libstore: asyncify writeDerivation

Change-Id: Ia4e25dbc84e522b27c5257564febbd1ccf4df8a3

lix/libexpr/primops.cc

@@ -1109,7 +1109,7 @@ drvName, Bindings * attrs, Value & v)
     }
 
     /* Write the resulting term into the Nix store directory. */
-    auto drvPath = writeDerivation(*state.ctx.store, drv, state.ctx.repair);
+    auto drvPath = state.aio.blockOn(writeDerivation(*state.ctx.store, drv, state.ctx.repair));
     auto drvPathS = state.ctx.store->printStorePath(drvPath);
 
     printMsg(lvlChatty, "instantiated '%1%' -> '%2%'", drvName, drvPathS);

lix/libstore/build/derivation-goal.cc

@@ -604,7 +604,7 @@ try {
             assert(attempt);
             Derivation drvResolved { std::move(*attempt) };
 
-            auto pathResolved = writeDerivation(worker.store, drvResolved);
+            auto pathResolved = TRY_AWAIT(writeDerivation(worker.store, drvResolved));
 
             auto msg = fmt("resolved derivation: '%s' -> '%s'",
                 worker.store.printStorePath(drvPath),

lix/libstore/daemon.cc

@@ -645,7 +645,7 @@ static void performOp(AsyncIoRoot & aio, TunnelLogger * logger, ref<Store> store
 
             Derivation drv2;
             static_cast<BasicDerivation &>(drv2) = drv;
-            drvPath = writeDerivation(*store, Derivation { drv2 });
+            drvPath = aio.blockOn(writeDerivation(*store, Derivation { drv2 }));
         }
 
         auto res = aio.blockOn(store->buildDerivation(drvPath, drv, buildMode));

lix/libstore/derivations.cc

@@ -134,9 +134,9 @@ bool BasicDerivation::isBuiltin() const
 }
 
 
-StorePath writeDerivation(Store & store,
+kj::Promise<Result<StorePath>> writeDerivation(Store & store,
     const Derivation & drv, RepairFlag repair, bool readOnly)
-{
+try {
     auto references = drv.inputSrcs;
     for (auto & i : drv.inputDrvs.map)
         references.insert(i.first);
@@ -145,9 +145,11 @@ StorePath writeDerivation(Store & store,
        held during a garbage collection). */
     auto suffix = std::string(drv.name) + drvExtension;
     auto contents = drv.unparse(store, false);
-    return readOnly || settings.readOnlyMode
+    co_return readOnly || settings.readOnlyMode
         ? store.computeStorePathForText(suffix, contents, references)
         : store.addTextToStore(suffix, contents, references, repair);
+} catch (...) {
+    co_return result::current_exception();
 }
 
 

lix/libstore/derivations.hh

@@ -2,6 +2,7 @@
 ///@file
 
 #include "lix/libstore/path.hh"
+#include "lix/libutil/result.hh"
 #include "lix/libutil/types.hh"
 #include "lix/libutil/hash.hh"
 #include "lix/libstore/content-address.hh"
@@ -11,6 +12,7 @@
 #include "lix/libutil/comparator.hh"
 #include "lix/libutil/variant-wrapper.hh"
 
+#include <kj/async.h>
 #include <map>
 #include <variant>
 
@@ -382,7 +384,7 @@ class Store;
 /**
  * Write a derivation to the Nix store, and return its path.
  */
-StorePath writeDerivation(Store & store,
+kj::Promise<Result<StorePath>> writeDerivation(Store & store,
     const Derivation & drv,
     RepairFlag repair = NoRepair,
     bool readOnly = false);

lix/libstore/store-api.cc

@@ -1433,7 +1433,7 @@ try {
         // resolved derivation, so we need to get it first
         auto resolvedDrv = drv.tryResolve(*this);
         if (resolvedDrv)
-            co_return writeDerivation(*this, *resolvedDrv, NoRepair, true);
+            co_return TRY_AWAIT(writeDerivation(*this, *resolvedDrv, NoRepair, true));
     }
 
     co_return path;

lix/nix/derivation-add.cc

@@ -32,11 +32,11 @@ struct CmdAddDerivation : MixDryRun, StoreCommand
 
         auto drv = Derivation::fromJSON(*store, json);
 
-        auto drvPath = writeDerivation(*store, drv, NoRepair, /* read only */ dryRun);
+        auto drvPath = aio().blockOn(writeDerivation(*store, drv, NoRepair, /* read only */ dryRun));
 
         drv.checkInvariants(*store, drvPath);
 
-        writeDerivation(*store, drv, NoRepair, dryRun);
+        aio().blockOn(writeDerivation(*store, drv, NoRepair, dryRun));
 
         logger->cout("%s", store->printStorePath(drvPath));
     }

lix/nix/develop.cc

@@ -256,7 +256,7 @@ try {
         }
     }
 
-    auto shellDrvPath = writeDerivation(*evalStore, drv);
+    auto shellDrvPath = TRY_AWAIT(writeDerivation(*evalStore, drv));
 
     /* Build the derivation. */
     TRY_AWAIT(store->buildPaths(