, MA 02139, USA. */ - -#include <obstack.h> -#include <stdlib.h> -#include <string.h> -#include <values.h> - -#include "hash.h" - -#define obstack_chunk_alloc xmalloc -#define obstack_chunk_free free - -void *xmalloc (size_t n); - -typedef struct hash_entry - { - int used; - char *key; - void *data; - struct hash_entry *next; - } -hash_entry; - -/* Prototypes for local functions. */ -static size_t lookup (hash_table *htab, const char *key, size_t keylen, - unsigned long hval); -static unsigned long compute_hashval(const char *key, size_t keylen); -static unsigned long next_prime(unsigned long seed); -static int is_prime(unsigned long candidate); - - -int -init_hash(hash_table *htab, unsigned long init_size) -{ - /* We need the size to be a prime. */ - init_size = next_prime (init_size); - - /* Initialize the data structure. */ - htab->size = init_size; - htab->filled = 0; - htab->first = NULL; - htab->table = calloc (init_size + 1, sizeof (hash_entry)); - obstack_init (&htab->mem_pool); - - return htab->table == NULL; -} - - -int -delete_hash(hash_table *htab) -{ - free (htab->table); - obstack_free (&htab->mem_pool, NULL); - return 0; -} - - -int -insert_entry (hash_table *htab, const char *key, size_t keylen, void *data) -{ - unsigned long hval = compute_hashval (key, keylen); - hash_entry *table = (hash_entry *) htab->table; - size_t idx = lookup (htab, key, keylen, hval); - - if (table[idx].used) - /* We don't want to overwrite the old value. */ - return 1; - else - { - hash_entry **p; - - /* An empty bucket has been found. */ - table[idx].used = hval; - table[idx].key = obstack_copy0 (&htab->mem_pool, key, keylen); - table[idx].data = data; - - /* List the new value in the ordered list. */ - for (p = (hash_entry **) &htab->first; *p != NULL && (*p)->data < data; - p = &(*p)->next); - if (*p == NULL || (*p)->data > data) - /* Insert new value in the list. */ - { - table[idx].next = *p; - *p = &table[idx]; - } - - ++htab->filled; - if (100 * htab->filled > 90 * htab->size) - { - /* Resize the table. */ - unsigned long old_size = htab->size; - - htab->size = next_prime (htab->size * 2); - htab->filled = 0; - htab->first = NULL; - htab->table = calloc (htab->size, sizeof (hash_entry)); - - for (idx = 1; idx <= old_size; ++idx) - if (table[idx].used) - insert_entry (htab, table[idx].key, strlen(table[idx].key), - table[idx].data); - - free (table); - } - return 0; - } - /* NOTREACHED */ -} - - -int -find_entry (hash_table *htab, const char *key, size_t keylen, void **result) -{ - hash_entry *table = (hash_entry *) htab->table; - size_t idx = lookup (htab, key, keylen, compute_hashval (key, keylen)); - int retval; - - retval = table[idx].used; - *result = retval ? table[idx].data : NULL; - - return retval; -} - - -int -iterate_table (hash_table *htab, void **ptr, void **result) -{ - if (*ptr == NULL) - *ptr = (void *) htab->first; - else - { - *ptr = (void *) (((hash_entry *) *ptr)->next); - if (*ptr == NULL) - return 0; - } - - *result = ((hash_entry *) *ptr)->data; - return 1; -} - - -static size_t -lookup (hash_table *htab, const char *key, size_t keylen, unsigned long hval) -{ - unsigned long hash; - size_t idx; - hash_entry *table = (hash_entry *) htab->table; - - /* First hash function: simply take the modul but prevent zero. */ - hash = 1 + hval % htab->size; - - idx = hash; - - if (table[idx].used) - { - if (table[idx].used == hval && table[idx].key[keylen] == '\0' - && strncmp (key, table[idx].key, keylen) == 0) - return idx; - - /* Second hash function as suggested in [Knuth]. */ - hash = 1 + hash % (htab->size - 2); - - do - { - if (idx <= hash) - idx = htab->size + idx - hash; - else - idx -= hash; - - /* If entry is found use it. */ - if (table[idx].used == hval && table[idx].key[keylen] == '\0' - && strncmp (key, table[idx].key, keylen) == 0) - return idx; - } - while (table[idx].used); - } - return idx; -} - - -static unsigned long -compute_hashval(const char *key, size_t keylen) -{ - size_t cnt; - unsigned long hval, g; - /* Compute the hash value for the given string. */ - cnt = 0; - hval = keylen; - while (cnt < keylen) - { - hval <<= 4; - hval += key[cnt++]; - g = hval & (0xfL << (LONGBITS - 4)); - if (g != 0) - { - hval ^= g >> (LONGBITS - 8); - hval ^= g; - } - } - return hval; -} - - -static unsigned long -next_prime(unsigned long seed) -{ - /* Make it definitely odd. */ - seed |= 1; - - while (!is_prime (seed)) - seed += 2; - - return seed; -} - - -static int -is_prime(unsigned long candidate) -{ - /* No even number and none less than 10 will be passwd here. */ - unsigned long div = 3; - unsigned long sq = div * div; - - while (sq < candidate && candidate % div != 0) - { - ++div; - sq += 4 * div; - ++div; - } - - return candidate % div != 0; -} - -/* - * Local Variables: - * mode:c - * c-basic-offset:2 - * End: - */ |