co.cask.tephra.snapshot.SnapshotCodecV4.java Source code

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Here is the source code for co.cask.tephra.snapshot.SnapshotCodecV4.java

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/*
 * Copyright  2015 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.tephra.snapshot;

import co.cask.tephra.TransactionManager;
import co.cask.tephra.TransactionType;
import com.google.common.collect.Maps;
import it.unimi.dsi.fastutil.longs.LongArrayList;

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[]}.
 *
 */
public class SnapshotCodecV4 extends SnapshotCodecV2 {
    @Override
    public int getVersion() {
        return 4;
    }

    @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.writeLong(entry.getValue().getVisibilityUpperBound());
                encoder.writeInt(entry.getValue().getType().ordinal());
                // write checkpoint tx IDs
                LongArrayList checkpointPointers = entry.getValue().getCheckpointWritePointers();
                if (checkpointPointers != null && !checkpointPointers.isEmpty()) {
                    encoder.writeInt(checkpointPointers.size());
                    for (int i = 0; i < checkpointPointers.size(); i++) {
                        encoder.writeLong(checkpointPointers.getLong(i));
                    }
                }
                encoder.writeInt(0);
            }
        }
        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) {
                long txId = decoder.readLong();
                long expiration = decoder.readLong();
                long visibilityUpperBound = decoder.readLong();
                int txTypeIdx = decoder.readInt();
                TransactionType txType;
                try {
                    txType = TransactionType.values()[txTypeIdx];
                } catch (ArrayIndexOutOfBoundsException e) {
                    throw new IOException("Type enum ordinal value is out of range: " + txTypeIdx);
                }
                // read checkpoint tx IDs
                int checkpointPointerSize = decoder.readInt();
                LongArrayList checkpointPointers = new LongArrayList(checkpointPointerSize);
                while (checkpointPointerSize != 0) {
                    for (int checkpointRemaining = checkpointPointerSize; checkpointRemaining > 0; --checkpointRemaining) {
                        checkpointPointers.add(decoder.readLong());
                    }
                    checkpointPointerSize = decoder.readInt();
                }
                inProgress.put(txId, new TransactionManager.InProgressTx(visibilityUpperBound, expiration, txType,
                        checkpointPointers));
            }
            size = decoder.readInt();
        }
        return inProgress;
    }
}