co.cask.cdap.data2.transaction.snapshot.SnapshotCodecV1.java Source code

Introduction

Here is the source code for co.cask.cdap.data2.transaction.snapshot.SnapshotCodecV1.java

Source

/*
 * Copyright  2014 Cask Data, Inc.
 *
 * 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 co.cask.cdap.data2.transaction.snapshot;

import co.cask.tephra.TransactionManager;
import co.cask.tephra.snapshot.BinaryDecoder;
import co.cask.tephra.snapshot.BinaryEncoder;
import com.google.common.collect.Maps;

import java.io.IOException;
import java.util.Map;
import java.util.NavigableMap;

/**
 * Handles serialization/deserialization of a {@link co.cask.tephra.persist.TransactionSnapshot} and
 * its elements to {@code byte[]}.
 * @deprecated Replaced by use of {@code co.cask.tephra.snapshot.SnapshotCodecV3}.
 */
@Deprecated
public class SnapshotCodecV1 extends AbstractSnapshotCodec {
    public static final int VERSION = 1;

    @Override
    public int getVersion() {
        return VERSION;
    }

    @Override
    protected void decodeObsoleteAttributes(BinaryDecoder decoder) throws IOException {
        // watermark attribute was removed
        decoder.readLong();
    }

    @Override
    protected void encodeObsoleteAttributes(BinaryEncoder encoder) throws IOException {
        // writing watermark attribute (that was removed in newer codecs), 55L - any random value, will not be used anywhere
        encoder.writeLong(55L);
    }

    @Override
    protected void encodeInProgress(BinaryEncoder encoder, Map<Long, TransactionManager.InProgressTx> inProgress)
            throws IOException {

        if (!inProgress.isEmpty()) {
            encoder.writeInt(inProgress.size());
            for (Map.Entry<Long, TransactionManager.InProgressTx> entry : inProgress.entrySet()) {
                encoder.writeLong(entry.getKey()); // tx id
                encoder.writeLong(entry.getValue().getExpiration());
            }
        }
        encoder.writeInt(0); // zero denotes end of list as per AVRO spec
    }

    @Override
    protected NavigableMap<Long, TransactionManager.InProgressTx> decodeInProgress(BinaryDecoder decoder)
            throws IOException {

        int size = decoder.readInt();
        NavigableMap<Long, TransactionManager.InProgressTx> inProgress = Maps.newTreeMap();
        while (size != 0) { // zero denotes end of list as per AVRO spec
            for (int remaining = size; remaining > 0; --remaining) {
                inProgress.put(decoder.readLong(),
                        // 1st version did not store visibilityUpperBound. It is safe to set firstInProgress to 0,
                        // it may decrease performance until this tx is finished, but correctness will be preserved.
                        new TransactionManager.InProgressTx(0L, decoder.readLong()));
            }
            size = decoder.readInt();
        }
        return inProgress;
    }
}