| /* |
| * 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.boundedint; |
| |
| import static org.apache.parquet.Log.DEBUG; |
| |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| |
| import org.apache.parquet.Log; |
| import org.apache.parquet.bytes.BytesUtils; |
| import org.apache.parquet.column.values.ValuesReader; |
| import org.apache.parquet.io.ParquetDecodingException; |
| |
| /** |
| * @see BoundedIntValuesWriter |
| */ |
| class BoundedIntValuesReader extends ValuesReader { |
| private static final Log LOG = Log.getLog(BoundedIntValuesReader.class); |
| |
| private int currentValueCt = 0; |
| private int currentValue = 0; |
| private final int bitsPerValue; |
| private BitReader bitReader = new BitReader(); |
| private int nextOffset; |
| |
| public BoundedIntValuesReader(int bound) { |
| if (bound == 0) { |
| throw new ParquetDecodingException("Value bound cannot be 0. Use DevNullColumnReader instead."); |
| } |
| bitsPerValue = BytesUtils.getWidthFromMaxInt(bound); |
| } |
| |
| @Override |
| public int readInteger() { |
| try { |
| if (currentValueCt > 0) { |
| currentValueCt--; |
| return currentValue; |
| } |
| if (bitReader.readBit()) { |
| currentValue = bitReader.readNBitInteger(bitsPerValue); |
| currentValueCt = bitReader.readUnsignedVarint() - 1; |
| } else { |
| currentValue = bitReader.readNBitInteger(bitsPerValue); |
| } |
| return currentValue; |
| } catch (IOException e) { |
| throw new ParquetDecodingException("could not read int", e); |
| } |
| } |
| |
| // This forces it to deserialize into memory. If it wanted |
| // to, it could just read the bytes (though that number of |
| // bytes would have to be serialized). This is the flip-side |
| // to BoundedIntColumnWriter.writeData(BytesOutput) |
| @Override |
| public void initFromPage(int valueCount, ByteBuffer in, int offset) throws IOException { |
| if (DEBUG) LOG.debug("reading size at "+ offset + ": " + in.get(offset) + " " + in.get(offset + 1) + " " + in.get(offset + 2) + " " + in.get(offset + 3) + " "); |
| int totalBytes = BytesUtils.readIntLittleEndian(in, offset); |
| if (DEBUG) LOG.debug("will read "+ totalBytes + " bytes"); |
| currentValueCt = 0; |
| currentValue = 0; |
| bitReader.prepare(in, offset + 4, totalBytes); |
| if (DEBUG) LOG.debug("will read next from " + (offset + totalBytes + 4)); |
| this.nextOffset = offset + totalBytes + 4; |
| } |
| |
| @Override |
| public int getNextOffset() { |
| return this.nextOffset; |
| } |
| |
| @Override |
| public void skip() { |
| readInteger(); |
| } |
| } |