1 /* Copyright (C) 1995, 2000-2003, 2005-2006 Free Software Foundation, Inc. 2 3 This program is free software: you can redistribute it and/or modify 4 it under the terms of the GNU General Public License as published by 5 the Free Software Foundation; either version 3 of the License, or 6 (at your option) any later version. 7 8 This program is distributed in the hope that it will be useful, 9 but WITHOUT ANY WARRANTY; without even the implied warranty of 10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 GNU General Public License for more details. 12 13 You should have received a copy of the GNU General Public License 14 along with this program. If not, see <https://www.gnu.org/licenses/>. */ 15 16 #ifndef _HASH_H 17 #define _HASH_H 18 19 #include "obstack.h" 20 21 #ifdef __cplusplus 22 extern "C" { 23 #endif 24 25 struct hash_entry; 26 27 typedef struct hash_table 28 { 29 unsigned long int size; /* Number of allocated entries. */ 30 unsigned long int filled; /* Number of used entries. */ 31 struct hash_entry *first; /* Pointer to head of list of entries. */ 32 struct hash_entry *table; /* Pointer to array of entries. */ 33 struct obstack mem_pool; /* Memory pool holding the keys. */ 34 } 35 hash_table; 36 37 /* Initialize a hash table. INIT_SIZE > 1 is the initial number of available 38 entries. 39 Return 0 upon successful completion, -1 upon memory allocation error. */ 40 extern int hash_init (hash_table *htab, unsigned long int init_size); 41 42 /* Delete a hash table's contents. 43 Return 0 always. */ 44 extern int hash_destroy (hash_table *htab); 45 46 /* Look up the value of a key in the given table. 47 If found, return 0 and set *RESULT to it. Otherwise return -1. */ 48 extern int hash_find_entry (hash_table *htab, 49 const void *key, size_t keylen, 50 void **result); 51 52 /* Try to insert the pair (KEY[0..KEYLEN-1], DATA) in the hash table. 53 Return non-NULL (more precisely, the address of the KEY inside the table's 54 memory pool) if successful, or NULL if there is already an entry with the 55 given key. */ 56 extern const void * hash_insert_entry (hash_table *htab, 57 const void *key, size_t keylen, 58 void *data); 59 60 /* Insert the pair (KEY[0..KEYLEN-1], DATA) in the hash table. 61 Return 0. */ 62 extern int hash_set_value (hash_table *htab, 63 const void *key, size_t keylen, 64 void *data); 65 66 /* Steps *PTR forward to the next used entry in the given hash table. *PTR 67 should be initially set to NULL. Store information about the next entry 68 in *KEY, *KEYLEN, *DATA. 69 Return 0 normally, -1 when the whole hash table has been traversed. */ 70 extern int hash_iterate (hash_table *htab, void **ptr, 71 const void **key, size_t *keylen, 72 void **data); 73 74 /* Steps *PTR forward to the next used entry in the given hash table. *PTR 75 should be initially set to NULL. Store information about the next entry 76 in *KEY, *KEYLEN, *DATAP. *DATAP is set to point to the storage of the 77 value; modifying **DATAP will modify the value of the entry. 78 Return 0 normally, -1 when the whole hash table has been traversed. */ 79 extern int hash_iterate_modify (hash_table *htab, void **ptr, 80 const void **key, size_t *keylen, 81 void ***datap); 82 83 /* Given SEED > 1, return the smallest odd prime number >= SEED. */ 84 extern unsigned long int next_prime (unsigned long int seed); 85 86 #ifdef __cplusplus 87 } 88 #endif 89 90 #endif /* not _HASH_H */ 91