LinkValueType.java

/*
 * Copyright 2010 Outerthought bvba
 *
 * Licensed 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.lilyproject.repository.impl.valuetype;

import java.util.Comparator;

import org.lilyproject.bytes.api.DataInput;
import org.lilyproject.bytes.api.DataOutput;
import org.lilyproject.repository.api.IdGenerator;
import org.lilyproject.repository.api.IdentityRecordStack;
import org.lilyproject.repository.api.Link;
import org.lilyproject.repository.api.RecordId;
import org.lilyproject.repository.api.RepositoryException;
import org.lilyproject.repository.api.TypeManager;
import org.lilyproject.repository.api.ValueType;
import org.lilyproject.repository.api.ValueTypeFactory;
import org.lilyproject.repository.impl.compat.Lily11RecordIdDecoder;
import org.lilyproject.repository.impl.compat.Lily20LinkDecoder;

public class LinkValueType extends AbstractValueType implements ValueType {

    public final static String NAME = "LINK";
    private String fullName;

    private final IdGenerator idGenerator;

    /**
     * Original encoding up to (and including) Lily 1.1.x
     */
    private static final byte VERSION_ONE = 1;
    /**
     * Changes to the recordId encoding (not the link encoding itself).
     */
    private static final byte VERSION_TWO = 2;

    /**
     * Addition of optional table name to Link fields.
     */
    private static final byte VERSION_THREE = 3;

    public LinkValueType(IdGenerator idGenerator, TypeManager typeManager, String recordTypeName) throws IllegalArgumentException, RepositoryException, InterruptedException {
        this.idGenerator = idGenerator;
        if (recordTypeName != null) {
            this.fullName = NAME + "<" + recordTypeName + ">";
        } else {
            fullName = NAME;
        }
    }

    @Override
    public String getBaseName() {
        return NAME;
    }

    @Override
    public String getName() {
        return fullName;
    }

    @Override
    public ValueType getDeepestValueType() {
        return this;
    }

    @Override
    public Link read(DataInput dataInput) {
        // Read the encoding version byte, but ignore it for the moment since there is only one encoding
        byte version = dataInput.readByte();
        Link link;
        switch (version) {
            case VERSION_ONE:
                link = Lily11RecordIdDecoder.decodeLink(dataInput, idGenerator);
                break;
            case VERSION_TWO:
                link = Lily20LinkDecoder.decode(dataInput, idGenerator);
                break;
            case VERSION_THREE:
                link = Link.read(dataInput, idGenerator);
                break;
            default:
                throw new RuntimeException("Unsupported encoding version for link value type: " + version);
        }
        return link;
    }

    @Override
    public void write(Object value, DataOutput dataOutput, IdentityRecordStack parentRecords) {
        // We're not storing any recordType information together with the data
        // The recordType information is only available in the schema
        dataOutput.writeByte(VERSION_THREE);
        ((Link)value).write(dataOutput);
    }

    @Override
    public Class getType() {
        return Link.class;
    }

    @Override
    public Comparator getComparator() {
        return null;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + fullName.hashCode();
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        return fullName.equals(((LinkValueType) obj).fullName);
    }

    //
    // Factory
    //
    public static ValueTypeFactory factory(IdGenerator idGenerator, TypeManager typeManager) {
        return new LinkValueTypeFactory(idGenerator, typeManager);
    }

    public static class LinkValueTypeFactory implements ValueTypeFactory {
        private final TypeManager typeManager;
        private final IdGenerator idGenerator;

        LinkValueTypeFactory(IdGenerator idGenerator, TypeManager typeManager){
            this.idGenerator = idGenerator;
            this.typeManager = typeManager;
        }

        @Override
        public ValueType getValueType(String recordTypeName) throws IllegalArgumentException, RepositoryException, InterruptedException {
            return new LinkValueType(idGenerator, typeManager, recordTypeName);
        }
    }
}