content: /*
   * 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.bookkeeper.statelib.impl.rocksdb.checkpoint.dlog;
  
  import com.google.common.collect.Lists;
  import java.io.BufferedInputStream;
  import java.io.BufferedOutputStream;
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.nio.file.FileAlreadyExistsException;
  import java.nio.file.NoSuchFileException;
  import java.util.Iterator;
  import java.util.List;
  import java.util.concurrent.ExecutionException;
  import lombok.extern.slf4j.Slf4j;
  import org.apache.bookkeeper.statelib.api.checkpoint.CheckpointStore;
  import org.apache.bookkeeper.statelib.impl.Constants;
  import org.apache.distributedlog.DLSN;
  import org.apache.distributedlog.api.AsyncLogWriter;
  import org.apache.distributedlog.api.DistributedLogManager;
  import org.apache.distributedlog.api.LogReader;
  import org.apache.distributedlog.api.namespace.Namespace;
  import org.apache.distributedlog.bk.LedgerMetadata;
  import org.apache.distributedlog.exceptions.DLInterruptedException;
  import org.apache.distributedlog.exceptions.LogEmptyException;
  import org.apache.distributedlog.exceptions.LogExistsException;
  import org.apache.distributedlog.exceptions.LogNotFoundException;
  import org.apache.distributedlog.util.Utils;
  
  /**
   * Dlog based checkpoint store.
   */
  @Slf4j
  public class DLCheckpointStore implements CheckpointStore {
  
      private final Namespace namespace;
  
      public DLCheckpointStore(Namespace namespace) {
          this.namespace = namespace;
      }
  
      private static FileNotFoundException createFileNotFoundException(String filePath, Throwable t) {
          FileNotFoundException fnfe = new FileNotFoundException(filePath);
          fnfe.initCause(t);
          return fnfe;
      }
  
      @Override
      public List<String> listFiles(String filePath) throws IOException {
          return Lists.newArrayList(namespace.getLogs(filePath));
      }
  
      @Override
      public boolean fileExists(String filePath) throws IOException {
          return namespace.logExists(filePath);
      }
  
      @Override
      public long getFileLength(String filePath) throws IOException {
          try (DistributedLogManager dlm = namespace.openLog(filePath)) {
              return dlm.getLastTxId();
          } catch (LogNotFoundException e) {
              throw createFileNotFoundException(filePath, e);
          } catch (LogEmptyException e) {
              return 0;
          }
      }
  
      @Override
      public InputStream openInputStream(String filePath) throws IOException {
          try {
              DistributedLogManager dlm = namespace.openLog(filePath);
              LogReader reader;
              try {
                  reader = dlm.openLogReader(DLSN.InitialDLSN);
              } catch (LogNotFoundException | LogEmptyException e) {
                  throw createFileNotFoundException(filePath, e);
              }
              return new BufferedInputStream(
                  new DLInputStream(dlm, reader, 0L), 128 * 1024);
          } catch (LogNotFoundException e) {
              throw createFileNotFoundException(filePath, e);
          }
      }
  
      @Override
      public OutputStream openOutputStream(String filePath) throws IOException {
          try {
              DistributedLogManager dlm = namespace.openLog(
                  filePath);
              LedgerMetadata metadata = new LedgerMetadata();
              metadata.setApplication(Constants.LEDGER_METADATA_APPLICATION_STREAM_STORAGE);
              metadata.setComponent("checkpoint-store");
              AsyncLogWriter writer = Utils.ioResult(dlm.openAsyncLogWriter(metadata));
              return new BufferedOutputStream(
                  new DLOutputStream(dlm, writer), 128 * 1024);
          } catch (LogNotFoundException le) {
              throw createFileNotFoundException(filePath, le);
          }
      }
  
      @Override
      public void rename(String srcLog, String dstLog) throws IOException {
          log.info("Renaming {} to {}", srcLog, dstLog);
          try {
              namespace.renameLog(srcLog, dstLog).get();
          } catch (InterruptedException e) {
              Thread.currentThread().interrupt();
              throw new DLInterruptedException("Interrupted at renaming " + srcLog + " to " + dstLog, e);
          } catch (ExecutionException e) {
              if (e.getCause() instanceof LogExistsException) {
                  throw new FileAlreadyExistsException("Dest file already exists : " + dstLog);
              } else if (e.getCause() instanceof LogNotFoundException) {
                  throw new NoSuchFileException("Src file or dest directory is not found");
              } else if (e.getCause() instanceof IOException) {
                  throw (IOException) e.getCause();
              } else {
                  throw new IOException("Failed to rename " + srcLog + " to " + dstLog, e.getCause());
              }
          }
      }
  
      @Override
      public void deleteRecursively(String srcPath) throws IOException {
          Iterator<String> logs = namespace.getLogs(srcPath);
          while (logs.hasNext()) {
              String child = logs.next();
              deleteRecursively(srcPath + "/" + child);
          }
          namespace.deleteLog(srcPath);
      }
  
      @Override
      public void delete(String srcPath) throws IOException {
          namespace.deleteLog(srcPath);
      }
  
      @Override
      public void createDirectories(String srcPath) throws IOException {
          namespace.createLog(srcPath);
      }
  
      @Override
      public void close() {
          namespace.close();
      }
  }
  