Implementation of distributed locking feature

This feature is a very basic implementation of a distributed locking
system.

Issue-ID: POLICY-699
Change-Id: I012fd37926ccbbdd87a3e4acb2788b53680115f0
Signed-off-by: Magnusen, Drew (dm741q) <dm741q@att.com>

2 files changed, 256 insertions, 0 deletions

diff --git a/feature-distributed-locking/src/test/java/org/onap/policy/distributed/locking/test/DistributedLockingFeatureExceptionTest.java b/feature-distributed-locking/src/test/java/org/onap/policy/distributed/locking/test/DistributedLockingFeatureExceptionTest.java
new file mode 100644
index 00000000..ea53e522
--- /dev/null
+++ b/feature-distributed-locking/src/test/java/org/onap/policy/distributed/locking/test/DistributedLockingFeatureExceptionTest.java
@@ -0,0 +1,36 @@
+/*
+ * ============LICENSE_START=======================================================
+ * feature-distributed-locking
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.distributed.locking.test;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+import org.onap.policy.common.utils.test.ExceptionsTester;
+import org.onap.policy.distributed.locking.DistributedLockingFeatureException;
+
+public class DistributedLockingFeatureExceptionTest extends ExceptionsTester{
+	
+	@Test
+	public void test() {
+		assertEquals(1, test(DistributedLockingFeatureException.class)); 
+	}
+
+}
diff --git a/feature-distributed-locking/src/test/java/org/onap/policy/distributed/locking/test/TargetLockTest.java b/feature-distributed-locking/src/test/java/org/onap/policy/distributed/locking/test/TargetLockTest.java
new file mode 100644
index 00000000..e624afb9
--- /dev/null
+++ b/feature-distributed-locking/src/test/java/org/onap/policy/distributed/locking/test/TargetLockTest.java
@@ -0,0 +1,220 @@
+/*
+ * ============LICENSE_START=======================================================
+ * feature-distributed-locking
+ * ================================================================================
+ * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.distributed.locking.test;
+
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.onap.policy.distributed.locking.DistributedLockingFeature;
+import org.onap.policy.drools.persistence.SystemPersistence;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+
+public class TargetLockTest {
+	private static final Logger logger = LoggerFactory.getLogger(TargetLockTest.class);
+	private static final String DB_CONNECTION = "jdbc:h2:mem:pooling;INIT=CREATE SCHEMA IF NOT EXISTS pooling\\;SET SCHEMA pooling";
+	private static final String DB_USER = "user";
+	private static final String DB_PASSWORD = "password";
+	private static Connection conn = null;
+	private static DistributedLockingFeature distLockFeat;
+
+	@BeforeClass
+	public static void setup() {
+		getDBConnection();
+		createTable();
+		SystemPersistence.manager.setConfigurationDir("src/test/resources");
+		distLockFeat = new DistributedLockingFeature();
+		distLockFeat.afterStart(null);
+	
+	}
+	
+	@AfterClass
+	public static void cleanUp() {
+		distLockFeat.beforeShutdown(null);
+		try {
+			conn.close();
+		} catch (SQLException e) {
+			logger.error("Error in TargetLockTest.cleanUp()", e);
+		}
+	}
+	
+	@Before
+	public void wipeDb() {
+		
+		try (PreparedStatement lockDelete = conn.prepareStatement("DELETE FROM pooling.locks");){
+			lockDelete.executeUpdate();
+		} catch (SQLException e) {
+			logger.error("Error in TargetLockTest.wipeDb()", e);
+			throw new RuntimeException(e);
+		}
+
+	}
+	
+	@Test
+	public void testGrabLockSuccess() throws InterruptedException, ExecutionException {
+		assertTrue(distLockFeat.beforeLock("resource1", "owner1", null).get());
+	
+			//attempt to grab expiredLock
+		try (PreparedStatement updateStatement = conn.prepareStatement("UPDATE pooling.locks SET expirationTime = ? WHERE resourceId = ?");)
+		{
+			updateStatement.setLong(1, System.currentTimeMillis() - 1000);
+			updateStatement.setString(2, "resource1");
+			updateStatement.executeUpdate();
+				
+		} catch (SQLException e) {
+			logger.error("Error in TargetLockTest.testGrabLockSuccess()", e);
+			throw new RuntimeException(e);
+		}
+		
+		assertTrue(distLockFeat.beforeLock("resource1", "owner1", null).get());
+	}
+
+	@Test
+	public void testExpiredLocks() throws InterruptedException, ExecutionException {
+		CountDownLatch latch = new CountDownLatch(1);
+		
+		distLockFeat.beforeLock("resource1", "owner1", null);
+		
+		try {
+			latch.await(1000, TimeUnit.MILLISECONDS);
+		} catch (InterruptedException e) {
+			logger.error("Error in testExpiredLocks", e);
+		}
+		
+			//Heartbeat should keep it active
+		assertFalse(distLockFeat.beforeLock("resource1", "owner1", null).get());
+	}
+	
+	@Test
+	public void testGrabLockFail() throws InterruptedException, ExecutionException {
+		CountDownLatch latch = new CountDownLatch(1);
+		
+		distLockFeat.beforeLock("resource1", "owner1", null);
+		
+		try {
+			latch.await(10, TimeUnit.MILLISECONDS);
+		} catch (InterruptedException e) {
+			logger.error("Error in testExpiredLocks", e);
+		}
+		assertFalse(distLockFeat.beforeLock("resource1", "owner1", null).get());
+
+	}
+	
+	
+	@Test
+	public void testUnlock() throws InterruptedException, ExecutionException {
+		distLockFeat.beforeLock("resource1", "owner1", null);
+
+		assertTrue(distLockFeat.beforeUnlock("resource1", "owner1"));
+		assertTrue(distLockFeat.beforeLock("resource1", "owner1", null).get());
+	}
+	
+	@Test
+	public void testIsActive() {
+		assertFalse(distLockFeat.beforeIsLockedBy("resource1", "owner1"));
+		distLockFeat.beforeLock("resource1", "owner1", null);
+		assertTrue(distLockFeat.beforeIsLockedBy("resource1", "owner1"));
+		assertFalse(distLockFeat.beforeIsLockedBy("resource1", "owner2"));
+
+		// isActive on expiredLock
+		try (PreparedStatement updateStatement = conn
+				.prepareStatement("UPDATE pooling.locks SET expirationTime = ? WHERE resourceId = ?");) {
+			updateStatement.setLong(1, System.currentTimeMillis() - 5000);
+			updateStatement.setString(2, "resource1");
+			updateStatement.executeUpdate();
+
+		} catch (SQLException e) {
+			logger.error("Error in TargetLockTest.testIsActive()", e);
+			throw new RuntimeException(e);
+		}
+
+		assertFalse(distLockFeat.beforeIsLockedBy("resource1", "owner1"));
+
+		distLockFeat.beforeLock("resource1", "owner1", null);
+			//Unlock record, next isActive attempt should fail
+		distLockFeat.beforeUnlock("resource1", "owner1");
+		assertFalse(distLockFeat.beforeIsLockedBy("resource1", "owner1"));
+		
+	}
+	
+	@Test
+	public void testHeartbeat() {
+		CountDownLatch latch = new CountDownLatch(1);
+		
+		distLockFeat.beforeLock("resource1", "owner1", null);
+		try {
+			latch.await(1000, TimeUnit.MILLISECONDS);
+		} catch (InterruptedException e) {
+			logger.error("Error in testExpiredLocks", e);
+		}
+		
+			// This test always returns true.
+		assertTrue(distLockFeat.beforeIsLocked("resource1"));
+	}
+	
+	@Test
+	public void unlockBeforeLock() {
+		assertFalse(distLockFeat.beforeUnlock("resource1", "owner1"));
+		distLockFeat.beforeLock("resource1", "owner1", null);
+		assertTrue(distLockFeat.beforeUnlock("resource1", "owner1"));
+		assertFalse(distLockFeat.beforeUnlock("resource1", "owner1"));
+	}
+	
+	@Test
+	public void testIsLocked() {
+		assertFalse(distLockFeat.beforeIsLocked("resource1"));
+		distLockFeat.beforeLock("resource1", "owner1", null);
+		assertTrue(distLockFeat.beforeIsLocked("resource1"));
+	
+	}
+	
+	private static void getDBConnection() {
+		try {
+			conn = DriverManager.getConnection(DB_CONNECTION, DB_USER, DB_PASSWORD);
+		} catch (SQLException e) {
+			logger.error("Error in TargetLockTest.getDBConnection()", e);
+		}
+	}
+
+	private static void createTable() {
+		String createString = "create table if not exists pooling.locks (resourceId VARCHAR(128), host VARCHAR(128), owner VARCHAR(128), expirationTime BIGINT, PRIMARY KEY (resourceId))";
+		try (PreparedStatement createStmt = conn.prepareStatement(createString);) {
+			createStmt.executeUpdate();
+			
+		} catch (SQLException e) {
+			logger.error("Error in TargetLockTest.createTable()", e);
+		}
+	}	
+	 
+
+}