libstore: asyncify Store::derivationFromPath

Change-Id: Ic6b54642da08f258c113d5076b34b7c13096f540

lix/legacy/nix-build.cc

@@ -327,7 +327,7 @@ static void main_nix_build(AsyncIoRoot & aio, std::string programName, Strings a
             throw UsageError("nix-shell requires a single derivation");
 
         auto & drvInfo = drvs.front();
-        auto drv = evalStore->derivationFromPath(drvInfo.requireDrvPath(*state));
+        auto drv = aio.blockOn(evalStore->derivationFromPath(drvInfo.requireDrvPath(*state)));
 
         std::vector<DerivedPath> pathsToBuild;
         RealisedPath::Set pathsToCopy;

lix/legacy/nix-store.cc

@@ -69,7 +69,7 @@ try {
     if (path.path.isDerivation()) {
         if (build) TRY_AWAIT(store->buildPaths({path.toDerivedPath()}));
         auto outputPaths = store->queryDerivationOutputMap(path.path);
-        Derivation drv = store->derivationFromPath(path.path);
+        Derivation drv = TRY_AWAIT(store->derivationFromPath(path.path));
         rootNr++;
 
         /* FIXME: Encode this empty special case explicitly in the type. */
@@ -232,7 +232,7 @@ static kj::Promise<Result<StorePathSet>> maybeUseOutputs(const StorePath & store
 try {
     if (forceRealise) TRY_AWAIT(realisePath({storePath}));
     if (useOutput && storePath.isDerivation()) {
-        auto drv = store->derivationFromPath(storePath);
+        auto drv = TRY_AWAIT(store->derivationFromPath(storePath));
         StorePathSet outputs;
         if (forceRealise)
             co_return store->queryDerivationOutputs(storePath);
@@ -394,7 +394,7 @@ static void opQuery(AsyncIoRoot & aio, Strings opFlags, Strings opArgs)
         case qBinding:
             for (auto & i : opArgs) {
                 auto path = useDeriver(store->followLinksToStorePath(i));
-                Derivation drv = store->derivationFromPath(path);
+                Derivation drv = aio.blockOn(store->derivationFromPath(path));
                 StringPairs::iterator j = drv.env.find(bindingName);
                 if (j == drv.env.end())
                     throw Error("derivation '%s' has no environment binding named '%s'",
@@ -479,7 +479,7 @@ static void opPrintEnv(AsyncIoRoot & aio, Strings opFlags, Strings opArgs)
     if (opArgs.size() != 1) throw UsageError("'--print-env' requires one derivation store path");
 
     Path drvPath = opArgs.front();
-    Derivation drv = store->derivationFromPath(store->parseStorePath(drvPath));
+    Derivation drv = aio.blockOn(store->derivationFromPath(store->parseStorePath(drvPath)));
 
     /* Print each environment variable in the derivation in a format
      * that can be sourced by the shell. */

lix/libexpr/get-drvs.cc

@@ -25,7 +25,7 @@ DrvInfo::DrvInfo(ref<Store> store, const std::string & drvPathWithOutputs)
 
     this->drvPath = drvPath;
 
-    auto drv = store->derivationFromPath(drvPath);
+    auto drv = RUN_ASYNC_IN_NEW_THREAD(store->derivationFromPath(drvPath));
 
     name = drvPath.name();
 

lix/libstore/misc.cc

@@ -235,7 +235,7 @@ struct QueryMissingContext
         }
         if (knownOutputPaths && invalid.empty()) return;
 
-        auto drv = make_ref<Derivation>(store.derivationFromPath(drvPath));
+        auto drv = make_ref<Derivation>(aio.blockOn(store.derivationFromPath(drvPath)));
         ParsedDerivation parsedDrv(StorePath(drvPath), *drv);
 
         if (!knownOutputPaths && settings.useSubstitutes && parsedDrv.substitutesAllowed()) {

lix/libstore/store-api.cc

@@ -937,7 +937,7 @@ StorePathSet Store::exportReferences(const StorePathSet & storePaths, const Stor
 
     for (auto & j : paths2) {
         if (j.isDerivation()) {
-            Derivation drv = derivationFromPath(j);
+            Derivation drv = RUN_ASYNC_IN_NEW_THREAD(derivationFromPath(j));
             for (auto & k : drv.outputsAndOptPaths(*this)) {
                 if (!k.second.second)
                     /* FIXME: I am confused why we are calling
@@ -1359,10 +1359,12 @@ std::string showPaths(const PathSet & paths)
 }
 
 
-Derivation Store::derivationFromPath(const StorePath & drvPath)
-{
-    RUN_ASYNC_IN_NEW_THREAD(ensurePath(drvPath));
-    return readDerivation(drvPath);
+kj::Promise<Result<Derivation>> Store::derivationFromPath(const StorePath & drvPath)
+try {
+    TRY_AWAIT(ensurePath(drvPath));
+    co_return readDerivation(drvPath);
+} catch (...) {
+    co_return result::current_exception();
 }
 
 Derivation readDerivationCommon(Store& store, const StorePath& drvPath, bool requireValidPath)

lix/libstore/store-api.hh

@@ -732,7 +732,7 @@ public:
      * Read a derivation, after ensuring its existence through
      * ensurePath().
      */
-    Derivation derivationFromPath(const StorePath & drvPath);
+    kj::Promise<Result<Derivation>> derivationFromPath(const StorePath & drvPath);
 
     /**
      * Read a derivation (which must already be valid).

lix/nix/develop.cc

@@ -212,7 +212,7 @@ const static std::string getEnvSh =
    environment to a file and exits. */
 static kj::Promise<Result<StorePath>> getDerivationEnvironment(ref<Store> store, ref<Store> evalStore, const StorePath & drvPath)
 try {
-    auto drv = evalStore->derivationFromPath(drvPath);
+    auto drv = TRY_AWAIT(evalStore->derivationFromPath(drvPath));
 
     auto builder = baseNameOf(drv.builder);
     if (builder != "bash")

perl/lib/Nix/Store.xs

@@ -17,6 +17,7 @@
 #include "lix/libstore/globals.hh"
 #include "lix/libstore/store-api.hh"
 #include "lix/libstore/crypto.hh"
+#include "lix/libutil/async.hh"
 
 #include <sodium.h>
 #include <nlohmann/json.hpp>
@@ -39,6 +40,12 @@ static ref<Store> store()
     return ref<Store>(_store);
 }
 
+static AsyncIoRoot & aio()
+{
+    static thread_local AsyncIoRoot root;
+    return root;
+}
+
 
 MODULE = Nix::Store PACKAGE = Nix::Store
 PROTOTYPES: ENABLE
@@ -313,7 +320,7 @@ SV * derivationFromPath(char * drvPath)
         HV *hash;
     CODE:
         try {
-            Derivation drv = store()->derivationFromPath(store()->parseStorePath(drvPath));
+            Derivation drv = aio().blockOn(store()->derivationFromPath(store()->parseStorePath(drvPath)));
             hash = newHV();
 
             HV * outputs = newHV();