Make ValidPathInfo have plain StorePathSet references like before

This change can wait for another PR.

perl/lib/Nix/Store.xs

@@ -69,7 +69,7 @@ int isValidPath(char * path)
 SV * queryReferences(char * path)
     PPCODE:
         try {
-            for (auto & i : store()->queryPathInfo(store()->parseStorePath(path))->referencesPossiblyToSelf())
+            for (auto & i : store()->queryPathInfo(store()->parseStorePath(path))->references)
                 XPUSHs(sv_2mortal(newSVpv(store()->printStorePath(i).c_str(), 0)));
         } catch (Error & e) {
             croak("%s", e.what());
@@ -110,7 +110,7 @@ SV * queryPathInfo(char * path, int base32)
             mXPUSHi(info->registrationTime);
             mXPUSHi(info->narSize);
             AV * refs = newAV();
-            for (auto & i : info->referencesPossiblyToSelf())
+            for (auto & i : info->references)
                 av_push(refs, newSVpv(store()->printStorePath(i).c_str(), 0));
             XPUSHs(sv_2mortal(newRV((SV *) refs)));
             AV * sigs = newAV();

src/libexpr/primops.cc

@@ -1544,8 +1544,7 @@ static void prim_readFile(EvalState & state, const PosIdx pos, Value * * args, V
     StorePathSet refs;
     if (state.store->isInStore(path)) {
         try {
-            // FIXME: Are self references becoming non-self references OK?
-            refs = state.store->queryPathInfo(state.store->toStorePath(path).first)->referencesPossiblyToSelf();
+            refs = state.store->queryPathInfo(state.store->toStorePath(path).first)->references;
         } catch (Error &) { // FIXME: should be InvalidPathError
         }
         // Re-scan references to filter down to just the ones that actually occur in the file.
@@ -1980,7 +1979,7 @@ static void addPath(
             try {
                 auto [storePath, subPath] = state.store->toStorePath(path);
                 // FIXME: we should scanForReferences on the path before adding it
-                refs = state.store->queryPathInfo(storePath)->referencesPossiblyToSelf();
+                refs = state.store->queryPathInfo(storePath)->references;
                 path = state.store->toRealPath(storePath) + subPath;
             } catch (Error &) { // FIXME: should be InvalidPathError
             }

src/libstore/binary-cache-store.cc

@@ -180,11 +180,11 @@ ref<const ValidPathInfo> BinaryCacheStore::addToStoreCommon(
         duration);
 
     /* Verify that all references are valid. This may do some .narinfo
-       reads, but typically they'll already be cached. Note that
-       self-references are always valid. */
-    for (auto & ref : info.references.others)
+       reads, but typically they'll already be cached. */
+    for (auto & ref : info.references)
         try {
-            queryPathInfo(ref);
+            if (ref != info.path)
+                queryPathInfo(ref);
         } catch (InvalidPath &) {
             throw Error("cannot add '%s' to the binary cache because the reference '%s' is not valid",
                 printStorePath(info.path), printStorePath(ref));

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

@@ -2523,7 +2523,10 @@ DrvOutputs LocalDerivationGoal::registerOutputs()
                 auto narHashAndSize = hashPath(htSHA256, actualPath);
                 ValidPathInfo newInfo0 { requiredFinalPath, narHashAndSize.first };
                 newInfo0.narSize = narHashAndSize.second;
-                newInfo0.references = rewriteRefs();
+                auto refs = rewriteRefs();
+                newInfo0.references = std::move(refs.others);
+                if (refs.self)
+                    newInfo0.references.insert(newInfo0.path);
                 return newInfo0;
             },
 
@@ -2774,12 +2777,12 @@ void LocalDerivationGoal::checkOutputs(const std::map<std::string, ValidPathInfo
                 auto i = outputsByPath.find(worker.store.printStorePath(path));
                 if (i != outputsByPath.end()) {
                     closureSize += i->second.narSize;
-                    for (auto & ref : i->second.referencesPossiblyToSelf())
+                    for (auto & ref : i->second.references)
                         pathsLeft.push(ref);
                 } else {
                     auto info = worker.store.queryPathInfo(path);
                     closureSize += info->narSize;
-                    for (auto & ref : info->referencesPossiblyToSelf())
+                    for (auto & ref : info->references)
                         pathsLeft.push(ref);
                 }
             }
@@ -2819,7 +2822,7 @@ void LocalDerivationGoal::checkOutputs(const std::map<std::string, ValidPathInfo
 
                 auto used = recursive
                     ? getClosure(info.path).first
-                    : info.referencesPossiblyToSelf();
+                    : info.references;
 
                 if (recursive && checks.ignoreSelfRefs)
                     used.erase(info.path);

src/libstore/build/substitution-goal.cc

@@ -165,8 +165,9 @@ void PathSubstitutionGoal::tryNext()
 
     /* To maintain the closure invariant, we first have to realise the
        paths referenced by this one. */
-    for (auto & i : info->references.others)
-        addWaitee(worker.makePathSubstitutionGoal(i));
+    for (auto & i : info->references)
+        if (i != storePath) /* ignore self-references */
+            addWaitee(worker.makePathSubstitutionGoal(i));
 
     if (waitees.empty()) /* to prevent hang (no wake-up event) */
         referencesValid();
@@ -187,8 +188,9 @@ void PathSubstitutionGoal::referencesValid()
         return;
     }
 
-    for (auto & i : info->references.others)
-        assert(worker.store.isValidPath(i));
+    for (auto & i : info->references)
+        if (i != storePath) /* ignore self-references */
+            assert(worker.store.isValidPath(i));
 
     state = &PathSubstitutionGoal::tryToRun;
     worker.wakeUp(shared_from_this());

src/libstore/content-address.cc

@@ -151,6 +151,16 @@ Hash getContentAddressHash(const ContentAddress & ca)
     }, ca);
 }
 
+bool StoreReferences::empty() const
+{
+    return !self && others.empty();
+}
+
+size_t StoreReferences::size() const
+{
+    return (self ? 1 : 0) + others.size();
+}
+
 ContentAddressWithReferences caWithoutRefs(const ContentAddress & ca) {
     return std::visit(overloaded {
         [&](const TextHash & h) -> ContentAddressWithReferences {

src/libstore/content-address.hh

@@ -4,7 +4,6 @@
 #include "hash.hh"
 #include "path.hh"
 #include "comparator.hh"
-#include "reference-set.hh"
 
 namespace nix {
 
@@ -95,7 +94,15 @@ Hash getContentAddressHash(const ContentAddress & ca);
  * References set
  */
 
-typedef References<StorePath> StoreReferences;
+struct StoreReferences {
+    StorePathSet others;
+    bool self = false;
+
+    bool empty() const;
+    size_t size() const;
+
+    GENERATE_CMP(StoreReferences, me->self, me->others);
+};
 
 /*
  * Full content address

src/libstore/daemon.cc

@@ -336,7 +336,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         logger->startWork();
         StorePathSet paths;
         if (op == wopQueryReferences)
-            for (auto & i : store->queryPathInfo(path)->referencesPossiblyToSelf())
+            for (auto & i : store->queryPathInfo(path)->references)
                 paths.insert(i);
         else if (op == wopQueryReferrers)
             store->queryReferrers(path, paths);
@@ -758,7 +758,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         else {
             to << 1
                << (i->second.deriver ? store->printStorePath(*i->second.deriver) : "");
-            worker_proto::write(*store, to, i->second.references.possiblyToSelf(path));
+            worker_proto::write(*store, to, i->second.references);
             to << i->second.downloadSize
                << i->second.narSize;
         }
@@ -781,7 +781,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         for (auto & i : infos) {
             to << store->printStorePath(i.first)
                << (i.second.deriver ? store->printStorePath(*i.second.deriver) : "");
-            worker_proto::write(*store, to, i.second.references.possiblyToSelf(i.first));
+            worker_proto::write(*store, to, i.second.references);
             to << i.second.downloadSize << i.second.narSize;
         }
         break;
@@ -863,7 +863,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         ValidPathInfo info { path, narHash };
         if (deriver != "")
             info.deriver = store->parseStorePath(deriver);
-        info.setReferencesPossiblyToSelf(worker_proto::read(*store, from, Phantom<StorePathSet> {}));
+        info.references = worker_proto::read(*store, from, Phantom<StorePathSet> {});
         from >> info.registrationTime >> info.narSize >> info.ultimate;
         info.sigs = readStrings<StringSet>(from);
         info.ca = parseContentAddressOpt(readString(from));

src/libstore/export-import.cc

@@ -45,7 +45,7 @@ void Store::exportPath(const StorePath & path, Sink & sink)
     teeSink
         << exportMagic
         << printStorePath(path);
-    worker_proto::write(*this, teeSink, info->referencesPossiblyToSelf());
+    worker_proto::write(*this, teeSink, info->references);
     teeSink
         << (info->deriver ? printStorePath(*info->deriver) : "")
         << 0;
@@ -80,7 +80,7 @@ StorePaths Store::importPaths(Source & source, CheckSigsFlag checkSigs)
         ValidPathInfo info { path, narHash };
         if (deriver != "")
             info.deriver = parseStorePath(deriver);
-        info.setReferencesPossiblyToSelf(std::move(references));
+        info.references = references;
         info.narSize = saved.s.size();
 
         // Ignore optional legacy signature.

src/libstore/legacy-ssh-store.cc

@@ -137,7 +137,7 @@ struct LegacySSHStore : public virtual LegacySSHStoreConfig, public virtual Stor
             auto deriver = readString(conn->from);
             if (deriver != "")
                 info->deriver = parseStorePath(deriver);
-            info->setReferencesPossiblyToSelf(worker_proto::read(*this, conn->from, Phantom<StorePathSet> {}));
+            info->references = worker_proto::read(*this, conn->from, Phantom<StorePathSet> {});
             readLongLong(conn->from); // download size
             info->narSize = readLongLong(conn->from);
 
@@ -171,7 +171,7 @@ struct LegacySSHStore : public virtual LegacySSHStoreConfig, public virtual Stor
                 << printStorePath(info.path)
                 << (info.deriver ? printStorePath(*info.deriver) : "")
                 << info.narHash.to_string(Base16, false);
-            worker_proto::write(*this, conn->to, info.referencesPossiblyToSelf());
+            worker_proto::write(*this, conn->to, info.references);
             conn->to
                 << info.registrationTime
                 << info.narSize
@@ -200,7 +200,7 @@ struct LegacySSHStore : public virtual LegacySSHStoreConfig, public virtual Stor
             conn->to
                 << exportMagic
                 << printStorePath(info.path);
-            worker_proto::write(*this, conn->to, info.referencesPossiblyToSelf());
+            worker_proto::write(*this, conn->to, info.references);
             conn->to
                 << (info.deriver ? printStorePath(*info.deriver) : "")
                 << 0

src/libstore/local-store.cc

@@ -938,8 +938,7 @@ std::shared_ptr<const ValidPathInfo> LocalStore::queryPathInfoInternal(State & s
     auto useQueryReferences(state.stmts->QueryReferences.use()(info->id));
 
     while (useQueryReferences.next())
-        info->insertReferencePossiblyToSelf(
-            parseStorePath(useQueryReferences.getStr(0)));
+        info->references.insert(parseStorePath(useQueryReferences.getStr(0)));
 
     return info;
 }
@@ -1206,7 +1205,7 @@ void LocalStore::registerValidPaths(const ValidPathInfos & infos)
 
         for (auto & [_, i] : infos) {
             auto referrer = queryValidPathId(*state, i.path);
-            for (auto & j : i.referencesPossiblyToSelf())
+            for (auto & j : i.references)
                 state->stmts->AddReference.use()(referrer)(queryValidPathId(*state, j)).exec();
         }
 
@@ -1227,7 +1226,7 @@ void LocalStore::registerValidPaths(const ValidPathInfos & infos)
         topoSort(paths,
             {[&](const StorePath & path) {
                 auto i = infos.find(path);
-                return i == infos.end() ? StorePathSet() : i->second.references.others;
+                return i == infos.end() ? StorePathSet() : i->second.references;
             }},
             {[&](const StorePath & path, const StorePath & parent) {
                 return BuildError(
@@ -1525,8 +1524,7 @@ StorePath LocalStore::addTextToStore(
 
             ValidPathInfo info { dstPath, narHash };
             info.narSize = sink.s.size();
-            // No self reference allowed with text-hashing
-            info.references.others = references;
+            info.references = references;
             info.ca = TextHash { .hash = hash };
             registerValidPath(info);
         }

src/libstore/make-content-addressed.cc

@@ -28,8 +28,9 @@ std::map<StorePath, StorePath> makeContentAddressed(
         StringMap rewrites;
 
         StoreReferences refs;
-        refs.self = oldInfo->references.self;
-        for (auto & ref : oldInfo->references.others) {
+        for (auto & ref : oldInfo->references) {
+            if (ref == path)
+                refs.self = true;
             auto i = remappings.find(ref);
             auto replacement = i != remappings.end() ? i->second : ref;
             // FIXME: warn about unremapped paths?

src/libstore/misc.cc

@@ -40,8 +40,9 @@ void Store::computeFSClosure(const StorePathSet & startPaths,
                         std::future<ref<const ValidPathInfo>> & fut) {
             StorePathSet res;
             auto info = fut.get();
-            for (auto & ref : info->references.others)
-                res.insert(ref);
+            for (auto & ref : info->references)
+                if (ref != path)
+                    res.insert(ref);
 
             if (includeOutputs && path.isDerivation())
                 for (auto & [_, maybeOutPath] : queryPartialDerivationOutputMap(path))
@@ -223,7 +224,7 @@ void Store::queryMissing(const std::vector<DerivedPath> & targets,
                 state->narSize += info->second.narSize;
             }
 
-            for (auto & ref : info->second.references.others)
+            for (auto & ref : info->second.references)
                 pool.enqueue(std::bind(doPath, DerivedPath::Opaque { ref }));
           },
         }, req.raw());
@@ -241,7 +242,7 @@ StorePaths Store::topoSortPaths(const StorePathSet & paths)
     return topoSort(paths,
         {[&](const StorePath & path) {
             try {
-                return queryPathInfo(path)->references.others;
+                return queryPathInfo(path)->references;
             } catch (InvalidPath &) {
                 return StorePathSet();
             }
@@ -297,7 +298,7 @@ std::map<DrvOutput, StorePath> drvOutputReferences(
 
     auto info = store.queryPathInfo(outputPath);
 
-    return drvOutputReferences(Realisation::closure(store, inputRealisations), info->referencesPossiblyToSelf());
+    return drvOutputReferences(Realisation::closure(store, inputRealisations), info->references);
 }
 
 OutputPathMap resolveDerivedPath(Store & store, const DerivedPath::Built & bfd, Store * evalStore_)

src/libstore/nar-info-disk-cache.cc

@@ -248,7 +248,7 @@ class NarInfoDiskCacheImpl : public NarInfoDiskCache
             narInfo->fileSize = queryNAR.getInt(5);
             narInfo->narSize = queryNAR.getInt(7);
             for (auto & r : tokenizeString<Strings>(queryNAR.getStr(8), " "))
-                narInfo->insertReferencePossiblyToSelf(StorePath(r));
+                narInfo->references.insert(StorePath(r));
             if (!queryNAR.isNull(9))
                 narInfo->deriver = StorePath(queryNAR.getStr(9));
             for (auto & sig : tokenizeString<Strings>(queryNAR.getStr(10), " "))

src/libstore/nar-info.cc

@@ -63,7 +63,7 @@ NarInfo::NarInfo(const Store & store, const std::string & s, const std::string &
             auto refs = tokenizeString<Strings>(value, " ");
             if (!references.empty()) throw corrupt();
             for (auto & r : refs)
-                insertReferencePossiblyToSelf(StorePath(r));
+                references.insert(StorePath(r));
         }
         else if (name == "Deriver") {
             if (value != "unknown-deriver")