Crudely make worker only provide a Store, not LocalStore

We downcast in a few places, this will be refactored to be better later.

src/libstore/build/derivation-goal.cc

@@ -848,14 +848,16 @@ void DerivationGoal::buildDone()
                So instead, check if the disk is (nearly) full now.  If
                so, we don't mark this build as a permanent failure. */
 #if HAVE_STATVFS
+            if (auto localStore = dynamic_cast<LocalStore *>(&worker.store)) {
                 uint64_t required = 8ULL * 1024 * 1024; // FIXME: make configurable
                 struct statvfs st;
-            if (statvfs(worker.store.realStoreDir.c_str(), &st) == 0 &&
+                if (statvfs(localStore->realStoreDir.c_str(), &st) == 0 &&
                     (uint64_t) st.f_bavail * st.f_bsize < required)
                     diskFull = true;
                 if (statvfs(tmpDir.c_str(), &st) == 0 &&
                     (uint64_t) st.f_bavail * st.f_bsize < required)
                     diskFull = true;
+            }
 #endif
 
             deleteTmpDir(false);
@@ -1215,13 +1217,16 @@ void DerivationGoal::startBuilder()
             useChroot = !(derivationIsImpure(derivationType)) && !noChroot;
     }
 
-    if (worker.store.storeDir != worker.store.realStoreDir) {
+    if (auto localStoreP = dynamic_cast<LocalStore *>(&worker.store)) {
+        auto & localStore = *localStoreP;
+        if (localStore.storeDir != localStore.realStoreDir) {
             #if __linux__
                 useChroot = true;
             #else
                 throw Error("building using a diverted store is not supported on this platform");
             #endif
         }
+    }
 
     /* Create a temporary directory where the build will take
        place. */
@@ -2182,7 +2187,8 @@ void DerivationGoal::startDaemon()
     Store::Params params;
     params["path-info-cache-size"] = "0";
     params["store"] = worker.store.storeDir;
-    params["root"] = worker.store.rootDir;
+    if (auto localStore = dynamic_cast<LocalStore *>(&worker.store))
+        params["root"] = localStore->rootDir;
     params["state"] = "/no-such-path";
     params["log"] = "/no-such-path";
     auto store = make_ref<RestrictedStore>(params,
@@ -3246,7 +3252,13 @@ void DerivationGoal::registerOutputs()
             }
         }
 
+        auto localStoreP = dynamic_cast<LocalStore *>(&worker.store);
+        if (!localStoreP)
+            Unsupported("Can only register outputs with local store");
+        auto & localStore = *localStoreP;
+
         if (buildMode == bmCheck) {
+
             if (!worker.store.isValidPath(newInfo.path)) continue;
             ValidPathInfo oldInfo(*worker.store.queryPathInfo(newInfo.path));
             if (newInfo.narHash != oldInfo.narHash) {
@@ -3271,8 +3283,8 @@ void DerivationGoal::registerOutputs()
             /* Since we verified the build, it's now ultimately trusted. */
             if (!oldInfo.ultimate) {
                 oldInfo.ultimate = true;
-                worker.store.signPathInfo(oldInfo);
-                worker.store.registerValidPaths({{oldInfo.path, oldInfo}});
+                localStore.signPathInfo(oldInfo);
+                localStore.registerValidPaths({{oldInfo.path, oldInfo}});
             }
 
             continue;
@@ -3288,13 +3300,13 @@ void DerivationGoal::registerOutputs()
         }
 
         if (curRound == nrRounds) {
-            worker.store.optimisePath(actualPath); // FIXME: combine with scanForReferences()
+            localStore.optimisePath(actualPath); // FIXME: combine with scanForReferences()
             worker.markContentsGood(newInfo.path);
         }
 
         newInfo.deriver = drvPath;
         newInfo.ultimate = true;
-        worker.store.signPathInfo(newInfo);
+        localStore.signPathInfo(newInfo);
 
         finish(newInfo.path);
 
@@ -3302,7 +3314,7 @@ void DerivationGoal::registerOutputs()
            isn't statically known so that we can safely unlock the path before
            the next iteration */
         if (newInfo.ca)
-            worker.store.registerValidPaths({{newInfo.path, newInfo}});
+            localStore.registerValidPaths({{newInfo.path, newInfo}});
 
         infos.emplace(outputName, std::move(newInfo));
     }
@@ -3375,11 +3387,16 @@ void DerivationGoal::registerOutputs()
        paths referenced by each of them.  If there are cycles in the
        outputs, this will fail. */
     {
+        auto localStoreP = dynamic_cast<LocalStore *>(&worker.store);
+        if (!localStoreP)
+            Unsupported("Can only register outputs with local store");
+        auto & localStore = *localStoreP;
+
         ValidPathInfos infos2;
         for (auto & [outputName, newInfo] : infos) {
             infos2.insert_or_assign(newInfo.path, newInfo);
         }
-        worker.store.registerValidPaths(infos2);
+        localStore.registerValidPaths(infos2);
     }
 
     /* In case of a fixed-output derivation hash mismatch, throw an
@@ -3577,7 +3594,12 @@ Path DerivationGoal::openLogFile()
     auto baseName = std::string(baseNameOf(worker.store.printStorePath(drvPath)));
 
     /* Create a log file. */
-    Path dir = fmt("%s/%s/%s/", worker.store.logDir, worker.store.drvsLogDir, string(baseName, 0, 2));
+    Path logDir;
+    if (auto localStore = dynamic_cast<LocalStore *>(&worker.store))
+        logDir = localStore->logDir;
+    else
+        logDir = settings.nixLogDir;
+    Path dir = fmt("%s/%s/%s/", logDir, LocalFSStore::drvsLogDir, string(baseName, 0, 2));
     createDirs(dir);
 
     Path logFileName = fmt("%s/%s%s", dir, string(baseName, 2),

src/libstore/build/worker.cc

@@ -8,7 +8,7 @@
 
 namespace nix {
 
-Worker::Worker(LocalStore & store)
+Worker::Worker(Store & store)
     : act(*logger, actRealise)
     , actDerivations(*logger, actBuilds)
     , actSubstitutions(*logger, actCopyPaths)
@@ -229,7 +229,9 @@ void Worker::run(const Goals & _topGoals)
 
         checkInterrupt();
 
-        store.autoGC(false);
+        // TODO GC interface?
+        if (auto localStore = dynamic_cast<LocalStore *>(&store))
+            localStore->autoGC(false);
 
         /* Call every wake goal (in the ordering established by
            CompareGoalPtrs). */

src/libstore/build/worker.hh

@@ -2,9 +2,12 @@
 
 #include "types.hh"
 #include "lock.hh"
-#include "local-store.hh"
+#include "store-api.hh"
 #include "goal.hh"
 
+#include <future>
+#include <thread>
+
 namespace nix {
 
 /* Forward definition. */
@@ -102,7 +105,7 @@ public:
     /* Set if at least one derivation is not deterministic in check mode. */
     bool checkMismatch;
 
-    LocalStore & store;
+    Store & store;
 
     std::unique_ptr<HookInstance> hook;
 
@@ -124,7 +127,7 @@ public:
        it answers with "decline-permanently", we don't try again. */
     bool tryBuildHook = true;
 
-    Worker(LocalStore & store);
+    Worker(Store & store);
     ~Worker();
 
     /* Make a goal (with caching). */