/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (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 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */



#include <limits.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <locale.h>
#include <libintl.h>
#include <pkglib.h>
#include <libadm.h>

#define ERR_MEMORY      "memory allocation failure, errno=%d"

/*
 * using factor of eight limits maximum
 * memory fragmentation to 12.5%
 */
#define MEMSIZ  PATH_MAX*8

struct dup {
        char    mem[MEMSIZ];
        struct dup *next;
};

static struct dup *head, *tail, *new;

static int      size, initialized;
static void     pathinit();
static void     growstore();

/*
 * These functions allocate space for all the path names required
 * in the packaging code. They are all allocated here so as to reduce
 * memory fragmentation.
 */

/* Initialize storage area. */
static void
pathinit()
{
        if (head == NULL)
                size = (-1);
        else {
                /* free all memory used except initial structure */
                tail = head->next;
                while (tail) {
                        new = tail->next;
                        free(tail);
                        tail = new;
                }
                tail = head;
                size = MEMSIZ;
        }

        initialized = 1;
}

/* Allocate additional space for storage area. */
static void
growstore()
{
        /* need more memory */
        new = calloc(1, sizeof (struct dup));
        if (new == NULL) {
                progerr(gettext(ERR_MEMORY), errno);
                quit(99);
        }
        if (head == NULL)
                head = new;
        else
                tail->next = new;
        tail = new;
        size = MEMSIZ;
}

/* Allocate and return a pointer. If n == 0, initialize. */
char *
pathalloc(int n)
{
        char    *pt;

        if (n <= 0) {
                pathinit();
                pt = NULL;
        } else {
                if (!initialized)
                        pathinit();

                n++;    /* Account for terminating null. */

                if (size < n)
                        growstore();

                pt = &tail->mem[MEMSIZ-size];
                size -= n;
        }

        return (pt);
}

/* Allocate and insert a pathname returning a pointer to the new string. */
char *
pathdup(char *s)
{
        char    *pt;
        int     n;

        if (s == NULL) {
                pathinit();
                pt = NULL;
        } else {
                if (!initialized)
                        pathinit();

                n = strlen(s) + 1;      /* string + null terminator */

                if (size < n)
                        growstore();

                pt = &tail->mem[MEMSIZ-size];
                size -= n;

                (void) strcpy(pt, s);
        }

        return (pt);
}