io.druid.segment.data.BlockLayoutDoubleSupplierSerializer.java Source code

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Here is the source code for io.druid.segment.data.BlockLayoutDoubleSupplierSerializer.java

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/*
 * Licensed to Metamarkets Group Inc. (Metamarkets) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. Metamarkets 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 io.druid.segment.data;

import com.google.common.io.ByteSink;
import com.google.common.io.ByteStreams;
import com.google.common.io.CountingOutputStream;
import com.google.common.primitives.Doubles;
import com.google.common.primitives.Ints;
import io.druid.collections.ResourceHolder;
import io.druid.collections.StupidResourceHolder;
import io.druid.java.util.common.io.smoosh.FileSmoosher;
import io.druid.segment.CompressedPools;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.ByteOrder;
import java.nio.DoubleBuffer;
import java.nio.channels.Channels;
import java.nio.channels.WritableByteChannel;

public class BlockLayoutDoubleSupplierSerializer implements DoubleSupplierSerializer {
    private final IOPeon ioPeon;
    private final int sizePer;
    private final GenericIndexedWriter<ResourceHolder<DoubleBuffer>> flattener;
    private final CompressedObjectStrategy.CompressionStrategy compression;
    private final String metaFile;

    private long metaCount = 0;
    private int numInserted = 0;
    private DoubleBuffer endBuffer;

    public BlockLayoutDoubleSupplierSerializer(IOPeon ioPeon, String filenameBase, ByteOrder order,
            CompressedObjectStrategy.CompressionStrategy compression) {
        this.ioPeon = ioPeon;
        this.sizePer = CompressedPools.BUFFER_SIZE / Doubles.BYTES;
        this.flattener = new GenericIndexedWriter<>(ioPeon, filenameBase,
                CompressedDoubleBufferObjectStrategy.getBufferForOrder(order, compression, sizePer));
        this.metaFile = filenameBase + ".format";
        this.compression = compression;

        endBuffer = DoubleBuffer.allocate(sizePer);
        endBuffer.mark();
    }

    @Override
    public void open() throws IOException {
        flattener.open();
    }

    @Override
    public int size() {
        return numInserted;
    }

    @Override
    public void add(double value) throws IOException {
        if (!endBuffer.hasRemaining()) {
            endBuffer.rewind();
            flattener.write(StupidResourceHolder.create(endBuffer));
            endBuffer = DoubleBuffer.allocate(sizePer);
            endBuffer.mark();
        }

        endBuffer.put(value);
        ++numInserted;
    }

    @Override
    public void closeAndConsolidate(ByteSink consolidatedOut) throws IOException {
        close();
        try (OutputStream out = consolidatedOut.openStream(); InputStream meta = ioPeon.makeInputStream(metaFile)) {
            ByteStreams.copy(meta, out);
            ByteStreams.copy(flattener.combineStreams(), out);
        }
    }

    @Override
    public long getSerializedSize() {
        return metaCount + flattener.getSerializedSize();
    }

    @Override
    public void writeToChannel(WritableByteChannel channel, FileSmoosher smoosher) throws IOException {
        try (InputStream meta = ioPeon.makeInputStream(metaFile)) {
            ByteStreams.copy(Channels.newChannel(meta), channel);
            flattener.writeToChannel(channel, smoosher);
        }
    }

    @Override
    public void close() throws IOException {
        endBuffer.limit(endBuffer.position());
        endBuffer.rewind();
        flattener.write(StupidResourceHolder.create(endBuffer));
        endBuffer = null;
        flattener.close();

        try (CountingOutputStream metaOut = new CountingOutputStream(ioPeon.makeOutputStream(metaFile))) {
            metaOut.write(CompressedDoublesIndexedSupplier.version);
            metaOut.write(Ints.toByteArray(numInserted));
            metaOut.write(Ints.toByteArray(sizePer));
            metaOut.write(compression.getId());
            metaOut.close();
            metaCount = metaOut.getCount();
        }
    }
}