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"""module contains all db related stuff"""
import contextlib
from typing import Any, Iterator, Protocol, Tuple
from urllib.parse import urlparse
import MySQLdb as mdb
import xapian
from flask import current_app
def parse_db_url(sql_uri: str) -> Tuple:
"""function to parse SQL_URI env variable note:there\
is a default value for SQL_URI so a tuple result is\
always expected"""
parsed_db = urlparse(sql_uri)
return (
parsed_db.hostname, parsed_db.username, parsed_db.password,
parsed_db.path[1:], parsed_db.port)
# pylint: disable=missing-class-docstring, missing-function-docstring, too-few-public-methods
class Connection(Protocol):
"""Type Annotation for MySQLdb's connection object"""
def cursor(self, *args) -> Any:
"""A cursor in which queries may be performed"""
...
## We need to decouple current_app from this module and function, but since this
## function is used throughout the code, that will require careful work to update
## all the code to pass the `sql_uri` argument, and make it a compulsory argument
## rather than its current optional state.
@contextlib.contextmanager
def database_connection(sql_uri: str = "") -> Iterator[Connection]:
"""Connect to MySQL database."""
host, user, passwd, db_name, port = parse_db_url(
sql_uri or current_app.config["SQL_URI"])
connection = mdb.connect(db=db_name,
user=user,
passwd=passwd or '',
host=host,
port=port or 3306)
try:
yield connection
finally:
connection.close()
@contextlib.contextmanager
def xapian_database(path):
"""Open xapian database read-only."""
# pylint: disable-next=invalid-name
db = xapian.Database(path)
try:
yield db
finally:
db.close()
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