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 com.datastax.oss.driver.internal.core.type.codec.extras.array;
  
  import com.datastax.oss.driver.api.core.ProtocolVersion;
  import com.datastax.oss.driver.api.core.type.ListType;
  import com.datastax.oss.driver.api.core.type.reflect.GenericType;
  import edu.umd.cs.findbugs.annotations.NonNull;
  import edu.umd.cs.findbugs.annotations.Nullable;
  import java.lang.reflect.Array;
  import java.nio.ByteBuffer;
  import java.util.Objects;
  
  /**
   * Base class for all codecs dealing with Java primitive arrays. This class provides a more
   * efficient implementation of {@link #encode(Object, ProtocolVersion)} and {@link
   * #decode(ByteBuffer, ProtocolVersion)} for primitive arrays.
   *
   * @param <PrimitiveArrayT> The Java primitive array type this codec handles
   */
  public abstract class AbstractPrimitiveListToArrayCodec<PrimitiveArrayT>
      extends AbstractListToArrayCodec<PrimitiveArrayT> {
  
    /**
     * @param cqlType The CQL type. Must be a list type.
     * @param javaClass The Java type. Must be an array class.
     */
    protected AbstractPrimitiveListToArrayCodec(
        @NonNull ListType cqlType, @NonNull GenericType<PrimitiveArrayT> javaClass) {
      super(cqlType, javaClass);
      GenericType<?> componentType = Objects.requireNonNull(javaClass.getComponentType());
      if (!componentType.isPrimitive()) {
        throw new IllegalArgumentException(
            "Expecting primitive array component type, got " + componentType);
      }
    }
  
    @Nullable
    @Override
    public ByteBuffer encode(
        @Nullable PrimitiveArrayT array, @NonNull ProtocolVersion protocolVersion) {
      if (array == null) {
        return null;
      }
      int length = Array.getLength(array);
      int sizeOfElement = 4 + sizeOfComponentType();
      int totalSize = 4 + length * sizeOfElement;
      ByteBuffer output = ByteBuffer.allocate(totalSize);
      output.putInt(length);
      for (int i = 0; i < length; i++) {
        output.putInt(sizeOfComponentType());
        serializeElement(output, array, i, protocolVersion);
      }
      output.flip();
      return output;
    }
  
    @Nullable
    @Override
    public PrimitiveArrayT decode(
        @Nullable ByteBuffer bytes, @NonNull ProtocolVersion protocolVersion) {
      if (bytes == null || bytes.remaining() == 0) {
        return newInstance(0);
      }
      ByteBuffer input = bytes.duplicate();
      int length = input.getInt();
      PrimitiveArrayT array = newInstance(length);
      for (int i = 0; i < length; i++) {
        int elementSize = input.getInt();
        // Null elements can happen on the decode path, but we cannot tolerate them
        if (elementSize < 0) {
          throw new NullPointerException("Primitive arrays cannot store null elements");
        } else {
          deserializeElement(input, array, i, protocolVersion);
        }
      }
      return array;
    }
  
    /**
     * Return the size in bytes of the array component type.
     *
     * @return the size in bytes of the array component type.
     */
    protected abstract int sizeOfComponentType();
  
    /**
     * Write the {@code index}th element of {@code array} to {@code output}.
     *
     * @param output The ByteBuffer to write to.
     * @param array The array to read from.
     * @param index The element index.
     * @param protocolVersion The protocol version to use.
     */
    protected abstract void serializeElement(
        @NonNull ByteBuffer output,
        @NonNull PrimitiveArrayT array,
        int index,
        @NonNull ProtocolVersion protocolVersion);
  
    /**
     * Read the {@code index}th element of {@code array} from {@code input}.
     *
     * @param input The ByteBuffer to read from.
     * @param array The array to write to.
     * @param index The element index.
     * @param protocolVersion The protocol version to use.
     */
    protected abstract void deserializeElement(
        @NonNull ByteBuffer input,
        @NonNull PrimitiveArrayT array,
        int index,
        @NonNull ProtocolVersion protocolVersion);
  }
  