Package dev.frostlake.task

Class TaskScheduler

java.lang.Object

dev.frostlake.task.TaskScheduler

public class TaskScheduler
extends Object

Schedules and executes tasks

Constructor Summary

Constructors

Constructor	Description
TaskScheduler(Catalog catalog, TaskExecutor taskExecutor)

Method Summary

Modifier and Type	Method	Description
static Task	currentTask()	The task whose body is executing on the current thread, or null outside a task run.
void	executeTaskManually(String qualifiedTaskName)	Execute a task manually by name (for EXECUTE TASK command)
void	executeTaskNow(String qualifiedTaskName, Task task)	Execute a task immediately (for testing)
boolean	hasRunningExecutions(String qualifiedTaskName)	Whether a run of this task is in flight right now.
boolean	isRunning()
boolean	isScheduled(String qualifiedTaskName)	Whether this task currently holds a live timer entry.
void	resumeTask(String qualifiedTaskName, Task task)
static String	schedulerKey(String databaseName, String schemaName, String taskName)	The scheduler key for a task: DB.SCHEMA.TASK, upper-cased.
void	scheduleTask(String qualifiedTaskName, Task task)
void	start()	Start the scheduler and arm every task already in the STARTED state.
void	stop()
void	suspendTask(String qualifiedTaskName, Task task)
void	unscheduleTask(String qualifiedTaskName)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

TaskScheduler

public TaskScheduler(Catalog catalog,
 TaskExecutor taskExecutor)

Method Details

currentTask

public static Task currentTask()

The task whose body is executing on the current thread, or null outside a task run.

schedulerKey

public static String schedulerKey(String databaseName,
 String schemaName,
 String taskName)

The scheduler key for a task: DB.SCHEMA.TASK, upper-cased. Every path that arms or cancels a task must build it the same way, or a later SUSPEND cancels nothing because it looks up a key that RESUME never wrote. Shared by ALTER TASK … RESUME/SUSPEND and by start()'s arming scan.

start

public void start()

Start the scheduler and arm every task already in the STARTED state.

The scan matters because a task can reach STARTED without anyone calling resumeTask(java.lang.String, dev.frostlake.metastore.model.Task): a snapshot restore writes the state straight onto the model (CatalogSnapshotReader), so a task that was running when the engine was persisted comes back STARTED but unarmed, and would never fire again until it was manually RESUMEd. Arming here makes "it was running before the restart" survive the restart.

Still OPT-IN — nothing starts the scheduler at engine boot, so an embedded engine spawns no timer threads unless the embedder asks for them (or a RESUME lazy-starts it).

stop

public void stop()

scheduleTask

public void scheduleTask(String qualifiedTaskName,
 Task task)

unscheduleTask

public void unscheduleTask(String qualifiedTaskName)

resumeTask

public void resumeTask(String qualifiedTaskName,
 Task task)

suspendTask

public void suspendTask(String qualifiedTaskName,
 Task task)

executeTaskNow

public void executeTaskNow(String qualifiedTaskName,
 Task task)

Execute a task immediately (for testing)

executeTaskManually

public void executeTaskManually(String qualifiedTaskName)

Execute a task manually by name (for EXECUTE TASK command)

isRunning

public boolean isRunning()

isScheduled

public boolean isScheduled(String qualifiedTaskName)

Whether this task currently holds a live timer entry. The key must be built with schedulerKey(java.lang.String, java.lang.String, java.lang.String); anything else answers false because it is not the key the scheduler armed under.

hasRunningExecutions

public boolean hasRunningExecutions(String qualifiedTaskName)

Whether a run of this task is in flight right now. Only tracked for tasks that forbid overlapping execution (the default) — a task with ALLOW_OVERLAPPING_EXECUTION = TRUE needs no in-flight bookkeeping, so it always reports false.