Output data from javascriptrrd for use with D3js

rrd2D3.js

// return an array of objects containing D3elements, one per DS
//
// data = [
//         {
//           name: <DS name>,
//  		 values: [{ date: <timestamp>, value: 1}, { date: <timestamp>, value: 2}]
//         },
//         {
//           name: <DS name>,
//  		 values: [{ date: <timestamp>, value: 1}, { date: <timestamp>, value: 2}]
//         }
//        ];

function rrdRRA2D3Obj(rrd_file,rra_idx,ds_list,want_rounding) {
	var rra=rrd_file.getRRA(rra_idx);
	var rra_rows=rra.getNrRows();
	var last_update=rrd_file.getLastUpdate();
	var step=rra.getStep();
	if (want_rounding!=false) {
		// round last_update to step
		// so that all elements are sync
		last_update-=(last_update%step);
	}

	var first_el=last_update-(rra_rows-1)*step;

	var out_el = [];

	var ds_list_len = ds_list.length;
	for (var ds_list_idx=0; ds_list_idx<ds_list_len; ++ds_list_idx) {
		var ds_id=ds_list[ds_list_idx];
		var ds=rrd_file.getDS(ds_id);
		var ds_name=ds.getName();
		var ds_idx=ds.getIdx();

		var timestamp=first_el;
		var ds_series=[];
		for (var i=0;i<rra_rows;i++) {
			var el=rra.getEl(i,ds_idx);
			if (el != undefined) {
				if (+el > 213000000000000) { // remove erroneous spikes from RRD data
					el = 0;
				}
				// Convert timestamp to JS ticks
				ds_series.push( { "date": timestamp * 1000, "value": +el } );
			} else {
				// Convert timestamp to JS ticks, return null for missing values
				ds_series.push( { "date": timestamp * 1000, "value": null } );
			}
			timestamp+=step;
		} // end for

		var ds_name=ds.getName();

		out_el.push({"name": ds_name,
					 "values": ds_series});

	} //end for ds_list_idx
	return out_el;
}

function rfs_format_time(s) {
	if (s<120) {
		return s+"s";
	} else {
		var s60=s%60;
		var m=(s-s60)/60;
		if ((m<10) && (s60>9)) {
			return m+":"+s60+" min";
		} if (m<120) {
			return m+" min";
		} else {
			var m60=m%60;
			var h=(m-m60)/60;
			if ((h<12) && (m60>9)) {
				return h+":"+m60+" hrs";
			} if (h<48) {
				return h+" hrs";
			} else {
				var h24=h%24;
				var d=(h-h24)/24;
				if ((d<7) && (h24>0)) {
					return d+" days "+h24+"h";
				} if (d<60) {
					return d+" days";
				} else {
					var d30=d%30;
					var mt=(d-d30)/30;
					return mt+" months";
				}
			}
		}

	}
}