libstore: remove Goal::StillAlive

this was a triumph. i'm making a note here: huge success. it's hard to
overstate my satisfaction! i'm not even angry. i'm being so sincere ri

actually, no. we *are* angry. this was one dumbass odyssey. nobody has
asked for this. but not doing it would have locked us into old, broken
protocols forever or (possibly worse) forced us to write our own async
framework building on the old did-you-mean-continuations in Worker. if
we had done that we'd be locked into ever more, and ever more complex,
manual state management all over the place. this just could not stand.

Change-Id: I43a6de1035febff59d2eff83be9ad52af4659871

1 files changed, 2 insertions, 16 deletions

diff --git a/src/libstore/build/worker.cc b/src/libstore/build/worker.cc
index e063ede71..0ca805b4d 100644
--- a/src/libstore/build/worker.cc
+++ b/src/libstore/build/worker.cc
@@ -193,7 +193,7 @@ static void removeGoal(std::shared_ptr<G> goal, auto & goalMap)
 }
 
 
-void Worker::goalFinished(GoalPtr goal, Goal::Finished & f)
+void Worker::goalFinished(GoalPtr goal, Goal::WorkResult & f)
 {
     goal->trace("done");
     assert(!goal->exitCode.has_value());
@@ -210,20 +210,6 @@ void Worker::goalFinished(GoalPtr goal, Goal::Finished & f)
     goal->cleanup();
 }
 
-void Worker::handleWorkResult(GoalPtr goal, Goal::WorkResult how)
-{
-    std::visit(
-        overloaded{
-            [&](Goal::StillAlive) {
-                childStarted(goal, kj::evalLater([goal] { return goal->work(); }));
-            },
-            [&](Goal::Finished & f) { goalFinished(goal, f); },
-        },
-        how
-    );
-    updateStatistics();
-}
-
 void Worker::removeGoal(GoalPtr goal)
 {
     if (auto drvGoal = std::dynamic_pointer_cast<DerivationGoal>(goal))
@@ -250,7 +236,7 @@ void Worker::childStarted(GoalPtr goal, kj::Promise<Result<Goal::WorkResult>> pr
     children.add(promise
         .then([this, goal](auto result) {
             if (result.has_value()) {
-                handleWorkResult(goal, std::move(result.assume_value()));
+                goalFinished(goal, result.assume_value());
             } else {
                 childException = result.assume_error();
             }