First Commit

analyzer/utils/lsm.go

@@ -0,0 +1,54 @@
+package utils
+
+type LSMAction int
+
+const (
+	LSMActionPause LSMAction = iota
+	LSMActionNext
+	LSMActionReset
+	LSMActionCancel
+)
+
+type LinearStateMachine struct {
+	Steps []func() LSMAction
+
+	index     int
+	cancelled bool
+}
+
+func NewLinearStateMachine(steps ...func() LSMAction) *LinearStateMachine {
+	return &LinearStateMachine{
+		Steps: steps,
+	}
+}
+
+// Run runs the state machine until it pauses, finishes or is cancelled.
+func (lsm *LinearStateMachine) Run() (cancelled bool, done bool) {
+	if lsm.index >= len(lsm.Steps) {
+		return lsm.cancelled, true
+	}
+	for lsm.index < len(lsm.Steps) {
+		action := lsm.Steps[lsm.index]()
+		switch action {
+		case LSMActionPause:
+			return false, false
+		case LSMActionNext:
+			lsm.index++
+		case LSMActionReset:
+			lsm.index = 0
+		case LSMActionCancel:
+			lsm.cancelled = true
+			return true, true
+		}
+	}
+	return false, true
+}
+
+func (lsm *LinearStateMachine) AppendSteps(steps ...func() LSMAction) {
+	lsm.Steps = append(lsm.Steps, steps...)
+}
+
+func (lsm *LinearStateMachine) Reset() {
+	lsm.index = 0
+	lsm.cancelled = false
+}