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|
package recording
/*
In this file we implement task lifecycle management.
Concrete task works are done in the `runner.go` file.
*/
import (
"context"
"fmt"
"github.com/keuin/slbr/logging"
)
type TaskStatus int
const (
StNotStarted TaskStatus = iota
StRunning
StRestarting
StStopped
)
var (
ErrTaskIsAlreadyStarted = fmt.Errorf("task is already started")
ErrTaskIsStopped = fmt.Errorf("restarting a stopped task is not allowed")
)
// RunningTask is an augmented TaskConfig struct
// that contains volatile runtime information.
type RunningTask struct {
TaskConfig
// ctx: the biggest context this task uses. It may create children contexts.
ctx context.Context
// result: if the task is ended, here is the returned error
result error
// status: running status
status TaskStatus
// hookStarted: called asynchronously when the task is started. This won't be called when restarting.
hookStarted func()
// hookStopped: called asynchronously when the task is stopped. This won't be called when restarting.
hookStopped func()
// logger: where to print logs
logger logging.Logger
}
func NewRunningTask(
config TaskConfig,
ctx context.Context,
hookStarted func(),
hookStopped func(),
logger logging.Logger,
) RunningTask {
return RunningTask{
TaskConfig: config,
ctx: ctx,
status: StNotStarted,
hookStarted: hookStarted,
hookStopped: hookStopped,
logger: logger,
}
}
func (t *RunningTask) StartTask() error {
st := t.status
switch st {
case StNotStarted:
// TODO real start
go func() {
defer func() { t.status = StStopped }()
t.hookStarted()
defer t.hookStopped()
// do the task
_ = t.runTaskWithAutoRestart()
}()
return nil
case StRunning:
return ErrTaskIsAlreadyStarted
case StRestarting:
return ErrTaskIsAlreadyStarted
case StStopped:
// we don't allow starting a stopped task
// because some state needs to be reset
// just create a new task and run
return ErrTaskIsStopped
}
panic(fmt.Errorf("invalid task status: %v", st))
}
|
