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    1: 
    2: /*
    3:  * Copyright (c) 2001-2002 Packet Design, LLC.
    4:  * All rights reserved.
    5:  * 
    6:  * Subject to the following obligations and disclaimer of warranty,
    7:  * use and redistribution of this software, in source or object code
    8:  * forms, with or without modifications are expressly permitted by
    9:  * Packet Design; provided, however, that:
   10:  * 
   11:  *    (i)  Any and all reproductions of the source or object code
   12:  *         must include the copyright notice above and the following
   13:  *         disclaimer of warranties; and
   14:  *    (ii) No rights are granted, in any manner or form, to use
   15:  *         Packet Design trademarks, including the mark "PACKET DESIGN"
   16:  *         on advertising, endorsements, or otherwise except as such
   17:  *         appears in the above copyright notice or in the software.
   18:  * 
   19:  * THIS SOFTWARE IS BEING PROVIDED BY PACKET DESIGN "AS IS", AND
   20:  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, PACKET DESIGN MAKES NO
   21:  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING
   22:  * THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED
   23:  * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE,
   24:  * OR NON-INFRINGEMENT.  PACKET DESIGN DOES NOT WARRANT, GUARANTEE,
   25:  * OR MAKE ANY REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS
   26:  * OF THE USE OF THIS SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY,
   27:  * RELIABILITY OR OTHERWISE.  IN NO EVENT SHALL PACKET DESIGN BE
   28:  * LIABLE FOR ANY DAMAGES RESULTING FROM OR ARISING OUT OF ANY USE
   29:  * OF THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, ANY DIRECT,
   30:  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, PUNITIVE, OR CONSEQUENTIAL
   31:  * DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, LOSS OF
   32:  * USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY THEORY OF
   33:  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   34:  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
   35:  * THE USE OF THIS SOFTWARE, EVEN IF PACKET DESIGN IS ADVISED OF
   36:  * THE POSSIBILITY OF SUCH DAMAGE.
   37:  *
   38:  * Author: Archie Cobbs <archie@freebsd.org>
   39:  */
   40: 
   41: #ifndef _PDEL_UTIL_GHASH_H_
   42: #define _PDEL_UTIL_GHASH_H_
   43: 
   44: /*
   45:  * General purpose hash table stuff.
   46:  */
   47: 
   48: /**********************************************************************
   49: 			HASH TABLE FUNCTION TYPES
   50: **********************************************************************/
   51: 
   52: struct ghash;
   53: struct ghash_walk;
   54: 
   55: /*
   56:  * How to compare two items for equality.
   57:  *
   58:  * If this function is not specified, then "item1 == item2" is used.
   59:  */
   60: typedef int	ghash_equal_t(struct ghash *g,
   61: 			const void *item1, const void *item2);
   62: 
   63: /*
   64:  * How to compute the hash value for an item.
   65:  *
   66:  * If this function is not specified, then "(u_int32_t)item" is used.
   67:  */
   68: typedef u_int32_t ghash_hash_t(struct ghash *g, const void *item);
   69: 
   70: /*
   71:  * Notification that an item is being added to the table.
   72:  *
   73:  * Supplying this function is optional.
   74:  */
   75: typedef void	ghash_add_t(struct ghash *g, void *item);
   76: 
   77: /*
   78:  * Notification that an item is being removed from the table.
   79:  *
   80:  * Supplying this function is optional.
   81:  */
   82: typedef void	ghash_del_t(struct ghash *g, void *item);
   83: 
   84: /**********************************************************************
   85: 			HASH TABLE METHODS
   86: **********************************************************************/
   87: 
   88: __BEGIN_DECLS
   89: 
   90: /*
   91:  * Create a new hash table.
   92:  *
   93:  * "isize" is the initial table size, or zero for the default.
   94:  *
   95:  * "maxload" is the maximum hash table load in percent, or zero
   96:  * for the default which is 75 (i.e., 75%).
   97:  *
   98:  * The "hash", "equal", "add", and "del" methods are optional (see above).
   99:  */
  100: extern struct	ghash *ghash_create(void *arg, u_int isize, u_int maxload,
  101: 			const char *mtype, ghash_hash_t *hash,
  102: 			ghash_equal_t *equal, ghash_add_t *add,
  103: 			ghash_del_t *del);
  104: 
  105: /*
  106:  * Destroy a hash table.
  107:  *
  108:  * Any items remaining in the table will be removed first.
  109:  */
  110: extern void	ghash_destroy(struct ghash **gp);
  111: 
  112: /*
  113:  * Get the argument supplied to ghash_create().
  114:  */
  115: extern void	*ghash_arg(struct ghash *g);
  116: 
  117: /*
  118:  * Get an item.
  119:  *
  120:  * Returns the item, or NULL if the item does not exist.
  121:  */
  122: extern void	*ghash_get(struct ghash *g, const void *item);
  123: 
  124: /*
  125:  * Put an item.
  126:  *
  127:  * Returns 0 if the item is new, 1 if it replaces an existing
  128:  * item, and -1 if there was an error.
  129:  */
  130: extern int	ghash_put(struct ghash *g, const void *item);
  131: 
  132: /*
  133:  * Remove an item.
  134:  *
  135:  * Returns 1 if the item was found and removed, 0 if not found.
  136:  */
  137: extern int	ghash_remove(struct ghash *g, const void *item);
  138: 
  139: /*
  140:  * Get the size of the table.
  141:  */
  142: extern u_int	ghash_size(struct ghash *g);
  143: 
  144: /*
  145:  * Get an array of all items in the table.
  146:  *
  147:  * Returns number of items in the list, or -1 if error.
  148:  * Caller must free the list.
  149:  */
  150: extern int	ghash_dump(struct ghash *g, void ***listp, const char *mtype);
  151: 
  152: /*
  153:  * Start a hash table walk. Caller must supply a pointer to a
  154:  * 'struct ghash_walk' (see below) which is used to store the
  155:  * position in the table for ghash_walk_next().
  156:  */
  157: extern void	ghash_walk_init(struct ghash *g, struct ghash_walk *walk);
  158: 
  159: /*
  160:  * Get the next item in the hash table walk, or NULL if the walk
  161:  * is finished (ENOENT) or the table has been modified (EINVAL).
  162:  *
  163:  * This is only valid if the hash table has not been modified
  164:  * since the previous call to ghash_walk_init() or ghash_walk_next().
  165:  */
  166: extern void	*ghash_walk_next(struct ghash *g, struct ghash_walk *walk);
  167: 
  168: __END_DECLS
  169: 
  170: struct ghash_walk {
  171: 	u_int		mods;
  172: 	u_int		bucket;
  173: 	struct gent	*e;
  174: };
  175: 
  176: /**********************************************************************
  177: 			ITERATOR METHODS
  178: **********************************************************************/
  179: 
  180: struct ghash_iter;
  181: 
  182: __BEGIN_DECLS
  183: 
  184: extern int	ghash_iter_has_next(struct ghash_iter *iter);
  185: extern void	*ghash_iter_next(struct ghash_iter *iter);
  186: extern int	ghash_iter_remove(struct ghash_iter *iter);
  187: 
  188: extern struct	ghash_iter *ghash_iter_create(struct ghash *g);
  189: extern void	ghash_iter_destroy(struct ghash_iter **iterp);
  190: 
  191: __END_DECLS
  192: 
  193: #endif	/* _PDEL_UTIL_GHASH_H_ */
  194: