ClickHouse/src/Interpreters/AggregationCommon.h
2024-03-18 08:00:09 +00:00

314 lines
10 KiB
C++

#pragma once
#include <array>
#include <Common/SipHash.h>
#include <Common/memcpySmall.h>
#include <Common/assert_cast.h>
#include <Core/Defines.h>
#include <base/StringRef.h>
#include <Columns/IColumn.h>
#include <Columns/ColumnsNumber.h>
#include <Columns/ColumnFixedString.h>
#include <Columns/ColumnLowCardinality.h>
#if defined(__SSSE3__) && !defined(MEMORY_SANITIZER)
#include <tmmintrin.h>
#endif
namespace DB
{
namespace ErrorCodes
{
extern const int LOGICAL_ERROR;
}
class Arena;
using Sizes = std::vector<size_t>;
/// When packing the values of nullable columns at a given row, we have to
/// store the fact that these values are nullable or not. This is achieved
/// by encoding this information as a bitmap. Let S be the size in bytes of
/// a packed values binary blob and T the number of bytes we may place into
/// this blob, the size that the bitmap shall occupy in the blob is equal to:
/// ceil(T/8). Thus we must have: S = T + ceil(T/8). Below we indicate for
/// each value of S, the corresponding value of T, and the bitmap size:
///
/// 32,28,4
/// 16,14,2
/// 8,7,1
/// 4,3,1
/// 2,1,1
///
template <typename T>
constexpr auto getBitmapSize()
{
return
(sizeof(T) == 32) ?
4 :
(sizeof(T) == 16) ?
2 :
((sizeof(T) == 8) ?
1 :
((sizeof(T) == 4) ?
1 :
((sizeof(T) == 2) ?
1 :
0)));
}
template<typename T, size_t step>
void fillFixedBatch(size_t num_rows, const T * source, T * dest)
{
for (size_t i = 0; i < num_rows; ++i)
{
*dest = *source;
++source;
dest += step;
}
}
/// Move keys of size T into binary blob, starting from offset.
/// It is assumed that offset is aligned to sizeof(T).
/// Example: sizeof(key) = 16, sizeof(T) = 4, offset = 8
/// out[0] : [--------****----]
/// out[1] : [--------****----]
/// ...
template<typename T, typename Key>
void fillFixedBatch(size_t keys_size, const ColumnRawPtrs & key_columns, const Sizes & key_sizes, PaddedPODArray<Key> & out, size_t & offset)
{
for (size_t i = 0; i < keys_size; ++i)
{
if (key_sizes[i] == sizeof(T))
{
const auto * column = key_columns[i];
size_t num_rows = column->size();
out.resize_fill(num_rows);
/// Note: here we violate strict aliasing.
/// It should be ok as log as we do not reffer to any value from `out` before filling.
const char * source = static_cast<const ColumnFixedSizeHelper *>(column)->getRawDataBegin<sizeof(T)>();
size_t offset_to = offset;
if constexpr (std::endian::native == std::endian::big)
offset_to = sizeof(Key) - sizeof(T) - offset;
T * dest = reinterpret_cast<T *>(reinterpret_cast<char *>(out.data()) + offset_to);
fillFixedBatch<T, sizeof(Key) / sizeof(T)>(num_rows, reinterpret_cast<const T *>(source), dest); /// NOLINT(bugprone-sizeof-expression)
offset += sizeof(T);
}
}
}
/// Pack into a binary blob of type T a set of fixed-size keys. Granted that all the keys fit into the
/// binary blob. Keys are placed starting from the longest one.
template <typename T>
void packFixedBatch(size_t keys_size, const ColumnRawPtrs & key_columns, const Sizes & key_sizes, PaddedPODArray<T> & out)
{
size_t offset = 0;
fillFixedBatch<UInt128>(keys_size, key_columns, key_sizes, out, offset);
fillFixedBatch<UInt64>(keys_size, key_columns, key_sizes, out, offset);
fillFixedBatch<UInt32>(keys_size, key_columns, key_sizes, out, offset);
fillFixedBatch<UInt16>(keys_size, key_columns, key_sizes, out, offset);
fillFixedBatch<UInt8>(keys_size, key_columns, key_sizes, out, offset);
}
template <typename T>
using KeysNullMap = std::array<UInt8, getBitmapSize<T>()>;
/// Pack into a binary blob of type T a set of fixed-size keys. Granted that all the keys fit into the
/// binary blob, they are disposed in it consecutively.
template <typename T, bool has_low_cardinality = false>
static inline T ALWAYS_INLINE packFixed(
size_t i, size_t keys_size, const ColumnRawPtrs & key_columns, const Sizes & key_sizes,
const ColumnRawPtrs * low_cardinality_positions [[maybe_unused]] = nullptr,
const Sizes * low_cardinality_sizes [[maybe_unused]] = nullptr)
{
T key{};
char * bytes = reinterpret_cast<char *>(&key);
size_t offset = 0;
for (size_t j = 0; j < keys_size; ++j)
{
size_t index = i;
const IColumn * column = key_columns[j];
if constexpr (has_low_cardinality)
{
if (const IColumn * positions = (*low_cardinality_positions)[j])
{
switch ((*low_cardinality_sizes)[j])
{
case sizeof(UInt8): index = assert_cast<const ColumnUInt8 *>(positions)->getElement(i); break;
case sizeof(UInt16): index = assert_cast<const ColumnUInt16 *>(positions)->getElement(i); break;
case sizeof(UInt32): index = assert_cast<const ColumnUInt32 *>(positions)->getElement(i); break;
case sizeof(UInt64): index = assert_cast<const ColumnUInt64 *>(positions)->getElement(i); break;
default: throw Exception(ErrorCodes::LOGICAL_ERROR, "Unexpected size of index type for low cardinality column.");
}
}
}
switch (key_sizes[j])
{
case 1:
{
memcpy(bytes + offset, static_cast<const ColumnFixedSizeHelper *>(column)->getRawDataBegin<1>() + index, 1);
offset += 1;
}
break;
case 2:
if constexpr (sizeof(T) >= 2) /// To avoid warning about memcpy exceeding object size.
{
memcpy(bytes + offset, static_cast<const ColumnFixedSizeHelper *>(column)->getRawDataBegin<2>() + index * 2, 2);
offset += 2;
}
break;
case 4:
if constexpr (sizeof(T) >= 4)
{
memcpy(bytes + offset, static_cast<const ColumnFixedSizeHelper *>(column)->getRawDataBegin<4>() + index * 4, 4);
offset += 4;
}
break;
case 8:
if constexpr (sizeof(T) >= 8)
{
memcpy(bytes + offset, static_cast<const ColumnFixedSizeHelper *>(column)->getRawDataBegin<8>() + index * 8, 8);
offset += 8;
}
break;
default:
memcpy(bytes + offset, static_cast<const ColumnFixedSizeHelper *>(column)->getRawDataBegin<1>() + index * key_sizes[j], key_sizes[j]);
offset += key_sizes[j];
}
}
return key;
}
/// Similar as above but supports nullable values.
template <typename T>
static inline T ALWAYS_INLINE packFixed(
size_t i, size_t keys_size, const ColumnRawPtrs & key_columns, const Sizes & key_sizes,
const KeysNullMap<T> & bitmap)
{
union
{
T key;
char bytes[sizeof(key)] = {};
};
size_t offset = 0;
static constexpr auto bitmap_size = std::tuple_size<KeysNullMap<T>>::value;
static constexpr bool has_bitmap = bitmap_size > 0;
if (has_bitmap)
{
memcpy(bytes + offset, bitmap.data(), bitmap_size * sizeof(UInt8));
offset += bitmap_size;
}
for (size_t j = 0; j < keys_size; ++j)
{
bool is_null;
if (!has_bitmap)
is_null = false;
else
{
size_t bucket = j / 8;
size_t off = j % 8;
is_null = ((bitmap[bucket] >> off) & 1) == 1;
}
if (is_null)
continue;
switch (key_sizes[j])
{
case 1:
memcpy(bytes + offset, static_cast<const ColumnFixedSizeHelper *>(key_columns[j])->getRawDataBegin<1>() + i, 1);
offset += 1;
break;
case 2:
memcpy(bytes + offset, static_cast<const ColumnFixedSizeHelper *>(key_columns[j])->getRawDataBegin<2>() + i * 2, 2);
offset += 2;
break;
case 4:
memcpy(bytes + offset, static_cast<const ColumnFixedSizeHelper *>(key_columns[j])->getRawDataBegin<4>() + i * 4, 4);
offset += 4;
break;
case 8:
memcpy(bytes + offset, static_cast<const ColumnFixedSizeHelper *>(key_columns[j])->getRawDataBegin<8>() + i * 8, 8);
offset += 8;
break;
default:
memcpy(bytes + offset, static_cast<const ColumnFixedSizeHelper *>(key_columns[j])->getRawDataBegin<1>() + i * key_sizes[j], key_sizes[j]);
offset += key_sizes[j];
}
}
return key;
}
/// Hash a set of keys into a UInt128 value.
static inline UInt128 ALWAYS_INLINE hash128( /// NOLINT
size_t i, size_t keys_size, const ColumnRawPtrs & key_columns)
{
SipHash hash;
for (size_t j = 0; j < keys_size; ++j)
key_columns[j]->updateHashWithValue(i, hash);
return hash.get128();
}
/** Serialize keys into a continuous chunk of memory.
*/
static inline StringRef ALWAYS_INLINE serializeKeysToPoolContiguous( /// NOLINT
size_t i, size_t keys_size, const ColumnRawPtrs & key_columns, Arena & pool)
{
const char * begin = nullptr;
size_t sum_size = 0;
for (size_t j = 0; j < keys_size; ++j)
sum_size += key_columns[j]->serializeValueIntoArena(i, pool, begin).size;
return {begin, sum_size};
}
/** Pack elements with shuffle instruction.
* See the explanation in ColumnsHashing.h
*/
#if defined(__SSSE3__) && !defined(MEMORY_SANITIZER)
template <typename T>
static T inline packFixedShuffle(
const char * __restrict * __restrict srcs,
size_t num_srcs,
const size_t * __restrict elem_sizes,
size_t idx,
const uint8_t * __restrict masks)
{
assert(num_srcs > 0);
__m128i res = _mm_shuffle_epi8(
_mm_loadu_si128(reinterpret_cast<const __m128i *>(srcs[0] + elem_sizes[0] * idx)),
_mm_loadu_si128(reinterpret_cast<const __m128i *>(masks)));
for (size_t i = 1; i < num_srcs; ++i)
{
res = _mm_xor_si128(res,
_mm_shuffle_epi8(
_mm_loadu_si128(reinterpret_cast<const __m128i *>(srcs[i] + elem_sizes[i] * idx)),
_mm_loadu_si128(reinterpret_cast<const __m128i *>(&masks[i * sizeof(T)]))));
}
T out;
__builtin_memcpy(&out, &res, sizeof(T));
return out;
}
#endif
}