/*
 * 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.paimon.data;

import org.apache.paimon.fs.SeekableInputStream;

import java.io.IOException;
import java.io.Serializable;

/**
 * The placeholder blob, mainly for blob update in data-evolution. It should never be exposed to
 * users.
 */
public class BlobPlaceholder implements Blob, Serializable {

    private static final long serialVersionUID = 1L;

    public static final BlobPlaceholder INSTANCE = new BlobPlaceholder();

    private BlobPlaceholder() {}

    private Object readResolve() {
        return INSTANCE;
    }

    @Override
    public byte[] toData() {
        throw new UnsupportedOperationException(
                "Should never call this method for placeholder blob.");
    }

    @Override
    public BlobDescriptor toDescriptor() {
        throw new UnsupportedOperationException(
                "Should never call this method for placeholder blob.");
    }

    @Override
    public SeekableInputStream newInputStream() throws IOException {
        throw new UnsupportedOperationException(
                "Should never call this method for placeholder blob.");
    }
}
