private static void updateDataSources(String rrdPath, Sampleable[] sampleables)
throws IOException {
for (Sampleable sampleable : sampleables) {
LOG.warn("Updating RRDB structure, adding: " + sampleable.getName());
RrdToolkit.addDatasource(rrdPath, createDsDef(sampleable), true);
}
}
private static Sampleable[] checkDataSources(String rrdPath, Sampleable[] sampleables)
throws IOException {
RrdDb rrdDb = new RrdDb(rrdPath, true);
List<Sampleable> missing = new ArrayList<Sampleable>();
for (Sampleable sampleable : sampleables) {
if (rrdDb.getDatasource(sampleable.getName()) == null) {
missing.add(sampleable);
}
}
rrdDb.close();
return missing.toArray(new Sampleable[missing.size()]);
}
/**
* Adds (partial) transparency to a sampleable. This decorator multiplies the alpha channel of the
* base sampleable by an opacity factor, {@code alpha}. If the base sampleable is opaque, then
* {@code alpha} gives the opacity of the result, but to the extent that the base sampleable is
* semi-transparent, {@code alpha} applies additional transparency on top of that by multiplying
* the alpha at each point.
*
* @param alpha the opacity of the resulting sampleable
* @param base the sampleable to make partially transparent
* @return the partially transparent sampleable
*/
public static Sampleable addTransparency(double alpha, Sampleable base) {
return new AbstractSampleable(base.getBoundingBox()) {
@Override
public Color getColorAt(Point<Double> point) {
Color c = base.getColorAt(point);
return Colors.rgba(c.red(), c.green(), c.blue(), alpha * c.alpha());
}
};
}
/**
* Scales a sampleable by the given factor. The position of the origin is fixed.
*
* @param factor the factor to scale by
* @param base the sampleable to scale
* @return the scaled sampleable
*/
public static Sampleable scale(double factor, Sampleable base) {
BoundingBox bb = base.getBoundingBox();
return new AbstractSampleable(
factor * bb.top(), factor * bb.bottom(),
factor * bb.left(), factor * bb.right()) {
@Override
public Color getColorAt(Point<Double> point) {
return base.getColorAt(point.scaleBy(1 / factor));
}
};
}
private static DsDef createDsDef(Sampleable sampleable) {
return new DsDef(sampleable.getName(), sampleable.getType(), 120 * STEP_SIZE, NaN, NaN);
}