85 lines
2.8 KiB
Python
85 lines
2.8 KiB
Python
|
import logging
|
||
|
|
from typing import Optional
|
||
|
|
|
||
|
|
from django.db.models import Max
|
||
|
|
from mypy_extensions import TypedDict
|
||
|
|
|
||
|
|
|
||
|
|
logger = logging.getLogger(__name__)
|
||
|
|
SchemaVersion = TypedDict("SchemaVersion", {"migration": int, "config": int, "db": str})
|
||
|
|
|
||
|
|
|
||
|
|
class SchemaVersionHandler:
|
||
|
|
"""
|
||
|
|
Handler for the schema version of this running OpenSlides instance.
|
||
|
|
What is a schema version? This is an indictor of the current schema of the data
|
||
|
|
in the database, config variables, and the database itself. E.b. with a migration,
|
||
|
|
new/changed config variables or with a database change, the schema of the data changes.
|
||
|
|
|
||
|
|
To detect this is needed to reset the cache, so it does not hold any old data. This
|
||
|
|
affects the server cache, but also the client uses this technique to flush the cache.
|
||
|
|
|
||
|
|
Get the current schema with `get`. The schema version is built just once. After a change
|
||
|
|
in the schema, all workers needs a restart!
|
||
|
|
"""
|
||
|
|
|
||
|
|
def __init__(self) -> None:
|
||
|
|
self._schema_version: Optional[SchemaVersion] = None
|
||
|
|
|
||
|
|
def get(self) -> SchemaVersion:
|
||
|
|
if self._schema_version is not None:
|
||
|
|
return self._schema_version
|
||
|
|
|
||
|
|
from django.db.migrations.recorder import MigrationRecorder
|
||
|
|
|
||
|
|
migration = MigrationRecorder.Migration.objects.aggregate(Max("id"))["id__max"]
|
||
|
|
|
||
|
|
from openslides.core.config import ConfigStore
|
||
|
|
|
||
|
|
try:
|
||
|
|
config = ConfigStore.objects.get(key="config_version").value
|
||
|
|
except ConfigStore.DoesNotExist:
|
||
|
|
config = 0
|
||
|
|
try:
|
||
|
|
db = ConfigStore.objects.get(key="db_id").value
|
||
|
|
except ConfigStore.DoesNotExist:
|
||
|
|
db = ""
|
||
|
|
|
||
|
|
self._schema_version = {"migration": migration, "config": config, "db": db}
|
||
|
|
return self._schema_version
|
||
|
|
|
||
|
|
def compare(self, other: Optional[SchemaVersion]) -> bool:
|
||
|
|
current = self.get()
|
||
|
|
|
||
|
|
if not other:
|
||
|
|
logger.info("No old schema version")
|
||
|
|
return False
|
||
|
|
|
||
|
|
equal = True
|
||
|
|
if current["db"] != other["db"]:
|
||
|
|
other_db = other["db"] or "<empty>"
|
||
|
|
logger.info(f"DB changed from {other_db} to {current['db']}")
|
||
|
|
equal = False
|
||
|
|
if current["config"] != other["config"]:
|
||
|
|
other_config = other["config"] or "<empty>"
|
||
|
|
logger.info(f"Config changed from {other_config} to {current['config']}")
|
||
|
|
equal = False
|
||
|
|
if current["migration"] != other["migration"]:
|
||
|
|
logger.info(
|
||
|
|
f"Migration changed from {other['migration']} to {current['migration']}"
|
||
|
|
)
|
||
|
|
equal = False
|
||
|
|
return equal
|
||
|
|
|
||
|
|
def log_current(self) -> None:
|
||
|
|
current = self.get()
|
||
|
|
logger.info(
|
||
|
|
f"""Schema version:
|
||
|
|
DB: {current["db"]}
|
||
|
|
migration: {current["migration"]}
|
||
|
|
config: {current["config"]}"""
|
||
|
|
)
|
||
|
|
|
||
|
|
|
||
|
|
schema_version_handler = SchemaVersionHandler()
|