openenv/echo_env

1# SPDX-License-Identifier: BSD-3-Clause2 3"""Custom exceptions for environment server operations."""4 5from typing import Optional6 7 8class OpenEnvError(Exception):9    """Base exception for all OpenEnv errors."""10 11    pass12 13 14class ConcurrencyConfigurationError(OpenEnvError):15    """16    Raised when an environment is misconfigured for concurrent sessions.17 18    This error is raised during server startup when max_concurrent_envs > 119    is specified for an environment that is not marked as SUPPORTS_CONCURRENT_SESSIONS.20    """21 22    def __init__(23        self,24        environment_name: str,25        max_concurrent_envs: int,26        message: Optional[str] = None,27    ):28        self.environment_name = environment_name29        self.max_concurrent_envs = max_concurrent_envs30 31        if message is None:32            message = (33                f"Environment '{environment_name}' is not marked as SUPPORTS_CONCURRENT_SESSIONS. "34                f"Cannot run with max_concurrent_envs={max_concurrent_envs}. "35                f"Either set max_concurrent_envs=1 or ensure the environment "36                f"properly isolates session state and set SUPPORTS_CONCURRENT_SESSIONS=True."37            )38 39        super().__init__(message)40 41 42class SessionCapacityError(OpenEnvError):43    """44    Raised when the server cannot accept new sessions due to capacity limits.45 46    This error is raised when a new WebSocket connection is attempted but47    the server has already reached max_concurrent_envs active sessions.48    """49 50    def __init__(51        self,52        active_sessions: int,53        max_sessions: int,54        message: Optional[str] = None,55    ):56        self.active_sessions = active_sessions57        self.max_sessions = max_sessions58 59        if message is None:60            message = (61                f"Server at capacity: {active_sessions}/{max_sessions} sessions active. "62                f"Cannot accept new connections."63            )64 65        super().__init__(message)66 67 68class SessionNotFoundError(OpenEnvError):69    """Raised when attempting to access a session that does not exist."""70 71    def __init__(self, session_id: str, message: Optional[str] = None):72        self.session_id = session_id73 74        if message is None:75            message = f"Session '{session_id}' not found."76 77        super().__init__(message)78 79 80class SessionCreationError(OpenEnvError):81    """Raised when a session cannot be created."""82 83    def __init__(self, reason: str, message: Optional[str] = None):84        self.reason = reason85 86        if message is None:87            message = f"Failed to create session: {reason}"88 89        super().__init__(message)90 91 92class EnvironmentFactoryError(OpenEnvError):93    """Raised when the environment factory fails to create an instance."""94 95    def __init__(self, factory_name: str, message: Optional[str] = None):96        self.factory_name = factory_name97 98        if message is None:99            message = f"Environment factory '{factory_name}' failed to create instance."100 101        super().__init__(message)102