/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#ifndef lint
static char *sccsid = "@(#)strings.c	5.2 (Berkeley) 6/21/85";
#endif /* !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 "glob.h"

/*
 * The pointers for the string allocation routines,
 * there are NSPACE independent areas.
 * The first holds STRINGSIZE bytes, the next
 * twice as much, and so on.
 */

#define NSPACE	25			/* Total number of string spaces */
struct strings {
	char    *s_topFree;		/* Beginning of this area */
	char    *s_nextFree;		/* Next alloctable place here */
	unsigned s_nleft;		/* Number of bytes left here */
} stringdope[NSPACE];


/*
 * 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, index;
	register struct strings *sp;

	s = size;
#if defined(SVR3) || defined(_SVR4_SOURCE)
	s += (sizeof(long)-1);
	s &= ~(sizeof(long)-1);
#else
	s++;
	s &= ~01;
#endif
	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 = (char *) calloc((size_t)STRINGSIZE << index,
		    				(size_t) 1);
		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++;
	}
}

/*
 * Return a pointer to a dynamic copy of the argument.
 */

char *
savestr(str)
	char *str;
{
	register char *cp, *cp2, *top;

	for (cp = str; *cp; cp++)
		;
	top = salloc(cp-str + 1);
	if (top == NOSTR)
		return(NOSTR);
	for (cp = str, cp2 = top; *cp; cp++)
		*cp2++ = *cp;
	*cp2 = 0;
	return(top);
}