/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include	"mk.h" static Bufblock *freelist;#define	QUANTA	4096 Bufblock *newbuf(void){	Bufblock *p; 	if (freelist) {		p = freelist;		freelist = freelist->next;	} else {		p = (Bufblock *) Malloc(sizeof(Bufblock));		p->start = Malloc(QUANTA*sizeof(*p->start));		p->end = p->start+QUANTA;	}	p->current = p->start;	*p->start = 0;	p->next = 0;	return p;} voidfreebuf(Bufblock *p){	p->next = freelist;	freelist = p;} voidgrowbuf(Bufblock *p){	int n;	Bufblock *f;	char *cp; 	n = p->end-p->start+QUANTA;		/* search the free list for a big buffer */	for (f = freelist; f; f = f->next) {		if (f->end-f->start >= n) {			memcpy(f->start, p->start, p->end-p->start);			cp = f->start;			f->start = p->start;			p->start = cp;			cp = f->end;			f->end = p->end;			p->end = cp;			f->current = f->start;			break;		}	}	if (!f) {		/* not found - grow it */		p->start = Realloc(p->start, n);		p->end = p->start+n;	}	p->current = p->start+n-QUANTA;} voidbufcpy(Bufblock *buf, char *cp, int n){ 	while (n--)		insert(buf, *cp++);} voidinsert(Bufblock *buf, int c){ 	if (buf->current >= buf->end)		growbuf(buf);	*buf->current++ = c;} voidrinsert(Bufblock *buf, Rune r){	int n; 	n = runelen(r);	if (buf->current+n > buf->end)		growbuf(buf);	runetochar(buf->current, &r);	buf->current += n;}