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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_RLE_HH
#define ORC_RLE_HH
#include "io/InputStream.hh"
#include "io/OutputStream.hh"
#include <memory>
namespace orc {
inline int64_t zigZag(int64_t value) {
return (value << 1) ^ (value >> 63);
}
inline int64_t unZigZag(uint64_t value) {
return value >> 1 ^ -(value & 1);
}
class RleEncoder {
public:
// must be non-inline!
virtual ~RleEncoder();
RleEncoder(
std::unique_ptr<BufferedOutputStream> outStream,
bool hasSigned):
outputStream(std::move(outStream)),
bufferPosition(0),
bufferLength(0),
numLiterals(0),
isSigned(hasSigned),
buffer(nullptr){
//pass
}
/**
* Encode the next batch of values.
* @param data the array to read from
* @param numValues the number of values to write
* @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 int64_t* data, uint64_t numValues,
const char* notNull);
/**
* Get size of buffer used so far.
*/
uint64_t getBufferSize() const {
return outputStream->getSize();
}
/**
* Flushing underlying BufferedOutputStream
*/
virtual uint64_t flush() = 0;
/**
* record current position
* @param recorder use the recorder to record current positions
*/
virtual void recordPosition(PositionRecorder* recorder) const;
virtual void write(int64_t val) = 0;
protected:
std::unique_ptr<BufferedOutputStream> outputStream;
size_t bufferPosition;
size_t bufferLength;
size_t numLiterals;
int64_t* literals;
bool isSigned;
char* buffer;
virtual void writeByte(char c);
virtual void writeVulong(int64_t val);
virtual void writeVslong(int64_t val);
};
class RleDecoder {
public:
// must be non-inline!
virtual ~RleDecoder();
/**
* 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(int64_t* data, uint64_t numValues,
const char* notNull) = 0;
};
/**
* Create an RLE encoder.
* @param output the output stream to write to
* @param isSigned true if the number sequence is signed
* @param version version of RLE decoding to do
* @param pool memory pool to use for allocation
*/
std::unique_ptr<RleEncoder> createRleEncoder
(std::unique_ptr<BufferedOutputStream> output,
bool isSigned,
RleVersion version,
MemoryPool& pool,
bool alignedBitpacking);
/**
* Create an RLE decoder.
* @param input the input stream to read from
* @param isSigned true if the number sequence is signed
* @param version version of RLE decoding to do
* @param pool memory pool to use for allocation
*/
std::unique_ptr<RleDecoder> createRleDecoder
(std::unique_ptr<SeekableInputStream> input,
bool isSigned,
RleVersion version,
MemoryPool& pool);
} // namespace orc
#endif // ORC_RLE_HH
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