feat: implemented a pipelining system for the lobby to pipeline events through a number of segments for processing them

Server/src/main/java/uulm/teamname/marvelous/server/Lobby/pipelining/PauseSegment.java

@@ -1,2 +1,99 @@
-package uulm.teamname.marvelous.server.Lobby.pipelining;public class PauseSegment {
+package uulm.teamname.marvelous.server.Lobby.pipelining;
+
+import uulm.teamname.marvelous.gamelibrary.Tuple;
+import uulm.teamname.marvelous.gamelibrary.events.Event;
+import uulm.teamname.marvelous.gamelibrary.events.EventBuilder;
+import uulm.teamname.marvelous.gamelibrary.events.EventType;
+import uulm.teamname.marvelous.gamelibrary.requests.Request;
+import uulm.teamname.marvelous.gamelibrary.requests.RequestBuilder;
+import uulm.teamname.marvelous.gamelibrary.requests.RequestType;
+
+import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+public class PauseSegment implements Segment {
+
+    private boolean paused;
+
+    public PauseSegment(){
+        paused = false;
+    }
+
+    public void pauseGame(){
+        if(!paused)
+            paused = true;
+    }
+    public void pauseEnd(){
+        if(paused)
+            paused = false;
+    }
+
+    public boolean isPaused() {
+        return paused;
+    }
+
+
+    /**
+     * Pipelining method to process a set of requests.
+     * The list of requests will be processed according to the following rules:
+     * <ul>
+     *     <li>If there is a PauseStartRequest, the paused value will be set to true</li>
+     *     <li>Any CharacterRequests will be removed from the requests if the game is paused. These include:
+     *     <ul>
+     *         <li>MeeleAttackRequest</li>
+     *         <li>RangedAttackRequest</li>
+     *         <li>MoveRequest</li>
+     *         <li>ExchangeInfinityStoneRequest</li>
+     *         <li>UseInfinityStoneRequest</li>
+     *         <li>EndRoundRequest</li>
+     *     </ul>
+     *     </li>
+     *     <li>If a mistake is made (request is sent while pause active), the client will get an error</li>
+     *     <li>If there is a PauseStopRequest the game will be unpaused</li>
+     * </ul>
+     * @param packet
+     */
+    @Override
+    public void processRequests(List<Request> packet, List<Event> carrier, AtomicBoolean abort) {
+        // check if there is a pause request (either start or stop)
+        if (packet.contains(new RequestBuilder(RequestType.PauseStartRequest).buildGameRequest())) {
+            if (!paused) {
+                // pause the game
+                pauseGame();
+                // create a new PauseStartEvent
+                carrier.add(new EventBuilder(EventType.PauseStartEvent).buildGameEvent());
+            } else { // if the game is already paused
+                abort.set(true);
+                return;
+            }
+        } else if (packet.contains(new RequestBuilder(RequestType.PauseStopRequest).buildGameRequest())) {
+            if (paused) {
+                // pause the game
+                pauseEnd();
+                // create a new PauseStartRequest
+                carrier.add(new EventBuilder(EventType.PauseStopEvent).buildGameEvent());
+            } else { // if the game is not paused
+                abort.set(true);
+                return;
+            }
+        }
+
+        // filter the events
+        if (paused) {
+            for (Request request: packet) {
+                switch (request.type) {
+                    case MeleeAttackRequest,
+                            RangedAttackRequest,
+                            MoveRequest,
+                            ExchangeInfinityStoneRequest,
+                            UseInfinityStoneRequest,
+                            EndRoundRequest,
+                            PauseStopRequest,
+                            PauseStartRequest -> packet.remove(request);
+
+                    case DisconnectRequest, Req -> { /* do nothing */ }
+                }
+            }
+        }
+    }
 }

Server/src/main/java/uulm/teamname/marvelous/server/Lobby/pipelining/Pipeline.java

@@ -1,23 +1,65 @@
-package uulm.teamname.marvelous.server.Lobby;
+package uulm.teamname.marvelous.server.Lobby.pipelining;
 
+import uulm.teamname.marvelous.gamelibrary.Tuple;
+import uulm.teamname.marvelous.gamelibrary.events.Event;
 import uulm.teamname.marvelous.gamelibrary.requests.Request;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
 
+/**
+ * The {@link Pipeline} class pipelines {@link Request Requests} through {@link Segment Segments} to
+ * create {@link Event Events}. To add functionality without dabbling in the game library, create a new {@link Segment}.
+ */
 public class Pipeline {
 
-    private final Segment[] segments;
+    /** The segments of the pipeline, which will be executed from left to right (index 0 to segments.size()) */
+    private final ArrayList<Segment> segments;
 
-    public Pipeline(Segment[] segments) {
+    /**
-        this.segments = segments;
+     * Creates a new empty {@link Pipeline} object
+     */
+    public Pipeline() {
+        this.segments = new ArrayList<>();
     }
 
-    public void processEvents(Request[] requests) {
+    /**
-        Request[] out;
+     * Pipeline the {@link Request Requests} through all {@link Segment Segments} that are in the pipeline.
+     * The {@link Request Requests} are declared as the <b>Packet</b>. The {@link Request Requests} are filtered
+     * by each {@link Segment segment}, whereby each {@link Segment segment} takes (and thereby removes) all
+     * {@link Event events} relevant to the {@link Segment segment}. The {@link Event Events} are returned at the
+     * end of the pipeline.
+     * @param requests are the requests that are being pipelined through the pipeline
+     * @return a {@link Tuple}<{@link Boolean}, {@link Event}[]>, whereby the {@link Boolean} declares whether the
+     *         execution of the {@link Pipeline} is successful. <b>If that is the case, the events can be ignored,
+     *         and an error message can be sent to the client</b>.
+     */
+    public Tuple<Boolean, Event[]> processRequests(Request[] requests) {
+        List<Request> packet = Arrays.asList(requests);
+        List<Event> carrier = new ArrayList<>();
+        AtomicBoolean abort = new AtomicBoolean();
+        abort.set(false);
         for (Segment segment: segments) {
-            out = segment.processEvents(requests);
+            segment.processRequests(packet, carrier, abort);
+            if (packet.size() == 0 || abort.get()) {
+                break;
+            }
         }
+        return new Tuple<Boolean, Event[]> (abort.get(), carrier.toArray(new Event[0]));
     }
 
-
+    /**
+     * Adds a segment to the pipeline. Note that <b>ORDER MATTERS!</b> The first segment added will be the
+     * first segment to process events. Also note that segments <b>cannot be removed once added</b>. This is by
+     * design, as removing segments would give the pipeline runtime customizability, which it is not supposed to
+     * possess in the first place.
+     * @param toAdd is the segment that will be added to the pipeline
+     * @return the pipeline itself for chaining
+     */
+    public Pipeline addSegment(Segment toAdd) {
+        this.segments.add(toAdd);
+        return this;
+    }
 }

Server/src/main/java/uulm/teamname/marvelous/server/Lobby/pipelining/Segment.java

@@ -1,8 +1,26 @@
-package uulm.teamname.marvelous.server.Lobby;
+package uulm.teamname.marvelous.server.Lobby.pipelining;
 
+import uulm.teamname.marvelous.gamelibrary.Tuple;
 import uulm.teamname.marvelous.gamelibrary.events.Event;
 import uulm.teamname.marvelous.gamelibrary.requests.Request;
 
+import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
+
 public interface Segment {
-    public Request[] processEvents(Request[] events);
+    /**
+     * Pipelining method to process a set of requests.
+     * The list of requests will be processed according to some set of rules. Hereby,
+     * the {@link Request Requests} in the packet will be filtered out as appropriate,
+     * whereby the resulting {@link Event Events} are appended to the carrier.
+     * @param packet is a {@link List} of {@link Request Requests} that is filtered
+     *               by the {@link Segment} as appropriate
+     * @param carrier is a {@link List} of {@link Event Events} that is appended to
+     *                if new requests are generated from the execution of the {@link Segment}
+     * @param abort is an {@link AtomicBoolean} describing whether an error has occurred during the execution of
+     *         the {@link Segment} Note that <b>error</b> here does <b>not describe an execution error</b>
+     *         of the segment, but instead an error in the events passed to it, like for example moving into a Rock.
+     *         The conventional way of setting this boolean is to write {@code abort.set(true); return;}
+     */
+    public void processRequests(List<Request> packet, List<Event> carrier, AtomicBoolean abort);
 }

Server/src/test/java/uulm/teamname/marvelous/server/Lobby/pipelining/PauseSegmentTest.java

@@ -1,5 +1,44 @@
+package uulm.teamname.marvelous.server.Lobby.pipelining;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import static org.assertj.core.api.Assertions.*;
+
 import static org.mockito.Mockito.*;
 import static org.junit.jupiter.api.Assertions.*;
+
 class PauseSegmentTest {
 
+    PauseSegment pauseSegment;
+
+    @BeforeEach
+    void setUp() {
+        pauseSegment = new PauseSegment();
+    }
+
+    @Test
+    void pauseGame() {
+        assertThat(pauseSegment.isPaused()).isFalse();
+        pauseSegment.pauseGame();
+        assertThat(pauseSegment.isPaused()).isTrue();
+        pauseSegment.pauseGame();
+        assertThat(pauseSegment.isPaused()).isTrue();
+    }
+
+    @Test
+    void pauseEnd() {
+        assertThat(pauseSegment.isPaused()).isFalse();
+        pauseSegment.pauseEnd();
+        assertThat(pauseSegment.isPaused()).isFalse();
+        pauseSegment.pauseGame();
+        assertThat(pauseSegment.isPaused()).isTrue();
+        pauseSegment.pauseEnd();
+        assertThat(pauseSegment.isPaused()).isFalse();
+    }
+
+    @Test
+    void processEvents() {
+        // TODO: check that events get pipelined normally if not paused, but filtered if paused
+        // and check that events work properly
+    }
 }