1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
|
#pragma once
#include <base/types.h>
#include <Common/PODArray.h>
#include <algorithm>
#include <cctype>
#include <cmath>
#include <memory>
#include <queue>
#include <utility>
namespace DB
{
template <size_t MaxNumHints>
class NamePrompter
{
public:
using DistanceIndex = std::pair<size_t, size_t>;
using DistanceIndexQueue = std::priority_queue<DistanceIndex>;
static std::vector<String> getHints(const String & name, const std::vector<String> & prompting_strings)
{
DistanceIndexQueue queue;
for (size_t i = 0; i < prompting_strings.size(); ++i)
appendToQueue(i, name, queue, prompting_strings);
return release(queue, prompting_strings);
}
private:
static size_t levenshteinDistance(const String & lhs, const String & rhs)
{
size_t m = lhs.size();
size_t n = rhs.size();
PODArrayWithStackMemory<size_t, 64> row(n + 1);
for (size_t i = 1; i <= n; ++i)
row[i] = i;
for (size_t j = 1; j <= m; ++j)
{
row[0] = j;
size_t prev = j - 1;
for (size_t i = 1; i <= n; ++i)
{
size_t old = row[i];
row[i] = std::min(prev + (std::tolower(lhs[j - 1]) != std::tolower(rhs[i - 1])),
std::min(row[i - 1], row[i]) + 1);
prev = old;
}
}
return row[n];
}
static void appendToQueue(size_t ind, const String & name, DistanceIndexQueue & queue, const std::vector<String> & prompting_strings)
{
const String & prompt = prompting_strings[ind];
/// Clang SimpleTypoCorrector logic
const size_t min_possible_edit_distance = std::abs(static_cast<int64_t>(name.size()) - static_cast<int64_t>(prompt.size()));
const size_t mistake_factor = (name.size() + 2) / 3;
if (min_possible_edit_distance > 0 && name.size() / min_possible_edit_distance < 3)
return;
if (prompt.size() <= name.size() + mistake_factor && prompt.size() + mistake_factor >= name.size())
{
size_t distance = levenshteinDistance(prompt, name);
if (distance <= mistake_factor)
{
queue.emplace(distance, ind);
if (queue.size() > MaxNumHints)
queue.pop();
}
}
}
static std::vector<String> release(DistanceIndexQueue & queue, const std::vector<String> & prompting_strings)
{
std::vector<String> answer;
answer.reserve(queue.size());
while (!queue.empty())
{
auto top = queue.top();
queue.pop();
answer.push_back(prompting_strings[top.second]);
}
std::reverse(answer.begin(), answer.end());
return answer;
}
};
String getHintsErrorMessageSuffix(const std::vector<String> & hints);
void appendHintsMessage(String & error_message, const std::vector<String> & hints);
template <size_t MaxNumHints, typename Self>
class IHints
{
public:
virtual std::vector<String> getAllRegisteredNames() const = 0;
std::vector<String> getHints(const String & name) const
{
return prompter.getHints(name, getAllRegisteredNames());
}
std::vector<String> getHints(const String & name, const std::vector<String> & prompting_strings) const
{
return prompter.getHints(name, prompting_strings);
}
void appendHintsMessage(String & error_message, const String & name) const
{
auto hints = getHints(name);
DB::appendHintsMessage(error_message, hints);
}
String getHintsMessage(const String & name) const
{
return getHintsErrorMessageSuffix(getHints(name));
}
IHints() = default;
IHints(const IHints &) = default;
IHints(IHints &&) noexcept = default;
IHints & operator=(const IHints &) = default;
IHints & operator=(IHints &&) noexcept = default;
virtual ~IHints() = default;
private:
NamePrompter<MaxNumHints> prompter;
};
}
|
