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// Author: Artyom.
// A module for storing arbitrary variable-bitsize numbers in a compressed form so that later
// you can access any number searching it by index or sum of numbers preceeding and including searched number.
#pragma once
/*
#include "std/function.hpp"
#include "std/stdint.hpp"
#include "std/vector.hpp"
// Forward declarations.
class Reader;
class Writer;
// Number of nums in a chunk per one table entry.
uint64_t const NUM_ELEM_PER_TABLE_ENTRY = 1024;
// A source of nums.
typedef function<uint64_t (uint64_t pos)> NumsSourceFuncT;
// Builds CompressedVarnumVector based on source of numbers.
// If supportSums is true then sums are included in the table otherwise sums are not computed.
void BuildCompressedVarnumVector(Writer & writer, NumsSourceFuncT numsSource, uint64_t numsCnt, bool supportSums);
// Reader of CompressedVarnumVector.
class CompressedVarnumVectorReader
{
public:
// Bytes are read from Reader on the flight while decoding.
CompressedVarnumVectorReader(Reader & reader);
~CompressedVarnumVectorReader();
// Set current number decoding context to number at given index.
// sumBefore will contain total sum of numbers before indexed number, computed only if sums are supported.
void FindByIndex(uint64_t index, uint64_t & sumBefore);
// Works only if sums are supported. Finds ith number by total sum of numbers in the range [0, i], i.e.
// finds such first number that sum of all number before and including it are equal or greater to sum.
// sumIncl will contain the actual sum including found number, cntIncl contains count of numbers including
// found one. Function returns found number.
uint64_t FindBySum(uint64_t sum, uint64_t & sumIncl, uint64_t & cntIncl);
// After setting position by FindByIndex and FindBySum functions Read() function will sequentially read
// next number. It is only allowed to read numbers in same chunk as the first number found (one chunk is
// created for one table entry).
uint64_t Read();
private:
void SetDecodeContext(uint64_t table_entry_index);
private:
Reader & m_reader;
uint64_t m_numsCnt;
uint64_t m_numElemPerTableEntry;
bool m_supportSums;
uint64_t m_numsEncodedOffset;
vector<uint32_t> m_distrTable;
vector<uint64_t> m_tablePos;
vector<uint64_t> m_tableSum;
// Decode context.
struct DecodeContext;
DecodeContext * m_decodeCtx;
};
*/
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