Start development on 386BSD 0.1

[unix-history] / .ref-386BSD-0.0 / usr / src / usr.bin / mail / strings.c

/*
* Copyright (c) 1980 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed by the University of
*      California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#ifndef lint
static char sccsid[] = "@(#)strings.c   5.9 (Berkeley) 6/1/90";
#endif /* not lint */

/*
* Mail -- a mail program
*
* String allocation routines.
* Strings handed out here are reclaimed at the top of the command
* loop each time, so they need not be freed.
*/

#include "rcv.h"

/*
* Allocate size more bytes of space and return the address of the
* first byte to the caller.  An even number of bytes are always
* allocated so that the space will always be on a word boundary.
* The string spaces are of exponentially increasing size, to satisfy
* the occasional user with enormous string size requests.
*/

char *
salloc(size)
{
       register char *t;
       register int s;
       register struct strings *sp;
       int index;

       s = size;
       s += 3;
       s &= ~03;
       index = 0;
       for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
               if (sp->s_topFree == NOSTR && (STRINGSIZE << index) >= s)
                       break;
               if (sp->s_nleft >= s)
                       break;
               index++;
       }
       if (sp >= &stringdope[NSPACE])
               panic("String too large");
       if (sp->s_topFree == NOSTR) {
               index = sp - &stringdope[0];
               sp->s_topFree = malloc(STRINGSIZE << index);
               if (sp->s_topFree == NOSTR) {
                       fprintf(stderr, "No room for space %d\n", index);
                       panic("Internal error");
               }
               sp->s_nextFree = sp->s_topFree;
               sp->s_nleft = STRINGSIZE << index;
       }
       sp->s_nleft -= s;
       t = sp->s_nextFree;
       sp->s_nextFree += s;
       return(t);
}

/*
* Reset the string area to be empty.
* Called to free all strings allocated
* since last reset.
*/
sreset()
{
       register struct strings *sp;
       register int index;

       if (noreset)
               return;
       index = 0;
       for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
               if (sp->s_topFree == NOSTR)
                       continue;
               sp->s_nextFree = sp->s_topFree;
               sp->s_nleft = STRINGSIZE << index;
               index++;
       }
}

/*
* Make the string area permanent.
* Meant to be called in main, after initialization.
*/
spreserve()
{
       register struct strings *sp;

       for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
               sp->s_topFree = NOSTR;
}