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
138
139
140
141
142
143
144
|
#include <Columns/ColumnString.h>
#include <Functions/FunctionFactory.h>
#include <Functions/FunctionStringToString.h>
#include <base/find_symbols.h>
namespace DB
{
namespace ErrorCodes
{
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
}
namespace
{
struct EncodeXMLComponentName
{
static constexpr auto name = "encodeXMLComponent";
};
class FunctionEncodeXMLComponentImpl
{
public:
static void vector(
const ColumnString::Chars & data,
const ColumnString::Offsets & offsets,
ColumnString::Chars & res_data,
ColumnString::Offsets & res_offsets)
{
/// 6 is the maximum size amplification (the maximum length of encoded entity: ")
res_data.resize(data.size() * 6);
size_t size = offsets.size();
res_offsets.resize(size);
size_t prev_offset = 0;
size_t res_offset = 0;
for (size_t i = 0; i < size; ++i)
{
const char * src_data = reinterpret_cast<const char *>(&data[prev_offset]);
size_t src_size = offsets[i] - prev_offset;
size_t dst_size = execute(src_data, src_size, reinterpret_cast<char *>(res_data.data() + res_offset));
res_offset += dst_size;
res_offsets[i] = res_offset;
prev_offset = offsets[i];
}
res_data.resize(res_offset);
}
[[noreturn]] static void vectorFixed(const ColumnString::Chars &, size_t, ColumnString::Chars &)
{
throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT, "Function encodeXML cannot work with FixedString argument");
}
private:
static size_t execute(const char * src, size_t src_size, char * dst)
{
const char * src_prev_pos = src;
const char * src_curr_pos = src;
const char * src_end = src + src_size;
char * dst_pos = dst;
while (true)
{
src_curr_pos = find_first_symbols<'<', '&', '>', '"', '\''>(src_curr_pos, src_end);
if (src_curr_pos == src_end)
{
break;
}
else if (*src_curr_pos == '<')
{
size_t bytes_to_copy = src_curr_pos - src_prev_pos;
memcpySmallAllowReadWriteOverflow15(dst_pos, src_prev_pos, bytes_to_copy);
dst_pos += bytes_to_copy;
memcpy(dst_pos, "<", 4);
dst_pos += 4;
src_prev_pos = src_curr_pos + 1;
++src_curr_pos;
}
else if (*src_curr_pos == '&')
{
size_t bytes_to_copy = src_curr_pos - src_prev_pos;
memcpySmallAllowReadWriteOverflow15(dst_pos, src_prev_pos, bytes_to_copy);
dst_pos += bytes_to_copy;
memcpy(dst_pos, "&", 5);
dst_pos += 5;
src_prev_pos = src_curr_pos + 1;
++src_curr_pos;
}
else if (*src_curr_pos == '>')
{
size_t bytes_to_copy = src_curr_pos - src_prev_pos;
memcpySmallAllowReadWriteOverflow15(dst_pos, src_prev_pos, bytes_to_copy);
dst_pos += bytes_to_copy;
memcpy(dst_pos, ">", 4);
dst_pos += 4;
src_prev_pos = src_curr_pos + 1;
++src_curr_pos;
}
else if (*src_curr_pos == '"')
{
size_t bytes_to_copy = src_curr_pos - src_prev_pos;
memcpySmallAllowReadWriteOverflow15(dst_pos, src_prev_pos, bytes_to_copy);
dst_pos += bytes_to_copy;
memcpy(dst_pos, """, 6);
dst_pos += 6;
src_prev_pos = src_curr_pos + 1;
++src_curr_pos;
}
else if (*src_curr_pos == '\'')
{
size_t bytes_to_copy = src_curr_pos - src_prev_pos;
memcpySmallAllowReadWriteOverflow15(dst_pos, src_prev_pos, bytes_to_copy);
dst_pos += bytes_to_copy;
memcpy(dst_pos, "'", 6);
dst_pos += 6;
src_prev_pos = src_curr_pos + 1;
++src_curr_pos;
}
}
if (src_prev_pos < src_curr_pos)
{
size_t bytes_to_copy = src_curr_pos - src_prev_pos;
memcpySmallAllowReadWriteOverflow15(dst_pos, src_prev_pos, bytes_to_copy);
dst_pos += bytes_to_copy;
}
return dst_pos - dst;
}
};
using FunctionEncodeXMLComponent = FunctionStringToString<FunctionEncodeXMLComponentImpl, EncodeXMLComponentName>;
}
REGISTER_FUNCTION(EncodeXMLComponent)
{
factory.registerFunction<FunctionEncodeXMLComponent>();
}
}
|
