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A fork of the Apache Cassandra Project that uses Lucene indexes for providing near real time search such as ElasticSearch or Solr, including full text search capabilities, multi-dimensional queries, and relevance scoring.
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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;
import org.apache.cassandra.utils.Pair;

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

    public final TypeSerializer keys;
    public final TypeSerializer values;

    public static synchronized  MapSerializer getInstance(TypeSerializer keys, TypeSerializer values)
    {
        Pair, TypeSerializer> p = Pair., TypeSerializer>create(keys, values);
        MapSerializer t = instances.get(p);
        if (t == null)
        {
            t = new MapSerializer(keys, values);
            instances.put(p, t);
        }
        return t;
    }

    private MapSerializer(TypeSerializer keys, TypeSerializer values)
    {
        this.keys = keys;
        this.values = values;
    }

    public List serializeValues(Map map)
    {
        List buffers = new ArrayList<>(map.size() * 2);
        for (Map.Entry entry : map.entrySet())
        {
            buffers.add(keys.serialize(entry.getKey()));
            buffers.add(values.serialize(entry.getValue()));
        }
        return buffers;
    }

    public int getElementCount(Map 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++)
            {
                keys.validate(readValue(input, version));
                values.validate(readValue(input, version));
            }
        }
        catch (BufferUnderflowException e)
        {
            throw new MarshalException("Not enough bytes to read a set");
        }
    }

    public Map deserializeForNativeProtocol(ByteBuffer bytes, int version)
    {
        try
        {
            ByteBuffer input = bytes.duplicate();
            int n = readCollectionSize(input, version);
            Map m = new LinkedHashMap(n);
            for (int i = 0; i < n; i++)
            {
                ByteBuffer kbb = readValue(input, version);
                keys.validate(kbb);

                ByteBuffer vbb = readValue(input, version);
                values.validate(vbb);

                m.put(keys.deserialize(kbb), values.deserialize(vbb));
            }
            return m;
        }
        catch (BufferUnderflowException e)
        {
            throw new MarshalException("Not enough bytes to read a map");
        }
    }

    public String toString(Map value)
    {
        StringBuilder sb = new StringBuilder();
        boolean isFirst = true;
        for (Map.Entry element : value.entrySet())
        {
            if (isFirst)
            {
                isFirst = false;
            }
            else
            {
                sb.append("; ");
            }
            sb.append('(');
            sb.append(keys.toString(element.getKey()));
            sb.append(", ");
            sb.append(values.toString(element.getValue()));
            sb.append(')');
        }
        return sb.toString();
    }

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