libstore: asyncify Store::importPaths

Change-Id: Ic330b9213209fd7d3cccf90af7f3d6b41aede9b5

lix/legacy/nix-store.cc

@@ -716,7 +716,7 @@ static void opImport(AsyncIoRoot & aio, Strings opFlags, Strings opArgs)
     if (!opArgs.empty()) throw UsageError("no arguments expected");
 
     FdSource source(STDIN_FILENO);
-    auto paths = store->importPaths(source, NoCheckSigs);
+    auto paths = aio.blockOn(store->importPaths(source, NoCheckSigs));
 
     for (auto & i : paths)
         cout << fmt("%s\n", store->printStorePath(i)) << std::flush;
@@ -910,7 +910,7 @@ static void opServe(AsyncIoRoot & aio, Strings opFlags, Strings opArgs)
 
             case ServeProto::Command::ImportPaths: {
                 if (!writeAllowed) throw Error("importing paths is not allowed");
-                store->importPaths(in, NoCheckSigs); // FIXME: should we skip sig checking?
+                aio.blockOn(store->importPaths(in, NoCheckSigs)); // FIXME: should we skip sig checking?
                 out << 1; // indicate success
                 break;
             }

lix/libstore/export-import.cc

@@ -49,8 +49,8 @@ void Store::exportPath(const StorePath & path, Sink & sink)
         << 0;
 }
 
-StorePaths Store::importPaths(Source & source, CheckSigsFlag checkSigs)
-{
+kj::Promise<Result<StorePaths>> Store::importPaths(Source & source, CheckSigsFlag checkSigs)
+try {
     StorePaths res;
     while (true) {
         auto n = readNum<uint64_t>(source);
@@ -91,7 +91,9 @@ StorePaths Store::importPaths(Source & source, CheckSigsFlag checkSigs)
         res.push_back(info.path);
     }
 
-    return res;
+    co_return res;
+} catch (...) {
+    co_return result::current_exception();
 }
 
 }

lix/libstore/store-api.hh

@@ -796,7 +796,8 @@ public:
      * Nix store. Optionally, the contents of the NARs are preloaded
      * into the specified FS accessor to speed up subsequent access.
      */
-    StorePaths importPaths(Source & source, CheckSigsFlag checkSigs = CheckSigs);
+    kj::Promise<Result<StorePaths>>
+    importPaths(Source & source, CheckSigsFlag checkSigs = CheckSigs);
 
     struct Stats
     {

perl/lib/Nix/Store.xs

@@ -207,7 +207,7 @@ void importPaths(int fd, int dontCheckSigs)
     PPCODE:
         try {
             FdSource source(fd);
-            store()->importPaths(source, dontCheckSigs ? NoCheckSigs : CheckSigs);
+            aio().blockOn(store()->importPaths(source, dontCheckSigs ? NoCheckSigs : CheckSigs));
         } catch (Error & e) {
             croak("%s", e.what());
         }