crates/rust-analyzer/src/op_queue.rs

   1 //! Bookkeeping to make sure only one long-running operation is being executed
   2 //! at a time.
   3
   4 pub(crate) struct OpQueue<Args, Output> {
   5     op_scheduled: Option<Args>,
   6     op_in_progress: bool,
   7     last_op_result: Output,
   8 }
   9
  10 impl<Args, Output: Default> Default for OpQueue<Args, Output> {
  11     fn default() -> Self {
  12         Self { op_scheduled: None, op_in_progress: false, last_op_result: Default::default() }
  13     }
  14 }
  15
  16 impl<Args, Output> OpQueue<Args, Output> {
  17     pub(crate) fn request_op(&mut self, data: Args) {
  18         self.op_scheduled = Some(data);
  19     }
  20     pub(crate) fn should_start_op(&mut self) -> Option<Args> {
  21         if self.op_in_progress {
  22             return None;
  23         }
  24         self.op_in_progress = self.op_scheduled.is_some();
  25         self.op_scheduled.take()
  26     }
  27     pub(crate) fn op_completed(&mut self, result: Output) {
  28         assert!(self.op_in_progress);
  29         self.op_in_progress = false;
  30         self.last_op_result = result;
  31     }
  32
  33     #[allow(unused)]
  34     pub(crate) fn last_op_result(&self) -> &Output {
  35         &self.last_op_result
  36     }
  37 }