[wip] initial commit

extracted useful snippets from other projects

src/de/pzzz/vertx/worker/QueueProcessingStatus.java

@@ -0,0 +1,70 @@
+package de.pzzz.vertx.worker;
+
+import java.io.Serializable;
+import java.util.LinkedList;
+import java.util.Queue;
+
+public class QueueProcessingStatus<T> implements Serializable {
+	private static final long serialVersionUID = 7560765077464782742L;
+
+	private transient Queue<T> requestsToProcess = new LinkedList<>();
+	private boolean calculate = false;
+	private int runningCalculations = 0;
+
+	public T startProcessing() {
+		if (requestsToProcess.isEmpty()) {
+			throw new IllegalStateException("No requests to process!");
+		}
+		calculate = true;
+		runningCalculations = 1;
+		return requestsToProcess.poll();
+	}
+
+	public void stopProcessing() {
+		calculate = false;
+	}
+
+	public boolean hasNext() {
+		return !requestsToProcess.isEmpty();
+	}
+
+	public T processNext() {
+		runningCalculations += 1;
+		return requestsToProcess.poll();
+	}
+
+	public void complete() {
+		runningCalculations -= 1;
+		if (runningCalculations == 0 && requestsToProcess.isEmpty()) {
+			calculate = false;
+		}
+	}
+
+	public void enqueue(final T request) {
+		requestsToProcess.add(request);
+	}
+
+	public void clear() {
+		requestsToProcess.clear();
+	}
+
+	public boolean isCalculate() {
+		return calculate;
+	}
+
+	public void setCalculate(final boolean calculate) {
+		this.calculate = calculate;
+	}
+
+	public int getRunningCalculations() {
+		return runningCalculations;
+	}
+
+	public void setRunningCalculations(final int running) {
+		this.runningCalculations = running;
+	}
+
+	public int getQueueLength() {
+		return requestsToProcess.size();
+	}
+}