import multiprocessing
import os
import shutil
import sqlite3
import sys
from pathlib import Path
from django.db import NotSupportedError
from django.db.backends.base.creation import BaseDatabaseCreation
class DatabaseCreation(BaseDatabaseCreation):
@staticmethod
def is_in_memory_db(database_name):
return not isinstance(database_name, Path) and (
database_name == ":memory:" or "mode=memory" in database_name
)
def _get_test_db_name(self):
test_database_name = self.connection.settings_dict["TEST"]["NAME"] or ":memory:"
if test_database_name == ":memory:":
return "file:memorydb_%s?mode=memory&cache=shared" % self.connection.alias
return test_database_name
def _create_test_db(self, verbosity, autoclobber, keepdb=False):
test_database_name = self._get_test_db_name()
if keepdb:
return test_database_name
if not self.is_in_memory_db(test_database_name):
# Erase the old test database
if verbosity >= 1:
self.log(
"Destroying old test database for alias %s..."
% (self._get_database_display_str(verbosity, test_database_name),)
)
if os.access(test_database_name, os.F_OK):
if not autoclobber:
confirm = input(
"Type 'yes' if you would like to try deleting the test "
"database '%s', or 'no' to cancel: " % test_database_name
)
if autoclobber or confirm == "yes":
try:
os.remove(test_database_name)
except Exception as e:
self.log("Got an error deleting the old test database: %s" % e)
sys.exit(2)
else:
self.log("Tests cancelled.")
sys.exit(1)
return test_database_name
def get_test_db_clone_settings(self, suffix):
orig_settings_dict = self.connection.settings_dict
source_database_name = orig_settings_dict["NAME"] or ":memory:"
if not self.is_in_memory_db(source_database_name):
root, ext = os.path.splitext(source_database_name)
return {**orig_settings_dict, "NAME": f"{root}_{suffix}{ext}"}
start_method = multiprocessing.get_start_method()
if start_method == "fork":
return orig_settings_dict
if start_method == "spawn":
return {
**orig_settings_dict,
"NAME": f"{self.connection.alias}_{suffix}.sqlite3",
}
raise NotSupportedError(
f"Cloning with start method {start_method!r} is not supported."
)
def _clone_test_db(self, suffix, verbosity, keepdb=False):
source_database_name = self.connection.settings_dict["NAME"]
target_database_name = self.get_test_db_clone_settings(suffix)["NAME"]
if not self.is_in_memory_db(source_database_name):
# Erase the old test database
if os.access(target_database_name, os.F_OK):
if keepdb:
return
if verbosity >= 1:
self.log(
"Destroying old test database for alias %s..."
% (
self._get_database_display_str(
verbosity, target_database_name
),
)
)
try:
os.remove(target_database_name)
except Exception as e:
self.log("Got an error deleting the old test database: %s" % e)
sys.exit(2)
try:
shutil.copy(source_database_name, target_database_name)
except Exception as e:
self.log("Got an error cloning the test database: %s" % e)
sys.exit(2)
# Forking automatically makes a copy of an in-memory database.
# Spawn requires migrating to disk which will be re-opened in
# setup_worker_connection.
elif multiprocessing.get_start_method() == "spawn":
ondisk_db = sqlite3.connect(target_database_name, uri=True)
self.connection.connection.backup(ondisk_db)
ondisk_db.close()
def _destroy_test_db(self, test_database_name, verbosity):
if test_database_name and not self.is_in_memory_db(test_database_name):
# Remove the SQLite database file
os.remove(test_database_name)
def test_db_signature(self):
"""
Return a tuple that uniquely identifies a test database.
This takes into account the special cases of ":memory:" and "" for
SQLite since the databases will be distinct despite having the same
TEST NAME. See https://www.sqlite.org/inmemorydb.html
"""
test_database_name = self._get_test_db_name()
sig = [self.connection.settings_dict["NAME"]]
if self.is_in_memory_db(test_database_name):
sig.append(self.connection.alias)
else:
sig.append(test_database_name)
return tuple(sig)
def setup_worker_connection(self, _worker_id):
settings_dict = self.get_test_db_clone_settings(_worker_id)
# connection.settings_dict must be updated in place for changes to be
# reflected in django.db.connections. Otherwise new threads would
# connect to the default database instead of the appropriate clone.
start_method = multiprocessing.get_start_method()
if start_method == "fork":
# Update settings_dict in place.
self.connection.settings_dict.update(settings_dict)
self.connection.close()
elif start_method == "spawn":
alias = self.connection.alias
connection_str = (
f"file:memorydb_{alias}_{_worker_id}?mode=memory&cache=shared"
)
source_db = self.connection.Database.connect(
f"file:{alias}_{_worker_id}.sqlite3?mode=ro", uri=True
)
target_db = sqlite3.connect(connection_str, uri=True)
source_db.backup(target_db)
source_db.close()
# Update settings_dict in place.
self.connection.settings_dict.update(settings_dict)
self.connection.settings_dict["NAME"] = connection_str
# Re-open connection to in-memory database before closing copy
# connection.
self.connection.connect()
target_db.close()
if os.environ.get("RUNNING_DJANGOS_TEST_SUITE") == "true":
self.mark_expected_failures_and_skips()