1#include "parseRemoteDescription.h"
2#include <Common/Exception.h>
3#include <IO/WriteHelpers.h>
4
5namespace DB
6{
7
8namespace ErrorCodes
9{
10 extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
11 extern const int BAD_ARGUMENTS;
12}
13
14/// The Cartesian product of two sets of rows, the result is written in place of the first argument
15static void append(std::vector<String> & to, const std::vector<String> & what, size_t max_addresses)
16{
17 if (what.empty())
18 return;
19
20 if (to.empty())
21 {
22 to = what;
23 return;
24 }
25
26 if (what.size() * to.size() > max_addresses)
27 throw Exception("Table function 'remote': first argument generates too many result addresses",
28 ErrorCodes::BAD_ARGUMENTS);
29 std::vector<String> res;
30 for (size_t i = 0; i < to.size(); ++i)
31 for (size_t j = 0; j < what.size(); ++j)
32 res.push_back(to[i] + what[j]);
33
34 to.swap(res);
35}
36
37
38/// Parse number from substring
39static bool parseNumber(const String & description, size_t l, size_t r, size_t & res)
40{
41 res = 0;
42 for (size_t pos = l; pos < r; pos ++)
43 {
44 if (!isNumericASCII(description[pos]))
45 return false;
46 res = res * 10 + description[pos] - '0';
47 if (res > 1e15)
48 return false;
49 }
50 return true;
51}
52
53
54
55/* Parse a string that generates shards and replicas. Separator - one of two characters | or ,
56 * depending on whether shards or replicas are generated.
57 * For example:
58 * host1,host2,... - generates set of shards from host1, host2, ...
59 * host1|host2|... - generates set of replicas from host1, host2, ...
60 * abc{8..10}def - generates set of shards abc8def, abc9def, abc10def.
61 * abc{08..10}def - generates set of shards abc08def, abc09def, abc10def.
62 * abc{x,yy,z}def - generates set of shards abcxdef, abcyydef, abczdef.
63 * abc{x|yy|z} def - generates set of replicas abcxdef, abcyydef, abczdef.
64 * abc{1..9}de{f,g,h} - is a direct product, 27 shards.
65 * abc{1..9}de{0|1} - is a direct product, 9 shards, in each 2 replicas.
66 */
67std::vector<String> parseRemoteDescription(const String & description, size_t l, size_t r, char separator, size_t max_addresses)
68{
69 std::vector<String> res;
70 std::vector<String> cur;
71
72 /// An empty substring means a set of an empty string
73 if (l >= r)
74 {
75 res.push_back("");
76 return res;
77 }
78
79 for (size_t i = l; i < r; ++i)
80 {
81 /// Either the numeric interval (8..10) or equivalent expression in brackets
82 if (description[i] == '{')
83 {
84 int cnt = 1;
85 int last_dot = -1; /// The rightmost pair of points, remember the index of the right of the two
86 size_t m;
87 std::vector<String> buffer;
88 bool have_splitter = false;
89
90 /// Look for the corresponding closing bracket
91 for (m = i + 1; m < r; ++m)
92 {
93 if (description[m] == '{') ++cnt;
94 if (description[m] == '}') --cnt;
95 if (description[m] == '.' && description[m-1] == '.') last_dot = m;
96 if (description[m] == separator) have_splitter = true;
97 if (cnt == 0) break;
98 }
99 if (cnt != 0)
100 throw Exception("Table function 'remote': incorrect brace sequence in first argument",
101 ErrorCodes::BAD_ARGUMENTS);
102 /// The presence of a dot - numeric interval
103 if (last_dot != -1)
104 {
105 size_t left, right;
106 if (description[last_dot - 1] != '.')
107 throw Exception("Table function 'remote': incorrect argument in braces (only one dot): " + description.substr(i, m - i + 1),
108 ErrorCodes::BAD_ARGUMENTS);
109 if (!parseNumber(description, i + 1, last_dot - 1, left))
110 throw Exception("Table function 'remote': incorrect argument in braces (Incorrect left number): "
111 + description.substr(i, m - i + 1),
112 ErrorCodes::BAD_ARGUMENTS);
113 if (!parseNumber(description, last_dot + 1, m, right))
114 throw Exception("Table function 'remote': incorrect argument in braces (Incorrect right number): "
115 + description.substr(i, m - i + 1),
116 ErrorCodes::BAD_ARGUMENTS);
117 if (left > right)
118 throw Exception("Table function 'remote': incorrect argument in braces (left number is greater then right): "
119 + description.substr(i, m - i + 1),
120 ErrorCodes::BAD_ARGUMENTS);
121 if (right - left + 1 > max_addresses)
122 throw Exception("Table function 'remote': first argument generates too many result addresses",
123 ErrorCodes::BAD_ARGUMENTS);
124 bool add_leading_zeroes = false;
125 size_t len = last_dot - 1 - (i + 1);
126 /// If the left and right borders have equal numbers, then you must add leading zeros.
127 /// TODO The code is somewhat awful.
128 if (last_dot - 1 - (i + 1) == m - (last_dot + 1))
129 add_leading_zeroes = true;
130 for (size_t id = left; id <= right; ++id)
131 {
132 String id_str = toString<UInt64>(id);
133 if (add_leading_zeroes)
134 {
135 while (id_str.size() < len)
136 id_str = "0" + id_str;
137 }
138 buffer.push_back(id_str);
139 }
140 }
141 else if (have_splitter) /// If there is a current delimiter inside, then generate a set of resulting rows
142 buffer = parseRemoteDescription(description, i + 1, m, separator, max_addresses);
143 else /// Otherwise just copy, spawn will occur when you call with the correct delimiter
144 buffer.push_back(description.substr(i, m - i + 1));
145 /// Add all possible received extensions to the current set of lines
146 append(cur, buffer, max_addresses);
147 i = m;
148 }
149 else if (description[i] == separator)
150 {
151 /// If the delimiter, then add found rows
152 res.insert(res.end(), cur.begin(), cur.end());
153 cur.clear();
154 }
155 else
156 {
157 /// Otherwise, simply append the character to current lines
158 std::vector<String> buffer;
159 buffer.push_back(description.substr(i, 1));
160 append(cur, buffer, max_addresses);
161 }
162 }
163
164 res.insert(res.end(), cur.begin(), cur.end());
165 if (res.size() > max_addresses)
166 throw Exception("Table function 'remote': first argument generates too many result addresses",
167 ErrorCodes::BAD_ARGUMENTS);
168
169 return res;
170}
171
172}
173