typesystem/src/main/java/org/apache/atlas/typesystem/Struct.java

/**
 * 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.atlas.typesystem;

import org.apache.atlas.AtlasException;
import org.apache.atlas.classification.InterfaceAudience;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

public class Struct implements IStruct {

    public final String typeName;
    private final Map<String, Object> values;

    public Struct(String typeName) {
        this.typeName = typeName;
        values = new HashMap<>();
    }

    @InterfaceAudience.Private
    public Struct(String typeName, Map<String, Object> values) {
        this(typeName);
        if (values != null) {
            this.values.putAll(values);
        }
    }

    /**
     * No-arg constructor for serialization.
     */
    @SuppressWarnings("unused")
    private Struct() {
        this("", Collections.<String, Object>emptyMap());
    }


    @Override
    public String getTypeName() {
        return typeName;
    }

    @Override
    public Object get(String attrName) {
        return values.get(attrName);
    }

    @Override
    public void set(String attrName, Object value) {
        values.put(attrName, value);
    }

    @Override
    public void setNull(String attrName) throws AtlasException {
        values.put(attrName, null);
    }

    @Override
    public Map<String, Object> getValuesMap() {
        return values;
    }

    @Override
    public String toShortString() {
        return String.format("struct[type=%s]", typeName);
    }

    @Override
    public int hashCode() {
        int result = typeName.hashCode();
        result = 31 * result + values.hashCode();
        return result;
    }

    /**
     * equalContents instead of equals since values is a mutable attribute and could lead
     * to incorrect behaviour when added to collections and mutated after that
     * i.e when the attribute is mutated collections.contains(struct) returns false
     * due to hashcode having changed for the struct.
     * @param o
     * @return
     */
    public boolean equalsContents(Object o) {
        if (this == o) {
            return true;
        }

        if (o == null) {
            return false;
        }

        if (o.getClass() != getClass()) {
            return false;
        }

        Struct obj = (Struct)o;
        if(!typeName.equals(obj.getTypeName())) {
            return false;
        }

        if(!values.equals(obj.getValuesMap())) {
            return false;
        }

        return true;
    }
}