urweb/src/main/java/at/acdp/urweb/sclient/URLog.java

package at.acdp.urweb.sclient;

import at.acdp.urweb.sclient.data.IJsonObject;
import at.acdp.urweb.sclient.data.LogHolder;

public class URLog {
    private final static int LENGTH = 100;
    private static LogHolder[] list = new LogHolder[LENGTH];
    private static int pos = 0;

    public static void add(IJsonObject jo) {
        synchronized (list) {
            String type = jo.getClass().getSimpleName();
            list[++pos % LENGTH] = new LogHolder(type, jo);
        }
    }

    public static LogEntries get(int from) {
        from %= LENGTH;
        int to = pos % LENGTH;
        synchronized (list) {
            int length = to - from;
            if (from > to) {
                var ret = new LogHolder[LENGTH - from + to];
                System.arraycopy(list, from, ret, 0, LENGTH - from);
                System.arraycopy(list, 0, ret, LENGTH - from, to);
                return new LogEntries(ret, pos);
            } else {
                var ret = new LogHolder[length];
                System.arraycopy(list, from, ret, 0, length);
                return new LogEntries(ret, pos);
            }
        }
    }
}