- """Save to database."""
- cursor = db_conn.exec('REPLACE INTO process_steps VALUES (?, ?, ?, ?)',
- (self.id_, self.owner_id, self.step_process_id,
- self.parent_step_id))
- self.id_ = cursor.lastrowid
-
-
-class VersionedAttribute:
- """Attributes whose values are recorded as a timestamped history."""
-
- def __init__(self,
- parent: Process, name: str, default: str | float) -> None:
- self.parent = parent
- self.name = name
- self.default = default
- self.history: dict[str, str | float] = {}
-
- @property
- def _newest_timestamp(self) -> str:
- """Return most recent timestamp."""
- return sorted(self.history.keys())[-1]
-
- @property
- def newest(self) -> str | float:
- """Return most recent value, or self.default if self.history empty."""
- if 0 == len(self.history):
- return self.default
- return self.history[self._newest_timestamp]
-
- def set(self, value: str | float) -> None:
- """Add to self.history if and only if not same value as newest one."""
- if 0 == len(self.history) \
- or value != self.history[self._newest_timestamp]:
- self.history[datetime.now().strftime('%Y-%m-%d %H:%M:%S')] = value
-
- def at(self, queried_time: str) -> str | float:
- """Retrieve value of timestamp nearest queried_time from the past."""
- sorted_timestamps = sorted(self.history.keys())
- if 0 == len(sorted_timestamps):
- return self.default
- selected_timestamp = sorted_timestamps[0]
- for timestamp in sorted_timestamps[1:]:
- if timestamp > queried_time:
- break
- selected_timestamp = timestamp
- return self.history[selected_timestamp]
-
- def save(self, db_conn: DatabaseConnection) -> None:
- """Save as self.history entries, but first wipe old ones."""
- db_conn.exec(f'DELETE FROM process_{self.name}s WHERE process_id = ?',
- (self.parent.id_,))
- for timestamp, value in self.history.items():
- db_conn.exec(f'INSERT INTO process_{self.name}s VALUES (?, ?, ?)',
- (self.parent.id_, timestamp, value))