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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
|
#include "PostgreSQLSource.h"
#include "Common/Exception.h"
#if USE_LIBPQXX
#include <Columns/ColumnNullable.h>
#include <Columns/ColumnString.h>
#include <Columns/ColumnArray.h>
#include <Columns/ColumnsNumber.h>
#include <Columns/ColumnDecimal.h>
#include <DataTypes/IDataType.h>
#include <DataTypes/DataTypeNullable.h>
#include <DataTypes/DataTypeArray.h>
#include <DataTypes/DataTypesDecimal.h>
#include <Interpreters/convertFieldToType.h>
#include <IO/ReadHelpers.h>
#include <IO/WriteHelpers.h>
#include <IO/ReadBufferFromString.h>
#include <Common/assert_cast.h>
#include <base/range.h>
#include <Common/logger_useful.h>
namespace DB
{
namespace ErrorCodes
{
extern const int TOO_MANY_COLUMNS;
}
template<typename T>
PostgreSQLSource<T>::PostgreSQLSource(
postgres::ConnectionHolderPtr connection_holder_,
const std::string & query_str_,
const Block & sample_block,
UInt64 max_block_size_)
: ISource(sample_block.cloneEmpty())
, query_str(query_str_)
, max_block_size(max_block_size_)
, connection_holder(std::move(connection_holder_))
{
init(sample_block);
}
template<typename T>
PostgreSQLSource<T>::PostgreSQLSource(
std::shared_ptr<T> tx_,
const std::string & query_str_,
const Block & sample_block,
UInt64 max_block_size_,
bool auto_commit_)
: ISource(sample_block.cloneEmpty())
, query_str(query_str_)
, tx(std::move(tx_))
, max_block_size(max_block_size_)
, auto_commit(auto_commit_)
{
init(sample_block);
}
template<typename T>
void PostgreSQLSource<T>::init(const Block & sample_block)
{
description.init(sample_block);
for (const auto idx : collections::range(0, description.sample_block.columns()))
if (description.types[idx].first == ExternalResultDescription::ValueType::vtArray)
preparePostgreSQLArrayInfo(array_info, idx, description.sample_block.getByPosition(idx).type);
/// pqxx::stream_from uses COPY command, will get error if ';' is present
if (query_str.ends_with(';'))
query_str.resize(query_str.size() - 1);
}
template<typename T>
void PostgreSQLSource<T>::onStart()
{
if (!tx)
{
try
{
auto & conn = connection_holder->get();
tx = std::make_shared<T>(conn);
}
catch (const pqxx::broken_connection &)
{
connection_holder->update();
tx = std::make_shared<T>(connection_holder->get());
}
}
stream = std::make_unique<pqxx::stream_from>(*tx, pqxx::from_query, std::string_view{query_str});
}
template<typename T>
IProcessor::Status PostgreSQLSource<T>::prepare()
{
if (!started)
{
onStart();
started = true;
}
auto status = ISource::prepare();
if (status == Status::Finished)
onFinish();
return status;
}
template<typename T>
Chunk PostgreSQLSource<T>::generate()
{
/// Check if pqxx::stream_from is finished
if (!stream || !(*stream))
return {};
MutableColumns columns = description.sample_block.cloneEmptyColumns();
size_t num_rows = 0;
while (true)
{
const std::vector<pqxx::zview> * row{stream->read_row()};
/// row is nullptr if pqxx::stream_from is finished
if (!row)
break;
if (row->size() > description.sample_block.columns())
throw Exception(ErrorCodes::TOO_MANY_COLUMNS,
"Row has too many columns: {}, expected structure: {}",
row->size(), description.sample_block.dumpStructure());
for (const auto idx : collections::range(0, row->size()))
{
const auto & sample = description.sample_block.getByPosition(idx);
/// if got NULL type, then pqxx::zview will return nullptr in c_str()
if ((*row)[idx].c_str())
{
if (description.types[idx].second)
{
ColumnNullable & column_nullable = assert_cast<ColumnNullable &>(*columns[idx]);
const auto & data_type = assert_cast<const DataTypeNullable &>(*sample.type);
insertPostgreSQLValue(
column_nullable.getNestedColumn(), (*row)[idx],
description.types[idx].first, data_type.getNestedType(), array_info, idx);
column_nullable.getNullMapData().emplace_back(0);
}
else
{
insertPostgreSQLValue(
*columns[idx], (*row)[idx], description.types[idx].first, sample.type, array_info, idx);
}
}
else
{
insertDefaultPostgreSQLValue(*columns[idx], *sample.column);
}
}
if (++num_rows == max_block_size)
break;
}
return Chunk(std::move(columns), num_rows);
}
template<typename T>
void PostgreSQLSource<T>::onFinish()
{
if (stream)
stream->close();
if (tx && auto_commit)
tx->commit();
is_completed = true;
}
template<typename T>
PostgreSQLSource<T>::~PostgreSQLSource()
{
if (!is_completed)
{
try
{
stream.reset();
tx.reset();
}
catch (...)
{
tryLogCurrentException(__PRETTY_FUNCTION__);
}
connection_holder->setBroken();
}
}
template
class PostgreSQLSource<pqxx::ReplicationTransaction>;
template
class PostgreSQLSource<pqxx::ReadTransaction>;
}
#endif
|
