1 files changed, 50 insertions, 27 deletions

diff --git a/src/libstore/build/worker.hh b/src/libstore/build/worker.hh
index 1a913ca16..369e58b41 100644
--- a/src/libstore/build/worker.hh
+++ b/src/libstore/build/worker.hh
@@ -85,8 +85,40 @@ protected:
 class Worker : public WorkerBase
 {
 public:
-    using Targets = std::map<GoalPtr, kj::Promise<Result<Goal::WorkResult>>>;
-    using Results = std::map<GoalPtr, Goal::WorkResult>;
+    using Targets = std::vector<std::pair<GoalPtr, kj::Promise<Result<Goal::WorkResult>>>>;
+    struct Results {
+        /** Results of individual goals, if available. Goal results will be
+          * added to this map with the index they had in the `Targets` list
+          * returned by the goal factory function passed to `work`. If some
+          * goals did not complete processing, e.g. due to an early exit on
+          * goal failures, not all indices will be set. This may be used to
+          * detect which of the goals were cancelled before they completed.
+          */
+        std::map<size_t, Goal::WorkResult> goals;
+
+        /**
+         * The exit status in case of failure.
+         *
+         * In the case of a build failure, returned value follows this
+         * bitmask:
+         *
+         * ```
+         * 0b1100100
+         *      ^^^^
+         *      |||`- timeout
+         *      ||`-- output hash mismatch
+         *      |`--- build failure
+         *      `---- not deterministic
+         * ```
+         *
+         * In other words, the failure code is at least 100 (0b1100100), but
+         * might also be greater.
+         *
+         * Otherwise (no build failure, but some other sort of failure by
+         * assumption), this returned value is 1.
+         */
+        unsigned int failingExitStatus;
+    };
 
 private:
 
@@ -192,6 +224,7 @@ public:
     NotifyingCounter<uint64_t> expectedNarSize{[this] { updateStatisticsLater(); }};
     NotifyingCounter<uint64_t> doneNarSize{[this] { updateStatisticsLater(); }};
 
+private:
     Worker(Store & store, Store & evalStore, kj::AsyncIoContext & aio);
     ~Worker();
 
@@ -202,7 +235,6 @@ public:
     /**
      * @ref DerivationGoal "derivation goal"
      */
-private:
     template<typename ID, std::derived_from<Goal> G>
     std::pair<std::shared_ptr<G>, kj::Promise<Result<Goal::WorkResult>>> makeGoalCommon(
         std::map<ID, CachedGoal<G>> & map,
@@ -246,30 +278,7 @@ public:
     /**
      * Loop until the specified top-level goals have finished.
      */
-    Results run(std::function<Targets (GoalFactory &)> req);
-
-    /***
-     * The exit status in case of failure.
-     *
-     * In the case of a build failure, returned value follows this
-     * bitmask:
-     *
-     * ```
-     * 0b1100100
-     *      ^^^^
-     *      |||`- timeout
-     *      ||`-- output hash mismatch
-     *      |`--- build failure
-     *      `---- not deterministic
-     * ```
-     *
-     * In other words, the failure code is at least 100 (0b1100100), but
-     * might also be greater.
-     *
-     * Otherwise (no build failure, but some other sort of failure by
-     * assumption), this returned value is 1.
-     */
-    unsigned int failingExitStatus();
+    kj::Promise<Result<Results>> run(std::function<Targets (GoalFactory &)> req);
 
     /**
      * Check whether the given valid path exists and has the right
@@ -278,6 +287,20 @@ public:
     bool pathContentsGood(const StorePath & path);
 
     void markContentsGood(const StorePath & path);
+
+    template<typename MkGoals>
+    friend kj::Promise<Result<Results>> processGoals(
+        Store & store, Store & evalStore, kj::AsyncIoContext & aio, MkGoals && mkGoals
+    ) noexcept;
 };
 
+template<typename MkGoals>
+kj::Promise<Result<Worker::Results>> processGoals(
+    Store & store, Store & evalStore, kj::AsyncIoContext & aio, MkGoals && mkGoals
+) noexcept
+try {
+    co_return co_await Worker(store, evalStore, aio).run(std::forward<MkGoals>(mkGoals));
+} catch (...) {
+    co_return result::failure(std::current_exception());
+}
 }