#include "../h/param.h"#include "../h/tty.h"#include "../h/systm.h"#include "../h/conf.h"#include "../h/buf.h"struct cblock {	struct cblock *c_next;	char	c_info[CBSIZE];};struct	cblock	cfree[NCLIST];struct	cblock	*cfreelist;int	cbad;/* * Character list get/put */getc(p)register struct clist *p;{	register struct cblock *bp;	register int c, s;	s = spl6();	if (p->c_cc <= 0) {		c = -1;		p->c_cc = 0;		p->c_cf = p->c_cl = NULL;	} else {		c = *p->c_cf++ & 0377;		if (--p->c_cc<=0) {			bp = (struct cblock *)(p->c_cf-1);			bp = (struct cblock *) ((int)bp & ~CROUND);			p->c_cf = NULL;			p->c_cl = NULL;			bp->c_next = cfreelist;			cfreelist = bp;		} else if (((int)p->c_cf & CROUND) == 0){			bp = (struct cblock *)(p->c_cf);			bp--;			p->c_cf = bp->c_next->c_info;			bp->c_next = cfreelist;			cfreelist = bp;		}	}	splx(s);	return(c);}/* * copy clist to buffer. * return number of bytes moved. */q_to_b(q, cp, cc)register struct clist *q;register char *cp;{	register struct cblock *bp;	register int s;	char *acp;	if (cc <= 0)		return(0);	s = spl6();	if (q->c_cc <= 0) {		q->c_cc = 0;		q->c_cf = q->c_cl = NULL;		return(0);	}	acp = cp;	cc++;	while (--cc) {		*cp++ = *q->c_cf++;		if (--q->c_cc <= 0) {			bp = (struct cblock *)(q->c_cf-1);			bp = (struct cblock *)((int)bp & ~CROUND);			q->c_cf = q->c_cl = NULL;			bp->c_next = cfreelist;			cfreelist = bp;			break;		}		if (((int)q->c_cf & CROUND) == 0) {			bp = (struct cblock *)(q->c_cf);			bp--;			q->c_cf = bp->c_next->c_info;			bp->c_next = cfreelist;			cfreelist = bp;		}	}	splx(s);	return(cp-acp);}/* * Return count of contiguous characters * in clist starting at q->c_cf. * Stop counting if flag&character is non-null. */ndqb(q, flag)register struct clist *q;{register cc;int s;	s = spl6();	if (q->c_cc <= 0) {		cc = -q->c_cc;		goto out;	}	cc = ((int)q->c_cf + CBSIZE) & ~CROUND;	cc -= (int)q->c_cf;	if (q->c_cc < cc)		cc = q->c_cc;	if (flag) {		register char *p, *end;		p = q->c_cf;		end = p;		end += cc;		while (p < end) {			if (*p & flag) {				cc = (int)p;				cc -= (int)q->c_cf;				break;			}			p++;		}	}out:	splx(s);	return(cc);}/* * Update clist to show that cc characters * were removed.  It is assumed that cc < CBSIZE. */ndflush(q, cc)register struct clist *q;register cc;{register s;	s = spl6();	if (q->c_cc < 0) {		if (q->c_cf != NULL) {			q->c_cc += cc;			q->c_cf += cc;			goto out;		}		q->c_cc = 0;		goto out;	}	if (q->c_cc == 0) {		goto out;	}	if (cc > CBSIZE || cc <= 0) {		cbad++;		goto out;	}	q->c_cc -= cc;	q->c_cf += cc;	if (((int)q->c_cf & CROUND) == 0) {		register struct cblock *bp;		bp = (struct cblock *)(q->c_cf) -1;		if (bp->c_next) {			q->c_cf = bp->c_next->c_info;		} else {			q->c_cf = q->c_cl = NULL;		}		bp->c_next = cfreelist;		cfreelist = bp;	} else	if (q->c_cc == 0) {		register struct cblock *bp;		q->c_cf = (char *)((int)q->c_cf & ~CROUND);		bp = (struct cblock *)(q->c_cf);		bp->c_next = cfreelist;		cfreelist = bp;		q->c_cf = q->c_cl = NULL;	}out:	splx(s);}putc(c, p)register struct clist *p;{	register struct cblock *bp;	register char *cp;	register s;	s = spl6();	if ((cp = p->c_cl) == NULL || p->c_cc < 0 ) {		if ((bp = cfreelist) == NULL) {			splx(s);			return(-1);		}		cfreelist = bp->c_next;		bp->c_next = NULL;		p->c_cf = cp = bp->c_info;	} else if (((int)cp & CROUND) == 0) {		bp = (struct cblock *)cp - 1;		if ((bp->c_next = cfreelist) == NULL) {			splx(s);			return(-1);		}		bp = bp->c_next;		cfreelist = bp->c_next;		bp->c_next = NULL;		cp = bp->c_info;	}	*cp++ = c;	p->c_cc++;	p->c_cl = cp;	splx(s);	return(0);}/* * copy buffer to clist. * return number of bytes not transfered. */b_to_q(cp, cc, q)register char *cp;struct clist *q;register int cc;{	register char *cq;	register struct cblock *bp;	register s, acc;	if (cc <= 0)		return(0);	acc = cc;	s = spl6();	if ((cq = q->c_cl) == NULL || q->c_cc < 0) {		if ((bp = cfreelist) == NULL) 			goto out;		cfreelist = bp->c_next;		bp->c_next = NULL;		q->c_cf = cq = bp->c_info;	}	while (cc) {		if (((int)cq & CROUND) == 0) {			bp = (struct cblock *) cq - 1;			if ((bp->c_next = cfreelist) == NULL) 				goto out;			bp = bp->c_next;			cfreelist = bp->c_next;			bp->c_next = NULL;			cq = bp->c_info;		}		*cq++ = *cp++;		cc--;	}out:	q->c_cl = cq;	q->c_cc += acc-cc;	splx(s);	return(cc);}/* * Initialize clist by freeing all character blocks, then count * number of character devices. (Once-only routine) */cinit(){	register int ccp;	register struct cblock *cp;	register struct cdevsw *cdp;	ccp = (int)cfree;	ccp = (ccp+CROUND) & ~CROUND;	for(cp=(struct cblock *)ccp; cp <= &cfree[NCLIST-1]; cp++) {		cp->c_next = cfreelist;		cfreelist = cp;	}	ccp = 0;	for(cdp = cdevsw; cdp->d_open; cdp++)		ccp++;	nchrdev = ccp;}/* * integer (2-byte) get/put * using clists */getw(p)register struct clist *p;{	register int s;	if (p->c_cc <= 1)		return(-1);	s = getc(p);	return(s | (getc(p)<<8));}putw(c, p)register struct clist *p;{	register s;	s = spl6();	if (cfreelist==NULL) {		splx(s);		return(-1);	}	putc(c, p);	putc(c>>8, p);	splx(s);	return(0);}