pgadmin4/web/pgadmin/utils/driver/psycopg2/connection.py
2018-08-06 15:35:03 +05:30

1856 lines
65 KiB
Python

##########################################################################
#
# pgAdmin 4 - PostgreSQL Tools
#
# Copyright (C) 2013 - 2018, The pgAdmin Development Team
# This software is released under the PostgreSQL Licence
#
##########################################################################
"""
Implementation of Connection.
It is a wrapper around the actual psycopg2 driver, and connection
object.
"""
import random
import select
import sys
import datetime
from collections import deque
import simplejson as json
import psycopg2
from flask import g, current_app
from flask_babelex import gettext
from flask_security import current_user
from pgadmin.utils.crypto import decrypt
from psycopg2.extensions import adapt, encodings
import config
from pgadmin.model import Server, User
from pgadmin.utils.exception import ConnectionLost
from pgadmin.utils import get_complete_file_path
from ..abstract import BaseDriver, BaseConnection
from .cursor import DictCursor
from .typecast import register_global_typecasters, \
register_string_typecasters, register_binary_typecasters, \
register_array_to_string_typecasters, ALL_JSON_TYPES
if sys.version_info < (3,):
# Python2 in-built csv module do not handle unicode
# backports.csv module ported from PY3 csv module for unicode handling
from backports import csv
from StringIO import StringIO
IS_PY2 = True
else:
from io import StringIO
import csv
IS_PY2 = False
_ = gettext
# Register global type caster which will be applicable to all connections.
register_global_typecasters()
class Connection(BaseConnection):
"""
class Connection(object)
A wrapper class, which wraps the psycopg2 connection object, and
delegate the execution to the actual connection object, when required.
Methods:
-------
* connect(**kwargs)
- Connect the PostgreSQL/EDB Postgres Advanced Server using the psycopg2
driver
* execute_scalar(query, params, formatted_exception_msg)
- Execute the given query and returns single datum result
* execute_async(query, params, formatted_exception_msg)
- Execute the given query asynchronously and returns result.
* execute_void(query, params, formatted_exception_msg)
- Execute the given query with no result.
* execute_2darray(query, params, formatted_exception_msg)
- Execute the given query and returns the result as a 2 dimensional
array.
* execute_dict(query, params, formatted_exception_msg)
- Execute the given query and returns the result as an array of dict
(column name -> value) format.
* connected()
- Get the status of the connection.
Returns True if connected, otherwise False.
* reset()
- Reconnect the database server (if possible)
* transaction_status()
- Transaction Status
* ping()
- Ping the server.
* _release()
- Release the connection object of psycopg2
* _reconnect()
- Attempt to reconnect to the database
* _wait(conn)
- This method is used to wait for asynchronous connection. This is a
blocking call.
* _wait_timeout(conn)
- This method is used to wait for asynchronous connection with timeout.
This is a non blocking call.
* poll(formatted_exception_msg)
- This method is used to poll the data of query running on asynchronous
connection.
* status_message()
- Returns the status message returned by the last command executed on
the server.
* rows_affected()
- Returns the no of rows affected by the last command executed on
the server.
* cancel_transaction(conn_id, did=None)
- This method is used to cancel the transaction for the
specified connection id and database id.
* messages()
- Returns the list of messages/notices sends from the PostgreSQL database
server.
* _formatted_exception_msg(exception_obj, formatted_msg)
- This method is used to parse the psycopg2.Error object and returns the
formatted error message if flag is set to true else return
normal error message.
* check_notifies(required_polling)
- Check for the notify messages by polling the connection or after
execute is there in notifies.
* get_notifies()
- This function will returns list of notifies received from database
server.
* pq_encrypt_password_conn()
- This function will return the encrypted password for database server
- greater than or equal to 10.
"""
def __init__(self, manager, conn_id, db, auto_reconnect=True, async_=0,
use_binary_placeholder=False, array_to_string=False):
assert (manager is not None)
assert (conn_id is not None)
self.conn_id = conn_id
self.manager = manager
self.db = db if db is not None else manager.db
self.conn = None
self.auto_reconnect = auto_reconnect
self.async_ = async_
self.__async_cursor = None
self.__async_query_id = None
self.__backend_pid = None
self.execution_aborted = False
self.row_count = 0
self.__notices = None
self.__notifies = None
self.password = None
# This flag indicates the connection status (connected/disconnected).
self.wasConnected = False
# This flag indicates the connection reconnecting status.
self.reconnecting = False
self.use_binary_placeholder = use_binary_placeholder
self.array_to_string = array_to_string
super(Connection, self).__init__()
def as_dict(self):
"""
Returns the dictionary object representing this object.
"""
# In case, it cannot be auto reconnectable, or already been released,
# then we will return None.
if not self.auto_reconnect and not self.conn:
return None
res = dict()
res['conn_id'] = self.conn_id
res['database'] = self.db
res['async_'] = self.async_
res['wasConnected'] = self.wasConnected
res['auto_reconnect'] = self.auto_reconnect
res['use_binary_placeholder'] = self.use_binary_placeholder
res['array_to_string'] = self.array_to_string
return res
def __repr__(self):
return "PG Connection: {0} ({1}) -> {2} (ajax:{3})".format(
self.conn_id, self.db,
'Connected' if self.conn and not self.conn.closed else
"Disconnected",
self.async_
)
def __str__(self):
return "PG Connection: {0} ({1}) -> {2} (ajax:{3})".format(
self.conn_id, self.db,
'Connected' if self.conn and not self.conn.closed else
"Disconnected",
self.async_
)
def connect(self, **kwargs):
if self.conn:
if self.conn.closed:
self.conn = None
else:
return True, None
pg_conn = None
password = None
passfile = None
manager = self.manager
encpass = kwargs['password'] if 'password' in kwargs else None
passfile = kwargs['passfile'] if 'passfile' in kwargs else None
tunnel_password = kwargs['tunnel_password'] if 'tunnel_password' in \
kwargs else ''
# Check SSH Tunnel needs to be created
if manager.use_ssh_tunnel == 1 and not manager.tunnel_created:
status, error = manager.create_ssh_tunnel(tunnel_password)
if not status:
return False, error
# Check SSH Tunnel is alive or not.
if manager.use_ssh_tunnel == 1:
manager.check_ssh_tunnel_alive()
if encpass is None:
encpass = self.password or getattr(manager, 'password', None)
# Reset the existing connection password
if self.reconnecting is not False:
self.password = None
if encpass:
# Fetch Logged in User Details.
user = User.query.filter_by(id=current_user.id).first()
if user is None:
return False, gettext("Unauthorized request.")
try:
password = decrypt(encpass, user.password)
# Handling of non ascii password (Python2)
if hasattr(str, 'decode'):
password = password.decode('utf-8').encode('utf-8')
# password is in bytes, for python3 we need it in string
elif isinstance(password, bytes):
password = password.decode()
except Exception as e:
manager.stop_ssh_tunnel()
current_app.logger.exception(e)
return False, \
_(
"Failed to decrypt the saved password.\nError: {0}"
).format(str(e))
# If no password credential is found then connect request might
# come from Query tool, ViewData grid, debugger etc tools.
# we will check for pgpass file availability from connection manager
# if it's present then we will use it
if not password and not encpass and not passfile:
passfile = manager.passfile if manager.passfile else None
try:
if hasattr(str, 'decode'):
database = self.db.encode('utf-8')
user = manager.user.encode('utf-8')
conn_id = self.conn_id.encode('utf-8')
else:
database = self.db
user = manager.user
conn_id = self.conn_id
import os
os.environ['PGAPPNAME'] = '{0} - {1}'.format(
config.APP_NAME, conn_id)
pg_conn = psycopg2.connect(
host=manager.local_bind_host if manager.use_ssh_tunnel
else manager.host,
hostaddr=manager.local_bind_host if manager.use_ssh_tunnel
else manager.hostaddr,
port=manager.local_bind_port if manager.use_ssh_tunnel
else manager.port,
database=database,
user=user,
password=password,
async_=self.async_,
passfile=get_complete_file_path(passfile),
sslmode=manager.ssl_mode,
sslcert=get_complete_file_path(manager.sslcert),
sslkey=get_complete_file_path(manager.sslkey),
sslrootcert=get_complete_file_path(manager.sslrootcert),
sslcrl=get_complete_file_path(manager.sslcrl),
sslcompression=True if manager.sslcompression else False,
service=manager.service,
connect_timeout=manager.connect_timeout
)
# If connection is asynchronous then we will have to wait
# until the connection is ready to use.
if self.async_ == 1:
self._wait(pg_conn)
except psycopg2.Error as e:
manager.stop_ssh_tunnel()
if e.pgerror:
msg = e.pgerror
elif e.diag.message_detail:
msg = e.diag.message_detail
else:
msg = str(e)
current_app.logger.info(
u"Failed to connect to the database server(#{server_id}) for "
u"connection ({conn_id}) with error message as below"
u":{msg}".format(
server_id=self.manager.sid,
conn_id=conn_id,
msg=msg.decode('utf-8') if hasattr(str, 'decode') else msg
)
)
return False, msg
# Overwrite connection notice attr to support
# more than 50 notices at a time
pg_conn.notices = deque([], self.ASYNC_NOTICE_MAXLENGTH)
self.conn = pg_conn
self.wasConnected = True
try:
status, msg = self._initialize(conn_id, **kwargs)
except Exception as e:
manager.stop_ssh_tunnel()
current_app.logger.exception(e)
self.conn = None
if not self.reconnecting:
self.wasConnected = False
raise e
if status:
manager._update_password(encpass)
else:
if not self.reconnecting:
self.wasConnected = False
return status, msg
def _initialize(self, conn_id, **kwargs):
self.execution_aborted = False
self.__backend_pid = self.conn.get_backend_pid()
setattr(g, "{0}#{1}".format(
self.manager.sid,
self.conn_id.encode('utf-8')
), None)
status, cur = self.__cursor()
formatted_exception_msg = self._formatted_exception_msg
manager = self.manager
def _execute(cur, query, params=None):
try:
self.__internal_blocking_execute(cur, query, params)
except psycopg2.Error as pe:
cur.close()
return formatted_exception_msg(pe, False)
return None
# autocommit flag does not work with asynchronous connections.
# By default asynchronous connection runs in autocommit mode.
if self.async_ == 0:
if 'autocommit' in kwargs and kwargs['autocommit'] is False:
self.conn.autocommit = False
else:
self.conn.autocommit = True
register_string_typecasters(self.conn)
if self.array_to_string:
register_array_to_string_typecasters(self.conn)
# Register type casters for binary data only after registering array to
# string type casters.
if self.use_binary_placeholder:
register_binary_typecasters(self.conn)
if self.conn.encoding in ('SQL_ASCII', 'SQLASCII',
'MULE_INTERNAL', 'MULEINTERNAL'):
status = _execute(cur, "SET DateStyle=ISO;"
"SET client_min_messages=notice;"
"SET bytea_output=escape;"
"SET client_encoding='{0}';"
.format(self.conn.encoding))
self.python_encoding = 'raw_unicode_escape'
else:
status = _execute(cur, "SET DateStyle=ISO;"
"SET client_min_messages=notice;"
"SET bytea_output=escape;"
"SET client_encoding='UNICODE';")
self.python_encoding = 'utf-8'
# Replace the python encoding for original name and renamed encodings
# psycopg2 removes the underscore in conn.encoding
# Setting the encodings dict value will only help for select statements
# because for parameterized DML, param values are converted based on
# python encoding of pyscopg2s internal encodings dict.
for key, val in encodings.items():
if key.replace('_', '') == self.conn.encoding:
encodings[key] = self.python_encoding
if status is not None:
self.conn.close()
self.conn = None
return False, status
if manager.role:
status = _execute(cur, u"SET ROLE TO %s", [manager.role])
if status is not None:
self.conn.close()
self.conn = None
current_app.logger.error(
"Connect to the database server (#{server_id}) for "
"connection ({conn_id}), but - failed to setup the role "
"with error message as below:{msg}".format(
server_id=self.manager.sid,
conn_id=conn_id,
msg=status
)
)
return False, \
_(
"Failed to setup the role with error message:\n{0}"
).format(status)
if manager.ver is None:
status = _execute(cur, "SELECT version()")
if status is not None:
self.conn.close()
self.conn = None
self.wasConnected = False
current_app.logger.error(
"Failed to fetch the version information on the "
"established connection to the database server "
"(#{server_id}) for '{conn_id}' with below error "
"message:{msg}".format(
server_id=self.manager.sid,
conn_id=conn_id,
msg=status)
)
return False, status
if cur.rowcount > 0:
row = cur.fetchmany(1)[0]
manager.ver = row['version']
manager.sversion = self.conn.server_version
status = _execute(cur, """
SELECT
db.oid as did, db.datname, db.datallowconn,
pg_encoding_to_char(db.encoding) AS serverencoding,
has_database_privilege(db.oid, 'CREATE') as cancreate, datlastsysoid
FROM
pg_database db
WHERE db.datname = current_database()""")
if status is None:
manager.db_info = manager.db_info or dict()
if cur.rowcount > 0:
res = cur.fetchmany(1)[0]
manager.db_info[res['did']] = res.copy()
# We do not have database oid for the maintenance database.
if len(manager.db_info) == 1:
manager.did = res['did']
status = _execute(cur, """
SELECT
oid as id, rolname as name, rolsuper as is_superuser,
rolcreaterole as can_create_role, rolcreatedb as can_create_db
FROM
pg_catalog.pg_roles
WHERE
rolname = current_user""")
if status is None:
manager.user_info = dict()
if cur.rowcount > 0:
manager.user_info = cur.fetchmany(1)[0]
if 'password' in kwargs:
manager.password = kwargs['password']
server_types = None
if 'server_types' in kwargs and isinstance(
kwargs['server_types'], list):
server_types = manager.server_types = kwargs['server_types']
if server_types is None:
from pgadmin.browser.server_groups.servers.types import ServerType
server_types = ServerType.types()
for st in server_types:
if st.instanceOf(manager.ver):
manager.server_type = st.stype
manager.server_cls = st
break
manager.update_session()
return True, None
def __cursor(self, server_cursor=False):
# Check SSH Tunnel is alive or not. If used by the database
# server for the connection.
if self.manager.use_ssh_tunnel == 1:
self.manager.check_ssh_tunnel_alive()
if self.wasConnected is False:
raise ConnectionLost(
self.manager.sid,
self.db,
None if self.conn_id[0:3] == u'DB:' else self.conn_id[5:]
)
cur = getattr(g, "{0}#{1}".format(
self.manager.sid,
self.conn_id.encode('utf-8')
), None)
if self.connected() and cur and not cur.closed:
if not server_cursor or (server_cursor and cur.name):
return True, cur
if not self.connected():
errmsg = ""
current_app.logger.warning(
"Connection to database server (#{server_id}) for the "
"connection - '{conn_id}' has been lost.".format(
server_id=self.manager.sid,
conn_id=self.conn_id
)
)
if self.auto_reconnect and not self.reconnecting:
self.__attempt_execution_reconnect(None)
else:
raise ConnectionLost(
self.manager.sid,
self.db,
None if self.conn_id[0:3] == u'DB:' else self.conn_id[5:]
)
try:
if server_cursor:
# Providing name to cursor will create server side cursor.
cursor_name = "CURSOR:{0}".format(self.conn_id)
cur = self.conn.cursor(
name=cursor_name, cursor_factory=DictCursor
)
else:
cur = self.conn.cursor(cursor_factory=DictCursor)
except psycopg2.Error as pe:
current_app.logger.exception(pe)
errmsg = gettext(
"Failed to create cursor for psycopg2 connection with error "
"message for the server#{1}:{2}:\n{0}"
).format(
str(pe), self.manager.sid, self.db
)
current_app.logger.error(errmsg)
if self.conn.closed:
self.conn = None
if self.auto_reconnect and not self.reconnecting:
current_app.logger.info(
gettext(
"Attempting to reconnect to the database server "
"(#{server_id}) for the connection - '{conn_id}'."
).format(
server_id=self.manager.sid,
conn_id=self.conn_id
)
)
return self.__attempt_execution_reconnect(
self.__cursor, server_cursor
)
else:
raise ConnectionLost(
self.manager.sid,
self.db,
None if self.conn_id[0:3] == u'DB:'
else self.conn_id[5:]
)
setattr(
g, "{0}#{1}".format(
self.manager.sid, self.conn_id.encode('utf-8')
), cur
)
return True, cur
def escape_params_sqlascii(self, params):
# The data is unescaped using string_typecasters when selected
# We need to esacpe the data so that it does not fail when
# it is encoded with python ascii
# unicode_escape helps in escaping and unescaping
if self.conn:
if self.conn.encoding in ('SQL_ASCII', 'SQLASCII',
'MULE_INTERNAL', 'MULEINTERNAL')\
and params is not None and type(params) == dict:
params = dict(
(key, val.encode('unicode_escape')
.decode('raw_unicode_escape'))
for key, val in params.items()
)
return params
def __internal_blocking_execute(self, cur, query, params):
"""
This function executes the query using cursor's execute function,
but in case of asynchronous connection we need to wait for the
transaction to be completed. If self.async_ is 1 then it is a
blocking call.
Args:
cur: Cursor object
query: SQL query to run.
params: Extra parameters
"""
if sys.version_info < (3,):
if type(query) == unicode:
query = query.encode('utf-8')
else:
query = query.encode('utf-8')
params = self.escape_params_sqlascii(params)
cur.execute(query, params)
if self.async_ == 1:
self._wait(cur.connection)
def execute_on_server_as_csv(self,
query, params=None,
formatted_exception_msg=False,
records=2000):
"""
To fetch query result and generate CSV output
Args:
query: SQL
params: Additional parameters
formatted_exception_msg: For exception
records: Number of initial records
Returns:
Generator response
"""
status, cur = self.__cursor(server_cursor=True)
self.row_count = 0
if not status:
return False, str(cur)
query_id = random.randint(1, 9999999)
if IS_PY2 and type(query) == unicode:
query = query.encode('utf-8')
current_app.logger.log(
25,
u"Execute (with server cursor) for server #{server_id} - "
u"{conn_id} (Query-id: {query_id}):\n{query}".format(
server_id=self.manager.sid,
conn_id=self.conn_id,
query=query.decode('utf-8') if
sys.version_info < (3,) else query,
query_id=query_id
)
)
try:
self.__internal_blocking_execute(cur, query, params)
except psycopg2.Error as pe:
cur.close()
errmsg = self._formatted_exception_msg(pe, formatted_exception_msg)
current_app.logger.error(
u"failed to execute query ((with server cursor) "
u"for the server #{server_id} - {conn_id} "
u"(query-id: {query_id}):\nerror message:{errmsg}".format(
server_id=self.manager.sid,
conn_id=self.conn_id,
query=query,
errmsg=errmsg,
query_id=query_id
)
)
return False, errmsg
def handle_json_data(json_columns, results):
"""
[ This is only for Python2.x]
This function will be useful to handle json data types.
We will dump json data as proper json instead of unicode values
Args:
json_columns: Columns which contains json data
results: Query result
Returns:
results
"""
# Only if Python2 and there are columns with JSON type
if IS_PY2 and len(json_columns) > 0:
temp_results = []
for row in results:
res = dict()
for k, v in row.items():
if k in json_columns:
res[k] = json.dumps(v)
else:
res[k] = v
temp_results.append(res)
results = temp_results
return results
def convert_keys_to_unicode(results, conn_encoding):
"""
[ This is only for Python2.x]
We need to convert all keys to unicode as psycopg2
sends them as string
Args:
res: Query result set from psycopg2
conn_encoding: Connection encoding
Returns:
Result set (With all the keys converted to unicode)
"""
new_results = []
for row in results:
new_results.append(
dict([(k.decode(conn_encoding), v)
for k, v in row.items()])
)
return new_results
def gen(quote='strings', quote_char="'", field_separator=','):
results = cur.fetchmany(records)
if not results:
if not cur.closed:
cur.close()
yield gettext('The query executed did not return any data.')
return
header = []
json_columns = []
conn_encoding = encodings[cur.connection.encoding]
for c in cur.ordered_description():
# This is to handle the case in which column name is non-ascii
column_name = c.to_dict()['name']
if IS_PY2:
column_name = column_name.decode(conn_encoding)
header.append(column_name)
if c.to_dict()['type_code'] in ALL_JSON_TYPES:
json_columns.append(column_name)
if IS_PY2:
results = convert_keys_to_unicode(results, conn_encoding)
res_io = StringIO()
if quote == 'strings':
quote = csv.QUOTE_NONNUMERIC
elif quote == 'all':
quote = csv.QUOTE_ALL
else:
quote = csv.QUOTE_NONE
if hasattr(str, 'decode'):
# Decode the field_separator
try:
field_separator = field_separator.decode('utf-8')
except Exception as e:
current_app.logger.error(e)
# Decode the quote_char
try:
quote_char = quote_char.decode('utf-8')
except Exception as e:
current_app.logger.error(e)
csv_writer = csv.DictWriter(
res_io, fieldnames=header, delimiter=field_separator,
quoting=quote,
quotechar=quote_char
)
csv_writer.writeheader()
results = handle_json_data(json_columns, results)
csv_writer.writerows(results)
yield res_io.getvalue()
while True:
results = cur.fetchmany(records)
if not results:
if not cur.closed:
cur.close()
break
res_io = StringIO()
csv_writer = csv.DictWriter(
res_io, fieldnames=header, delimiter=field_separator,
quoting=quote,
quotechar=quote_char
)
if IS_PY2:
results = convert_keys_to_unicode(results, conn_encoding)
results = handle_json_data(json_columns, results)
csv_writer.writerows(results)
yield res_io.getvalue()
return True, gen
def execute_scalar(self, query, params=None,
formatted_exception_msg=False):
status, cur = self.__cursor()
self.row_count = 0
if not status:
return False, str(cur)
query_id = random.randint(1, 9999999)
current_app.logger.log(
25,
u"Execute (scalar) for server #{server_id} - {conn_id} (Query-id: "
u"{query_id}):\n{query}".format(
server_id=self.manager.sid,
conn_id=self.conn_id,
query=query,
query_id=query_id
)
)
try:
self.__internal_blocking_execute(cur, query, params)
except psycopg2.Error as pe:
cur.close()
if not self.connected():
if self.auto_reconnect and not self.reconnecting:
return self.__attempt_execution_reconnect(
self.execute_dict, query, params,
formatted_exception_msg
)
raise ConnectionLost(
self.manager.sid,
self.db,
None if self.conn_id[0:3] == u'DB:' else self.conn_id[5:]
)
errmsg = self._formatted_exception_msg(pe, formatted_exception_msg)
current_app.logger.error(
u"Failed to execute query (execute_scalar) for the server "
u"#{server_id} - {conn_id} (Query-id: {query_id}):\n"
u"Error Message:{errmsg}".format(
server_id=self.manager.sid,
conn_id=self.conn_id,
query=query,
errmsg=errmsg,
query_id=query_id
)
)
return False, errmsg
self.row_count = cur.rowcount
if cur.rowcount > 0:
res = cur.fetchone()
if len(res) > 0:
return True, res[0]
return True, None
def execute_async(self, query, params=None, formatted_exception_msg=True):
"""
This function executes the given query asynchronously and returns
result.
Args:
query: SQL query to run.
params: extra parameters to the function
formatted_exception_msg: if True then function return the
formatted exception message
"""
if sys.version_info < (3,):
if type(query) == unicode:
query = query.encode('utf-8')
else:
query = query.encode('utf-8')
# Convert the params based on python_encoding
params = self.escape_params_sqlascii(params)
self.__async_cursor = None
status, cur = self.__cursor()
if not status:
return False, str(cur)
query_id = random.randint(1, 9999999)
current_app.logger.log(
25,
u"Execute (async) for server #{server_id} - {conn_id} (Query-id: "
u"{query_id}):\n{query}".format(
server_id=self.manager.sid,
conn_id=self.conn_id,
query=query.decode('utf-8'),
query_id=query_id
)
)
try:
self.__notices = []
self.__notifies = []
self.execution_aborted = False
cur.execute(query, params)
res = self._wait_timeout(cur.connection)
except psycopg2.Error as pe:
errmsg = self._formatted_exception_msg(pe, formatted_exception_msg)
current_app.logger.error(
u"Failed to execute query (execute_async) for the server "
u"#{server_id} - {conn_id}(Query-id: {query_id}):\n"
u"Error Message:{errmsg}".format(
server_id=self.manager.sid,
conn_id=self.conn_id,
query=query.decode('utf-8'),
errmsg=errmsg,
query_id=query_id
)
)
# Check for the asynchronous notifies.
self.check_notifies()
if self.is_disconnected(pe):
raise ConnectionLost(
self.manager.sid,
self.db,
None if self.conn_id[0:3] == u'DB:' else self.conn_id[5:]
)
return False, errmsg
self.__async_cursor = cur
self.__async_query_id = query_id
return True, res
def execute_void(self, query, params=None, formatted_exception_msg=False):
"""
This function executes the given query with no result.
Args:
query: SQL query to run.
params: extra parameters to the function
formatted_exception_msg: if True then function return the
formatted exception message
"""
status, cur = self.__cursor()
self.row_count = 0
if not status:
return False, str(cur)
query_id = random.randint(1, 9999999)
current_app.logger.log(
25,
u"Execute (void) for server #{server_id} - {conn_id} (Query-id: "
u"{query_id}):\n{query}".format(
server_id=self.manager.sid,
conn_id=self.conn_id,
query=query,
query_id=query_id
)
)
try:
self.__internal_blocking_execute(cur, query, params)
except psycopg2.Error as pe:
cur.close()
if not self.connected():
if self.auto_reconnect and not self.reconnecting:
return self.__attempt_execution_reconnect(
self.execute_void, query, params,
formatted_exception_msg
)
raise ConnectionLost(
self.manager.sid,
self.db,
None if self.conn_id[0:3] == u'DB:' else self.conn_id[5:]
)
errmsg = self._formatted_exception_msg(pe, formatted_exception_msg)
current_app.logger.error(
u"Failed to execute query (execute_void) for the server "
u"#{server_id} - {conn_id}(Query-id: {query_id}):\n"
u"Error Message:{errmsg}".format(
server_id=self.manager.sid,
conn_id=self.conn_id,
query=query,
errmsg=errmsg,
query_id=query_id
)
)
return False, errmsg
self.row_count = cur.rowcount
return True, None
def __attempt_execution_reconnect(self, fn, *args, **kwargs):
self.reconnecting = True
setattr(g, "{0}#{1}".format(
self.manager.sid,
self.conn_id.encode('utf-8')
), None)
try:
status, res = self.connect()
if status:
if fn:
status, res = fn(*args, **kwargs)
self.reconnecting = False
return status, res
except Exception as e:
current_app.logger.exception(e)
self.reconnecting = False
current_app.warning(
"Failed to reconnect the database server "
"(#{server_id})".format(
server_id=self.manager.sid,
conn_id=self.conn_id
)
)
self.reconnecting = False
raise ConnectionLost(
self.manager.sid,
self.db,
None if self.conn_id[0:3] == u'DB:' else self.conn_id[5:]
)
def execute_2darray(self, query, params=None,
formatted_exception_msg=False):
status, cur = self.__cursor()
self.row_count = 0
if not status:
return False, str(cur)
query_id = random.randint(1, 9999999)
current_app.logger.log(
25,
u"Execute (2darray) for server #{server_id} - {conn_id} "
u"(Query-id: {query_id}):\n{query}".format(
server_id=self.manager.sid,
conn_id=self.conn_id,
query=query,
query_id=query_id
)
)
try:
self.__internal_blocking_execute(cur, query, params)
except psycopg2.Error as pe:
cur.close()
if not self.connected():
if self.auto_reconnect and \
not self.reconnecting:
return self.__attempt_execution_reconnect(
self.execute_2darray, query, params,
formatted_exception_msg
)
errmsg = self._formatted_exception_msg(pe, formatted_exception_msg)
current_app.logger.error(
u"Failed to execute query (execute_2darray) for the server "
u"#{server_id} - {conn_id} (Query-id: {query_id}):\n"
u"Error Message:{errmsg}".format(
server_id=self.manager.sid,
conn_id=self.conn_id,
query=query,
errmsg=errmsg,
query_id=query_id
)
)
return False, errmsg
# Get Resultset Column Name, Type and size
columns = cur.description and [
desc.to_dict() for desc in cur.ordered_description()
] or []
rows = []
self.row_count = cur.rowcount
if cur.rowcount > 0:
for row in cur:
rows.append(row)
return True, {'columns': columns, 'rows': rows}
def execute_dict(self, query, params=None, formatted_exception_msg=False):
status, cur = self.__cursor()
self.row_count = 0
if not status:
return False, str(cur)
query_id = random.randint(1, 9999999)
current_app.logger.log(
25,
u"Execute (dict) for server #{server_id} - {conn_id} (Query-id: "
u"{query_id}):\n{query}".format(
server_id=self.manager.sid,
conn_id=self.conn_id,
query=query,
query_id=query_id
)
)
try:
self.__internal_blocking_execute(cur, query, params)
except psycopg2.Error as pe:
cur.close()
if not self.connected():
if self.auto_reconnect and not self.reconnecting:
return self.__attempt_execution_reconnect(
self.execute_dict, query, params,
formatted_exception_msg
)
raise ConnectionLost(
self.manager.sid,
self.db,
None if self.conn_id[0:3] == u'DB:' else self.conn_id[5:]
)
errmsg = self._formatted_exception_msg(pe, formatted_exception_msg)
current_app.logger.error(
u"Failed to execute query (execute_dict) for the server "
u"#{server_id}- {conn_id} (Query-id: {query_id}):\n"
u"Error Message:{errmsg}".format(
server_id=self.manager.sid,
conn_id=self.conn_id,
query_id=query_id,
errmsg=errmsg
)
)
return False, errmsg
# Get Resultset Column Name, Type and size
columns = cur.description and [
desc.to_dict() for desc in cur.ordered_description()
] or []
rows = []
self.row_count = cur.rowcount
if cur.rowcount > 0:
for row in cur:
rows.append(dict(row))
return True, {'columns': columns, 'rows': rows}
def async_fetchmany_2darray(self, records=2000,
formatted_exception_msg=False):
"""
User should poll and check if status is ASYNC_OK before calling this
function
Args:
records: no of records to fetch. use -1 to fetchall.
formatted_exception_msg:
Returns:
"""
cur = self.__async_cursor
if not cur:
return False, gettext(
"Cursor could not be found for the async connection."
)
if self.conn.isexecuting():
return False, gettext(
"Asynchronous query execution/operation underway."
)
if self.row_count > 0:
result = []
# For DDL operation, we may not have result.
#
# Because - there is not direct way to differentiate DML and
# DDL operations, we need to rely on exception to figure
# that out at the moment.
try:
if records == -1:
res = cur.fetchall()
else:
res = cur.fetchmany(records)
for row in res:
new_row = []
for col in self.column_info:
new_row.append(row[col['name']])
result.append(new_row)
except psycopg2.ProgrammingError as e:
result = None
else:
# User performed operation which dose not produce record/s as
# result.
# for eg. DDL operations.
return True, None
return True, result
def connected(self):
if self.conn:
if not self.conn.closed:
return True
self.conn = None
return False
def reset(self):
if self.conn:
if self.conn.closed:
self.conn = None
pg_conn = None
manager = self.manager
password = getattr(manager, 'password', None)
if password:
# Fetch Logged in User Details.
user = User.query.filter_by(id=current_user.id).first()
if user is None:
return False, gettext("Unauthorized request.")
password = decrypt(password, user.password).decode()
try:
pg_conn = psycopg2.connect(
host=manager.local_bind_host if manager.use_ssh_tunnel
else manager.host,
hostaddr=manager.local_bind_host if manager.use_ssh_tunnel
else manager.hostaddr,
port=manager.local_bind_port if manager.use_ssh_tunnel
else manager.port,
database=self.db,
user=manager.user,
password=password,
passfile=get_complete_file_path(manager.passfile),
sslmode=manager.ssl_mode,
sslcert=get_complete_file_path(manager.sslcert),
sslkey=get_complete_file_path(manager.sslkey),
sslrootcert=get_complete_file_path(manager.sslrootcert),
sslcrl=get_complete_file_path(manager.sslcrl),
sslcompression=True if manager.sslcompression else False,
service=manager.service,
connect_timeout=manager.connect_timeout
)
except psycopg2.Error as e:
msg = e.pgerror if e.pgerror else e.message \
if e.message else e.diag.message_detail \
if e.diag.message_detail else str(e)
current_app.logger.error(
gettext(
"""
Failed to reset the connection to the server due to following error:
{0}"""
).Format(msg)
)
return False, msg
pg_conn.notices = deque([], self.ASYNC_NOTICE_MAXLENGTH)
self.conn = pg_conn
self.__backend_pid = pg_conn.get_backend_pid()
return True, None
def transaction_status(self):
if self.conn:
return self.conn.get_transaction_status()
return None
def ping(self):
return self.execute_scalar('SELECT 1')
def _release(self):
if self.wasConnected:
if self.conn:
self.conn.close()
self.conn = None
self.password = None
self.wasConnected = False
def _wait(self, conn):
"""
This function is used for the asynchronous connection,
it will call poll method in a infinite loop till poll
returns psycopg2.extensions.POLL_OK. This is a blocking
call.
Args:
conn: connection object
"""
while 1:
state = conn.poll()
if state == psycopg2.extensions.POLL_OK:
break
elif state == psycopg2.extensions.POLL_WRITE:
select.select([], [conn.fileno()], [])
elif state == psycopg2.extensions.POLL_READ:
select.select([conn.fileno()], [], [])
else:
raise psycopg2.OperationalError(
"poll() returned %s from _wait function" % state)
def _wait_timeout(self, conn):
"""
This function is used for the asynchronous connection,
it will call poll method and return the status. If state is
psycopg2.extensions.POLL_WRITE and psycopg2.extensions.POLL_READ
function will wait for the given timeout.This is not a blocking call.
Args:
conn: connection object
time: wait time
"""
while 1:
state = conn.poll()
if state == psycopg2.extensions.POLL_OK:
return self.ASYNC_OK
elif state == psycopg2.extensions.POLL_WRITE:
# Wait for the given time and then check the return status
# If three empty lists are returned then the time-out is
# reached.
timeout_status = select.select(
[], [conn.fileno()], [], self.ASYNC_TIMEOUT
)
if timeout_status == ([], [], []):
return self.ASYNC_WRITE_TIMEOUT
elif state == psycopg2.extensions.POLL_READ:
# Wait for the given time and then check the return status
# If three empty lists are returned then the time-out is
# reached.
timeout_status = select.select(
[conn.fileno()], [], [], self.ASYNC_TIMEOUT
)
if timeout_status == ([], [], []):
return self.ASYNC_READ_TIMEOUT
else:
raise psycopg2.OperationalError(
"poll() returned %s from _wait_timeout function" % state
)
def poll(self, formatted_exception_msg=False, no_result=False):
"""
This function is a wrapper around connection's poll function.
It internally uses the _wait_timeout method to poll the
result on the connection object. In case of success it
returns the result of the query.
Args:
formatted_exception_msg: if True then function return the formatted
exception message, otherwise error string.
no_result: If True then only poll status will be returned.
"""
cur = self.__async_cursor
if not cur:
return False, gettext(
"Cursor could not be found for the async connection."
)
current_app.logger.log(
25,
"Polling result for (Query-id: {query_id})".format(
query_id=self.__async_query_id
)
)
is_error = False
try:
status = self._wait_timeout(self.conn)
except psycopg2.Error as pe:
if self.conn.closed:
raise ConnectionLost(
self.manager.sid,
self.db,
self.conn_id[5:]
)
errmsg = self._formatted_exception_msg(pe, formatted_exception_msg)
is_error = True
if self.conn.notices and self.__notices is not None:
self.__notices.extend(self.conn.notices)
self.conn.notices.clear()
# Check for the asynchronous notifies.
self.check_notifies()
# We also need to fetch notices before we return from function in case
# of any Exception, To avoid code duplication we will return after
# fetching the notices in case of any Exception
if is_error:
return False, errmsg
result = None
self.row_count = 0
self.column_info = None
if status == self.ASYNC_OK:
# if user has cancelled the transaction then changed the status
if self.execution_aborted:
status = self.ASYNC_EXECUTION_ABORTED
self.execution_aborted = False
return status, result
# Fetch the column information
if cur.description is not None:
self.column_info = [
desc.to_dict() for desc in cur.ordered_description()
]
pos = 0
for col in self.column_info:
col['pos'] = pos
pos += 1
self.row_count = cur.rowcount
if not no_result:
if cur.rowcount > 0:
result = []
# For DDL operation, we may not have result.
#
# Because - there is not direct way to differentiate DML
# and DDL operations, we need to rely on exception to
# figure that out at the moment.
try:
for row in cur:
new_row = []
for col in self.column_info:
new_row.append(row[col['name']])
result.append(new_row)
except psycopg2.ProgrammingError:
result = None
return status, result
def status_message(self):
"""
This function will return the status message returned by the last
command executed on the server.
"""
cur = self.__async_cursor
if not cur:
return gettext(
"Cursor could not be found for the async connection."
)
current_app.logger.log(
25,
"Status message for (Query-id: {query_id})".format(
query_id=self.__async_query_id
)
)
return cur.statusmessage
def rows_affected(self):
"""
This function will return the no of rows affected by the last command
executed on the server.
"""
return self.row_count
def get_column_info(self):
"""
This function will returns list of columns for last async sql command
executed on the server.
"""
return self.column_info
def cancel_transaction(self, conn_id, did=None):
"""
This function is used to cancel the running transaction
of the given connection id and database id using
PostgreSQL's pg_cancel_backend.
Args:
conn_id: Connection id
did: Database id (optional)
"""
cancel_conn = self.manager.connection(did=did, conn_id=conn_id)
query = """SELECT pg_cancel_backend({0});""".format(
cancel_conn.__backend_pid)
status = True
msg = ''
# if backend pid is same then create a new connection
# to cancel the query and release it.
if cancel_conn.__backend_pid == self.__backend_pid:
password = getattr(self.manager, 'password', None)
if password:
# Fetch Logged in User Details.
user = User.query.filter_by(id=current_user.id).first()
if user is None:
return False, gettext("Unauthorized request.")
password = decrypt(password, user.password).decode()
try:
pg_conn = psycopg2.connect(
host=self.manager.local_bind_host if
self.manager.use_ssh_tunnel else self.manager.host,
hostaddr=self.manager.local_bind_host if
self.manager.use_ssh_tunnel else
self.manager.hostaddr,
port=self.manager.local_bind_port if
self.manager.use_ssh_tunnel else self.manager.port,
database=self.db,
user=self.manager.user,
password=password,
passfile=get_complete_file_path(self.manager.passfile),
sslmode=self.manager.ssl_mode,
sslcert=get_complete_file_path(self.manager.sslcert),
sslkey=get_complete_file_path(self.manager.sslkey),
sslrootcert=get_complete_file_path(
self.manager.sslrootcert
),
sslcrl=get_complete_file_path(self.manager.sslcrl),
sslcompression=True if self.manager.sslcompression
else False,
service=self.manager.service,
connect_timeout=self.manager.connect_timeout
)
# Get the cursor and run the query
cur = pg_conn.cursor()
cur.execute(query)
# Close the connection
pg_conn.close()
pg_conn = None
except psycopg2.Error as e:
status = False
if e.pgerror:
msg = e.pgerror
elif e.diag.message_detail:
msg = e.diag.message_detail
else:
msg = str(e)
return status, msg
else:
if self.connected():
status, msg = self.execute_void(query)
if status:
cancel_conn.execution_aborted = True
else:
status = False
msg = gettext("Not connected to the database server.")
return status, msg
def messages(self):
"""
Returns the list of the messages/notices send from the database server.
"""
resp = []
while self.__notices:
resp.append(self.__notices.pop(0))
for notify in self.__notifies:
if notify.payload is not None and notify.payload is not '':
notify_msg = gettext(
"Asynchronous notification \"{0}\" with payload \"{1}\" "
"received from server process with PID {2}\n"
).format(notify.channel, notify.payload, notify.pid)
else:
notify_msg = gettext(
"Asynchronous notification \"{0}\" received from "
"server process with PID {1}\n"
).format(notify.channel, notify.pid)
resp.append(notify_msg)
return resp
def decode_to_utf8(self, value):
"""
This method will decode values to utf-8
Args:
value: String to be decode
Returns:
Decoded string
"""
is_error = False
if hasattr(str, 'decode'):
try:
value = value.decode('utf-8')
except UnicodeDecodeError:
# Let's try with python's preferred encoding
# On Windows lc_messages mostly has environment dependent
# encoding like 'French_France.1252'
try:
import locale
pref_encoding = locale.getpreferredencoding()
value = value.decode(pref_encoding)\
.encode('utf-8')\
.decode('utf-8')
except Exception:
is_error = True
except Exception:
is_error = True
# If still not able to decode then
if is_error:
value = value.decode('ascii', 'ignore')
return value
def _formatted_exception_msg(self, exception_obj, formatted_msg):
"""
This method is used to parse the psycopg2.Error object and returns the
formatted error message if flag is set to true else return
normal error message.
Args:
exception_obj: exception object
formatted_msg: if True then function return the formatted exception
message
"""
if exception_obj.pgerror:
errmsg = exception_obj.pgerror
elif exception_obj.diag.message_detail:
errmsg = exception_obj.diag.message_detail
else:
errmsg = str(exception_obj)
# errmsg might contains encoded value, lets decode it
errmsg = self.decode_to_utf8(errmsg)
# if formatted_msg is false then return from the function
if not formatted_msg:
return errmsg
# Do not append if error starts with `ERROR:` as most pg related
# error starts with `ERROR:`
if not errmsg.startswith(u'ERROR:'):
errmsg = u'ERROR: ' + errmsg + u'\n\n'
if exception_obj.diag.severity is not None \
and exception_obj.diag.message_primary is not None:
ex_diag_message = u"{0}: {1}".format(
self.decode_to_utf8(exception_obj.diag.severity),
self.decode_to_utf8(exception_obj.diag.message_primary)
)
# If both errors are different then only append it
if errmsg and ex_diag_message and \
ex_diag_message.strip().strip('\n').lower() not in \
errmsg.strip().strip('\n').lower():
errmsg += ex_diag_message
elif exception_obj.diag.message_primary is not None:
message_primary = self.decode_to_utf8(
exception_obj.diag.message_primary
)
if message_primary.lower() not in errmsg.lower():
errmsg += message_primary
if exception_obj.diag.sqlstate is not None:
if not errmsg.endswith('\n'):
errmsg += '\n'
errmsg += gettext('SQL state: ')
errmsg += self.decode_to_utf8(exception_obj.diag.sqlstate)
if exception_obj.diag.message_detail is not None:
if 'Detail:'.lower() not in errmsg.lower():
if not errmsg.endswith('\n'):
errmsg += '\n'
errmsg += gettext('Detail: ')
errmsg += self.decode_to_utf8(
exception_obj.diag.message_detail
)
if exception_obj.diag.message_hint is not None:
if 'Hint:'.lower() not in errmsg.lower():
if not errmsg.endswith('\n'):
errmsg += '\n'
errmsg += gettext('Hint: ')
errmsg += self.decode_to_utf8(exception_obj.diag.message_hint)
if exception_obj.diag.statement_position is not None:
if 'Character:'.lower() not in errmsg.lower():
if not errmsg.endswith('\n'):
errmsg += '\n'
errmsg += gettext('Character: ')
errmsg += self.decode_to_utf8(
exception_obj.diag.statement_position
)
if exception_obj.diag.context is not None:
if 'Context:'.lower() not in errmsg.lower():
if not errmsg.endswith('\n'):
errmsg += '\n'
errmsg += gettext('Context: ')
errmsg += self.decode_to_utf8(exception_obj.diag.context)
return errmsg
#####
# As per issue reported on pgsycopg2 github repository link is shared below
# conn.closed is not reliable enough to identify the disconnection from the
# database server for some unknown reasons.
#
# (https://github.com/psycopg/psycopg2/issues/263)
#
# In order to resolve the issue, sqlalchamey follows the below logic to
# identify the disconnection. It relies on exception message to identify
# the error.
#
# Reference (MIT license):
# https://github.com/zzzeek/sqlalchemy/blob/master/lib/sqlalchemy/dialects/postgresql/psycopg2.py
#
def is_disconnected(self, err):
if not self.conn.closed:
# checks based on strings. in the case that .closed
# didn't cut it, fall back onto these.
str_e = str(err).partition("\n")[0]
for msg in [
# these error messages from libpq: interfaces/libpq/fe-misc.c
# and interfaces/libpq/fe-secure.c.
'terminating connection',
'closed the connection',
'connection not open',
'could not receive data from server',
'could not send data to server',
# psycopg2 client errors, psycopg2/conenction.h,
# psycopg2/cursor.h
'connection already closed',
'cursor already closed',
# not sure where this path is originally from, it may
# be obsolete. It really says "losed", not "closed".
'losed the connection unexpectedly',
# these can occur in newer SSL
'connection has been closed unexpectedly',
'SSL SYSCALL error: Bad file descriptor',
'SSL SYSCALL error: EOF detected',
]:
idx = str_e.find(msg)
if idx >= 0 and '"' not in str_e[:idx]:
return True
return False
return True
def check_notifies(self, required_polling=False):
"""
Check for the notify messages by polling the connection or after
execute is there in notifies.
"""
if self.conn and required_polling:
self.conn.poll()
if self.conn and hasattr(self.conn, 'notifies') and \
len(self.conn.notifies) > 0:
self.__notifies.extend(self.conn.notifies)
self.conn.notifies = []
else:
self.__notifies = []
def get_notifies(self):
"""
This function will returns list of notifies received from database
server.
"""
notifies = None
# Convert list of Notify objects into list of Dict.
if self.__notifies is not None and len(self.__notifies) > 0:
notifies = [{'recorded_time': str(datetime.datetime.now()),
'channel': notify.channel,
'payload': notify.payload,
'pid': notify.pid
} for notify in self.__notifies
]
return notifies
def pq_encrypt_password_conn(self, password, user):
"""
This function will return the encrypted password for database server
greater than or equal to 10
:param password: password to be encrypted
:param user: user of the database server
:return:
"""
enc_password = None
if psycopg2.__libpq_version__ >= 100000 and \
hasattr(psycopg2.extensions, 'encrypt_password'):
if self.connected():
status, enc_algorithm = \
self.execute_scalar("SHOW password_encryption")
if status:
enc_password = psycopg2.extensions.encrypt_password(
password=password, user=user, scope=self.conn,
algorithm=enc_algorithm
)
elif psycopg2.__libpq_version__ < 100000:
current_app.logger.warning(
u"To encrypt passwords the required libpq version is "
u"greater than or equal to 100000. Current libpq version "
u"is {curr_ver}".format(
curr_ver=psycopg2.__libpq_version__
)
)
elif not hasattr(psycopg2.extensions, 'encrypt_password'):
current_app.logger.warning(
u"The psycopg2.extensions module does not have the"
u"'encrypt_password' method."
)
return enc_password