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/*
 * 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.cassandra.serializers;

import java.nio.BufferUnderflowException;
import java.nio.ByteBuffer;
import java.util.*;

import org.apache.cassandra.utils.ByteBufferUtil;

public class ListSerializer extends CollectionSerializer>
{
    // interning instances
    private static final Map, ListSerializer> instances = new HashMap, ListSerializer>();

    public final TypeSerializer elements;

    public static synchronized  ListSerializer getInstance(TypeSerializer elements)
    {
        ListSerializer t = instances.get(elements);
        if (t == null)
        {
            t = new ListSerializer(elements);
            instances.put(elements, t);
        }
        return t;
    }

    private ListSerializer(TypeSerializer elements)
    {
        this.elements = elements;
    }

    public List serializeValues(List values)
    {
        List buffers = new ArrayList<>(values.size());
        for (T value : values)
            buffers.add(elements.serialize(value));
        return buffers;
    }

    public int getElementCount(List value)
    {
        return value.size();
    }

    public void validateForNativeProtocol(ByteBuffer bytes, int version)
    {
        try
        {
            ByteBuffer input = bytes.duplicate();
            int n = readCollectionSize(input, version);
            for (int i = 0; i < n; i++)
                elements.validate(readValue(input, version));
        }
        catch (BufferUnderflowException e)
        {
            throw new MarshalException("Not enough bytes to read a list");
        }
    }

    public List deserializeForNativeProtocol(ByteBuffer bytes, int version)
    {
        try
        {
            ByteBuffer input = bytes.duplicate();
            int n = readCollectionSize(input, version);
            List l = new ArrayList(n);
            for (int i = 0; i < n; i++)
            {
                ByteBuffer databb = readValue(input, version);
                elements.validate(databb);
                l.add(elements.deserialize(databb));
            }
            return l;
        }
        catch (BufferUnderflowException e)
        {
            throw new MarshalException("Not enough bytes to read a list");
        }
    }

    public String toString(List value)
    {
        StringBuilder sb = new StringBuilder();
        boolean isFirst = true;
        for (T element : value)
        {
            if (isFirst)
            {
                isFirst = false;
            }
            else
            {
                sb.append("; ");
            }
            sb.append(elements.toString(element));
        }
        return sb.toString();
    }

    public Class> getType()
    {
        return (Class) List.class;
    }
}