Refactored crawler to use task dispatcher

internal/base_task.go

@@ -0,0 +1,64 @@
+package internal
+
+import (
+	"fmt"
+
+	"github.com/renstrom/shortuuid"
+)
+
+type BaseTask struct {
+	state TaskState
+	data  TaskData
+	err   error
+	id    string
+}
+
+func NewBaseTask() *BaseTask {
+	return &BaseTask{
+		data: make(TaskData),
+		id:   shortuuid.New(),
+	}
+}
+
+func (t *BaseTask) SetState(state TaskState) {
+	t.state = state
+}
+
+func (t *BaseTask) SetData(key, val string) {
+	if t.data == nil {
+		t.data = make(TaskData)
+	}
+	t.data[key] = val
+}
+
+func (t *BaseTask) Done() {
+	if t.err != nil {
+		t.state = TaskStateFailed
+	} else {
+		t.state = TaskStateComplete
+	}
+}
+
+func (t *BaseTask) Fail(err error) error {
+	t.err = err
+	return err
+}
+
+func (t *BaseTask) Result() TaskResult {
+	stateStr := t.state.String()
+	errStr := ""
+	if t.err != nil {
+		errStr = t.err.Error()
+	}
+
+	return TaskResult{
+		State: stateStr,
+		Error: errStr,
+		Data:  t.data,
+	}
+}
+
+func (t *BaseTask) String() string   { return fmt.Sprintf("%T: %s", t, t.ID()) }
+func (t *BaseTask) ID() string       { return t.id }
+func (t *BaseTask) State() TaskState { return t.state }
+func (t *BaseTask) Error() error     { return t.err }