Add basic networking

pom.xml

@@ -38,19 +38,19 @@
 					</execution>
 				</executions>
 			</plugin>
-				<plugin>
-					<groupId>org.apache.maven.plugins</groupId>
-					<artifactId>maven-source-plugin</artifactId>
-					<version>3.3.0</version>
-					<executions>
-						<execution>
-							<id>attach-sources</id>
-							<goals>
-								<goal>jar</goal>
-							</goals>
-						</execution>
-					</executions>
-				</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-source-plugin</artifactId>
+				<version>3.3.0</version>
+				<executions>
+					<execution>
+						<id>attach-sources</id>
+						<goals>
+							<goal>jar</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
 		</plugins>
 	</build>
 
@@ -61,5 +61,10 @@
 			<version>5.10.1</version>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.java-websocket</groupId>
+			<artifactId>Java-WebSocket</artifactId>
+			<version>1.5.4</version>
+		</dependency>
 	</dependencies>
 </project>

src/main/java/me/mrletsplay/shareclientcore/connection/Change.java

@@ -0,0 +1,5 @@
+package me.mrletsplay.shareclientcore.connection;
+
+import me.mrletsplay.shareclientcore.document.Char;
+
+public record Change(int document, ChangeType type, Char character) {}

src/main/java/me/mrletsplay/shareclientcore/connection/ChangeType.java

@@ -0,0 +1,9 @@
+package me.mrletsplay.shareclientcore.connection;
+
+public enum ChangeType {
+
+	ADD,
+	REMOVE,
+	;
+
+}

src/main/java/me/mrletsplay/shareclientcore/connection/DummyConnection.java

@@ -0,0 +1,32 @@
+package me.mrletsplay.shareclientcore.connection;
+
+import java.io.IOException;
+
+public class DummyConnection implements RemoteConnection {
+
+	@Override
+	public void connect() throws IOException, InterruptedException {
+
+	}
+
+	@Override
+	public int retrieveSiteID() {
+		return 0;
+	}
+
+	@Override
+	public void send(Change... changes) {
+
+	}
+
+	@Override
+	public void addListener(RemoteListener listener) {
+
+	}
+
+	@Override
+	public void removeListener(RemoteListener listener) {
+
+	}
+
+}

src/main/java/me/mrletsplay/shareclientcore/connection/RemoteConnection.java

@@ -0,0 +1,20 @@
+package me.mrletsplay.shareclientcore.connection;
+
+import java.io.IOException;
+
+/**
+ * Represents a connection to a remote user or server
+ */
+public interface RemoteConnection {
+
+	public void connect() throws IOException, InterruptedException;
+
+	public int retrieveSiteID();
+
+	public void send(Change... changes);
+
+	public void addListener(RemoteListener listener);
+
+	public void removeListener(RemoteListener listener);
+
+}

src/main/java/me/mrletsplay/shareclientcore/connection/RemoteListener.java

@@ -0,0 +1,10 @@
+package me.mrletsplay.shareclientcore.connection;
+
+/**
+ * Represents something that can receive remote changes
+ */
+public interface RemoteListener {
+
+	public void onRemoteChange(Change... changes);
+
+}

src/main/java/me/mrletsplay/shareclientcore/connection/WebSocketConnection.java

@@ -0,0 +1,146 @@
+package me.mrletsplay.shareclientcore.connection;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.net.URI;
+import java.nio.ByteBuffer;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Random;
+import java.util.Set;
+
+import org.java_websocket.client.WebSocketClient;
+import org.java_websocket.handshake.ServerHandshake;
+
+import me.mrletsplay.shareclientcore.document.Char;
+import me.mrletsplay.shareclientcore.document.Identifier;
+
+public class WebSocketConnection implements RemoteConnection {
+
+	private WSClient client;
+	private Set<RemoteListener> listeners;
+
+	public WebSocketConnection(URI uri, Map<String, String> httpHeaders) {
+		this.client = new WSClient(uri, httpHeaders);
+		this.listeners = new HashSet<>();
+	}
+
+	public WebSocketConnection(URI uri) {
+		this(uri, null);
+	}
+
+	@Override
+	public void connect() throws IOException, InterruptedException {
+		if(!client.connectBlocking()) throw new IOException("Failed to connect to WebSocket server");
+	}
+
+	@Override
+	public int retrieveSiteID() {
+		// TODO: implement
+		return new Random().nextInt();
+	}
+
+	@Override
+	public void send(Change... changes) {
+		for(Change c : changes) {
+			client.send(serialize(c));
+		}
+	}
+
+	@Override
+	public void addListener(RemoteListener listener) {
+		listeners.add(listener);
+	}
+
+	@Override
+	public void removeListener(RemoteListener listener) {
+		listeners.remove(listener);
+	}
+
+	private byte[] serialize(Change change) {
+		try {
+			ByteArrayOutputStream bOut = new ByteArrayOutputStream();
+			DataOutputStream dOut = new DataOutputStream(bOut);
+			dOut.writeInt(change.document());
+			dOut.writeUTF(change.type().name());
+
+			Char ch = change.character();
+			dOut.writeInt(ch.position().length);
+			for(int i = 0; i < ch.position().length; i++) {
+				Identifier id = ch.position()[i];
+				dOut.writeInt(id.digit());
+				dOut.writeInt(id.site());
+			}
+
+			dOut.writeInt(ch.lamport());
+			dOut.writeChar(ch.value());
+			return bOut.toByteArray();
+		}catch(IOException e) {
+			throw new RuntimeException("Something went very wrong", e);
+		}
+	}
+
+	private Change deserialize(byte[] bytes) {
+		try {
+			DataInputStream dIn = new DataInputStream(new ByteArrayInputStream(bytes));
+			int document = dIn.readInt();
+			ChangeType type = ChangeType.valueOf(dIn.readUTF());
+
+			Identifier[] pos = new Identifier[dIn.readInt()];
+			for(int i = 0; i < pos.length; i++) {
+				pos[i] = new Identifier(dIn.readInt(), dIn.readInt());
+			}
+
+			int lamport = dIn.readInt();
+			char value = dIn.readChar();
+			return new Change(document, type, new Char(pos, lamport, value));
+		}catch(IllegalArgumentException e) {
+			throw new IllegalArgumentException("Failed to deserialize change", e);
+		}catch(IOException e) {
+			throw new RuntimeException("Something went very wrong", e);
+		}
+	}
+
+	private class WSClient extends WebSocketClient {
+
+		public WSClient(URI serverUri) {
+			super(serverUri);
+		}
+
+		public WSClient(URI serverUri, Map<String, String> httpHeaders) {
+			super(serverUri, httpHeaders);
+		}
+
+		@Override
+		public void onOpen(ServerHandshake handshakedata) {
+			// TODO: request site id
+		}
+
+		@Override
+		public void onMessage(String message) {
+			System.out.println("Got text message: " + message);
+		}
+
+		@Override
+		public void onMessage(ByteBuffer bytes) {
+			byte[] bytesArray = new byte[bytes.remaining()];
+			bytes.get(bytesArray);
+			listeners.forEach(l -> l.onRemoteChange(deserialize(bytesArray)));
+		}
+
+		@Override
+		public void onClose(int code, String reason, boolean remote) {
+			// TODO: handle
+		}
+
+		@Override
+		public void onError(Exception ex) {
+			// TODO: handle
+		}
+
+	}
+
+}

src/main/java/me/mrletsplay/shareclientcore/document/ArrayCharBag.java

@@ -23,7 +23,7 @@ public class ArrayCharBag implements CharBag {
 		// TODO: use binary search
 		while(i < chars.size() && Util.comparePositions(chars.get(i).position(), character.position()) < 0) i++;
 		if(i == chars.size() || Util.comparePositions(chars.get(i).position(), character.position()) != 0) return -1;
-		chars.remove(character);
+		chars.remove(i);
 		return i;
 	}
 

src/main/java/me/mrletsplay/shareclientcore/document/Char.java

@@ -1,8 +1,31 @@
 package me.mrletsplay.shareclientcore.document;
 
+import java.util.Arrays;
+import java.util.Objects;
+
 public record Char(Identifier[] position, int lamport, char value) {
 
 	public static final Char START_OF_DOCUMENT = new Char(new Identifier[] { new Identifier(1, 0) }, 0, '^');
 	public static final Char END_OF_DOCUMENT = new Char(new Identifier[] { new Identifier(Util.BASE - 1, 0) }, 0, '$');
 
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+		result = prime * result + Arrays.hashCode(position);
+		result = prime * result + Objects.hash(lamport, value);
+		return result;
+	}
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		Char other = (Char) obj;
+		return lamport == other.lamport && Arrays.equals(position, other.position) && value == other.value;
+	}
+
 }

src/main/java/me/mrletsplay/shareclientcore/document/DocumentListener.java

@@ -0,0 +1,12 @@
+package me.mrletsplay.shareclientcore.document;
+
+/**
+ * Represents something that can receive local changes
+ */
+public interface DocumentListener {
+
+	public void onInsert(int index, char character);
+
+	public void onDelete(int index);
+
+}

src/main/java/me/mrletsplay/shareclientcore/document/SharedDocument.java

@@ -1,17 +1,34 @@
 package me.mrletsplay.shareclientcore.document;
 
-public class Document {
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
 
+import me.mrletsplay.shareclientcore.connection.Change;
+import me.mrletsplay.shareclientcore.connection.ChangeType;
+import me.mrletsplay.shareclientcore.connection.RemoteConnection;
+import me.mrletsplay.shareclientcore.connection.RemoteListener;
+
+public class SharedDocument implements RemoteListener {
+
+	private RemoteConnection connection;
 	private CharBag charBag;
+	private int document;
 	private int site;
 	private int lamport;
+	private Set<DocumentListener> listeners;
+
+	public SharedDocument(RemoteConnection connection) {
+		this.connection = connection;
+		connection.addListener(this);
 
-	public Document(int site) {
 		this.charBag = new ArrayCharBag();
 		charBag.add(Char.START_OF_DOCUMENT);
 		charBag.add(Char.END_OF_DOCUMENT);
 
-		this.site = site;
+		this.document = 0; // TODO: implement
+		this.site = connection.retrieveSiteID();
+		this.listeners = new HashSet<>();
 	}
 
 	/**
@@ -25,13 +42,18 @@ public class Document {
 		Char charBefore = charBag.get(index);
 		Char charAfter = charBag.get(index +1);
 
-		for(char c : str.toCharArray()) {
+		char[] chars = str.toCharArray();
+		Change[] changes = new Change[chars.length];
+		for(int i = 0; i < chars.length; i++) {
 			Identifier[] newPos = Util.generatePositionBetween(charBefore.position(), charAfter.position(), site);
 			lamport++;
-			Char ch = new Char(newPos, lamport, c);
+			Char ch = new Char(newPos, lamport, chars[i]);
 			charBag.add(ch);
+			changes[i] = new Change(document, ChangeType.ADD, ch);
 			charBefore = ch;
 		}
+
+		connection.send(changes);
 	}
 
 	/**
@@ -41,11 +63,17 @@ public class Document {
 	 */
 	public void localDelete(int index, int n) {
 		if(index < 0 || index + n >= charBag.size() - 1) throw new IllegalArgumentException("Index out of bounds");
+		if(n == 0) return;
 
+		Change[] changes = new Change[n];
 		while(n-- > 0) {
 			// TODO: more efficient implementation (e.g. range delete in CharBag)
-			charBag.remove(charBag.get(index + 1));
+			Char toRemove = charBag.get(index + 1);
+			changes[n] = new Change(document, ChangeType.REMOVE, toRemove);
+			charBag.remove(toRemove);
 		}
+
+		connection.send(changes);
 	}
 
 	/**
@@ -55,7 +83,10 @@ public class Document {
 	 */
 	public int remoteInsert(Char c) {
 		lamport = Math.max(c.lamport(), lamport) + 1;
-		return charBag.add(c);
+		int index = charBag.add(c);
+		if(index == -1) return -1;
+		listeners.forEach(l -> l.onInsert(index - 1, c.value()));
+		return index;
 	}
 
 	/**
@@ -65,7 +96,10 @@ public class Document {
 	 */
 	public int remoteDelete(Char c) {
 		lamport = Math.max(c.lamport(), lamport) + 1;
-		return charBag.remove(c);
+		int index = charBag.remove(c);
+		if(index == -1) return -1;
+		listeners.forEach(l -> l.onDelete(index - 1));
+		return index;
 	}
 
 	public CharBag getCharBag() {
@@ -77,4 +111,23 @@ public class Document {
 		return contents.substring(1, contents.length() - 1);
 	}
 
+	public void addListener(DocumentListener listener) {
+		listeners.add(listener);
+	}
+
+	public void removeListener(DocumentListener listener) {
+		listeners.add(listener);
+	}
+
+	@Override
+	public void onRemoteChange(Change... changes) {
+		for(Change c : changes) {
+			System.out.println("Change: " + c + " | " + Arrays.toString(c.character().position()));
+			switch(c.type()) {
+				case ADD -> remoteInsert(c.character());
+				case REMOVE -> remoteDelete(c.character());
+			}
+		}
+	}
+
 }

src/test/java/me/mrletsplay/shareclientcore/DocumentTest.java

@@ -5,13 +5,14 @@ import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import org.junit.jupiter.api.Test;
 
-import me.mrletsplay.shareclientcore.document.Document;
+import me.mrletsplay.shareclientcore.connection.DummyConnection;
+import me.mrletsplay.shareclientcore.document.SharedDocument;
 
 public class DocumentTest {
 
 	@Test
 	public void testLocalInsert() {
-		Document doc = new Document(1);
+		SharedDocument doc = new SharedDocument(new DummyConnection());
 		doc.localInsert(0, "Hello");
 		assertEquals("Hello", doc.getContents());
 		doc.localInsert(5, " World");
@@ -22,7 +23,7 @@ public class DocumentTest {
 
 	@Test
 	public void testLocalInsertInvalidIndexFails() {
-		Document doc = new Document(1);
+		SharedDocument doc = new SharedDocument(new DummyConnection());
 		doc.localInsert(0, "Hello");
 		assertThrows(IllegalArgumentException.class, () -> doc.localInsert(-1, "Test"));
 		assertThrows(IllegalArgumentException.class, () -> doc.localInsert(6, "Test"));
@@ -30,7 +31,7 @@ public class DocumentTest {
 
 	@Test
 	public void testLocalDelete() {
-		Document doc = new Document(1);
+		SharedDocument doc = new SharedDocument(new DummyConnection());
 		doc.localInsert(0, "Hello World!");
 		doc.localDelete(5, 6);
 		assertEquals("Hello!", doc.getContents());
@@ -38,7 +39,7 @@ public class DocumentTest {
 
 	@Test
 	public void testLocalDeleteInvalidIndexFails() {
-		Document doc = new Document(1);
+		SharedDocument doc = new SharedDocument(new DummyConnection());
 		doc.localInsert(0, "Hello World!");
 		assertThrows(IllegalArgumentException.class, () -> doc.localDelete(-1, 10));
 		assertThrows(IllegalArgumentException.class, () -> doc.localDelete(12, 1));