Source code for pg_scheduler.job_priority

"""
Job priority levels for PG Scheduler.

This module defines the priority system used for job scheduling.
Lower priority numbers indicate higher priority (execute first).
"""

from enum import Enum

# Module-level constants (created once at import time)
_PRIORITY_TO_DB = {
    "critical": 1,
    "high": 3,
    "normal": 5,
    "low": 8
}

_DB_TO_PRIORITY = {
    1: "CRITICAL",
    3: "HIGH",
    5: "NORMAL",
    8: "LOW"
}




class JobPriority(Enum):
    """
    Job priority levels for scheduling.
    
    Lower priority numbers indicate higher priority (jobs execute first).
    Jobs are processed in ascending priority order: 1 → 3 → 5 → 8.
    """
    
    CRITICAL = "critical"  # Highest priority (value: 1)
    HIGH = "high"          # High priority (value: 3)
    NORMAL = "normal"      # Default priority (value: 5)
    LOW = "low"            # Low priority (value: 8)
    
    @property
    def db_value(self) -> int:
        """
        Get the database integer value for this priority level.
        
        Returns:
            int: Database priority value (1, 3, 5, or 8)
            
        Note:
            Lower numbers = higher priority. Used for ORDER BY in SQL queries.
        """
        return _PRIORITY_TO_DB[self.value]
    


    @classmethod
    def from_db_value(cls, db_value: int) -> 'JobPriority':
        """
        Convert a database integer value back to a JobPriority enum.
        
        Args:
            db_value: The integer priority value from the database (1, 3, 5, or 8)
            
        Returns:
            JobPriority: The corresponding priority enum member
            
        Note:
            If an unknown value is provided, defaults to NORMAL.
        """
        member_name = _DB_TO_PRIORITY.get(db_value, "NORMAL")
        return cls[member_name]

    


    def __str__(self) -> str:
        """
        String representation of the priority.
        
        Returns:
            str: The priority label (e.g., "critical", "normal")
        """
        return self.value

    


    def __repr__(self) -> str:
        """
        Developer-friendly representation of the priority.
        
        Returns:
            str: Detailed representation with name, label, and db_value
        """
        return f"<JobPriority.{self.name}: {self.value} (db_value={self.db_value})>"