/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF 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 org.apache.parquet.column.values.deltalengthbytearray; import java.io.IOException; import org.apache.parquet.bytes.ByteBufferAllocator; import org.apache.parquet.bytes.BytesInput; import org.apache.parquet.bytes.CapacityByteArrayOutputStream; import org.apache.parquet.bytes.LittleEndianDataOutputStream; import org.apache.parquet.column.Encoding; import org.apache.parquet.column.values.ValuesWriter; import org.apache.parquet.column.values.delta.DeltaBinaryPackingValuesWriter; import org.apache.parquet.column.values.delta.DeltaBinaryPackingValuesWriterForInteger; import org.apache.parquet.io.ParquetEncodingException; import org.apache.parquet.io.api.Binary; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Write lengths of byte-arrays using delta encoding, followed by concatenated byte-arrays * <pre> * {@code * delta-length-byte-array : length* byte-array* * } * </pre> * */ public class DeltaLengthByteArrayValuesWriter extends ValuesWriter { private static final Logger LOG = LoggerFactory.getLogger(DeltaLengthByteArrayValuesWriter.class); private ValuesWriter lengthWriter; private CapacityByteArrayOutputStream arrayOut; private LittleEndianDataOutputStream out; public DeltaLengthByteArrayValuesWriter(int initialSize, int pageSize, ByteBufferAllocator allocator) { arrayOut = new CapacityByteArrayOutputStream(initialSize, pageSize, allocator); out = new LittleEndianDataOutputStream(arrayOut); lengthWriter = new DeltaBinaryPackingValuesWriterForInteger( DeltaBinaryPackingValuesWriter.DEFAULT_NUM_BLOCK_VALUES, DeltaBinaryPackingValuesWriter.DEFAULT_NUM_MINIBLOCKS, initialSize, pageSize, allocator); } @Override public void writeBytes(Binary v) { try { lengthWriter.writeInteger(v.length()); v.writeTo(out); } catch (IOException e) { throw new ParquetEncodingException("could not write bytes", e); } } @Override public long getBufferedSize() { return lengthWriter.getBufferedSize() + arrayOut.size(); } @Override public BytesInput getBytes() { try { out.flush(); } catch (IOException e) { throw new ParquetEncodingException("could not write page", e); } LOG.debug("writing a buffer of size {}", arrayOut.size()); return BytesInput.concat(lengthWriter.getBytes(), BytesInput.from(arrayOut)); } @Override public Encoding getEncoding() { return Encoding.DELTA_LENGTH_BYTE_ARRAY; } @Override public void reset() { lengthWriter.reset(); arrayOut.reset(); } @Override public void close() { lengthWriter.close(); arrayOut.close(); } @Override public long getAllocatedSize() { return lengthWriter.getAllocatedSize() + arrayOut.getCapacity(); } @Override public String memUsageString(String prefix) { return arrayOut.memUsageString(lengthWriter.memUsageString(prefix) + " DELTA_LENGTH_BYTE_ARRAY"); } }