#include	"misc.h"#include	"slug.h"#include	"range.h"#include	"page.h" queue	squeue;queue	bfqueue;queue	ufqueue; // We use the stream function current() to access a queue's head.// Thus, queue member curr should always point to its first range.void queue::check(char *whence){	if (dbg & 8) {		char *p;		if (this == &squeue)			p = "squeue";		else if (this == &bfqueue)			p = "bfqueue";		else if (this == &ufqueue)			p = "ufqueue";		else			p = "weird queue";		printf("#checking %s\n", p);	}	if (first != curr)		ERROR "check(%s): first != curr, line %d\n", whence, curr->rp->lineno() FATAL;} // When ranges are told to enqueue themselves, they are being rejected from the// stage back onto their original queues.// They reset any parameters that may have been altered by staging or trial// composition. void	range::enqueue(int block){	squeue.enqueue(this);	if (block)		squeue.block();} void	ufrange::enqueue(int block){	restore();			// both goal positions	ufqueue.enqueue(this);	if (block)		ufqueue.block();} void	bfrange::enqueue(int block){	restore();			// both goal positions	bfqueue.enqueue(this);	if (block)		bfqueue.block();} int anymore(){	return !(squeue.empty() && ufqueue.empty() && bfqueue.empty());} void mergestream::unblock(){	squeue.unblock();	bfqueue.unblock();	ufqueue.unblock();} // Fill the staging area with a minimal chunk of input ranges.int mergestream::prime(){	if (dbg & 4)		printf("#entering mergestream::prime()\n");	if (!empty())		return 1;	int brkok = 1;			// is it OK to break after the last					// VBOX that was added to the stage?	int needheight = -1;		// minimum acceptable height of the					// chunk being constructed on stage	// If the range at the head of any queue is breaking,	// deal with it first.	if (squeue.more() && squeue.current()->breaking())		enqueue(squeue.dequeue());	else if (bfqueue.more() && (bfqueue.current()->breaking() ||		(bfqueue.serialno() < squeue.serialno())))		enqueue(bfqueue.dequeue());	else if (ufqueue.more() && (ufqueue.current()->breaking() ||		(ufqueue.serialno() < squeue.serialno())))		enqueue(ufqueue.dequeue());	else while (squeue.more()) {		// Fill the stage with enough ranges to be a valid chunk.		range *r = squeue.dequeue();		if (r->isvbox()) {	// VBOX			if (dbg & 16)				printf("#VBOX: !empty: %d; brkok: %d; vsince: %d\n",					!empty(), brkok, currpage->vsince);			if (!empty()	// there's something there				&& brkok					// it's OK to break here				&& currpage->vsince >= 2					// enough stream has gone onto this page				&& rawht() >= needheight					// current need has been satisfied				) {					// the stage already contains enough					// ranges, so this one can wait				r->enqueue();				break;			} else {				if (r->rawht() > 0) {					++currpage->vsince;					brkok = r->brkafter();				}				enqueue(r);			}		} else if (r->isnested() || r->issp()) {	// US, SP			if (!empty() && rawht() >= needheight) {					// enough already, wait				r->enqueue();				break;			}			currpage->vsince = 0;			enqueue(r);			if (height() >= needheight)				break;		} else if (r->isneed()) {	// NE			if (!empty() && rawht() >= needheight) {					// not currently working on an unsatisfied NEed 				r->enqueue();				break;			}					// deal with overlapping NEeds			needheight = rawht() + max(needheight - rawht(), r->needht());			enqueue(r);		} else if (r->forceflush() == NO) {			enqueue(r);		} else if (r->forceflush() == YES) {			currpage->vsince = 0;			if (!empty()) {					// ready or not, r must wait				r->enqueue();				break;			}			enqueue(r);			break;		} else			ERROR "unexpected  %s[%s] in prime(), line %d\n",				r->typename(), r->headstr(), r->lineno() FATAL;	}	return more();			// 0 if nothing was staged} void page::cmdproc(){	if (stage->next())		ERROR "more than a single command on bsqueue\n" FATAL;	switch (stage->current()->cmdtype()) {	case FC:	// freeze the current 2-column range and start a new one		adddef(stage->dequeue());		twocol->compose(FINAL);		adddef(twocol);		twocol = new multicol(this);		break;	case BP:	// force a page break		adddef(stage->dequeue());		squeue.block();		break;	case FL:	// flush out all floatables that precede this range:			// no more stream input allowed until they're past		if (stage->serialno() > ufqueue.serialno() ||			stage->serialno() > bfqueue.serialno()) {			range *r = stage->dequeue();			r->enqueue(ANDBLOCK);		} else			adddef(stage->dequeue());		break;	default:		stage->current()->dump();		ERROR "unknown command\n" FATAL;	}} void page::parmproc(){	if (stage->next())		ERROR "more than a single parameter on bsqueue\n" FATAL;	switch (stage->current()->parmtype()) {	case NP:	// page top margin		if (blank())			pagetop = stage->current()->parm();		pagesize = pagebot - pagetop;		break;	case FO:		if (blank())			pagebot = stage->current()->parm();		pagesize = pagebot - pagetop;		break;	case PL:		if (blank())			physbot = stage->current()->parm();		break;	case MF:		minfull = 0.01*stage->current()->parm();		break;	case CT:		coltol = 0.01*stage->current()->parm();		break;	case WARN:		wantwarn = stage->current()->parm();		break;	case DBG:		dbg = stage->current()->parm();		break;	default:		stage->current()->dump();		ERROR "unknown parameter\n" FATAL;	}	adddef(stage->dequeue());} // Process the contents of the staging area; a relic that used to do more.void mergestream::pend(){	if (dbg & 4)		printf("#entering mergestream::pend()\n");	if (!more())		return;	if (current()->iscmd())		currpage->cmdproc();	else if (current()->isparm())		currpage->parmproc();	else		currpage->tryout();}