generic sorted message tree

briar-tests/src/org/briarproject/clients/MessageTreeTest.java

@@ -0,0 +1,102 @@
+package org.briarproject.clients;
+
+import org.briarproject.TestUtils;
+import org.briarproject.api.clients.MessageTree;
+import org.briarproject.api.sync.MessageId;
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.logging.Logger;
+
+import static org.junit.Assert.assertEquals;
+
+public class MessageTreeTest {
+
+	private static final Logger LOG =
+			Logger.getLogger(MessageTreeTest.class.getName());
+
+	private MessageTree<TestNode> tree;
+
+	@Test
+	public void testMessageTree() {
+		tree = new MessageTreeImpl<>();
+		testSimpleTree();
+		tree.clear();
+		testSimpleTree();
+	}
+
+	private void testSimpleTree() {
+		TestNode[] nodes = new TestNode[5];
+		for (int i = 0; i < nodes.length; i++) {
+			nodes[i] = new TestNode();
+		}
+		/*
+		Construct the following tree:
+		4
+		1 ->
+		   0  ->
+		       2
+		   3
+		 */
+		nodes[0].setParentId(nodes[1].getId());
+		nodes[2].setParentId(nodes[0].getId());
+		nodes[3].setParentId(nodes[1].getId());
+		long timestamp = System.currentTimeMillis();
+		nodes[4].setTimestamp(timestamp - 5);
+		nodes[1].setTimestamp(timestamp - 4);
+		nodes[0].setTimestamp(timestamp - 3);
+		nodes[3].setTimestamp(timestamp - 2);
+		nodes[2].setTimestamp(timestamp - 1);
+		// add all nodes except the last one
+		tree.add(Arrays.asList(Arrays.copyOf(nodes, nodes.length-1)));
+		tree.add(Collections.singletonList(nodes[nodes.length-1]));
+		TestNode[] sortedNodes = tree.depthFirstOrder().toArray(new TestNode[5]);
+		assertEquals(nodes[4], sortedNodes[0]);
+		assertEquals(nodes[1], sortedNodes[1]);
+		assertEquals(nodes[0], sortedNodes[2]);
+		assertEquals(nodes[2], sortedNodes[3]);
+		assertEquals(nodes[3], sortedNodes[4]);
+	}
+
+	private void printNodes(TestNode[] nodes, TestNode[] sortedNodes) {
+		for (int i = 0; i < sortedNodes.length; i++) {
+			for (int j = 0; j < nodes.length; j++) {
+				if (sortedNodes[i] == nodes[j]) {
+					LOG.info("index: " + j);
+					break;
+				}
+			}
+		}
+	}
+
+	class TestNode implements MessageTree.MessageNode {
+
+		private final MessageId id = new MessageId(TestUtils.getRandomId());
+		private MessageId parentId;
+		private long timestamp;
+
+		@Override
+		public MessageId getId() {
+			return id;
+		}
+
+		@Override
+		public MessageId getParentId() {
+			return parentId;
+		}
+
+		@Override
+		public long getTimestamp() {
+			return timestamp;
+		}
+
+		public void setParentId(MessageId parentId) {
+			this.parentId = parentId;
+		}
+
+		public void setTimestamp(long timestamp) {
+			this.timestamp = timestamp;
+		}
+	}
+}