//
//  Copyright (c) 1995, 1996, 1997-2002 by Brian Grayson (bgrayson@netbsd.org)
//
//  This file was written by Brian Grayson for the NetBSD and xosview
//    projects.
//  This file may be distributed under terms of the GPL or of the BSD
//    license, whichever you choose.  The full license notices are
//    contained in the files COPYING.GPL and COPYING.BSD, which you
//    should have received.  If not, contact one of the xosview
//    authors for a copy.
//

#include "diskmeter.h"
#include "kernel.h"
#include <stdlib.h>
#include <err.h>


DiskMeter::DiskMeter( XOSView *parent, double max )
	: FieldMeterGraph( parent, 3, "DISK", "READ/WRITE/IDLE" ) {
	dodecay_ = 0;
	maxBandwidth_ = max;
	total_ = max;
	if (!BSDDiskInit())
		disableMeter();

	/* Since at the first call, it will look like we transferred a
	 * gazillion bytes, let's reset total_ again and do another
	 * call.  This will force total_ to be something reasonable.  */
	getstats();
	total_ = max;
	getstats();
	IntervalTimerStart();
	/* By doing this check, we eliminate the startup situation where
	 * all fields are 0, and total is 0, leading to nothing being drawn
	 * on the meter.  So, make it look like nothing was transferred,
	 * out of a total of 1 bytes.  */
	fields_[0] = fields_[1] = 0.0;
	total_ = 1.0;
	fields_[2] = total_;
}

DiskMeter::~DiskMeter( void ) {
}

void DiskMeter::checkResources( void ) {
	FieldMeterGraph::checkResources();

	setfieldcolor( 0, parent_->getResource("diskReadColor") );
	setfieldcolor( 1, parent_->getResource("diskWriteColor") );
	setfieldcolor( 2, parent_->getResource("diskIdleColor") );
	priority_ = atoi( parent_->getResource("diskPriority") );
	dodecay_ = parent_->isResourceTrue("diskDecay");
	useGraph_ = parent_->isResourceTrue("diskGraph");
	SetUsedFormat( parent_->getResource("diskUsedFormat") );
}

void DiskMeter::checkevent( void ) {
	getstats();
	drawfields();
}

void DiskMeter::getstats( void ) {
	uint64_t reads = 0, writes = 0;
	//  Reset to desired full-scale settings.
	total_ = maxBandwidth_;

	IntervalTimerStop();
	BSDGetDiskXFerBytes(&reads, &writes);

	/*  Adjust this to bytes/second.  */
#if defined(HAVE_DEVSTAT)
	fields_[0] = reads / IntervalTimeInSecs();
	fields_[1] = writes / IntervalTimeInSecs();
#else
	fields_[0] = (reads - prevreads_) / IntervalTimeInSecs();
	fields_[1] = (writes - prevwrites_) / IntervalTimeInSecs();
	prevreads_ = reads;
	prevwrites_ = writes;
#endif
	IntervalTimerStart();

	/*  Adjust in case of first call.  */
	if (fields_[0] < 0.0)
		fields_[0] = 0.0;
	if (fields_[1] < 0.0)
		fields_[1] = 0.0;

	/*  Adjust total_ if needed.  */
	if (fields_[0] + fields_[1] > total_)
		total_ = fields_[0] + fields_[1];

	fields_[2] = total_ - (fields_[0] + fields_[1]);
	if (fields_[0] < 0.0)
		warnx("diskmeter: fields[0] of %f is < 0!", fields_[0]);
	if (fields_[1] < 0.0)
		warnx("diskmeter: fields[1] of %f is < 0!", fields_[1]);
	if (fields_[2] < 0.0)
		warnx("diskmeter: fields[2] of %f is < 0!", fields_[2]);

	setUsed(fields_[0] + fields_[1], total_);
}