libstore: return finishedness from Goal methods

this is the first step towards removing all result-related mutation of
Goal state from goal implementations themselves, and into Worker state
instead. once that is done we can treat all non-const Goal fields like
private state of the goal itself, and make threading of goals possible

Change-Id: I69ff7d02a6fd91a65887c6640bfc4f5fb785b45c

1 files changed, 8 insertions, 8 deletions

diff --git a/src/libstore/build/drv-output-substitution-goal.hh b/src/libstore/build/drv-output-substitution-goal.hh
index 598b119dc..a28347f15 100644
--- a/src/libstore/build/drv-output-substitution-goal.hh
+++ b/src/libstore/build/drv-output-substitution-goal.hh
@@ -58,20 +58,20 @@ class DrvOutputSubstitutionGoal : public Goal {
 public:
     DrvOutputSubstitutionGoal(const DrvOutput& id, Worker & worker, RepairFlag repair = NoRepair, std::optional<ContentAddress> ca = std::nullopt);
 
-    typedef void (DrvOutputSubstitutionGoal::*GoalState)();
+    typedef WorkResult (DrvOutputSubstitutionGoal::*GoalState)();
     GoalState state;
 
-    void init();
-    void tryNext();
-    void realisationFetched();
-    void outPathValid();
-    void finished();
+    WorkResult init();
+    WorkResult tryNext();
+    WorkResult realisationFetched();
+    WorkResult outPathValid();
+    WorkResult finished();
 
-    void timedOut(Error && ex) override { abort(); };
+    Finished timedOut(Error && ex) override { abort(); };
 
     std::string key() override;
 
-    void work() override;
+    WorkResult work() override;
 
     JobCategory jobCategory() const override {
         return JobCategory::Substitution;