libstore: asyncify Store::queryReferrers

Change-Id: Iec5c85a22738f1a427774936d369e5f30af1a8a5

lix/legacy/nix-store.cc

@@ -373,7 +373,7 @@ static void opQuery(AsyncIoRoot & aio, Strings opFlags, Strings opArgs)
                     }
                     else if (query == qReferrers) {
                         StorePathSet tmp;
-                        store->queryReferrers(j, tmp);
+                        aio.blockOn(store->queryReferrers(j, tmp));
                         for (auto & i : tmp)
                             paths.insert(i);
                     }

lix/libstore/build/local-derivation-goal.cc

@@ -1068,8 +1068,9 @@ struct RestrictedStore : public virtual IndirectRootStore, public virtual GcStor
             return nullptr;
     };
 
-    void queryReferrers(const StorePath & path, StorePathSet & referrers) override
-    { }
+    kj::Promise<Result<void>>
+    queryReferrers(const StorePath & path, StorePathSet & referrers) override
+    { return {result::success()}; }
 
     kj::Promise<Result<std::map<std::string, std::optional<StorePath>>>>
     queryPartialDerivationOutputMap(const StorePath & path, Store * evalStore = nullptr) override

lix/libstore/daemon.cc

@@ -349,7 +349,7 @@ static void performOp(AsyncIoRoot & aio, TunnelLogger * logger, ref<Store> store
         #pragma GCC diagnostic ignored "-Wswitch-enum"
         switch (op) {
             case WorkerProto::Op::QueryReferrers: {
-                store->queryReferrers(path, paths);
+                aio.blockOn(store->queryReferrers(path, paths));
                 break;
             }
             case WorkerProto::Op::QueryValidDerivers: {

lix/libstore/gc.cc

@@ -760,7 +760,7 @@ try {
                     auto i = referrersCache.find(*path);
                     if (i == referrersCache.end()) {
                         StorePathSet referrers;
-                        queryReferrers(*path, referrers);
+                        TRY_AWAIT(queryReferrers(*path, referrers));
                         referrersCache.emplace(*path, std::move(referrers));
                         i = referrersCache.find(*path);
                     }

lix/libstore/local-store.cc

@@ -1051,12 +1051,22 @@ void LocalStore::queryReferrers(DBState & state, const StorePath & path, StorePa
 }
 
 
-void LocalStore::queryReferrers(const StorePath & path, StorePathSet & referrers)
-{
-    return retrySQLite([&]() {
-        auto state = dbPool.get();
-        queryReferrers(*state, path, referrers);
-    }, always_progresses);
+kj::Promise<Result<void>>
+LocalStore::queryReferrers(const StorePath & path, StorePathSet & referrers)
+try {
+    // NOLINTNEXTLINE(cppcoreguidelines-avoid-capturing-lambda-coroutines)
+    TRY_AWAIT(retrySQLite([&]() -> kj::Promise<Result<void>> {
+        try {
+            auto state = dbPool.get();
+            queryReferrers(*state, path, referrers);
+            co_return result::success();
+        } catch (...) {
+            co_return result::current_exception();
+        }
+    }));
+    co_return result::success();
+} catch (...) {
+    co_return result::current_exception();
 }
 
 
@@ -1777,7 +1787,7 @@ try {
         /* Check any referrers first.  If we can invalidate them
            first, then we can invalidate this path as well. */
         bool canInvalidate = true;
-        StorePathSet referrers; queryReferrers(path, referrers);
+        StorePathSet referrers; TRY_AWAIT(queryReferrers(path, referrers));
         for (auto & i : referrers)
             if (i != path) {
                 TRY_AWAIT(verifyPath(i, storePathsInStoreDir, done, validPaths, repair, errors));

lix/libstore/local-store.hh

@@ -198,7 +198,8 @@ public:
 
     std::shared_ptr<const ValidPathInfo> queryPathInfoUncached(const StorePath & path) override;
 
-    void queryReferrers(const StorePath & path, StorePathSet & referrers) override;
+    kj::Promise<Result<void>>
+    queryReferrers(const StorePath & path, StorePathSet & referrers) override;
 
     kj::Promise<Result<StorePathSet>> queryValidDerivers(const StorePath & path) override;
 

lix/libstore/misc.cc

@@ -26,7 +26,7 @@ try {
             try {
                 StorePathSet res;
                 StorePathSet referrers;
-                queryReferrers(path, referrers);
+                TRY_AWAIT(queryReferrers(path, referrers));
                 for (auto& ref : referrers)
                     if (ref != path)
                         res.insert(ref);

lix/libstore/remote-store.cc

@@ -306,14 +306,17 @@ std::shared_ptr<const ValidPathInfo> RemoteStore::queryPathInfoUncached(const St
 }
 
 
-void RemoteStore::queryReferrers(const StorePath & path,
+kj::Promise<Result<void>> RemoteStore::queryReferrers(const StorePath & path,
     StorePathSet & referrers)
-{
+try {
     auto conn(getConnection());
     conn->to << WorkerProto::Op::QueryReferrers << printStorePath(path);
     conn.processStderr();
     for (auto & i : WorkerProto::Serialise<StorePathSet>::read(*this, *conn))
         referrers.insert(i);
+    co_return result::success();
+} catch (...) {
+    co_return result::current_exception();
 }
 
 

lix/libstore/remote-store.hh

@@ -59,7 +59,8 @@ public:
 
     std::shared_ptr<const ValidPathInfo> queryPathInfoUncached(const StorePath & path) override;
 
-    void queryReferrers(const StorePath & path, StorePathSet & referrers) override;
+    kj::Promise<Result<void>>
+    queryReferrers(const StorePath & path, StorePathSet & referrers) override;
 
     kj::Promise<Result<StorePathSet>> queryValidDerivers(const StorePath & path) override;
 

lix/libstore/store-api.hh

@@ -429,8 +429,9 @@ public:
      * Queries the set of incoming FS references for a store path.
      * The result is not cleared.
      */
-    virtual void queryReferrers(const StorePath & path, StorePathSet & referrers)
-    { unsupported("queryReferrers"); }
+    virtual kj::Promise<Result<void>>
+    queryReferrers(const StorePath & path, StorePathSet & referrers)
+    try { unsupported("queryReferrers"); } catch (...) { return {result::current_exception()}; }
 
     /**
      * @return all currently valid derivations that have `path` as an