content: /*
   * Copyright 2023 Aiven Oy
   *
   * Licensed 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 io.aiven.kafka.tieredstorage.transform;
  
  import java.util.Objects;
  
  import com.github.luben.zstd.Zstd;
  
  /**
   * The chunk de-transformation that does Zstd decompression.
   */
  public class DecompressionChunkEnumeration implements DetransformChunkEnumeration {
      private final DetransformChunkEnumeration inner;
  
      public DecompressionChunkEnumeration(final DetransformChunkEnumeration inner) {
          this.inner = Objects.requireNonNull(inner, "inner cannot be null");
      }
  
      @Override
      public boolean hasMoreElements() {
          return inner.hasMoreElements();
      }
  
      @Override
      public byte[] nextElement() {
          final byte[] chunk = inner.nextElement();
          final long decompressedSize = Zstd.decompressedSize(chunk);
          if (decompressedSize < 0) {
              throw new RuntimeException("Invalid decompressed size: " + decompressedSize);
          }
          return Zstd.decompress(chunk, (int) decompressedSize);
      }
  }
  