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strings.c revision 1.1 
      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[] = "@(#)strings.c	5.9 (Berkeley) 6/1/90";
     36 #endif /* not lint */
     37 
     38 /*
     39  * Mail -- a mail program
     40  *
     41  * String allocation routines.
     42  * Strings handed out here are reclaimed at the top of the command
     43  * loop each time, so they need not be freed.
     44  */
     45 
     46 #include "rcv.h"
     47 
     48 /*
     49  * Allocate size more bytes of space and return the address of the
     50  * first byte to the caller.  An even number of bytes are always
     51  * allocated so that the space will always be on a word boundary.
     52  * The string spaces are of exponentially increasing size, to satisfy
     53  * the occasional user with enormous string size requests.
     54  */
     55 
     56 char *
     57 salloc(size)
     58 {
     59 	register char *t;
     60 	register int s;
     61 	register struct strings *sp;
     62 	int index;
     63 
     64 	s = size;
     65 	s += 3;
     66 	s &= ~03;
     67 	index = 0;
     68 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
     69 		if (sp->s_topFree == NOSTR && (STRINGSIZE << index) >= s)
     70 			break;
     71 		if (sp->s_nleft >= s)
     72 			break;
     73 		index++;
     74 	}
     75 	if (sp >= &stringdope[NSPACE])
     76 		panic("String too large");
     77 	if (sp->s_topFree == NOSTR) {
     78 		index = sp - &stringdope[0];
     79 		sp->s_topFree = malloc(STRINGSIZE << index);
     80 		if (sp->s_topFree == NOSTR) {
     81 			fprintf(stderr, "No room for space %d\n", index);
     82 			panic("Internal error");
     83 		}
     84 		sp->s_nextFree = sp->s_topFree;
     85 		sp->s_nleft = STRINGSIZE << index;
     86 	}
     87 	sp->s_nleft -= s;
     88 	t = sp->s_nextFree;
     89 	sp->s_nextFree += s;
     90 	return(t);
     91 }
     92 
     93 /*
     94  * Reset the string area to be empty.
     95  * Called to free all strings allocated
     96  * since last reset.
     97  */
     98 sreset()
     99 {
    100 	register struct strings *sp;
    101 	register int index;
    102 
    103 	if (noreset)
    104 		return;
    105 	index = 0;
    106 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
    107 		if (sp->s_topFree == NOSTR)
    108 			continue;
    109 		sp->s_nextFree = sp->s_topFree;
    110 		sp->s_nleft = STRINGSIZE << index;
    111 		index++;
    112 	}
    113 }
    114 
    115 /*
    116  * Make the string area permanent.
    117  * Meant to be called in main, after initialization.
    118  */
    119 spreserve()
    120 {
    121 	register struct strings *sp;
    122 
    123 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
    124 		sp->s_topFree = NOSTR;
    125 }
    126