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.beam.sdk.io.fs;
  
  import com.google.auto.value.AutoValue;
  import java.io.File;
  import java.io.IOException;
  import java.io.Serializable;
  import java.util.List;
  import org.apache.beam.sdk.io.FileSystems;
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  /** The result of {@link org.apache.beam.sdk.io.FileSystem#match}. */
  public abstract class MatchResult {
  
    private MatchResult() {}
  
    /** Returns a {@link MatchResult} given the {@link Status} and {@link Metadata}. */
    public static MatchResult create(Status status, List<Metadata> metadata) {
      return new AutoValue_MatchResult_Success(status, metadata);
    }
  
    @AutoValue
    abstract static class Success extends MatchResult {
      abstract List<Metadata> getMetadata();
  
      @Override
      public List<Metadata> metadata() throws IOException {
        return getMetadata();
      }
    }
  
    /** Returns a {@link MatchResult} given the {@link Status} and {@link IOException}. */
    public static MatchResult create(final Status status, final IOException e) {
      return new AutoValue_MatchResult_Failure(status, e);
    }
  
    @AutoValue
    abstract static class Failure extends MatchResult {
      abstract IOException getException();
  
      @Override
      public List<Metadata> metadata() throws IOException {
        throw getException();
      }
    }
  
    /** Returns a {@link MatchResult} with {@link Status#UNKNOWN}. */
    public static MatchResult unknown() {
      return new AutoValue_MatchResult_Failure(
          Status.UNKNOWN,
          new IOException("MatchResult status is UNKNOWN, and metadata is not available."));
    }
  
    /** Status of the {@link MatchResult}. */
    public abstract Status status();
  
    /**
     * {@link Metadata} of matched files. Note that if {@link #status()} is {@link Status#NOT_FOUND},
     * this may either throw a {@link java.io.FileNotFoundException} or return an empty list,
     * depending on the {@link EmptyMatchTreatment} used in the {@link FileSystems#match} call.
     */
    public abstract List<Metadata> metadata() throws IOException;
  
    /** {@link Metadata} of a matched file. */
    @AutoValue
    public abstract static class Metadata implements Serializable {
      private static final long UNKNOWN_LAST_MODIFIED_MILLIS = 0L;
  
      public abstract ResourceId resourceId();
  
      public abstract long sizeBytes();
  
      public abstract boolean isReadSeekEfficient();
  
      /** An optional checksum to identify the contents of a file. */
      public abstract @Nullable String checksum();
  
      /**
       * Last modification timestamp in milliseconds since Unix epoch.
       *
       * <p>Note that this field is not encoded with the default {@link MetadataCoder} due to a need
       * for compatibility with previous versions of the Beam SDK. If you want to rely on {@code
       * lastModifiedMillis} values, be sure to explicitly set the coder to {@link MetadataCoderV2}.
       * Otherwise, all instances will have the default value of 0, consistent with the behavior of
       * {@link File#lastModified()}.
       *
       * <p>The following example sets the coder explicitly and accesses {@code lastModifiedMillis} to
       * set record timestamps:
       *
       * <pre>{@code
       * PCollection<Metadata> metadataWithTimestamp = p
       *     .apply(FileIO.match().filepattern("hdfs://path/to/*.gz"))
       *     .setCoder(MetadataCoderV2.of())
       *     .apply(WithTimestamps.of(metadata -> new Instant(metadata.lastModifiedMillis())));
       * }</pre>
       */
      public abstract long lastModifiedMillis();
  
      public static Builder builder() {
        return new AutoValue_MatchResult_Metadata.Builder()
            .setIsReadSeekEfficient(false)
            .setLastModifiedMillis(UNKNOWN_LAST_MODIFIED_MILLIS);
      }
  
      /** Builder class for {@link Metadata}. */
      @AutoValue.Builder
      public abstract static class Builder {
        public abstract Builder setResourceId(ResourceId value);
  
        public abstract Builder setSizeBytes(long value);
  
        public abstract Builder setIsReadSeekEfficient(boolean value);
  
        public abstract Builder setLastModifiedMillis(long value);
  
        public abstract Builder setChecksum(String value);
  
        public abstract Metadata build();
      }
    }
  
    /** Status of a {@link MatchResult}. */
    public enum Status {
      UNKNOWN,
      OK,
      NOT_FOUND,
      ERROR,
    }
  }
  