/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 *      Copyright (c) 1998 by Sun Microsystems, Inc.
 */
#ifndef _CACHE_DOT_H
#define _CACHE_DOT_H

/*
 * ld.so directory caching
 */
#include        <sys/types.h>

/*
 * Shared object lookup performance in the run-time link editor is
 * enhanced through the use of caches for directories that the editor
 * searches.  A given "cache" describes the contents of a single directory,
 * and each cache entry contains the canonical name for a shared object
 * as well as its absolute pathname.
 *
 * Within a cache, "pointers" are really relative addresses to some absolute
 * address (often the base address of the containing database).
 */

/*
 * Relative pointer macros.
 */
#define RELPTR(base, absptr) ((long)(absptr) - (long)(base))
#define AP(base) ((caddr_t)base)

/*
 * Definitions for cache structures.
 */
#define DB_HASH         11              /* number of hash buckets in caches */
#define LD_CACHE_MAGIC  0x041155        /* cookie to identify data structure */
#define LD_CACHE_VERSION 0              /* version number of cache structure */

struct  dbe     {                       /* element of a directory cache */
        long    dbe_next;               /* (rp) next element on this list */
        long    dbe_lop;                /* (rp) canonical name for object */
        long    dbe_name;               /* (rp) absolute name */
};

struct  db      {                       /* directory cache database */
        long    db_name;                /* (rp) directory contained here */
        struct  dbe db_hash[DB_HASH];   /* hash buckets */
        caddr_t db_chain;               /* private to database mapping */
};

struct dbf      {                       /* cache file image */
        long dbf_magic;                 /* identifying cookie */
        long dbf_version;               /* version no. of these dbs */
        long dbf_machtype;              /* machine type */
        long dbf_db;            /* directory cache dbs */
};

/*
 * Structures used to describe and access a database.
 */
struct  dbd     {                       /* data base descriptor */
        struct  dbd *dbd_next;          /* next one on this list */
        struct  db *dbd_db;             /* data base described by this */
};

struct  dd      {                       /* directory descriptor */
        struct  dd *dd_next;            /* next one on this list */
        struct  db *dd_db;              /* data base described by this */
};

/*
 * Interfaces imported/exported by the lookup code.
 */

char    *ask_db();                      /* ask db for highest minor number */
struct  db *lo_cache();                 /* obtain cache for directory name */

#endif