BaseScript¶

class lsst.ts.salobj.BaseScript(index: int, descr: str, help: str = '')¶

Bases: Controller, ABC

Abstract base class for SAL Scripts.

Parameters:

indexint: Index of SAL Script component. This must be non-zero and should be unique among all loaded SAL scripts (to avoid multiple scripts responding to a command).
descrstr: Short description of what the script does, for operator display.
helpstr, optional: Detailed help for the script. Markdown formatting is encouraged. This need not duplicate descriptions in the configuration schema.

Raises:

ValueError: If index=0. This is prohibited because index=0 would cause the script to respond to commands meant for every other script.

Attributes:

loglogging.Logger: A logger.
done_taskasyncio.Task: A task that is done when the script has fully executed.
timestampsdict [lsst.ts.idl.enums.ScriptState, float]: Dict of script state: TAI unix timestamp. Used to set timestamp data in the script event.

Attributes Summary

`checkpoints`	Get the checkpoints at which to pause and stop.
`domain`
`group_id`	Get the group ID (a `str`), or "" if not set.
`obs_id`	Get the block ID (a `str`), or "" if not set.
`state`	Get the current state.
`state_name`	Get the name of the current `state`.state.

Methods Summary

`amain`(**kwargs)	Run the script from the command line.
`assert_state`(action, states)	Assert that the current state is in `states` and the script is not exiting.
`checkpoint`([name])	Await this at any "nice" point your script can be paused or stopped.
`cleanup`()	Perform final cleanup, if any.
`close`([exception, cancel_start])	Shut down, clean up resources and set done_task done.
`close_tasks`()	Shut down pending tasks.
`configure`(config)	Configure the script.
`do_configure`(data)	Configure the currently loaded script.
`do_resume`(data)	Resume the currently paused script.
`do_run`(data)	Run the script and quit.
`do_setCheckpoints`(data)	Set or clear the checkpoints at which to pause and stop.
`do_setGroupId`(data)	Set or clear the group_id attribute.
`do_setLogLevel`(data)	Set logging level.
`do_stop`(data)	Stop the script.
`get_schema`()	Return a jsonschema to validate configuration, as a `dict`.
`make_from_cmd_line`(**kwargs)	Make a script from command-line arguments.
`next_supplemented_group_id`()	Return the group ID supplemented with a new subgroup.
`put_log_level`()	Output the logLevel event.
`run`()	Run the script.
`set_metadata`(metadata)	Set metadata fields in the provided struct, given the current configuration.
`set_state`([state, reason, keep_old_reason, ...])	Set the script state.
`start`()	Finish construction.
`start_phase2`()	Additional work after `start` before fully started.

Attributes Documentation

checkpoints¶

Get the checkpoints at which to pause and stop.

Returns self.evt_checkpoints.data which has these fields:

pause: checkpoints at which to pause, a regular expression
stop: checkpoints at which to stop, a regular expression

domain¶

group_id¶: Get the group ID (a str), or “” if not set.

obs_id¶: Get the block ID (a str), or “” if not set.

state¶

Get the current state.

Returns self.evt_state.data, which has these fields:

state: lsst.ts.idl.enums.Script.ScriptState
The current state.
lastCheckpoint: str
Name of most recently seen checkpoint.
reason: str
Reason for this state, if any.
numCheckpoints: int
The number of checkpoints seen.

state_name¶: Get the name of the current state.state.

Methods Documentation

async classmethod amain(**kwargs: Any) → None¶

Run the script from the command line.

Parameters:

kwargs: Keyword arguments for the script constructor. Must not include index. Ignored (other than testing for index) if the command specifies --schema.

Raises:

RuntimeError: If kwargs includes index.

Notes

The final return code will be:

0 if final state is lsst.ts.idl.enums.Script.ScriptState.DONE or lsst.ts.idl.enums.Script.ScriptState.STOPPED.
1 if final state is anything else, or if script.done_task is an exception (which would be raised by the script’s cleanup code).

Issues a RuntimeWarning if script.done_task is an exception and the final script state is anything other than Failed. This should never happen.

assert_state(action: str, states: Sequence[ScriptState]) → None¶

Assert that the current state is in states and the script is not exiting.

Parameters:

actionstr: Description of what you want to do.
stateslist [lsst.ts.idl.enums.Script.ScriptState]: Allowed states.

async checkpoint(name: str = '') → None¶

Await this at any “nice” point your script can be paused or stopped.

Parameters:

namestr, optional: Name of checkpoint; “” if it has no name.

Raises:

RuntimeError: If the state is not ScriptState.RUNNING. This likely means you called checkpoint from somewhere other than run.
RuntimeError: If _run_task is None or done. This probably means your code incorrectly set the state.

async cleanup() → None¶

Perform final cleanup, if any.

This method is called as the script state is exiting, unless the script had not yet started to run, or the script process is aborted by SIGTERM or SIGKILL.

async close(exception: Exception | None = None, cancel_start: bool = True) → None¶

Shut down, clean up resources and set done_task done.

May be called multiple times. The first call closes the Controller; subsequent calls wait until the Controller is closed.

Subclasses should override close_tasks instead of close, unless you have a good reason to do otherwise.

Parameters:

exceptionException, optional: The exception that caused stopping, if any, in which case the self.done_task exception is set to this value. Specify None for a normal exit, in which case the self.done_task result is set to None.
cancel_startbool, optional: Cancel the start task? Leave this true unless calling this from the start task.

Notes

Removes the SAL log handler, calls close_tasks to stop all background tasks, pauses briefly to allow final SAL messages to be sent, then closes the dds domain.

async close_tasks() → None¶

Shut down pending tasks. Called by close.

Perform all cleanup other than disabling logging to SAL and closing the dds domain.

abstract async configure(config: SimpleNamespace) → None¶

Configure the script.

Parameters:

configtypes.SimpleNamespace: Configuration.

Notes

This method is called by do_configure`. The script state will be ScriptState.UNCONFIGURED.

async do_configure(data: BaseMsgType) → None¶

Configure the currently loaded script.

Parameters:

datacmd_configure.DataType: Configuration.

Raises:

base.ExpectedError: If self.state.state is not lsst.ts.idl.enums.Script.ScriptState.UNCONFIGURED.

Notes

This method does the following:

Parse the config field as yaml-encoded dict and validate it (including setting default values).
Call configure.
Set the pause and stop checkpoints.
Set the log level if data.logLevel != 0.
Call set_metadata.
Output the metadata event.
Change the script state to lsst.ts.idl.enums.Script.ScriptState.CONFIGURED.

async do_resume(data: BaseMsgType) → None¶

Resume the currently paused script.

Parameters:

datacmd_resume.DataType: Ignored.

Raises:

base.ExpectedError: If self.state.state is not lsst.ts.idl.enums.Script.ScriptState.PAUSED.

async do_run(data: BaseMsgType) → None¶

Run the script and quit.

The script must have been configured and the group ID set.

Parameters:

datacmd_run.DataType: Ignored.

Raises:

base.ExpectedError: If self.state.state is not lsst.ts.idl.enums.Script.ScriptState.CONFIGURED. If self.group_id is blank.

async do_setCheckpoints(data: BaseMsgType) → None¶

Set or clear the checkpoints at which to pause and stop.

This command is deprecated. Please set the checkpoints using the configure command.

Parameters:

datacmd_setCheckpoints.DataType: Names of checkpoints for pausing and stopping, each a single regular expression; “” for no checkpoints, “.*” for all.

Raises:

base.ExpectedError

If self.state.state is not one of:

lsst.ts.idl.enums.Script.ScriptState.UNCONFIGURED
lsst.ts.idl.enums.Script.ScriptState.CONFIGURED
lsst.ts.idl.enums.Script.ScriptState.RUNNING
lsst.ts.idl.enums.Script.ScriptState.PAUSED

async do_setGroupId(data: BaseMsgType) → None¶

Set or clear the group_id attribute.

The script must be in the Configured state. This command may be called multiple times. It is typically called when the script reaches the top position on the script queue.

Parameters:

datacmd_setGroupId.DataType: Group ID, or “” to clear the group ID.

Raises:

base.ExpectedError: If state.state is not lsst.ts.idl.enums.Script.ScriptState.CONFIGURED.

async do_setLogLevel(data: BaseMsgType) → None¶

Set logging level.

Parameters:

datacmd_setLogLevel.DataType: Logging level.

async do_stop(data: BaseMsgType) → None¶

Stop the script.

Parameters:

datacmd_stop.DataType: Ignored.

Notes

This is a no-op if the script is already exiting. This does not wait for _exit to run.

abstract classmethod get_schema() → dict[str, Any] | None¶

Return a jsonschema to validate configuration, as a dict.

Please provide default values for all fields for which defaults make sense. This makes the script easier to use.

If your script has no configuration then return None, in which case the config field of the configure command must be an empty string.

classmethod make_from_cmd_line(**kwargs: Any) → lsst.ts.salobj.base_script.BaseScript | None¶

Make a script from command-line arguments.

Return None if --schema specified.

Parameters:

kwargs: Keyword arguments for the script constructor. Must not include index.

Raises:

RuntimeError: If kwargs includes index.

next_supplemented_group_id() → str¶

Return the group ID supplemented with a new subgroup.

The returned string has this format: f”{self.group_id}#{subgroup_id}”, where subgroup_id is an integer that starts at 1 and is incremented for every call to this method.

Raises:

RuntimeError: If there is no group ID.

async put_log_level() → None¶: Output the logLevel event.

abstract async run() → None¶

Run the script.

Your subclass must provide an implementation, as follows:

At points where you support pausing call checkpoint.
Raise an exception on error. Raise base.ExpectedError to avoid logging a traceback.

Notes

This method is only called when the script state is ScriptState.CONFIGURED. The remaining state transitions are handled automatically.

abstract set_metadata(metadata: BaseMsgType) → None¶

Set metadata fields in the provided struct, given the current configuration.

Parameters:

metadataself.evt_metadata.DataType(): Metadata to update. Set those fields for which you have useful information.

Notes

This method is called after configure by do_configure. The script state will be ScriptState.UNCONFIGURED.

async set_state(state: lsst.ts.xml.enums.Script.ScriptState | int | None = None, reason: str | None = None, keep_old_reason: bool = False, force_output: bool = False) → None¶

Set the script state.

Parameters:

stateScriptState or int, optional: New state, or None if no change
reasonstr, optional: Reason for state change. None for no new reason.
keep_old_reasonbool: If true, keep old reason; append the reason argument after “;” if it is is a non-empty string. If false replace with reason, or “” if reason is None.
force_outputbool, optional: If true the output even if not changed.

Notes

The lastCheckpoint field is set from self.last_checkpoint, and the numCheckpoints field is set from self.num_checkpoints.

async start() → None¶: Finish construction.

async start_phase2() → None¶

Additional work after start before fully started.

Used by BaseCsc to transition to handle the initial state.

Navigation

BaseScript¶