fixing lock manager bugs

-resetting buffers
-truncate file before write,
-logging

storage/storage/src/main/java/org/eclipse/store/storage/types/StorageFile.java

@@ -83,9 +83,11 @@ public default String identifier()
 	public boolean delete();
 
 	public void moveTo(AWritableFile target);
-
-
 
+	public void truncate(final long newLength);
+
+
+
 	public static VarString assembleNameAndSize(final VarString vs, final StorageFile file)
 	{
 		return vs.add(file.file().identifier() + "[" + file.file().size() + "]");
@@ -361,6 +363,7 @@ public final synchronized long copyFrom(
 			}
 		}
 
+		@Override
 		public synchronized void truncate(final long newLength)
 		{
 			this.ensureWritable().truncate(newLength);

storage/storage/src/main/java/org/eclipse/store/storage/types/StorageLockFileManager.java

@@ -27,8 +27,10 @@
 import org.eclipse.serializer.concurrency.XThreads;
 import org.eclipse.serializer.memory.XMemory;
 import org.eclipse.serializer.util.X;
+import org.eclipse.serializer.util.logging.Logging;
 import org.eclipse.store.storage.exceptions.StorageException;
 import org.eclipse.store.storage.exceptions.StorageExceptionInitialization;
+import org.slf4j.Logger;
 
 
 public interface StorageLockFileManager extends Runnable
@@ -64,6 +66,8 @@ public static StorageLockFileManager New(
 
 	public final class Default implements StorageLockFileManager
 	{
+		private final static Logger logger = Logging.getLogger(StorageLockFileManager.class);
+
 		///////////////////////////////////////////////////////////////////////////
 		// instance fields //
 		////////////////////
@@ -351,6 +355,8 @@ private boolean lockFileHasContent()
 
 		private void initialize()
 		{
+			logger.info("initializing lock file manager for storage {}", this.setup.processIdentity());
+
 			final StorageLiveFileProvider fileProvider = this.setup.lockFileProvider();
 			final AFile lockFile     = fileProvider.provideLockFile();
 			this.lockFile = StorageLockFile.New(lockFile);
@@ -386,6 +392,7 @@ private LockFileData validateExistingLockFileData(final boolean firstAttempt)
 			if(identifier.equals(existingFiledata.identifier))
 			{
 				// database is already owned by "this" process (e.g. crash shorty before), so just continue and reuse.
+				logger.info("Storage already owned by process!");
 				return existingFiledata;
 			}
 
@@ -395,13 +402,15 @@ private LockFileData validateExistingLockFileData(final boolean firstAttempt)
 				 * The lock file is no longer updated, meaning the database is not used anymore
 				 * and the lockfile is just a zombie, probably left by a crash.
 				 */
+				logger.info("Storage lock file outdated, aquiring storage!");
 				return existingFiledata;
 			}
 
 			// not owned and not expired
 			if(firstAttempt)
 			{
 				// wait one interval and try a second time
+				logger.warn("Non expired storage lock found!");
 				XThreads.sleep(existingFiledata.updateInterval);
 				return this.validateExistingLockFileData(false);
 
@@ -446,12 +455,15 @@ private void writeLockFileData()
 			}
 
 			this.lockFileData.update();
-
-
+
 			final ArrayView<ByteBuffer> bb = this.setToWriteBuffer(this.lockFileData);
 
 			// no need for the writer detour (for now) since it makes no sense to backup lock files.
+
+			//don't delete file!
+			this.lockFile.truncate(0);
 			this.lockFile.writeBytes(bb);
+
 		}
 
 		private ArrayView<ByteBuffer> setToWriteBuffer(final LockFileData lockFileData)
@@ -466,6 +478,7 @@ private ArrayView<ByteBuffer> setToWriteBuffer(final LockFileData lockFileData)
 			final ArrayView<ByteBuffer> bb = this.ensureWritingBuffer(bytes);
 
 			XMemory.copyArrayToAddress(bytes, XMemory.getDirectByteBufferAddress(this.directByteBuffer));
+			this.directByteBuffer.limit(bytes.length);
 
 			return bb;
 		}