org.apache.james.blob.cassandra.utils.DataChunker.java Source code

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Here is the source code for org.apache.james.blob.cassandra.utils.DataChunker.java

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package org.apache.james.blob.cassandra.utils;

import java.nio.ByteBuffer;
import java.util.stream.IntStream;
import java.util.stream.Stream;

import org.apache.commons.lang3.tuple.Pair;

import com.google.common.base.Preconditions;

public class DataChunker {

    public Stream<Pair<Integer, ByteBuffer>> chunk(byte[] data, int chunkSize) {
        Preconditions.checkNotNull(data);
        Preconditions.checkArgument(chunkSize > 0, "ChunkSize can not be negative");

        int size = data.length;
        int fullChunkCount = size / chunkSize;

        return Stream.concat(
                IntStream.range(0, fullChunkCount)
                        .mapToObj(i -> Pair.of(i, ByteBuffer.wrap(data, i * chunkSize, chunkSize))),
                lastChunk(data, chunkSize * fullChunkCount, fullChunkCount));
    }

    private Stream<Pair<Integer, ByteBuffer>> lastChunk(byte[] data, int offset, int index) {
        if (offset == data.length && index > 0) {
            return Stream.empty();
        }
        return Stream.of(Pair.of(index, ByteBuffer.wrap(data, offset, data.length - offset)));
    }

}