Github user kevinjmh commented on a diff in the pull request:
https://github.com/apache/carbondata/pull/2161#discussion_r243168473
--- Diff:
core/src/main/java/org/apache/carbondata/core/locks/AlluxioFileLock.java ---
@@ -0,0 +1,112 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.
+ */
+
+package org.apache.carbondata.core.locks;
+
+import java.io.DataOutputStream;
+import java.io.IOException;
+
+import org.apache.carbondata.common.logging.LogServiceFactory;
+import org.apache.carbondata.core.datastore.filesystem.AlluxioCarbonFile;
+import org.apache.carbondata.core.datastore.impl.FileFactory;
+import org.apache.carbondata.core.metadata.AbsoluteTableIdentifier;
+import org.apache.carbondata.core.util.path.CarbonTablePath;
+
+import org.apache.log4j.Logger;
+
+/**
+ * This class is used to handle the S3 File locking.
+ * This is acheived using the concept of acquiring the data out stream
using Append option.
+ */
+public class AlluxioFileLock extends AbstractCarbonLock {
+
+ /**
+ * LOGGER
+ */
+ private static final Logger LOGGER =
+
LogServiceFactory.getLogService(AlluxioCarbonFile.class.getName());
+ /**
+ * lockFilePath is the location of the lock file.
+ */
+ private String lockFilePath;
+
+ /**
+ * lockFileDir is the directory of the lock file.
+ */
+ private String lockFileDir;
+
+ private DataOutputStream dataOutputStream;
+
+ /**
+ * @param tableIdentifier
+ * @param lockFile
+ */
+ public AlluxioFileLock(AbsoluteTableIdentifier tableIdentifier, String
lockFile) {
+ this(tableIdentifier.getTablePath(), lockFile);
+ }
+
+ /**
+ * @param lockFileLocation
+ * @param lockFile
+ */
+ public AlluxioFileLock(String lockFileLocation, String lockFile) {
+ this.lockFileDir =
CarbonTablePath.getLockFilesDirPath(lockFileLocation);
+ this.lockFilePath = CarbonTablePath.getLockFilePath(lockFileLocation,
lockFile);
+ LOGGER.info("Alluxio lock path:" + this.lockFilePath);
+ initRetry();
+ }
+
+ /* (non-Javadoc)
+ * @see org.apache.carbondata.core.locks.ICarbonLock#unlock()
+ */
+ @Override
+ public boolean unlock() {
+ boolean status = false;
+ if (null != dataOutputStream) {
+ try {
+ dataOutputStream.close();
+ status = true;
+ } catch (IOException e) {
+ status = false;
+ }
+ }
+ return status;
+ }
+
+ /* (non-Javadoc)
+ * @see org.apache.carbondata.core.locks.ICarbonLock#lock()
+ */
+ @Override
+ public boolean lock() {
+ try {
+ if (!FileFactory.isFileExist(lockFileDir)) {
+ FileFactory.mkdirs(lockFileDir,
FileFactory.getFileType(lockFileDir));
+ }
+ if (!FileFactory.isFileExist(lockFilePath)) {
+ FileFactory.createNewLockFile(lockFilePath,
FileFactory.getFileType(lockFilePath));
+ }
+ dataOutputStream =
+ FileFactory.getDataOutputStreamUsingAppend(lockFilePath,
+ FileFactory.getFileType(lockFilePath));
--- End diff --
Can you insert data into table? I found that the implementation of `append`
function in Alluxio required to create a new file. It will fail if file
already exists. For line 100, carbon makes sure the file exists, and finally we
always fail when locking.
The code I mention in alluxio is this:
https://github.com/Alluxio/alluxio/blob/21a3a87747010f087d1937f48bba3caa883885f8/core/client/hdfs/src/main/java/alluxio/hadoop/AbstractFileSystem.java#L127-L138
---
