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
215
216
217
218
219
220
221
222
223
224
225
226
227
228
|
# Copyright 2015, 2016 OpenMarket Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import logging
from typing import TYPE_CHECKING, Any, Mapping, NoReturn, Optional, Tuple, cast
import psycopg2.extensions
from synapse.storage.engines._base import (
BaseDatabaseEngine,
IncorrectDatabaseSetup,
IsolationLevel,
)
from synapse.storage.types import Cursor
if TYPE_CHECKING:
from synapse.storage.database import LoggingDatabaseConnection
logger = logging.getLogger(__name__)
class PostgresEngine(
BaseDatabaseEngine[psycopg2.extensions.connection, psycopg2.extensions.cursor]
):
def __init__(self, database_config: Mapping[str, Any]):
super().__init__(psycopg2, database_config)
psycopg2.extensions.register_type(psycopg2.extensions.UNICODE)
# Disables passing `bytes` to txn.execute, c.f. #6186. If you do
# actually want to use bytes than wrap it in `bytearray`.
def _disable_bytes_adapter(_: bytes) -> NoReturn:
raise Exception("Passing bytes to DB is disabled.")
psycopg2.extensions.register_adapter(bytes, _disable_bytes_adapter)
self.synchronous_commit: bool = database_config.get("synchronous_commit", True)
self._version: Optional[int] = None # unknown as yet
self.isolation_level_map: Mapping[int, int] = {
IsolationLevel.READ_COMMITTED: psycopg2.extensions.ISOLATION_LEVEL_READ_COMMITTED,
IsolationLevel.REPEATABLE_READ: psycopg2.extensions.ISOLATION_LEVEL_REPEATABLE_READ,
IsolationLevel.SERIALIZABLE: psycopg2.extensions.ISOLATION_LEVEL_SERIALIZABLE,
}
self.default_isolation_level = (
psycopg2.extensions.ISOLATION_LEVEL_REPEATABLE_READ
)
self.config = database_config
@property
def single_threaded(self) -> bool:
return False
def get_db_locale(self, txn: Cursor) -> Tuple[str, str]:
txn.execute(
"SELECT datcollate, datctype FROM pg_database WHERE datname = current_database()"
)
collation, ctype = cast(Tuple[str, str], txn.fetchone())
return collation, ctype
def check_database(
self,
db_conn: psycopg2.extensions.connection,
allow_outdated_version: bool = False,
) -> None:
# Get the version of PostgreSQL that we're using. As per the psycopg2
# docs: The number is formed by converting the major, minor, and
# revision numbers into two-decimal-digit numbers and appending them
# together. For example, version 8.1.5 will be returned as 80105
self._version = db_conn.server_version
allow_unsafe_locale = self.config.get("allow_unsafe_locale", False)
# Are we on a supported PostgreSQL version?
if not allow_outdated_version and self._version < 110000:
raise RuntimeError("Synapse requires PostgreSQL 11 or above.")
with db_conn.cursor() as txn:
txn.execute("SHOW SERVER_ENCODING")
rows = txn.fetchall()
if rows and rows[0][0] != "UTF8":
raise IncorrectDatabaseSetup(
"Database has incorrect encoding: '%s' instead of 'UTF8'\n"
"See docs/postgres.md for more information." % (rows[0][0],)
)
collation, ctype = self.get_db_locale(txn)
if collation != "C":
logger.warning(
"Database has incorrect collation of %r. Should be 'C'",
collation,
)
if not allow_unsafe_locale:
raise IncorrectDatabaseSetup(
"Database has incorrect collation of %r. Should be 'C'\n"
"See docs/postgres.md for more information. You can override this check by"
"setting 'allow_unsafe_locale' to true in the database config.",
collation,
)
if ctype != "C":
if not allow_unsafe_locale:
logger.warning(
"Database has incorrect ctype of %r. Should be 'C'",
ctype,
)
raise IncorrectDatabaseSetup(
"Database has incorrect ctype of %r. Should be 'C'\n"
"See docs/postgres.md for more information. You can override this check by"
"setting 'allow_unsafe_locale' to true in the database config.",
ctype,
)
def check_new_database(self, txn: Cursor) -> None:
"""Gets called when setting up a brand new database. This allows us to
apply stricter checks on new databases versus existing database.
"""
collation, ctype = self.get_db_locale(txn)
errors = []
if collation != "C":
errors.append(" - 'COLLATE' is set to %r. Should be 'C'" % (collation,))
if ctype != "C":
errors.append(" - 'CTYPE' is set to %r. Should be 'C'" % (ctype,))
if errors:
raise IncorrectDatabaseSetup(
"Database is incorrectly configured:\n\n%s\n\n"
"See docs/postgres.md for more information." % ("\n".join(errors))
)
def convert_param_style(self, sql: str) -> str:
return sql.replace("?", "%s")
def on_new_connection(self, db_conn: "LoggingDatabaseConnection") -> None:
db_conn.set_isolation_level(self.default_isolation_level)
# Set the bytea output to escape, vs the default of hex
cursor = db_conn.cursor()
cursor.execute("SET bytea_output TO escape")
# Asynchronous commit, don't wait for the server to call fsync before
# ending the transaction.
# https://www.postgresql.org/docs/current/static/wal-async-commit.html
if not self.synchronous_commit:
cursor.execute("SET synchronous_commit TO OFF")
cursor.close()
db_conn.commit()
@property
def supports_using_any_list(self) -> bool:
"""Do we support using `a = ANY(?)` and passing a list"""
return True
@property
def supports_returning(self) -> bool:
"""Do we support the `RETURNING` clause in insert/update/delete?"""
return True
def is_deadlock(self, error: Exception) -> bool:
if isinstance(error, psycopg2.DatabaseError):
# https://www.postgresql.org/docs/current/static/errcodes-appendix.html
# "40001" serialization_failure
# "40P01" deadlock_detected
return error.pgcode in ["40001", "40P01"]
return False
def is_connection_closed(self, conn: psycopg2.extensions.connection) -> bool:
return bool(conn.closed)
def lock_table(self, txn: Cursor, table: str) -> None:
txn.execute("LOCK TABLE %s in EXCLUSIVE MODE" % (table,))
@property
def server_version(self) -> str:
"""Returns a string giving the server version. For example: '8.1.5'."""
# note that this is a bit of a hack because it relies on check_database
# having been called. Still, that should be a safe bet here.
numver = self._version
assert numver is not None
# https://www.postgresql.org/docs/current/libpq-status.html#LIBPQ-PQSERVERVERSION
if numver >= 100000:
return "%i.%i" % (numver / 10000, numver % 10000)
else:
return "%i.%i.%i" % (numver / 10000, (numver % 10000) / 100, numver % 100)
def in_transaction(self, conn: psycopg2.extensions.connection) -> bool:
return conn.status != psycopg2.extensions.STATUS_READY
def attempt_to_set_autocommit(
self, conn: psycopg2.extensions.connection, autocommit: bool
) -> None:
return conn.set_session(autocommit=autocommit)
def attempt_to_set_isolation_level(
self, conn: psycopg2.extensions.connection, isolation_level: Optional[int]
) -> None:
if isolation_level is None:
isolation_level = self.default_isolation_level
else:
isolation_level = self.isolation_level_map[isolation_level]
return conn.set_isolation_level(isolation_level)
@staticmethod
def executescript(cursor: psycopg2.extensions.cursor, script: str) -> None:
"""Execute a chunk of SQL containing multiple semicolon-delimited statements.
Psycopg2 seems happy to do this in DBAPI2's `execute()` function.
For consistency with SQLite, any ongoing transaction is committed before
executing the script in its own transaction. The script transaction is
left open and it is the responsibility of the caller to commit it.
"""
cursor.execute(f"COMMIT; BEGIN TRANSACTION; {script}")
|
