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#pragma once
 
#include "codecs.h" 
 
#include <util/ysaveload.h> 
#include <util/stream/null.h>
#include <util/stream/mem.h> 
#include <util/string/cast.h> 
#include <util/string/join.h> 
#include <util/system/align.h> 
#include <util/system/unaligned_mem.h> 
#include <util/generic/hash.h> 
#include <util/generic/cast.h> 
#include <util/generic/buffer.h> 
#include <util/generic/array_ref.h>
#include <util/generic/singleton.h> 
#include <util/generic/algorithm.h> 
#include <util/generic/mem_copy.h> 
 
namespace NBlockCodecs {
    struct TDecompressError: public TDataError { 
        TDecompressError(int code) { 
            *this << "cannot decompress (errcode " << code << ")"; 
        } 
 
        TDecompressError(size_t exp, size_t real) { 
            *this << "broken input (expected len: " << exp << ", got: " << real << ")"; 
        } 
    };

    struct TCompressError: public TDataError { 
        TCompressError(int code) { 
            *this << "cannot compress (errcode " << code << ")"; 
        } 
    };

    struct TNullCodec: public ICodec { 
        size_t DecompressedLength(const TData& in) const override {
            return in.size();
        } 
 
        size_t MaxCompressedLength(const TData& in) const override {
            return in.size();
        } 
 
        size_t Compress(const TData& in, void* out) const override {
            MemCopy((char*)out, in.data(), in.size());
 
            return in.size();
        } 
 
        size_t Decompress(const TData& in, void* out) const override {
            MemCopy((char*)out, in.data(), in.size());
 
            return in.size();
        } 
 
        TStringBuf Name() const noexcept override {
            return TStringBuf("null");
        } 
    }; 
 
    template <class T> 
    struct TAddLengthCodec: public ICodec { 
        static inline void Check(const TData& in) { 
            if (in.size() < sizeof(ui64)) {
                ythrow TDataError() << "too small input"; 
            } 
        } 
 
        size_t DecompressedLength(const TData& in) const override {
            Check(in); 
 
            return ReadUnaligned<ui64>(in.data());
        } 
 
        size_t MaxCompressedLength(const TData& in) const override {
            return T::DoMaxCompressedLength(in.size()) + sizeof(ui64);
        } 
 
        size_t Compress(const TData& in, void* out) const override {
            ui64* ptr = (ui64*)out; 
 
            WriteUnaligned<ui64>(ptr, (ui64) in.size());
 
            return Base()->DoCompress(!in ? TData(TStringBuf("")) : in, ptr + 1) + sizeof(*ptr);
        } 
 
        size_t Decompress(const TData& in, void* out) const override {
            Check(in); 
 
            const auto len = ReadUnaligned<ui64>(in.data());
 
            if (!len)
                return 0;

            Base()->DoDecompress(TData(in).Skip(sizeof(len)), out, len);
            return len;
        } 
 
        inline const T* Base() const noexcept {
            return static_cast<const T*>(this); 
        } 
    }; 
}