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AutonomicPerfectionistAutonomicPerfectionist
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Add AutoEjectFIFO service
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-7
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4 files changed

+284
-7
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‎src/main/java/org/myrobotlab/service/AutoEjectFIFO.java‎

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package org.myrobotlab.service;
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import org.myrobotlab.framework.Service;
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import org.myrobotlab.service.config.ServiceConfig;
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import java.util.List;
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import java.util.concurrent.BlockingDeque;
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import java.util.concurrent.LinkedBlockingDeque;
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import java.util.concurrent.locks.ReadWriteLock;
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import java.util.concurrent.locks.ReentrantReadWriteLock;
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/**
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* A simple service that acts as a circular FIFO queue.
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* This queue can store a number of items, but once
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* its max capacity is reached, any attempt to add more
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* items ejects the oldest element, i.e. the head.
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* <p></p>
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* This queue is not typed, i.e. it can store any type
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* of object, with the downside that no type checking is
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* performed. This is to allow the fifo to be used
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* in any situation, since we don't currently have a way
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* to create generic services.
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*
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* @author AutonomicPerfectionist
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*/
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public class AutoEjectFIFO extends Service<ServiceConfig> {
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public static final int DEFAULT_MAX_SIZE = 50;
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/**
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* Lock used to protect the fifo queue,
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* used instead of synchronized block to allow
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* multiple simultaneous readers so long as there
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* is no writer writing to the queue.
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*/
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private final ReadWriteLock lock = new ReentrantReadWriteLock();
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/**
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* The actual queue, whose initial maximum size is set to
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* {@link #DEFAULT_MAX_SIZE}.
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*/
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private BlockingDeque<Object> fifo = new LinkedBlockingDeque<>(DEFAULT_MAX_SIZE);
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/**
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* Constructor of service, reservedkey typically is a services name and inId
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* will be its process id
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*
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* @param reservedKey the service name
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* @param inId process id
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*/
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public AutoEjectFIFO(String reservedKey, String inId) {
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super(reservedKey, inId);
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}
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/**
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* Sets the size at which the FIFO will begin evicting
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* elements. If smaller than the current number of items,
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* then elements will be silently evicted.
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* @param size The new max size
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*/
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public void setMaxSize(int size) {
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lock.writeLock().lock();
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BlockingDeque<Object> newFifo = new LinkedBlockingDeque<>(size);
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newFifo.addAll(fifo);
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fifo = newFifo;
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lock.writeLock().unlock();
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}
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/**
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* Add a new element to the FIFO, if
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* it's full then this will trigger an
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* eviction
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* @param item The new item to be added to the tail
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*/
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public void add(Object item) {
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lock.writeLock().lock();
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try {
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if (!fifo.offer(item)) {
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Object head = fifo.removeFirst();
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invoke("publishEviction", head);
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fifo.add(item);
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}
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invoke("publishItemAdded", item);
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} catch (Exception e) {
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error(e);
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} finally {
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lock.writeLock().unlock();
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}
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}
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public void clear() {
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lock.writeLock().lock();
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fifo.clear();
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lock.writeLock().unlock();
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invoke("publishClear");
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}
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public List<Object> getAll() {
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lock.readLock().lock();
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List<Object> ret = List.copyOf(fifo);
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lock.readLock().unlock();
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invoke("publishAll", ret);
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return ret;
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}
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public Object getHead() {
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lock.readLock().lock();
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Object head = fifo.peek();
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lock.readLock().unlock();
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invoke("publishHead", head);
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return head;
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}
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public Object getTail() {
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lock.readLock().lock();
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Object tail = fifo.peekLast();
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lock.readLock().unlock();
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invoke("publishTail", tail);
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return tail;
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}
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public Object publishItemAdded(Object item) {
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return item;
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}
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public void publishClear() {
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// Do nothing
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}
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public List<Object> publishAll(List<Object> items) {
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return items;
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}
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public Object publishHead(Object head) {
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return head;
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}
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public Object publishTail(Object tail) {
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return tail;
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}
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public Object publishEviction(Object evicted) {
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return evicted;
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}
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}

‎src/main/java/org/myrobotlab/service/TestCatcher.java‎

Lines changed: 22 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -108,6 +108,8 @@ public Ball() {
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public BlockingQueue<String> strings = new LinkedBlockingDeque<>();
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public BlockingQueue<Object> objects = new LinkedBlockingQueue<>();
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/**
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* awesome override to simulate remote services - e.g. in
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* Serial.addByteListener
@@ -168,6 +170,9 @@ public void clear() {
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pinSet.clear();
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methodsCalled.clear();
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longs.clear();
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integers.clear();
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strings.clear();
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objects.clear();
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}
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public Message getMsg(long timeout) throws InterruptedException {
@@ -264,21 +269,25 @@ public void checkMsg(long timeout, String method, Object... checkParms) throws I
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throw new IOException(String.format("expected null parameters - got non-null"));
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}
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// Never reached since msg.data.length is accessed above and would throw NPE
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// Probably don't need this if we can assume that msg.data is always non-null
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// and may just be empty
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if (checkParms != null && msg.data == null) {
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log.error("{}", msg);
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throw new IOException(String.format("expected non null parameters - got null"));
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throw new IOException("expected non null parameters - got null");
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}
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if (!method.equals(msg.method)) {
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log.error("{}", msg);
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throw new IOException(String.format("unlike methods - expected %s got %s", method, msg.method));
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}
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for (int i = 0; i < checkParms.length; ++i) {
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Object expected = checkParms[i];
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Object got = msg.data[i];
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if (!expected.equals(got)) {
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throw new IOException(String.format("unlike methods - expected %s got %s", method, msg.method));
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if (checkParms != null) {
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for (int i = 0; i < checkParms.length; ++i) {
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Object expected = checkParms[i];
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Object got = msg.data[i];
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if (!expected.equals(got)) {
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throw new IOException(String.format("unlike methods - expected %s got %s", method, msg.method));
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}
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}
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}
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@@ -331,6 +340,12 @@ public double onDouble(double data) {
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return data;
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}
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public Object onObject(Object data) {
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log.info("onObject {}", data);
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objects.add(data);
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return data;
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}
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public int waitForThis(int data, long sleep) {
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sleep(sleep);
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log.info("waitForThis {}", data);

‎src/main/java/org/myrobotlab/service/meta/AutoEjectFIFOMeta.java‎

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package org.myrobotlab.service.meta;
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import org.myrobotlab.service.meta.abstracts.MetaData;
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public class AutoEjectFIFOMeta extends MetaData {
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public AutoEjectFIFOMeta() {
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addDescription("A simple sized FIFO that will auto-eject the oldest element when it reaches the given max size.");
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}
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}

‎src/test/java/org/myrobotlab/service/AutoEjectFIFOTest.java‎

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package org.myrobotlab.service;
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import org.junit.After;
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import org.junit.Before;
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import org.junit.Test;
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import org.myrobotlab.test.AbstractTest;
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import java.io.IOException;
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import java.util.ArrayList;
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import java.util.List;
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import static org.junit.Assert.assertArrayEquals;
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import static org.junit.Assert.assertEquals;
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public class AutoEjectFIFOTest extends AbstractTest {
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private AutoEjectFIFO fifo;
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private TestCatcher catcher;
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@Before
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public void createService() throws Exception {
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fifo = (AutoEjectFIFO) Runtime.start("fifo", "AutoEjectFIFO");
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catcher = (TestCatcher) Runtime.start("catcher", "TestCatcher");
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catcher.clear();
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fifo.clear();
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}
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@After
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public void releaseService() {
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Runtime.release(fifo.getFullName());
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Runtime.release(catcher.getFullName());
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}
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@Test
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public void testAdd10() throws IOException, InterruptedException {
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catcher.subscribe(fifo.getFullName(), "publishItemAdded", "onInteger");
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sleep(50);
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List<Integer> ints = new ArrayList<>();
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for (int i = 0; i < 10; i ++) {
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fifo.add(i);
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ints.add(i);
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}
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catcher.waitForMsgs(10, 2000);
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assertEquals(10, catcher.integers.size());
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assertEquals(0, fifo.getHead());
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// Last element was 9 since we added 0-9, not 1-10
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assertEquals(9, fifo.getTail());
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assertArrayEquals(ints.toArray(), fifo.getAll().toArray());
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}
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@Test
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public void testAddMax() throws IOException, InterruptedException {
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catcher.subscribe(fifo.getFullName(), "publishItemAdded", "onInteger");
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sleep(50);
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for (int i = 0; i < AutoEjectFIFO.DEFAULT_MAX_SIZE; i ++) {
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fifo.add(i);
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}
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catcher.waitForMsgs(AutoEjectFIFO.DEFAULT_MAX_SIZE, 2000);
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assertEquals(AutoEjectFIFO.DEFAULT_MAX_SIZE, catcher.integers.size());
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assertEquals(0, fifo.getHead());
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assertEquals(AutoEjectFIFO.DEFAULT_MAX_SIZE - 1, fifo.getTail());
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}
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@Test
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public void testAddMaxPlusOne() throws IOException, InterruptedException {
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catcher.subscribe(fifo.getFullName(), "publishItemAdded", "onInteger");
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catcher.subscribe(fifo.getFullName(), "publishEviction", "onObject");
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sleep(50);
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for (int i = 0; i < AutoEjectFIFO.DEFAULT_MAX_SIZE + 1; i ++) {
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fifo.add(i);
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}
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catcher.waitForMsgs(AutoEjectFIFO.DEFAULT_MAX_SIZE + 2, 2000);
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assertEquals(AutoEjectFIFO.DEFAULT_MAX_SIZE + 1, catcher.integers.size());
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assertEquals(1, catcher.objects.size());
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assertEquals(1, fifo.getHead());
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assertEquals(AutoEjectFIFO.DEFAULT_MAX_SIZE, fifo.getTail());
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}
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@Test
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public void testAddMaxPlusTwo() throws IOException, InterruptedException {
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catcher.subscribe(fifo.getFullName(), "publishItemAdded", "onInteger");
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catcher.subscribe(fifo.getFullName(), "publishEviction", "onObject");
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sleep(50);
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for (int i = 0; i < AutoEjectFIFO.DEFAULT_MAX_SIZE + 2; i ++) {
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fifo.add(i);
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}
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// Two more adds plus 2 evictions
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catcher.waitForMsgs(AutoEjectFIFO.DEFAULT_MAX_SIZE + 4, 2000);
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assertEquals(AutoEjectFIFO.DEFAULT_MAX_SIZE + 2, catcher.integers.size());
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assertEquals(2, catcher.objects.size());
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assertEquals(2, fifo.getHead());
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assertEquals(AutoEjectFIFO.DEFAULT_MAX_SIZE + 1, fifo.getTail());
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}
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}

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