HHH-7835 Inefficient implementation of

JarVisitorFactory.getBytesFromInputStream

hibernate-entitymanager/src/main/java/org/hibernate/jpa/packaging/internal/JarVisitorFactory.java

@@ -21,6 +21,7 @@
  */
 package org.hibernate.jpa.packaging.internal;
 
+import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
@@ -28,13 +29,13 @@ import java.net.MalformedURLException;
 import java.net.URISyntaxException;
 import java.net.URL;
 
-import org.jboss.logging.Logger;
-
-import org.hibernate.jpa.internal.EntityManagerMessageLogger;
 import org.hibernate.internal.util.StringHelper;
+import org.hibernate.jpa.internal.EntityManagerMessageLogger;
+import org.jboss.logging.Logger;
 
 /**
  * @author Emmanuel Bernard
+ * @author Brett Meyer
  */
 public class JarVisitorFactory {
 
@@ -194,18 +195,16 @@ public class JarVisitorFactory {
 		}
 	}
 
-	public static byte[] getBytesFromInputStream(InputStream inputStream) throws IOException {
-		int size;
-		byte[] tmpByte = new byte[ 4096 ];
-		byte[] entryBytes = new byte[0];
-		for ( ; ; ) {
-			size = inputStream.read( tmpByte );
-			if ( size == -1 ) break;
-			byte[] current = new byte[ entryBytes.length + size ];
-			System.arraycopy( entryBytes, 0, current, 0, entryBytes.length );
-			System.arraycopy( tmpByte, 0, current, entryBytes.length, size );
-			entryBytes = current;
+	public static byte[] getBytesFromInputStream(
+			InputStream inputStream) throws IOException {
+		
+		ByteArrayOutputStream buffer = new ByteArrayOutputStream();
+		int numBytes;
+		byte[] data = new byte[4096];
+		while ( ( numBytes = inputStream.read( data, 0, data.length ) ) != -1 ) {
+			buffer.write( data, 0, numBytes );
 		}
-		return entryBytes;
+		buffer.flush();
+		return buffer.toByteArray();
 	}
 }

hibernate-entitymanager/src/test/java/org/hibernate/jpa/test/packaging/JarVisitorTest.java

@@ -27,9 +27,13 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
+import java.io.BufferedInputStream;
 import java.io.File;
+import java.io.FileInputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.net.URL;
 import java.net.URLConnection;
 import java.net.URLStreamHandler;
@@ -61,6 +65,7 @@ import org.junit.Test;
 /**
  * @author Emmanuel Bernard
  * @author Hardy Ferentschik
+ * @author Brett Meyer
  */
 @RequiresDialect( H2Dialect.class ) // Nothing dialect-specific -- no need to run in matrix.
 @SuppressWarnings("unchecked")
@@ -308,6 +313,73 @@ public class JarVisitorTest extends PackagingTestCase {
 //		assertTrue( entries[1].contains( entry ) );
 	}
 	
+	@Test
+	@TestForIssue(jiraKey = "HHH-7835")
+	public void testGetBytesFromInputStream() {
+		try {
+			File file = buildLargeJar();
+
+			long start = System.currentTimeMillis();
+			InputStream stream = new BufferedInputStream(
+					new FileInputStream( file ) );
+			int oldLength = getBytesFromInputStream( stream ).length;
+			stream.close();
+			long oldTime = System.currentTimeMillis() - start;
+
+			start = System.currentTimeMillis();
+			stream = new BufferedInputStream( new FileInputStream( file ) );
+			int newLength = JarVisitorFactory.getBytesFromInputStream(
+					stream ).length;
+			stream.close();
+			long newTime = System.currentTimeMillis() - start;
+
+			assertEquals( oldLength, newLength );
+			assertTrue( oldTime > newTime );
+		}
+		catch ( Exception e ) {
+			fail( e.getMessage() );
+		}
+	}
+
+	// This is the old getBytesFromInputStream from JarVisitorFactory before
+	// it was changed by HHH-7835. Use it as a regression test.
+	private byte[] getBytesFromInputStream(
+			InputStream inputStream) throws IOException {
+		int size;
+
+		byte[] entryBytes = new byte[0];
+		for ( ;; ) {
+			byte[] tmpByte = new byte[4096];
+			size = inputStream.read( tmpByte );
+			if ( size == -1 )
+				break;
+			byte[] current = new byte[entryBytes.length + size];
+			System.arraycopy( entryBytes, 0, current, 0, entryBytes.length );
+			System.arraycopy( tmpByte, 0, current, entryBytes.length, size );
+			entryBytes = current;
+		}
+		return entryBytes;
+	}
+
+	@Test
+	@TestForIssue(jiraKey = "HHH-7835")
+	public void testGetBytesFromZeroInputStream() {
+		try {
+			// Ensure that JarVisitorFactory#getBytesFromInputStream
+			// can handle 0 length streams gracefully.
+			InputStream emptyStream = new BufferedInputStream( 
+					new FileInputStream( new File(
+					"src/test/resources/org/hibernate/jpa/test/packaging/empty.txt" ) ) );
+			int length = JarVisitorFactory.getBytesFromInputStream( 
+					emptyStream ).length;
+			assertEquals( length, 0 );
+			emptyStream.close();
+		}
+		catch ( Exception e ) {
+			fail( e.getMessage() );
+		}
+	}
+
 	private Filter[] getFilters() {
 		return new Filter[] {
 				new PackageFilter( false, null ) {

hibernate-entitymanager/src/test/java/org/hibernate/jpa/test/packaging/PackagingTestCase.java

@@ -73,6 +73,7 @@ import static org.junit.Assert.fail;
 
 /**
  * @author Hardy Ferentschik
+ * @author Brett Meyer
  */
 public abstract class PackagingTestCase extends BaseCoreFunctionalTestCase {
 	protected static ClassLoader originalClassLoader = Thread.currentThread().getContextClassLoader();
@@ -335,6 +336,18 @@ public abstract class PackagingTestCase extends BaseCoreFunctionalTestCase {
 		return testPackage;
 	}
 
+	protected File buildLargeJar() {
+		String fileName = "large.jar";
+		JavaArchive archive = ShrinkWrap.create( JavaArchive.class, fileName );
+		// Build a large jar by adding all EntityManager packages and
+		// subpackages on the classpath.
+		archive.addPackages(true, "org.hibernate.ejb", "org.hibernate.jpa" );
+
+		File testPackage = new File( packageTargetDir, fileName );
+		archive.as( ZipExporter.class ).exportTo( testPackage, true );
+		return testPackage;
+	}
+
 	protected File buildWar() {
 		String fileName = "war.war";
 		WebArchive archive = ShrinkWrap.create( WebArchive.class, fileName );