view flys-client/src/main/java/de/intevation/flys/client/shared/DoubleUtils.java @ 5779:ebec12def170

Datacage: Add a pool of builders to make it multi threadable. XML DOM is not thread safe. Therefore the old implementation only allowed one thread to use the builder at a time. As the complexity of the configuration has increased over time this has become a bottleneck of the whole application because it took quiet some time to build a result. Furthermore the builder code path is visited very frequent. So many concurrent requests were piled up resulting in long waits for the users. To mitigate this problem a round robin pool of builders is used now. Each of the pooled builders has an independent copy of the XML template and can be run in parallel. The number of builders is determined by the system property 'flys.datacage.pool.size'. It defaults to 4.
author Sascha L. Teichmann <teichmann@intevation.de>
date Sun, 21 Apr 2013 12:48:09 +0200
parents 51ed89b754ae
children
line wrap: on
line source
package de.intevation.flys.client.shared;


public final class DoubleUtils {

    public static final String DEFAULT_DELIM = " ";


    private DoubleUtils() {
    }


    public static Double getDouble(String value) {
        try {
            return Double.valueOf(value);
        }
        catch (NumberFormatException nfe) {
            // do nothing
        }

        return null;
    }


    public static double[] getMinMax(String value) {
        return getMinMax(value, DEFAULT_DELIM);
    }


    public static double[] getMinMax(String value, String delim) {
        if (value == null) {
            return null;
        }

        String[] values = value.split(delim);

        int     len = values != null ? values.length : 0;
        double[] mm = new double[] { Double.MAX_VALUE, -Double.MAX_VALUE };

        for (int i = 0; i < len; i++) {
            Double d = getDouble(values[i]);

            if (d != null) {
                mm[0] = mm[0] < d ? mm[0] : d;
                mm[1] = mm[1] > d ? mm[1] : d;
            }
        }

        return mm[0] != Double.MAX_VALUE && mm[1] != -Double.MAX_VALUE
            ? mm
            : null;
    }

    /** toIndex is not inclusive, fromIndex is. */
    static void fill(double[] array, int fromIndex, int toIndex, double val) {
        for (int i = fromIndex; i < toIndex; i++) {
            array[i] = val;
        }
    }

    /** @see java.util.Arrays.copyOf */
    public static double[] copyOf(double[] toCopy, int newLen) {
        double[] nArray = new double[newLen];

        if (toCopy == null) {
            fill(nArray, 0, nArray.length, 0d);
            return nArray;
        }

        int goTo = (newLen < toCopy.length)
            ? newLen
            : toCopy.length;

        for (int i = 0; i < goTo; i++) {
            nArray[i] = toCopy[i];
        }
        fill (nArray, goTo, nArray.length, 0d);
        return nArray;
    }
}
// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :

http://dive4elements.wald.intevation.org