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#ifndef VARINT_INL_H_
#error "Direct inclusion of this file is not allowed, include varint.h"
// For the sake of sane code completion.
#include "varint.h"
#endif
#include "zig_zag.h"
#include <library/cpp/yt/exception/exception.h>
#include <array>
namespace NYT {
////////////////////////////////////////////////////////////////////////////////
inline int WriteVarUint64(char* output, ui64 value)
{
output[0] = static_cast<ui8>(value);
if (Y_LIKELY(value < 0x80)) {
return 1;
}
output[0] |= 0x80;
value >>= 7;
output[1] = static_cast<ui8>(value);
if (Y_LIKELY(value < 0x80)) {
return 2;
}
int count = 2;
do {
output[count - 1] |= 0x80;
value >>= 7;
output[count] = static_cast<ui8>(value);
++count;
} while (Y_UNLIKELY(value >= 0x80));
return count;
}
inline int WriteVarUint64(IOutputStream* output, ui64 value)
{
std::array<char, MaxVarUint64Size> buffer;
auto size = WriteVarUint64(buffer.data(), value);
output->Write(buffer.data(), size);
return size;
}
////////////////////////////////////////////////////////////////////////////////
namespace NDetail {
template <class T, size_t N>
T ReadVarUintKnownSize(const char* buffer)
{
auto result = static_cast<T>(static_cast<ui8>(buffer[N - 1])) << (7 * (N - 1));
for (size_t i = 0, offset = 0; i < N - 1; i++, offset += 7) {
result += static_cast<T>(static_cast<ui8>(buffer[i]) - 0x80) << offset;
}
return result;
}
} // namespace NDetail
#define XX(type, size) \
if (static_cast<ui8>(input[size - 1]) < 0x80) { \
*value = NYT::NDetail::ReadVarUintKnownSize<type, size>(input); \
return size; \
}
Y_FORCE_INLINE int ReadVarUint32(const char* input, ui32* value)
{
XX(ui64, 1)
XX(ui64, 2)
XX(ui64, 3)
XX(ui64, 4)
XX(ui64, 5)
throw TSimpleException("Value is too big for varuint32");
}
Y_FORCE_INLINE int ReadVarUint64(const char* input, ui64* value)
{
XX(ui64, 1)
XX(ui64, 2)
XX(ui64, 3)
XX(ui64, 4)
XX(ui64, 5)
XX(ui64, 6)
XX(ui64, 7)
XX(ui64, 8)
XX(ui64, 9)
XX(ui64, 10)
throw TSimpleException("Value is too big for varuint64");
}
#undef XX
////////////////////////////////////////////////////////////////////////////////
namespace NDetail {
template <class TOutput>
Y_FORCE_INLINE int WriteVarUint32Impl(TOutput output, ui32 value)
{
return WriteVarUint64(output, static_cast<ui64>(value));
}
template <class TOutput>
Y_FORCE_INLINE int WriteVarInt32Impl(TOutput output, i32 value)
{
return WriteVarUint64(output, ZigZagEncode32(value));
}
template <class TOutput>
Y_FORCE_INLINE int WriteVarInt64Impl(TOutput output, i64 value)
{
return WriteVarUint64(output, ZigZagEncode64(value));
}
} // namespace NDetail
Y_FORCE_INLINE int WriteVarUint32(IOutputStream* output, ui32 value)
{
return NYT::NDetail::WriteVarUint32Impl(output, value);
}
Y_FORCE_INLINE int WriteVarUint32(char* output, ui32 value)
{
return NYT::NDetail::WriteVarUint32Impl(output, value);
}
Y_FORCE_INLINE int WriteVarInt32(IOutputStream* output, i32 value)
{
return NYT::NDetail::WriteVarInt32Impl(output, value);
}
Y_FORCE_INLINE int WriteVarInt32(char* output, i32 value)
{
return NYT::NDetail::WriteVarInt32Impl(output, value);
}
Y_FORCE_INLINE int WriteVarInt64(IOutputStream* output, i64 value)
{
return NYT::NDetail::WriteVarInt64Impl(output, value);
}
Y_FORCE_INLINE int WriteVarInt64(char* output, i64 value)
{
return NYT::NDetail::WriteVarInt64Impl(output, value);
}
////////////////////////////////////////////////////////////////////////////////
namespace NDetail {
template <class TReadCallback>
int ReadVarUint64Impl(ui64* value, TReadCallback&& doRead)
{
size_t count = 0;
ui64 result = 0;
ui8 byte;
do {
byte = doRead();
result |= (static_cast<ui64> (byte & 0x7F)) << (7 * count);
++count;
if (count > MaxVarUint64Size) {
throw TSimpleException("Value is too big for varuint64");
}
} while (byte & 0x80);
*value = result;
return count;
}
inline int ReadVarUint64Fallback(const char* input, const char* end, ui64* value)
{
return ReadVarUint64Impl(
value,
[&] {
if (input == end) {
throw TSimpleException("Premature end of data while reading varuint64");
}
return *input++;
});
}
} // namespace NDetail
inline int ReadVarUint64(IInputStream* input, ui64* value)
{
return NYT::NDetail::ReadVarUint64Impl(
value,
[&] {
char byte;
if (input->Read(&byte, 1) != 1) {
throw TSimpleException("Premature end of stream while reading varuint64");
}
return byte;
});
}
Y_FORCE_INLINE int ReadVarUint64(const char* input, const char* end, ui64* value)
{
if (Y_LIKELY(static_cast<size_t>(end - input) >= MaxVarUint64Size)) {
return ReadVarUint64(input, value);
} else {
return NYT::NDetail::ReadVarUint64Fallback(input, end, value);
}
}
////////////////////////////////////////////////////////////////////////////////
namespace NDetail {
template <class... TArgs>
Y_FORCE_INLINE int ReadVarUint32Impl(ui32* value, TArgs&&... args)
{
ui64 varInt;
int bytesRead = ReadVarUint64(std::forward<TArgs>(args)..., &varInt);
if (varInt > std::numeric_limits<ui32>::max()) {
throw TSimpleException("Value is too big for varuint32");
}
*value = static_cast<ui32>(varInt);
return bytesRead;
}
} // namespace NDetail
Y_FORCE_INLINE int ReadVarUint32(IInputStream* input, ui32* value)
{
return NYT::NDetail::ReadVarUint32Impl(value, input);
}
Y_FORCE_INLINE int ReadVarUint32(const char* input, const char* end, ui32* value)
{
return NYT::NDetail::ReadVarUint32Impl(value, input, end);
}
////////////////////////////////////////////////////////////////////////////////
namespace NDetail {
template <class... TArgs>
Y_FORCE_INLINE int ReadVarInt32Impl(i32* value, TArgs&&... args)
{
ui64 varInt;
int bytesRead = ReadVarUint64(std::forward<TArgs>(args)..., &varInt);
if (varInt > std::numeric_limits<ui32>::max()) {
throw TSimpleException("Value is too big for varint32");
}
*value = ZigZagDecode32(static_cast<ui32>(varInt));
return bytesRead;
}
} // namespace NDetail
Y_FORCE_INLINE int ReadVarInt32(IInputStream* input, i32* value)
{
return NYT::NDetail::ReadVarInt32Impl(value, input);
}
Y_FORCE_INLINE int ReadVarInt32(const char* input, i32* value)
{
return NYT::NDetail::ReadVarInt32Impl(value, input);
}
Y_FORCE_INLINE int ReadVarInt32(const char* input, const char* end, i32* value)
{
return NYT::NDetail::ReadVarInt32Impl(value, input, end);
}
////////////////////////////////////////////////////////////////////////////////
namespace NDetail {
template <class... TArgs>
Y_FORCE_INLINE int ReadVarInt64Impl(i64* value, TArgs&&... args)
{
ui64 varInt;
int bytesRead = ReadVarUint64(std::forward<TArgs>(args)..., &varInt);
*value = ZigZagDecode64(varInt);
return bytesRead;
}
} // namespace NDetail
Y_FORCE_INLINE int ReadVarInt64(IInputStream* input, i64* value)
{
return NYT::NDetail::ReadVarInt64Impl(value, input);
}
Y_FORCE_INLINE int ReadVarInt64(const char* input, i64* value)
{
return NYT::NDetail::ReadVarInt64Impl(value, input);
}
Y_FORCE_INLINE int ReadVarInt64(const char* input, const char* end, i64* value)
{
return NYT::NDetail::ReadVarInt64Impl(value, input, end);
}
////////////////////////////////////////////////////////////////////////////////
} // namespace NYT
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