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/**
* 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.
*/
#ifndef ORC_BYTE_RLE_HH
#define ORC_BYTE_RLE_HH
#include <memory>
#include "io/InputStream.hh"
#include "io/OutputStream.hh"
namespace orc {
class ByteRleEncoder {
public:
virtual ~ByteRleEncoder();
/**
* Encode the next batch of values
* @param data to be encoded
* @param numValues the number of values to be encoded
* @param notNull If the pointer is null, all values are read. If the
* pointer is not null, positions that are false are skipped.
*/
virtual void add(const char* data, uint64_t numValues,
const char* notNull) = 0;
/**
* Get size of buffer used so far.
*/
virtual uint64_t getBufferSize() const = 0;
/**
* Flushing underlying output stream
*/
virtual uint64_t flush() = 0;
/**
* record current position
* @param recorder use the recorder to record current positions
*/
virtual void recordPosition(PositionRecorder* recorder) const = 0;
/**
* suppress the data and reset to initial state
*/
virtual void suppress() = 0;
};
class ByteRleDecoder {
public:
virtual ~ByteRleDecoder();
/**
* Seek to a particular spot.
*/
virtual void seek(PositionProvider&) = 0;
/**
* Seek over a given number of values.
*/
virtual void skip(uint64_t numValues) = 0;
/**
* Read a number of values into the batch.
* @param data the array to read into
* @param numValues the number of values to read
* @param notNull If the pointer is null, all values are read. If the
* pointer is not null, positions that are false are skipped.
*/
virtual void next(char* data, uint64_t numValues, char* notNull) = 0;
};
/**
* Create a byte RLE encoder.
* @param output the output stream to write to
*/
std::unique_ptr<ByteRleEncoder> createByteRleEncoder
(std::unique_ptr<BufferedOutputStream> output);
/**
* Create a boolean RLE encoder.
* @param output the output stream to write to
*/
std::unique_ptr<ByteRleEncoder> createBooleanRleEncoder
(std::unique_ptr<BufferedOutputStream> output);
/**
* Create a byte RLE decoder.
* @param input the input stream to read from
*/
std::unique_ptr<ByteRleDecoder> createByteRleDecoder
(std::unique_ptr<SeekableInputStream> input);
/**
* Create a boolean RLE decoder.
*
* Unlike the other RLE decoders, the boolean decoder sets the data to 0
* if the value is masked by notNull. This is required for the notNull stream
* processing to properly apply multiple masks from nested types.
* @param input the input stream to read from
*/
std::unique_ptr<ByteRleDecoder> createBooleanRleDecoder
(std::unique_ptr<SeekableInputStream> input);
}
#endif
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