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strings.c revision 1.2 
      1 /*
      2  * Copyright (c) 1980 Regents of the University of California.
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. All advertising materials mentioning features or use of this software
     14  *    must display the following acknowledgement:
     15  *	This product includes software developed by the University of
     16  *	California, Berkeley and its contributors.
     17  * 4. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  */
     33 
     34 #ifndef lint
     35 /*static char sccsid[] = "from: @(#)strings.c	5.9 (Berkeley) 6/1/90";*/
     36 static char rcsid[] = "$Id: strings.c,v 1.2 1993/08/01 18:12:56 mycroft Exp $";
     37 #endif /* not lint */
     38 
     39 /*
     40  * Mail -- a mail program
     41  *
     42  * String allocation routines.
     43  * Strings handed out here are reclaimed at the top of the command
     44  * loop each time, so they need not be freed.
     45  */
     46 
     47 #include "rcv.h"
     48 
     49 /*
     50  * Allocate size more bytes of space and return the address of the
     51  * first byte to the caller.  An even number of bytes are always
     52  * allocated so that the space will always be on a word boundary.
     53  * The string spaces are of exponentially increasing size, to satisfy
     54  * the occasional user with enormous string size requests.
     55  */
     56 
     57 char *
     58 salloc(size)
     59 {
     60 	register char *t;
     61 	register int s;
     62 	register struct strings *sp;
     63 	int index;
     64 
     65 	s = size;
     66 	s += 3;
     67 	s &= ~03;
     68 	index = 0;
     69 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
     70 		if (sp->s_topFree == NOSTR && (STRINGSIZE << index) >= s)
     71 			break;
     72 		if (sp->s_nleft >= s)
     73 			break;
     74 		index++;
     75 	}
     76 	if (sp >= &stringdope[NSPACE])
     77 		panic("String too large");
     78 	if (sp->s_topFree == NOSTR) {
     79 		index = sp - &stringdope[0];
     80 		sp->s_topFree = malloc(STRINGSIZE << index);
     81 		if (sp->s_topFree == NOSTR) {
     82 			fprintf(stderr, "No room for space %d\n", index);
     83 			panic("Internal error");
     84 		}
     85 		sp->s_nextFree = sp->s_topFree;
     86 		sp->s_nleft = STRINGSIZE << index;
     87 	}
     88 	sp->s_nleft -= s;
     89 	t = sp->s_nextFree;
     90 	sp->s_nextFree += s;
     91 	return(t);
     92 }
     93 
     94 /*
     95  * Reset the string area to be empty.
     96  * Called to free all strings allocated
     97  * since last reset.
     98  */
     99 sreset()
    100 {
    101 	register struct strings *sp;
    102 	register int index;
    103 
    104 	if (noreset)
    105 		return;
    106 	index = 0;
    107 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
    108 		if (sp->s_topFree == NOSTR)
    109 			continue;
    110 		sp->s_nextFree = sp->s_topFree;
    111 		sp->s_nleft = STRINGSIZE << index;
    112 		index++;
    113 	}
    114 }
    115 
    116 /*
    117  * Make the string area permanent.
    118  * Meant to be called in main, after initialization.
    119  */
    120 spreserve()
    121 {
    122 	register struct strings *sp;
    123 
    124 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
    125 		sp->s_topFree = NOSTR;
    126 }
    127