hadoop CopyFromLocalOperation 源码

  • 2022-10-20
  • 浏览 (112)

haddop CopyFromLocalOperation 代码

文件路径:/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/impl/CopyFromLocalOperation.java

/*
 * 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.hadoop.fs.s3a.impl;

import java.io.Closeable;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.Serializable;
import java.net.URI;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashSet;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.Optional;
import java.util.Set;
import java.util.Stack;
import java.util.concurrent.CompletableFuture;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.commons.collections.comparators.ReverseComparator;
import org.apache.hadoop.fs.FileAlreadyExistsException;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.LocatedFileStatus;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.PathExistsException;
import org.apache.hadoop.fs.PathIOException;
import org.apache.hadoop.fs.RemoteIterator;
import org.apache.hadoop.fs.s3a.Retries;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.thirdparty.com.google.common.util.concurrent.ListeningExecutorService;
import org.apache.hadoop.thirdparty.com.google.common.util.concurrent.MoreExecutors;

import static org.apache.hadoop.fs.s3a.impl.CallableSupplier.submit;
import static org.apache.hadoop.fs.s3a.impl.CallableSupplier.waitForCompletion;
import static org.apache.hadoop.fs.store.audit.AuditingFunctions.callableWithinAuditSpan;

/**
 * Implementation of CopyFromLocalOperation.
 * <p>
 * This operation copies a file or directory (recursively) from a local
 * FS to an object store. Initially, this operation has been developed for
 * S3 (s3a) interaction, however, there's minimal work needed for it to
 * work with other stores.
 * </p>
 * <p>How the uploading of files works:</p>
 * <ul>
 *     <li> all source files and directories are scanned through;</li>
 *     <li> the LARGEST_N_FILES start uploading; </li>
 *     <li> the remaining files are shuffled and uploaded; </li>
 *     <li>
 *         any remaining empty directory is uploaded too to preserve local
 *         tree structure.
 *     </li>
 * </ul>
 */
public class CopyFromLocalOperation extends ExecutingStoreOperation<Void> {

  /**
   * Largest N files to be uploaded first.
   */
  private static final int LARGEST_N_FILES = 5;

  private static final Logger LOG = LoggerFactory.getLogger(
      CopyFromLocalOperation.class);

  /**
   * Callbacks to be used by this operation for external / IO actions.
   */
  private final CopyFromLocalOperationCallbacks callbacks;

  /**
   * Delete source after operation finishes.
   */
  private final boolean deleteSource;

  /**
   * Overwrite destination files / folders.
   */
  private final boolean overwrite;

  /**
   * Source path to file / directory.
   */
  private final Path source;

  /**
   * Async operations executor.
   */
  private final ListeningExecutorService executor;

  /**
   * Destination path.
   */
  private Path destination;

  /**
   * Destination file status.
   */
  private FileStatus destStatus;

  public CopyFromLocalOperation(
      final StoreContext storeContext,
      Path source,
      Path destination,
      boolean deleteSource,
      boolean overwrite,
      CopyFromLocalOperationCallbacks callbacks) {
    super(storeContext);
    this.callbacks = callbacks;
    this.deleteSource = deleteSource;
    this.overwrite = overwrite;
    this.source = source;
    this.destination = destination;

    // Capacity of 1 is a safe default for now since transfer manager can also
    // spawn threads when uploading bigger files.
    this.executor = MoreExecutors.listeningDecorator(
        storeContext.createThrottledExecutor(1)
    );
  }

  /**
   * Executes the {@link CopyFromLocalOperation}.
   *
   * @throws IOException         - if there are any failures with upload or deletion
   *                             of files. Check {@link CopyFromLocalOperationCallbacks} for specifics.
   * @throws PathExistsException - if the path exists and no overwrite flag
   *                             is set OR if the source is file and destination is a directory
   */
  @Override
  @Retries.RetryTranslated
  public Void execute()
      throws IOException, PathExistsException {
    LOG.debug("Copying local file from {} to {}", source, destination);
    File sourceFile = callbacks.pathToLocalFile(source);
    updateDestStatus(destination);

    // Handles bar/ -> foo/ => foo/bar and bar/ -> foo/bar/ => foo/bar/bar
    if (getDestStatus().isPresent() && getDestStatus().get().isDirectory()
        && sourceFile.isDirectory()) {
      destination = new Path(destination, sourceFile.getName());
      LOG.debug("Destination updated to: {}", destination);
      updateDestStatus(destination);
    }

    checkSource(sourceFile);
    checkDestination(destination, sourceFile, overwrite);
    uploadSourceFromFS();

    if (deleteSource) {
      callbacks.deleteLocal(source, true);
    }

    return null;
  }

  /**
   * Does a {@link CopyFromLocalOperationCallbacks#getFileStatus(Path)}
   * operation on the provided destination and updates the internal status of
   * destStatus field.
   *
   * @param  dest - destination Path
   * @throws IOException if getFileStatus fails
   */
  private void updateDestStatus(Path dest) throws IOException {
    try {
      destStatus = callbacks.getFileStatus(dest);
    } catch (FileNotFoundException e) {
      destStatus = null;
    }
  }

  /**
   * Starts async upload operations for files. Creating an empty directory
   * classifies as a "file upload".
   *
   * Check {@link CopyFromLocalOperation} for details on the order of
   * operations.
   *
   * @throws IOException - if listing or upload fail
   */
  private void uploadSourceFromFS() throws IOException {
    RemoteIterator<LocatedFileStatus> localFiles = listFilesAndDirs(source);
    List<CompletableFuture<Void>> activeOps = new ArrayList<>();

    // After all files are traversed, this set will contain only emptyDirs
    Set<Path> emptyDirs = new HashSet<>();
    List<UploadEntry> entries = new ArrayList<>();
    while (localFiles.hasNext()) {
      LocatedFileStatus sourceFile = localFiles.next();
      Path sourceFilePath = sourceFile.getPath();

      // Directory containing this file / directory isn't empty
      emptyDirs.remove(sourceFilePath.getParent());

      if (sourceFile.isDirectory()) {
        emptyDirs.add(sourceFilePath);
        continue;
      }

      Path destPath = getFinalPath(sourceFilePath);
      // UploadEntries: have a destination path, a file size
      entries.add(new UploadEntry(
          sourceFilePath,
          destPath,
          sourceFile.getLen()));
    }

    if (localFiles instanceof Closeable) {
      IOUtils.closeStream((Closeable) localFiles);
    }

    // Sort all upload entries based on size
    entries.sort(new ReverseComparator(new UploadEntry.SizeComparator()));

    // Take only top most N entries and upload
    final int sortedUploadsCount = Math.min(LARGEST_N_FILES, entries.size());
    List<UploadEntry> markedForUpload = new ArrayList<>();

    for (int uploadNo = 0; uploadNo < sortedUploadsCount; uploadNo++) {
      UploadEntry uploadEntry = entries.get(uploadNo);
      File file = callbacks.pathToLocalFile(uploadEntry.source);
      activeOps.add(submitUpload(file, uploadEntry));
      markedForUpload.add(uploadEntry);
    }

    // No files found, it's empty source directory
    if (entries.isEmpty()) {
      emptyDirs.add(source);
    }

    // Shuffle all remaining entries and upload them
    entries.removeAll(markedForUpload);
    Collections.shuffle(entries);
    for (UploadEntry uploadEntry : entries) {
      File file = callbacks.pathToLocalFile(uploadEntry.source);
      activeOps.add(submitUpload(file, uploadEntry));
    }

    for (Path emptyDir : emptyDirs) {
      Path emptyDirPath = getFinalPath(emptyDir);
      activeOps.add(submitCreateEmptyDir(emptyDirPath));
    }

    waitForCompletion(activeOps);
  }

  /**
   * Async call to create an empty directory.
   *
   * @param dir directory path
   * @return the submitted future
   */
  private CompletableFuture<Void> submitCreateEmptyDir(Path dir) {
    return submit(executor, callableWithinAuditSpan(
        getAuditSpan(), () -> {
          callbacks.createEmptyDir(dir, getStoreContext());
          return null;
        }
    ));
  }

  /**
   * Async call to upload a file.
   *
   * @param file        - File to be uploaded
   * @param uploadEntry - Upload entry holding the source and destination
   * @return the submitted future
   */
  private CompletableFuture<Void> submitUpload(
      File file,
      UploadEntry uploadEntry) {
    return submit(executor, callableWithinAuditSpan(
        getAuditSpan(), () -> {
          callbacks.copyLocalFileFromTo(
              file,
              uploadEntry.source,
              uploadEntry.destination);
          return null;
        }
    ));
  }

  /**
   * Checks the source before upload starts.
   *
   * @param src - Source file
   * @throws FileNotFoundException - if the file isn't found
   */
  private void checkSource(File src)
      throws FileNotFoundException {
    if (!src.exists()) {
      throw new FileNotFoundException("No file: " + src.getPath());
    }
  }

  /**
   * Check the destination path and make sure it's compatible with the source,
   * i.e. source and destination are both files / directories.
   *
   * @param dest      - Destination path
   * @param src       - Source file
   * @param overwrite - Should source overwrite destination
   * @throws PathExistsException - If the destination path exists and no
   *                             overwrite flag is set
   * @throws FileAlreadyExistsException - If source is file and destination is path
   */
  private void checkDestination(
      Path dest,
      File src,
      boolean overwrite) throws PathExistsException,
      FileAlreadyExistsException {
    if (!getDestStatus().isPresent()) {
      return;
    }

    if (src.isDirectory() && getDestStatus().get().isFile()) {
      throw new FileAlreadyExistsException(
          "Source '" + src.getPath() + "' is directory and " +
              "destination '" + dest + "' is file");
    }

    if (!overwrite) {
      throw new PathExistsException(dest + " already exists");
    }
  }

  /**
   * Get the final path of a source file with regards to its destination.
   *
   * @param src - source path
   * @return - the final path for the source file to be uploaded to
   * @throws PathIOException - if a relative path can't be created
   */
  private Path getFinalPath(Path src) throws PathIOException {
    URI currentSrcUri = src.toUri();
    URI relativeSrcUri = source.toUri().relativize(currentSrcUri);
    if (relativeSrcUri.equals(currentSrcUri)) {
      throw new PathIOException("Cannot get relative path for URI:"
          + relativeSrcUri);
    }

    Optional<FileStatus> status = getDestStatus();
    if (!relativeSrcUri.getPath().isEmpty()) {
      return new Path(destination, relativeSrcUri.getPath());
    } else if (status.isPresent() && status.get().isDirectory()) {
      // file to dir
      return new Path(destination, src.getName());
    } else {
      // file to file
      return destination;
    }
  }

  private Optional<FileStatus> getDestStatus() {
    return Optional.ofNullable(destStatus);
  }

  /**
   * {@link RemoteIterator} which lists all of the files and directories for
   * a given path. It's strikingly similar to
   * {@link org.apache.hadoop.fs.LocalFileSystem#listFiles(Path, boolean)}
   * however with the small addition that it includes directories.
   *
   * @param path - Path to list files and directories from
   * @return - an iterator
   * @throws IOException - if listing of a path file fails
   */
  private RemoteIterator<LocatedFileStatus> listFilesAndDirs(Path path)
      throws IOException {
    return new RemoteIterator<LocatedFileStatus>() {
      private final Stack<RemoteIterator<LocatedFileStatus>> iterators =
          new Stack<>();
      private RemoteIterator<LocatedFileStatus> current =
          callbacks.listLocalStatusIterator(path);
      private LocatedFileStatus curFile;

      @Override
      public boolean hasNext() throws IOException {
        while (curFile == null) {
          if (current.hasNext()) {
            handleFileStat(current.next());
          } else if (!iterators.empty()) {
            current = iterators.pop();
          } else {
            return false;
          }
        }
        return true;
      }

      /**
       * Process the input stat.
       * If it is a file or directory return the file stat.
       * If it is a directory, traverse the directory;
       * @param stat input status
       * @throws IOException if any IO error occurs
       */
      private void handleFileStat(LocatedFileStatus stat)
          throws IOException {
        if (stat.isFile()) { // file
          curFile = stat;
        } else { // directory
          curFile = stat;
          iterators.push(current);
          current = callbacks.listLocalStatusIterator(stat.getPath());
        }
      }

      @Override
      public LocatedFileStatus next() throws IOException {
        if (hasNext()) {
          LocatedFileStatus result = curFile;
          curFile = null;
          return result;
        }
        throw new NoSuchElementException("No more entry in "
            + path);
      }
    };
  }

  /**
   * <p>Represents an entry for a file to be moved.</p>
   * <p>
   * Helpful with sorting files by their size and keeping track of path
   * information for the upload.
   * </p>
   */
  private static final class UploadEntry {
    private final Path source;
    private final Path destination;
    private final long size;

    private UploadEntry(Path source, Path destination, long size) {
      this.source = source;
      this.destination = destination;
      this.size = size;
    }

    /**
     * Compares {@link UploadEntry} objects and produces DESC ordering.
     */
    static class SizeComparator implements Comparator<UploadEntry>,
        Serializable {
      @Override
      public int compare(UploadEntry entry1, UploadEntry entry2) {
        return Long.compare(entry1.size, entry2.size);
      }
    }
  }

  /**
   * Define the contract for {@link CopyFromLocalOperation} to interact
   * with any external resources.
   */
  public interface CopyFromLocalOperationCallbacks {
    /**
     * List all entries (files AND directories) for a path.
     *
     * @param path - path to list
     * @return an iterator for all entries
     * @throws IOException - for any failure
     */
    RemoteIterator<LocatedFileStatus> listLocalStatusIterator(Path path)
        throws IOException;

    /**
     * Get the file status for a path.
     *
     * @param path - target path
     * @return FileStatus
     * @throws IOException - for any failure
     */
    FileStatus getFileStatus(Path path) throws IOException;

    /**
     * Get the file from a path.
     *
     * @param path - target path
     * @return file at path
     */
    File pathToLocalFile(Path path);

    /**
     * Delete file / directory at path.
     *
     * @param path      - target path
     * @param recursive - recursive deletion
     * @return boolean result of operation
     * @throws IOException for any failure
     */
    boolean deleteLocal(Path path, boolean recursive) throws IOException;

    /**
     * Copy / Upload a file from a source path to a destination path.
     *
     * @param file        - target file
     * @param source      - source path
     * @param destination - destination path
     * @throws IOException for any failure
     */
    void copyLocalFileFromTo(
        File file,
        Path source,
        Path destination) throws IOException;

    /**
     * Create empty directory at path. Most likely an upload operation.
     *
     * @param path - target path
     * @param storeContext - store context
     * @return boolean result of operation
     * @throws IOException for any failure
     */
    boolean createEmptyDir(Path path, StoreContext storeContext)
        throws IOException;
  }
}

相关信息

hadoop 源码目录

相关文章

hadoop AbstractStoreOperation 源码

hadoop ActiveOperationContext 源码

hadoop BulkDeleteRetryHandler 源码

hadoop CallableSupplier 源码

hadoop ChangeDetectionPolicy 源码

hadoop ChangeTracker 源码

hadoop ConfigureShadedAWSSocketFactory 源码

hadoop ContextAccessors 源码

hadoop CopyOutcome 源码

hadoop CreateFileBuilder 源码

0  赞