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Merged
adamchainz merged 4 commits into from
Oct 30, 2025
Merged

Remove import-time string processing from cache backend and models #1169

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4bbc435
Initial plan
Copilot Oct 29, 2025
c34f785
Remove import-time dedent calls from cache backend
Copilot Oct 29, 2025
2af3a00
Replace collapse_spaces calls with plain strings
Copilot Oct 29, 2025
c9c88fd
Preserve indentation in SQL strings with fmt off/on
Copilot Oct 30, 2025
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169 changes: 84 additions & 85 deletions src/django_mysql/cache.py
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Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,6 @@
import zlib
from collections.abc import Iterable
from random import random
from textwrap import dedent
from time import time
from typing import Any, Callable, Literal, cast

Expand All @@ -15,7 +14,7 @@
from django.utils.encoding import force_bytes
from django.utils.module_loading import import_string

from django_mysql.utils import collapse_spaces, get_list_sql
from django_mysql.utils import get_list_sql

_EncodedKeyType = Literal["i", "p", "z"]

Expand Down Expand Up @@ -102,18 +101,18 @@ class MySQLCache(BaseDatabaseCache):
# 1970)
FOREVER_TIMEOUT = BIGINT_UNSIGNED_MAX >> 1

create_table_sql = dedent(
"""\
CREATE TABLE `{table_name}` (
cache_key varchar(255) CHARACTER SET utf8 COLLATE utf8_bin
NOT NULL PRIMARY KEY,
value longblob NOT NULL,
value_type char(1) CHARACTER SET latin1 COLLATE latin1_bin
NOT NULL DEFAULT 'p',
expires BIGINT UNSIGNED NOT NULL
);
"""
# fmt: off
create_table_sql = (
"CREATE TABLE `{table_name}` (\n"
" cache_key varchar(255) CHARACTER SET utf8 COLLATE utf8_bin\n"
" NOT NULL PRIMARY KEY,\n"
" value longblob NOT NULL,\n"
" value_type char(1) CHARACTER SET latin1 COLLATE latin1_bin\n"
" NOT NULL DEFAULT 'p',\n"
" expires BIGINT UNSIGNED NOT NULL\n"
");\n"
)
# fmt: on

@classmethod
def _now(cls) -> int:
Expand Down Expand Up @@ -162,14 +161,14 @@ def get(
value, value_type = row
return self.decode(value, value_type)

_get_query = collapse_spaces(
"""
SELECT value, value_type
FROM {table}
WHERE cache_key = %s AND
expires >= %s
"""
# fmt: off
_get_query = (
"SELECT value, value_type "
"FROM {table} "
"WHERE cache_key = %s AND "
"expires >= %s"
)
# fmt: on

def get_many(
self, keys: Iterable[str], version: int | None = None
Expand Down Expand Up @@ -199,14 +198,14 @@ def get_many(

return data

_get_many_query = collapse_spaces(
"""
SELECT cache_key, value, value_type
FROM {table}
WHERE cache_key IN {list_sql} AND
expires >= %s
"""
# fmt: off
_get_many_query = (
"SELECT cache_key, value, value_type "
"FROM {table} "
"WHERE cache_key IN {list_sql} AND "
"expires >= %s"
)
# fmt: on

def set(
self,
Expand Down Expand Up @@ -261,39 +260,39 @@ def _base_set(
insert_id = cursor.lastrowid
return insert_id != 444

_set_many_query = collapse_spaces(
"""
INSERT INTO {table} (cache_key, value, value_type, expires)
VALUES {{VALUES_CLAUSE}}
ON DUPLICATE KEY UPDATE
value=VALUES(value),
value_type=VALUES(value_type),
expires=VALUES(expires)
"""
# fmt: off
_set_many_query = (
"INSERT INTO {table} (cache_key, value, value_type, expires) "
"VALUES {{VALUES_CLAUSE}} "
"ON DUPLICATE KEY UPDATE "
"value=VALUES(value), "
"value_type=VALUES(value_type), "
"expires=VALUES(expires)"
)
# fmt: on

_set_query = _set_many_query.replace("{{VALUES_CLAUSE}}", "(%s, %s, %s, %s)")

# Uses the IFNULL / LEAST / LAST_INSERT_ID trick to communicate the special
# value of 444 back to the client (LAST_INSERT_ID is otherwise 0, since
# there is no AUTO_INCREMENT column)
_add_query = collapse_spaces(
"""
INSERT INTO {table} (cache_key, value, value_type, expires)
VALUES (%s, %s, %s, %s)
ON DUPLICATE KEY UPDATE
value=IF(expires > @tmp_now:=%s, value, VALUES(value)),
value_type=IF(expires > @tmp_now, value_type, VALUES(value_type)),
expires=IF(
expires > @tmp_now,
IFNULL(
LEAST(LAST_INSERT_ID(444), NULL),
expires
),
VALUES(expires)
)
"""
# fmt: off
_add_query = (
"INSERT INTO {table} (cache_key, value, value_type, expires) "
"VALUES (%s, %s, %s, %s) "
"ON DUPLICATE KEY UPDATE "
"value=IF(expires > @tmp_now:=%s, value, VALUES(value)), "
"value_type=IF(expires > @tmp_now, value_type, VALUES(value_type)), "
"expires=IF("
"expires > @tmp_now, "
"IFNULL("
"LEAST(LAST_INSERT_ID(444), NULL), "
"expires"
"), "
"VALUES(expires)"
")"
)
# fmt: on

def set_many(
self,
Expand Down Expand Up @@ -332,12 +331,12 @@ def delete(self, key: str, version: int | None = None) -> None:
with connections[db].cursor() as cursor:
cursor.execute(self._delete_query.format(table=table), (key,))

_delete_query = collapse_spaces(
"""
DELETE FROM {table}
WHERE cache_key = %s
"""
# fmt: off
_delete_query = (
"DELETE FROM {table} "
"WHERE cache_key = %s"
)
# fmt: on

def delete_many(self, keys: Iterable[str], version: int | None = None) -> None:
made_keys = [self.make_key(key, version=version) for key in keys]
Expand All @@ -355,12 +354,12 @@ def delete_many(self, keys: Iterable[str], version: int | None = None) -> None:
made_keys,
)

_delete_many_query = collapse_spaces(
"""
DELETE FROM {table}
WHERE cache_key IN {list_sql}
"""
# fmt: off
_delete_many_query = (
"DELETE FROM {table} "
"WHERE cache_key IN {list_sql}"
)
# fmt: on

def has_key(self, key: str, version: int | None = None) -> bool:
key = self.make_key(key, version=version)
Expand All @@ -373,12 +372,12 @@ def has_key(self, key: str, version: int | None = None) -> bool:
cursor.execute(self._has_key_query.format(table=table), (key, self._now()))
return cursor.fetchone() is not None

_has_key_query = collapse_spaces(
"""
SELECT 1 FROM {table}
WHERE cache_key = %s and expires > %s
"""
# fmt: off
_has_key_query = (
"SELECT 1 FROM {table} "
"WHERE cache_key = %s and expires > %s"
)
# fmt: on

def incr(self, key: str, delta: int = 1, version: int | None = None) -> int:
return self._base_delta(key, delta, version, "+")
Expand Down Expand Up @@ -412,18 +411,18 @@ def _base_delta(

# Looks a bit tangled to turn the blob back into an int for updating, but
# it works. Stores the new value for insert_id() with LAST_INSERT_ID
_delta_query = collapse_spaces(
"""
UPDATE {table}
SET value = LAST_INSERT_ID(
CAST(value AS SIGNED INTEGER)
{operation}
%s
)
WHERE cache_key = %s AND
value_type = 'i'
"""
# fmt: off
_delta_query = (
"UPDATE {table} "
"SET value = LAST_INSERT_ID("
"CAST(value AS SIGNED INTEGER) "
"{operation} "
"%s"
") "
"WHERE cache_key = %s AND "
"value_type = 'i'"
)
# fmt: on

def clear(self) -> None:
db = router.db_for_write(self.cache_model_class)
Expand All @@ -445,14 +444,14 @@ def touch(
)
return affected_rows > 0

_touch_query = collapse_spaces(
"""
UPDATE {table}
SET expires = %s
WHERE cache_key = %s AND
expires >= %s
"""
# fmt: off
_touch_query = (
"UPDATE {table} "
"SET expires = %s "
"WHERE cache_key = %s AND "
"expires >= %s"
)
# fmt: on

def validate_key(self, key: str) -> None:
"""
Expand Down
9 changes: 3 additions & 6 deletions src/django_mysql/management/commands/cull_mysql_caches.py
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Original file line number Diff line number Diff line change
Expand Up @@ -8,17 +8,14 @@
from django.core.management import BaseCommand, CommandError

from django_mysql.cache import MySQLCache
from django_mysql.utils import collapse_spaces


class Command(BaseCommand):
args = "<optional cache aliases>"

help = collapse_spaces(
"""
Runs cache.cull() on all your MySQLCache caches, or only those
specified aliases.
"""
help = (
"Runs cache.cull() on all your MySQLCache caches, or only those "
"specified aliases."
)

def add_arguments(self, parser: argparse.ArgumentParser) -> None:
Expand Down
7 changes: 1 addition & 6 deletions src/django_mysql/management/commands/mysql_cache_migration.py
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Original file line number Diff line number Diff line change
Expand Up @@ -8,17 +8,12 @@
from django.core.management import BaseCommand, CommandError

from django_mysql.cache import MySQLCache
from django_mysql.utils import collapse_spaces


class Command(BaseCommand):
args = "<app_name>"

help = collapse_spaces(
"""
Outputs a migration that will create a table.
"""
)
help = "Outputs a migration that will create a table."

def add_arguments(self, parser: argparse.ArgumentParser) -> None:
parser.add_argument(
Expand Down
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