ClickHouse/src/Functions/FunctionsStringDistance.cpp
2024-01-09 12:53:17 +00:00

517 lines
19 KiB
C++

#include <Columns/ColumnString.h>
#include <Columns/ColumnsNumber.h>
#include <DataTypes/DataTypeString.h>
#include <DataTypes/DataTypesNumber.h>
#include <Functions/FunctionFactory.h>
#include <Functions/FunctionsStringSimilarity.h>
#include <Common/PODArray.h>
#include <Common/UTF8Helpers.h>
#include <Common/iota.h>
#include <numeric>
#ifdef __SSE4_2__
# include <nmmintrin.h>
#endif
namespace DB
{
namespace ErrorCodes
{
extern const int BAD_ARGUMENTS;
extern const int TOO_LARGE_STRING_SIZE;
}
template <typename Op>
struct FunctionStringDistanceImpl
{
using ResultType = typename Op::ResultType;
static void constantConstant(const String & haystack, const String & needle, ResultType & res)
{
res = Op::process(haystack.data(), haystack.size(), needle.data(), needle.size());
}
static void vectorVector(
const ColumnString::Chars & haystack_data,
const ColumnString::Offsets & haystack_offsets,
const ColumnString::Chars & needle_data,
const ColumnString::Offsets & needle_offsets,
PaddedPODArray<ResultType> & res)
{
size_t size = res.size();
const char * haystack = reinterpret_cast<const char *>(haystack_data.data());
const char * needle = reinterpret_cast<const char *>(needle_data.data());
for (size_t i = 0; i < size; ++i)
{
res[i] = Op::process(
haystack + haystack_offsets[i - 1],
haystack_offsets[i] - haystack_offsets[i - 1] - 1,
needle + needle_offsets[i - 1],
needle_offsets[i] - needle_offsets[i - 1] - 1);
}
}
static void constantVector(
const String & haystack,
const ColumnString::Chars & needle_data,
const ColumnString::Offsets & needle_offsets,
PaddedPODArray<ResultType> & res)
{
const char * haystack_data = haystack.data();
size_t haystack_size = haystack.size();
const char * needle = reinterpret_cast<const char *>(needle_data.data());
size_t size = res.size();
for (size_t i = 0; i < size; ++i)
{
res[i] = Op::process(haystack_data, haystack_size,
needle + needle_offsets[i - 1], needle_offsets[i] - needle_offsets[i - 1] - 1);
}
}
static void vectorConstant(
const ColumnString::Chars & data,
const ColumnString::Offsets & offsets,
const String & needle,
PaddedPODArray<ResultType> & res)
{
constantVector(needle, data, offsets, res);
}
};
struct ByteHammingDistanceImpl
{
using ResultType = UInt64;
static ResultType process(
const char * __restrict haystack, size_t haystack_size, const char * __restrict needle, size_t needle_size)
{
UInt64 res = 0;
const char * haystack_end = haystack + haystack_size;
const char * needle_end = needle + needle_size;
#ifdef __SSE4_2__
static constexpr auto mode = _SIDD_UBYTE_OPS | _SIDD_CMP_EQUAL_EACH | _SIDD_NEGATIVE_POLARITY;
const char * haystack_end16 = haystack + haystack_size / 16 * 16;
const char * needle_end16 = needle + needle_size / 16 * 16;
for (; haystack < haystack_end16 && needle < needle_end16; haystack += 16, needle += 16)
{
__m128i s1 = _mm_loadu_si128(reinterpret_cast<const __m128i *>(haystack));
__m128i s2 = _mm_loadu_si128(reinterpret_cast<const __m128i *>(needle));
auto result_mask = _mm_cmpestrm(s1, 16, s2, 16, mode);
const __m128i mask_hi = _mm_unpackhi_epi64(result_mask, result_mask);
res += _mm_popcnt_u64(_mm_cvtsi128_si64(result_mask)) + _mm_popcnt_u64(_mm_cvtsi128_si64(mask_hi));
}
#endif
for (; haystack != haystack_end && needle != needle_end; ++haystack, ++needle)
res += *haystack != *needle;
res = res + (haystack_end - haystack) + (needle_end - needle);
return res;
}
};
template <bool is_utf8>
struct ByteJaccardIndexImpl
{
using ResultType = Float64;
static ResultType process(
const char * __restrict haystack, size_t haystack_size, const char * __restrict needle, size_t needle_size)
{
if (haystack_size == 0 || needle_size == 0)
return 0;
const char * haystack_end = haystack + haystack_size;
const char * needle_end = needle + needle_size;
/// For byte strings use plain array as a set
constexpr size_t max_size = std::numeric_limits<unsigned char>::max() + 1;
std::array<UInt8, max_size> haystack_set;
std::array<UInt8, max_size> needle_set;
/// For UTF-8 strings we also use sets of code points greater than max_size
std::set<UInt32> haystack_utf8_set;
std::set<UInt32> needle_utf8_set;
haystack_set.fill(0);
needle_set.fill(0);
while (haystack < haystack_end)
{
size_t len = 1;
if constexpr (is_utf8)
len = UTF8::seqLength(*haystack);
if (len == 1)
{
haystack_set[static_cast<unsigned char>(*haystack)] = 1;
++haystack;
}
else
{
auto code_point = UTF8::convertUTF8ToCodePoint(haystack, haystack_end - haystack);
if (code_point.has_value())
{
haystack_utf8_set.insert(code_point.value());
haystack += len;
}
else
{
throw Exception(ErrorCodes::BAD_ARGUMENTS, "Illegal UTF-8 sequence, while processing '{}'", StringRef(haystack, haystack_end - haystack));
}
}
}
while (needle < needle_end)
{
size_t len = 1;
if constexpr (is_utf8)
len = UTF8::seqLength(*needle);
if (len == 1)
{
needle_set[static_cast<unsigned char>(*needle)] = 1;
++needle;
}
else
{
auto code_point = UTF8::convertUTF8ToCodePoint(needle, needle_end - needle);
if (code_point.has_value())
{
needle_utf8_set.insert(code_point.value());
needle += len;
}
else
{
throw Exception(ErrorCodes::BAD_ARGUMENTS, "Illegal UTF-8 sequence, while processing '{}'", StringRef(needle, needle_end - needle));
}
}
}
UInt8 intersection = 0;
UInt8 union_size = 0;
if constexpr (is_utf8)
{
auto lit = haystack_utf8_set.begin();
auto rit = needle_utf8_set.begin();
while (lit != haystack_utf8_set.end() && rit != needle_utf8_set.end())
{
if (*lit == *rit)
{
++intersection;
++lit;
++rit;
}
else if (*lit < *rit)
++lit;
else
++rit;
}
union_size = haystack_utf8_set.size() + needle_utf8_set.size() - intersection;
}
for (size_t i = 0; i < max_size; ++i)
{
intersection += haystack_set[i] & needle_set[i];
union_size += haystack_set[i] | needle_set[i];
}
return static_cast<ResultType>(intersection) / static_cast<ResultType>(union_size);
}
};
static constexpr size_t max_string_size = 1u << 16;
struct ByteEditDistanceImpl
{
using ResultType = UInt64;
static ResultType process(
const char * __restrict haystack, size_t haystack_size, const char * __restrict needle, size_t needle_size)
{
if (haystack_size == 0 || needle_size == 0)
return haystack_size + needle_size;
/// Safety threshold against DoS, since we use two arrays to calculate the distance.
if (haystack_size > max_string_size || needle_size > max_string_size)
throw Exception(
ErrorCodes::TOO_LARGE_STRING_SIZE,
"The string size is too big for function editDistance, should be at most {}", max_string_size);
PaddedPODArray<ResultType> distances0(haystack_size + 1, 0);
PaddedPODArray<ResultType> distances1(haystack_size + 1, 0);
ResultType substitution = 0;
ResultType insertion = 0;
ResultType deletion = 0;
iota(distances0.data(), haystack_size + 1, ResultType(0));
for (size_t pos_needle = 0; pos_needle < needle_size; ++pos_needle)
{
distances1[0] = pos_needle + 1;
for (size_t pos_haystack = 0; pos_haystack < haystack_size; pos_haystack++)
{
deletion = distances0[pos_haystack + 1] + 1;
insertion = distances1[pos_haystack] + 1;
substitution = distances0[pos_haystack];
if (*(needle + pos_needle) != *(haystack + pos_haystack))
substitution += 1;
distances1[pos_haystack + 1] = std::min(deletion, std::min(substitution, insertion));
}
distances0.swap(distances1);
}
return distances0[haystack_size];
}
};
struct ByteDamerauLevenshteinDistanceImpl
{
using ResultType = UInt64;
static ResultType process(
const char * __restrict haystack, size_t haystack_size, const char * __restrict needle, size_t needle_size)
{
/// Safety threshold against DoS
if (haystack_size > max_string_size || needle_size > max_string_size)
throw Exception(
ErrorCodes::TOO_LARGE_STRING_SIZE,
"The string size is too big for function damerauLevenshteinDistance, should be at most {}", max_string_size);
/// Shortcuts:
if (haystack_size == 0)
return needle_size;
if (needle_size == 0)
return haystack_size;
if (haystack_size == needle_size && memcmp(haystack, needle, haystack_size) == 0)
return 0;
/// Implements the algorithm for optimal string alignment distance from
/// https://en.wikipedia.org/wiki/Damerau%E2%80%93Levenshtein_distance#Optimal_string_alignment_distance
/// Dynamically allocate memory for the 2D array
/// Allocating a 2D array, for convenience starts is an array of pointers to the start of the rows.
std::vector<int> d((needle_size + 1) * (haystack_size + 1));
std::vector<int *> starts(haystack_size + 1);
/// Setting the pointers in starts to the beginning of (needle_size + 1)-long intervals.
/// Also initialize the row values based on the mentioned algorithm.
for (size_t i = 0; i <= haystack_size; ++i)
{
starts[i] = d.data() + (needle_size + 1) * i;
starts[i][0] = static_cast<int>(i);
}
for (size_t j = 0; j <= needle_size; ++j)
{
starts[0][j] = static_cast<int>(j);
}
for (size_t i = 1; i <= haystack_size; ++i)
{
for (size_t j = 1; j <= needle_size; ++j)
{
int cost = (haystack[i - 1] == needle[j - 1]) ? 0 : 1;
starts[i][j] = std::min(starts[i - 1][j] + 1, /// deletion
std::min(starts[i][j - 1] + 1, /// insertion
starts[i - 1][j - 1] + cost) /// substitution
);
if (i > 1 && j > 1 && haystack[i - 1] == needle[j - 2] && haystack[i - 2] == needle[j - 1])
starts[i][j] = std::min(starts[i][j], starts[i - 2][j - 2] + 1); /// transposition
}
}
return starts[haystack_size][needle_size];
}
};
struct ByteJaroSimilarityImpl
{
using ResultType = Float64;
static ResultType process(
const char * __restrict haystack, size_t haystack_size, const char * __restrict needle, size_t needle_size)
{
/// Safety threshold against DoS
if (haystack_size > max_string_size || needle_size > max_string_size)
throw Exception(
ErrorCodes::TOO_LARGE_STRING_SIZE,
"The string size is too big for function jaroSimilarity, should be at most {}", max_string_size);
/// Shortcuts:
if (haystack_size == 0)
return needle_size;
if (needle_size == 0)
return haystack_size;
if (haystack_size == needle_size && memcmp(haystack, needle, haystack_size) == 0)
return 1.0;
const int s1len = static_cast<int>(haystack_size);
const int s2len = static_cast<int>(needle_size);
/// Window size to search for matches in the other string
const int max_range = std::max(0, std::max(s1len, s2len) / 2 - 1);
std::vector<int> s1_matching(s1len, -1);
std::vector<int> s2_matching(s2len, -1);
/// Calculate matching characters
size_t matching_characters = 0;
for (int i = 0; i < s1len; i++)
{
/// Matching window
const int min_index = std::max(i - max_range, 0);
const int max_index = std::min(i + max_range + 1, s2len);
for (int j = min_index; j < max_index; j++)
{
if (s2_matching[j] == -1 && haystack[i] == needle[j])
{
s1_matching[i] = i;
s2_matching[j] = j;
matching_characters++;
break;
}
}
}
if (matching_characters == 0)
return 0.0;
/// Transpositions (one-way only)
double transpositions = 0.0;
for (size_t i = 0, s1i = 0, s2i = 0; i < matching_characters; i++)
{
while (s1_matching[s1i] == -1)
s1i++;
while (s2_matching[s2i] == -1)
s2i++;
if (haystack[s1i] != needle[s2i])
transpositions += 0.5;
s1i++;
s2i++;
}
double m = static_cast<double>(matching_characters);
double jaro_similarity = 1.0 / 3.0 * (m / static_cast<double>(s1len)
+ m / static_cast<double>(s2len)
+ (m - transpositions) / m);
return jaro_similarity;
}
};
struct ByteJaroWinklerSimilarityImpl
{
using ResultType = Float64;
static ResultType process(
const char * __restrict haystack, size_t haystack_size, const char * __restrict needle, size_t needle_size)
{
static constexpr int max_prefix_length = 4;
static constexpr double scaling_factor = 0.1;
static constexpr double boost_threshold = 0.7;
/// Safety threshold against DoS
if (haystack_size > max_string_size || needle_size > max_string_size)
throw Exception(
ErrorCodes::TOO_LARGE_STRING_SIZE,
"The string size is too big for function jaroWinklerSimilarity, should be at most {}", max_string_size);
const int s1len = static_cast<int>(haystack_size);
const int s2len = static_cast<int>(needle_size);
ResultType jaro_winkler_similarity = ByteJaroSimilarityImpl::process(haystack, haystack_size, needle, needle_size);
if (jaro_winkler_similarity > boost_threshold)
{
const int common_length = std::min(max_prefix_length, std::min(s1len, s2len));
int common_prefix = 0;
while (common_prefix < common_length && haystack[common_prefix] == needle[common_prefix])
common_prefix++;
jaro_winkler_similarity += common_prefix * scaling_factor * (1.0 - jaro_winkler_similarity);
}
return jaro_winkler_similarity;
}
};
struct NameByteHammingDistance
{
static constexpr auto name = "byteHammingDistance";
};
using FunctionByteHammingDistance = FunctionsStringSimilarity<FunctionStringDistanceImpl<ByteHammingDistanceImpl>, NameByteHammingDistance>;
struct NameEditDistance
{
static constexpr auto name = "editDistance";
};
using FunctionEditDistance = FunctionsStringSimilarity<FunctionStringDistanceImpl<ByteEditDistanceImpl>, NameEditDistance>;
struct NameDamerauLevenshteinDistance
{
static constexpr auto name = "damerauLevenshteinDistance";
};
using FunctionDamerauLevenshteinDistance = FunctionsStringSimilarity<FunctionStringDistanceImpl<ByteDamerauLevenshteinDistanceImpl>, NameDamerauLevenshteinDistance>;
struct NameJaccardIndex
{
static constexpr auto name = "stringJaccardIndex";
};
using FunctionStringJaccardIndex = FunctionsStringSimilarity<FunctionStringDistanceImpl<ByteJaccardIndexImpl<false>>, NameJaccardIndex>;
struct NameJaccardIndexUTF8
{
static constexpr auto name = "stringJaccardIndexUTF8";
};
using FunctionStringJaccardIndexUTF8 = FunctionsStringSimilarity<FunctionStringDistanceImpl<ByteJaccardIndexImpl<true>>, NameJaccardIndexUTF8>;
struct NameJaroSimilarity
{
static constexpr auto name = "jaroSimilarity";
};
using FunctionJaroSimilarity = FunctionsStringSimilarity<FunctionStringDistanceImpl<ByteJaroSimilarityImpl>, NameJaroSimilarity>;
struct NameJaroWinklerSimilarity
{
static constexpr auto name = "jaroWinklerSimilarity";
};
using FunctionJaroWinklerSimilarity = FunctionsStringSimilarity<FunctionStringDistanceImpl<ByteJaroWinklerSimilarityImpl>, NameJaroWinklerSimilarity>;
REGISTER_FUNCTION(StringDistance)
{
factory.registerFunction<FunctionByteHammingDistance>(
FunctionDocumentation{.description = R"(Calculates Hamming distance between two byte-strings.)"});
factory.registerAlias("mismatches", NameByteHammingDistance::name);
factory.registerFunction<FunctionEditDistance>(
FunctionDocumentation{.description = R"(Calculates the edit distance between two byte-strings.)"});
factory.registerAlias("levenshteinDistance", NameEditDistance::name);
factory.registerFunction<FunctionDamerauLevenshteinDistance>(
FunctionDocumentation{.description = R"(Calculates the Damerau-Levenshtein distance two between two byte-string.)"});
factory.registerFunction<FunctionStringJaccardIndex>(
FunctionDocumentation{.description = R"(Calculates the Jaccard similarity index between two byte strings.)"});
factory.registerFunction<FunctionStringJaccardIndexUTF8>(
FunctionDocumentation{.description = R"(Calculates the Jaccard similarity index between two UTF8 strings.)"});
factory.registerFunction<FunctionJaroSimilarity>(
FunctionDocumentation{.description = R"(Calculates the Jaro similarity between two byte-string.)"});
factory.registerFunction<FunctionJaroWinklerSimilarity>(
FunctionDocumentation{.description = R"(Calculates the Jaro-Winkler similarity between two byte-string.)"});
}
}