org.eclipse.kapua.kura.simulator.generator.Generators Maven / Gradle / Ivy

/*******************************************************************************
 * Copyright (c) 2017 Red Hat Inc and others.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Red Hat Inc - initial API and implementation
 *******************************************************************************/
package org.eclipse.kapua.kura.simulator.generator;

import java.time.Duration;
import java.time.Instant;
import java.util.Collections;
import java.util.Map;
import java.util.function.Function;
import java.util.function.ToDoubleFunction;

import org.eclipse.kapua.kura.simulator.app.Application;
import org.eclipse.kapua.kura.simulator.app.ApplicationContext;
import org.eclipse.kapua.kura.simulator.app.Descriptor;
import org.eclipse.kapua.kura.simulator.app.Handler;
import org.eclipse.kapua.kura.simulator.app.data.SimplePeriodicGenerator;

public final class Generators {

    private Generators() {
    }

    public static Function sine(final Duration period, final double amplitude, final double offset, final Short shift) {
        final ToDoubleFunction func = sineDouble(period, amplitude, offset, shift);
        return timestamp -> func.applyAsDouble(timestamp);
    }

    public static ToDoubleFunction sineDouble(final Duration period, final double amplitude, final double offset, final Short shift) {
        final double freq = 1.0 / period.toMillis() * Math.PI * 2.0;
        if (shift == null) {
            return (timestamp) -> Math.sin(freq * timestamp.toEpochMilli()) * amplitude + offset;
        } else {
            final double radShift = Math.toRadians(shift);
            return (timestamp) -> Math.sin(freq * timestamp.toEpochMilli() + radShift) * amplitude + offset;
        }
    }

    public static Function sineBetween(final Duration period, final double lower, final double upper, final Short shift) {
        final ToDoubleFunction func = sineDoubleBetween(period, lower, upper, shift);
        return timestamp -> func.applyAsDouble(timestamp);
    }

    public static ToDoubleFunction sineDoubleBetween(final Duration period, final double lower, final double upper, final Short shift) {
        final double delta = Math.abs(upper - lower);
        final double amplitude = delta / 2.0D;
        final double offset = amplitude + Math.min(lower, upper);
        return sineDouble(period, amplitude, offset, shift);
    }

    public static Function> fromSingle(final String name, final Function function) {
        return function.andThen(value -> Collections.singletonMap(name, value));
    }

    public static Application simpleDataApplication(final String applicationId, final GeneratorScheduler scheduler, final String metricName,
            final Function metricFunction) {
        return createApplication(applicationId, scheduler, "metrics", Collections.singletonMap(metricName, metricFunction));
    }

    public static Application createApplication(final String applicationId, final GeneratorScheduler scheduler, final String dataTopic,
            final String metricName, final Function metricFunction) {
        return createApplication(applicationId, scheduler, dataTopic, Collections.singletonMap(metricName, metricFunction));
    }

    public static Application createApplication(final String applicationId, final GeneratorScheduler scheduler, final String dataTopic,
            final Map> generators) {

        final Descriptor descriptor = new Descriptor(applicationId);

        return new Application() {

            @Override
            public Descriptor getDescriptor() {
                return descriptor;
            }

            @Override
            public Handler createHandler(final ApplicationContext context) {
                return new SimplePeriodicGenerator(context, scheduler, dataTopic, generators);
            }

        };
    }
}