hadoop DeleteOperation 源码

  • 2022-10-20
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haddop DeleteOperation 代码


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 * 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,
 * See the License for the specific language governing permissions and
 * limitations under the License.

package org.apache.hadoop.fs.s3a.impl;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.stream.Collectors;

import com.amazonaws.services.s3.model.DeleteObjectsRequest;
import org.apache.hadoop.thirdparty.com.google.common.util.concurrent.ListeningExecutorService;
import org.apache.hadoop.thirdparty.com.google.common.util.concurrent.MoreExecutors;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.PathIsNotEmptyDirectoryException;
import org.apache.hadoop.fs.RemoteIterator;
import org.apache.hadoop.fs.s3a.Invoker;
import org.apache.hadoop.fs.s3a.Retries;
import org.apache.hadoop.fs.s3a.S3AFileStatus;
import org.apache.hadoop.fs.s3a.S3ALocatedFileStatus;
import org.apache.hadoop.fs.s3a.Tristate;
import org.apache.hadoop.util.DurationInfo;

import static org.apache.hadoop.fs.store.audit.AuditingFunctions.callableWithinAuditSpan;
import static org.apache.hadoop.util.Preconditions.checkArgument;
import static org.apache.hadoop.fs.s3a.impl.CallableSupplier.maybeAwaitCompletion;
import static org.apache.hadoop.fs.s3a.impl.CallableSupplier.submit;

 * Implementation of the delete() operation.
 * This issues only one bulk delete at a time,
 * intending to update S3Guard after every request succeeded.
 * Now that S3Guard has been removed, it
 * would be possible to issue multiple delete calls
 * in parallel.
 * If this is done, then it may be good to experiment with different
 * page sizes. The default value is
 * {@link InternalConstants#MAX_ENTRIES_TO_DELETE}, the maximum a single
 * POST permits.
 * <p>
 * Smaller pages executed in parallel may have different
 * performance characteristics when deleting very large directories.
 * Any exploration of options here MUST be done with performance
 * measurements taken from test runs in EC2 against local S3 stores,
 * so as to ensure network latencies do not skew the results.

public class DeleteOperation extends ExecutingStoreOperation<Boolean> {

  private static final Logger LOG = LoggerFactory.getLogger(

   * Pre-fetched source status.
  private final S3AFileStatus status;

   * Recursive delete?
  private final boolean recursive;

   * Callback provider.
  private final OperationCallbacks callbacks;

   * Number of entries in a page.
  private final int pageSize;

   * Executor for async operations.
  private final ListeningExecutorService executor;

   * List of keys built up for the next delete batch.
  private List<DeleteEntry> keys;

   * The single async delete operation, or null.
  private CompletableFuture<Void> deleteFuture;

   * Counter of deleted files.
  private long filesDeleted;

   * Constructor.
   * @param context store context
   * @param status  pre-fetched source status
   * @param recursive recursive delete?
   * @param callbacks callback provider
   * @param pageSize size of delete pages
  public DeleteOperation(final StoreContext context,
      final S3AFileStatus status,
      final boolean recursive,
      final OperationCallbacks callbacks,
      final int pageSize) {

    this.status = status;
    this.recursive = recursive;
    this.callbacks = callbacks;
    checkArgument(pageSize > 0
            && pageSize <= InternalConstants.MAX_ENTRIES_TO_DELETE,
        "page size out of range: %s", pageSize);
    this.pageSize = pageSize;
    executor = MoreExecutors.listeningDecorator(

  public long getFilesDeleted() {
    return filesDeleted;

   * Delete a file or directory tree.
   * <p>
   * This call does not create any fake parent directory; that is
   * left to the caller.
   * The actual delete call is done in a separate thread.
   * Only one delete at a time is submitted, however, to reduce the
   * complexity of recovering from failures.
   * <p>
   * With S3Guard removed, the problem of updating any
   * DynamoDB store has gone away -delete calls could now be issued
   * in parallel.
   * However, rate limiting may be required to keep write load
   * below the throttling point. Every entry in a single
   * bulk delete call counts as a single write request -overloading
   * an S3 partition with delete calls has been a problem in
   * the past.
   * @return true, except in the corner cases of root directory deletion
   * @throws PathIsNotEmptyDirectoryException if the path is a dir and this
   * is not a recursive delete.
   * @throws IOException list failures or an inability to delete a file.
  public Boolean execute() throws IOException {

    StoreContext context = getStoreContext();
    Path path = status.getPath();
    LOG.debug("Delete path {} - recursive {}", path, recursive);
    LOG.debug("Type = {}",
        status.isFile() ? "File"
            : (status.isEmptyDirectory() == Tristate.TRUE
                ? "Empty Directory"
                : "Directory"));

    String key = context.pathToKey(path);
    if (status.isDirectory()) {
      LOG.debug("delete: Path is a directory: {}", path);
          status.isEmptyDirectory() != Tristate.UNKNOWN,
          "File status must have directory emptiness computed");

      if (!key.endsWith("/")) {
        key = key + "/";

      if ("/".equals(key)) {
        LOG.error("S3A: Cannot delete the root directory."
                + " Path: {}. Recursive: {}",
            status.getPath(), recursive);
        return false;

      if (!recursive && status.isEmptyDirectory() == Tristate.FALSE) {
        throw new PathIsNotEmptyDirectoryException(path.toString());
      if (status.isEmptyDirectory() == Tristate.TRUE) {
        LOG.debug("deleting empty directory {}", path);
        deleteObjectAtPath(path, key, false);
      } else {
        deleteDirectoryTree(path, key);

    } else {
      // simple file.
      LOG.debug("deleting simple file {}", path);
      deleteObjectAtPath(path, key, true);
    LOG.debug("Deleted {} objects", filesDeleted);
    return true;

   * Delete a directory tree.
   * <p>
   * This is done by asking the filesystem for a list of all objects under
   * the directory path.
   * <p>
   * Once the first {@link #pageSize} worth of objects has been listed, a batch
   * delete is queued for execution in a separate thread; subsequent batches
   * block waiting for the first call to complete or fail before again,
   * being deleted in the separate thread.
   * <p>
   * After all listed objects are queued for deletion,
   * @param path directory path
   * @param dirKey directory key
   * @throws IOException failure
  protected void deleteDirectoryTree(final Path path,
      final String dirKey) throws IOException {

    try (DurationInfo ignored =
             new DurationInfo(LOG, false, "deleting %s", dirKey)) {

      // init the lists of keys and paths to delete
      deleteFuture = null;

      // list files
      LOG.debug("Getting objects for directory prefix {} to delete", dirKey);
      final RemoteIterator<S3ALocatedFileStatus> locatedFiles =
          callbacks.listFilesAndDirectoryMarkers(path, status,

      // iterate through and delete. The next() call will block when a new S3
      // page is required; this any active delete submitted to the executor
      // will run in parallel with this.
      while (locatedFiles.hasNext()) {
        // get the next entry in the listing.
        S3AFileStatus child = locatedFiles.next().toS3AFileStatus();
      LOG.debug("Deleting final batch of listed files");

    LOG.debug("Delete \"{}\" completed; deleted {} objects", path,

   * Build an S3 key for a delete request,
   * possibly adding a "/" if it represents directory and it does
   * not have a trailing slash already.
   * @param stat status to build the key from
   * @return a key for a delete request
  private String deletionKey(final S3AFileStatus stat) {
    return getStoreContext().fullKey(stat);

   * Queue for deletion.
   * @param stat status to queue
   * @throws IOException failure of the previous batch of deletions.
  private void queueForDeletion(
      final S3AFileStatus stat) throws IOException {
    queueForDeletion(deletionKey(stat), stat.isDirectory());

   * Queue keys for deletion.
   * Once a page of keys are ready to delete this
   * call is submitted to the executor, after waiting for the previous run to
   * complete.
   * @param key key to delete
   * @param isDirMarker is the entry a directory?
   * @throws IOException failure of the previous batch of deletions.
  private void queueForDeletion(final String key,
      boolean isDirMarker) throws IOException {
    LOG.debug("Adding object to delete: \"{}\"", key);
    keys.add(new DeleteEntry(key, isDirMarker));
    if (keys.size() == pageSize) {

   * Wait for the previous batch to finish then submit this page.
   * The lists of keys and pages are reset here.
   * @throws IOException failure of the previous batch of deletions.
  private void submitNextBatch()
      throws IOException {
    // delete a single page of keys and the metadata.
    // block for any previous batch.

    // delete the current page of keys and paths
    deleteFuture = submitDelete(keys);
    // reset the references so a new list can be built up.

   * Reset the lists of keys and paths so that a new batch of
   * entries can built up.
  private void resetDeleteList() {
    keys = new ArrayList<>(pageSize);

   * Delete a file or directory marker.
   * @param path path
   * @param key key
   * @param isFile is this a file?
   * @throws IOException failure
  private void deleteObjectAtPath(
      final Path path,
      final String key,
      final boolean isFile)
      throws IOException {
    LOG.debug("delete: {} {}", (isFile ? "file" : "dir marker"), key);
    callbacks.deleteObjectAtPath(path, key, isFile);

   * Delete a single page of keys.
   * If the list is empty no work is submitted and null is returned.
   * @param keyList keys to delete.
   * @return the submitted future or null
  private CompletableFuture<Void> submitDelete(
      final List<DeleteEntry> keyList) {

    if (keyList.isEmpty()) {
      return null;
    filesDeleted += keyList.size();
    return submit(executor,
            getAuditSpan(), () -> {
              return null;

   * The action called in the asynchronous thread to delete
   * the keys from S3 and paths from S3Guard.
   * @param keyList keys to delete.
   * entries logged?
   * @throws IOException failure
  private void asyncDeleteAction(
      final List<DeleteEntry> keyList)
      throws IOException {
    try (DurationInfo ignored =
             new DurationInfo(LOG, false,
                 "Delete page of %d keys", keyList.size())) {
      if (!keyList.isEmpty()) {
        // first delete the files.
        List<DeleteObjectsRequest.KeyVersion> files = keyList.stream()
            .filter(e -> !e.isDirMarker)
            .map(e -> e.keyVersion)
        LOG.debug("Deleting of {} file objects", files.size());
        Invoker.once("Remove S3 Files",
            () -> callbacks.removeKeys(
        // now the dirs
        List<DeleteObjectsRequest.KeyVersion> dirs = keyList.stream()
            .filter(e -> e.isDirMarker)
            .map(e -> e.keyVersion)
        LOG.debug("Deleting of {} directory markers", dirs.size());
        // This is invoked with deleteFakeDir.
        Invoker.once("Remove S3 Dir Markers",
            () -> callbacks.removeKeys(

   * Deletion entry; dir marker state is tracked to allow
   * delete requests to be split into file
   * and marker delete phases.
   * Without S3Guard, the split is only used
   * to choose which statistics to update.
  private static final class DeleteEntry {
    private final DeleteObjectsRequest.KeyVersion keyVersion;

    private final boolean isDirMarker;

    private DeleteEntry(final String key, final boolean isDirMarker) {
      this.keyVersion = new DeleteObjectsRequest.KeyVersion(key);
      this.isDirMarker = isDirMarker;

    public String getKey() {
      return keyVersion.getKey();

    public String toString() {
      return "DeleteEntry{" +
          "key='" + getKey() + '\'' +
          ", isDirMarker=" + isDirMarker +



hadoop 源码目录


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 CopyFromLocalOperation 源码

hadoop CopyOutcome 源码

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