Merge "libstore: remove operations that are never called by supported clients" into main

4 files changed, 80 insertions, 70 deletions

diff --git a/src/libstore/daemon.cc b/src/libstore/daemon.cc
index c89b5f5b3..6d64644d1 100644
--- a/src/libstore/daemon.cc
+++ b/src/libstore/daemon.cc
@@ -296,17 +296,6 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         break;
     }
 
-    case WorkerProto::Op::HasSubstitutes: {
-        auto path = store->parseStorePath(readString(from));
-        logger->startWork();
-        StorePathSet paths; // FIXME
-        paths.insert(path);
-        auto res = store->querySubstitutablePaths(paths);
-        logger->stopWork();
-        to << (res.count(path) != 0);
-        break;
-    }
-
     case WorkerProto::Op::QuerySubstitutablePaths: {
         auto paths = WorkerProto::Serialise<StorePathSet>::read(*store, rconn);
         logger->startWork();
@@ -316,36 +305,74 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         break;
     }
 
+    case WorkerProto::Op::HasSubstitutes: {
+        throw UnimplementedError("HasSubstitutes is not supported in Lix. This is not used if the declared server protocol is > 1.12 (Nix 1.0, 2012)");
+        break;
+    }
+
     case WorkerProto::Op::QueryPathHash: {
-        auto path = store->parseStorePath(readString(from));
-        logger->startWork();
-        auto hash = store->queryPathInfo(path)->narHash;
-        logger->stopWork();
-        to << hash.to_string(Base16, false);
+        throw UnimplementedError("QueryPathHash is not supported in Lix, client usages were removed in 2016 in e0204f8d462041387651af388074491fd0bf36d6");
+        break;
+    }
+
+    case WorkerProto::Op::QueryReferences: {
+        throw UnimplementedError("QueryReferences is not supported in Lix, client usages were removed in 2016 in e0204f8d462041387651af388074491fd0bf36d6");
+        break;
+    }
+
+    case WorkerProto::Op::QueryDeriver: {
+        throw UnimplementedError("QueryDeriver is not supported in Lix, client usages were removed in 2016 in e0204f8d462041387651af388074491fd0bf36d6");
+        break;
+    }
+
+    case WorkerProto::Op::ExportPath: {
+        throw UnimplementedError("ExportPath is not supported in Lix, client usage were removed in 2017 in 27dc76c1a5dbe654465245ff5f6bc22e2c8902da");
+        break;
+    }
+
+    case WorkerProto::Op::ImportPaths: {
+        throw UnimplementedError("ImportPaths is not supported in Lix. This is not used if the declared server protocol is >= 1.18 (Nix 2.0, 2016)");
         break;
     }
 
-    case WorkerProto::Op::QueryReferences:
     case WorkerProto::Op::QueryReferrers:
     case WorkerProto::Op::QueryValidDerivers:
     case WorkerProto::Op::QueryDerivationOutputs: {
         auto path = store->parseStorePath(readString(from));
         logger->startWork();
         StorePathSet paths;
-        if (op == WorkerProto::Op::QueryReferences)
-            for (auto & i : store->queryPathInfo(path)->references)
-                paths.insert(i);
-        else if (op == WorkerProto::Op::QueryReferrers)
-            store->queryReferrers(path, paths);
-        else if (op == WorkerProto::Op::QueryValidDerivers)
-            paths = store->queryValidDerivers(path);
-        else paths = store->queryDerivationOutputs(path);
+
+        #pragma GCC diagnostic push
+        #pragma GCC diagnostic ignored "-Wswitch-enum"
+        switch (op) {
+            case WorkerProto::Op::QueryReferrers: {
+                store->queryReferrers(path, paths);
+                break;
+            }
+            case WorkerProto::Op::QueryValidDerivers: {
+                paths = store->queryValidDerivers(path);
+                break;
+            }
+            case WorkerProto::Op::QueryDerivationOutputs: {
+                // Only sent if server presents proto version <= 1.21
+                REMOVE_AFTER_DROPPING_PROTO_MINOR(21);
+                paths = store->queryDerivationOutputs(path);
+                break;
+            }
+            default:
+                abort();
+                break;
+        }
+        #pragma GCC diagnostic pop
+
         logger->stopWork();
         WorkerProto::write(*store, wconn, paths);
         break;
     }
 
     case WorkerProto::Op::QueryDerivationOutputNames: {
+        // Unused in CppNix >= 2.4 (removed in 045b07200c77bf1fe19c0a986aafb531e7e1ba54)
+        REMOVE_AFTER_DROPPING_PROTO_MINOR(31);
         auto path = store->parseStorePath(readString(from));
         logger->startWork();
         auto names = store->readDerivation(path).outputNames();
@@ -363,15 +390,6 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         break;
     }
 
-    case WorkerProto::Op::QueryDeriver: {
-        auto path = store->parseStorePath(readString(from));
-        logger->startWork();
-        auto info = store->queryPathInfo(path);
-        logger->stopWork();
-        to << (info->deriver ? store->printStorePath(*info->deriver) : "");
-        break;
-    }
-
     case WorkerProto::Op::QueryPathFromHashPart: {
         auto hashPart = readString(from);
         logger->startWork();
@@ -493,29 +511,6 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         break;
     }
 
-    case WorkerProto::Op::ExportPath: {
-        auto path = store->parseStorePath(readString(from));
-        readInt(from); // obsolete
-        logger->startWork();
-        TunnelSink sink(to);
-        store->exportPath(path, sink);
-        logger->stopWork();
-        to << 1;
-        break;
-    }
-
-    case WorkerProto::Op::ImportPaths: {
-        logger->startWork();
-        TunnelSource source(from, to);
-        auto paths = store->importPaths(source,
-            trusted ? NoCheckSigs : CheckSigs);
-        logger->stopWork();
-        Strings paths2;
-        for (auto & i : paths) paths2.push_back(store->printStorePath(i));
-        to << paths2;
-        break;
-    }
-
     case WorkerProto::Op::BuildPaths: {
         auto drvs = WorkerProto::Serialise<DerivedPaths>::read(*store, rconn);
         BuildMode mode = buildModeFromInteger(readInt(from));
@@ -666,8 +661,10 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         break;
     }
 
-    // Obsolete.
+    // Obsolete since 9947f1646a26b339fff2e02b77798e9841fac7f0 (included in CppNix 2.5.0).
     case WorkerProto::Op::SyncWithGC: {
+        // CppNix 2.5.0 is 32
+        REMOVE_AFTER_DROPPING_PROTO_MINOR(31);
         logger->startWork();
         logger->stopWork();
         to << 1;
diff --git a/src/libstore/remote-store.cc b/src/libstore/remote-store.cc
index 575078289..b2f8a285d 100644
--- a/src/libstore/remote-store.cc
+++ b/src/libstore/remote-store.cc
@@ -307,6 +307,7 @@ StorePathSet RemoteStore::queryDerivationOutputs(const StorePath & path)
     if (GET_PROTOCOL_MINOR(getProtocol()) >= 22) {
         return Store::queryDerivationOutputs(path);
     }
+    REMOVE_AFTER_DROPPING_PROTO_MINOR(21);
     auto conn(getConnection());
     conn->to << WorkerProto::Op::QueryDerivationOutputs << printStorePath(path);
     conn.processStderr();
@@ -336,6 +337,7 @@ std::map<std::string, std::optional<StorePath>> RemoteStore::queryPartialDerivat
             return outputs;
         }
     } else {
+        REMOVE_AFTER_DROPPING_PROTO_MINOR(21);
         auto & evalStore = evalStore_ ? *evalStore_ : *this;
         // Fallback for old daemon versions.
         // For floating-CA derivations (and their co-dependencies) this is an
@@ -530,6 +532,7 @@ void RemoteStore::registerDrvOutput(const Realisation & info)
     auto conn(getConnection());
     conn->to << WorkerProto::Op::RegisterDrvOutput;
     if (GET_PROTOCOL_MINOR(conn->daemonVersion) < 31) {
+        REMOVE_AFTER_DROPPING_PROTO_MINOR(30);
         conn->to << info.id.to_string();
         conn->to << std::string(info.outPath.to_string());
     } else {
@@ -617,6 +620,7 @@ std::vector<KeyedBuildResult> RemoteStore::buildPathsWithResults(
         conn.processStderr();
         return WorkerProto::Serialise<std::vector<KeyedBuildResult>>::read(*this, *conn);
     } else {
+        REMOVE_AFTER_DROPPING_PROTO_MINOR(33);
         // Avoid deadlock.
         conn_.reset();
 
diff --git a/src/libstore/serve-protocol.hh b/src/libstore/serve-protocol.hh
index 3f82c8177..742320933 100644
--- a/src/libstore/serve-protocol.hh
+++ b/src/libstore/serve-protocol.hh
@@ -8,6 +8,11 @@ namespace nix {
 #define SERVE_MAGIC_1 0x390c9deb
 #define SERVE_MAGIC_2 0x5452eecb
 
+// This must remain at 2.7 (Nix 2.18) forever in Lix, since the protocol
+// versioning is monotonic, so if we ever change it in the future, it will
+// break compatibility with any potential CppNix-originated protocol changes.
+//
+// Lix intends to replace this protocol entirely.
 #define SERVE_PROTOCOL_VERSION (2 << 8 | 7)
 #define GET_PROTOCOL_MAJOR(x) ((x) & 0xff00)
 #define GET_PROTOCOL_MINOR(x) ((x) & 0x00ff)
diff --git a/src/libstore/worker-protocol.hh b/src/libstore/worker-protocol.hh
index 5f24c189f..36acf2a8d 100644
--- a/src/libstore/worker-protocol.hh
+++ b/src/libstore/worker-protocol.hh
@@ -23,6 +23,10 @@ namespace nix {
 #define GET_PROTOCOL_MINOR(x) ((x) & 0x00ff)
 
 
+#define REMOVE_AFTER_DROPPING_PROTO_MINOR(protoMinor) \
+    static_assert(MIN_SUPPORTED_MINOR_WORKER_PROTO_VERSION <= (protoMinor))
+
+
 #define STDERR_NEXT  0x6f6c6d67
 #define STDERR_READ  0x64617461 // data needed from source
 #define STDERR_WRITE 0x64617416 // data for sink
@@ -136,30 +140,30 @@ struct WorkerProto
 enum struct WorkerProto::Op : uint64_t
 {
     IsValidPath = 1,
-    HasSubstitutes = 3,
-    QueryPathHash = 4, // obsolete
-    QueryReferences = 5, // obsolete
+    HasSubstitutes = 3, // obsolete since 2012, stubbed to error
+    QueryPathHash = 4, // obsolete since 2016, stubbed to error
+    QueryReferences = 5, // obsolete since 2016, stubbed to error
     QueryReferrers = 6,
     AddToStore = 7,
-    AddTextToStore = 8, // obsolete since 1.25, Nix 3.0. Use WorkerProto::Op::AddToStore
+    AddTextToStore = 8, // obsolete since protocol 1.25, CppNix 2.4. Use WorkerProto::Op::AddToStore
     BuildPaths = 9,
     EnsurePath = 10,
     AddTempRoot = 11,
     AddIndirectRoot = 12,
-    SyncWithGC = 13,
+    SyncWithGC = 13, // obsolete since CppNix 2.5.0
     FindRoots = 14,
-    ExportPath = 16, // obsolete
-    QueryDeriver = 18, // obsolete
+    ExportPath = 16, // obsolete since 2017, stubbed to error
+    QueryDeriver = 18, // obsolete since 2016, stubbed to error
     SetOptions = 19,
     CollectGarbage = 20,
     QuerySubstitutablePathInfo = 21,
-    QueryDerivationOutputs = 22, // obsolete
+    QueryDerivationOutputs = 22, // obsolete since protocol 1.21, CppNix 2.4
     QueryAllValidPaths = 23,
-    QueryFailedPaths = 24,
-    ClearFailedPaths = 25,
+    QueryFailedPaths = 24, // obsolete, removed
+    ClearFailedPaths = 25, // obsolete, removed
     QueryPathInfo = 26,
-    ImportPaths = 27, // obsolete
-    QueryDerivationOutputNames = 28, // obsolete
+    ImportPaths = 27, // obsolete since 2016
+    QueryDerivationOutputNames = 28, // obsolete since CppNix 2.4
     QueryPathFromHashPart = 29,
     QuerySubstitutablePathInfos = 30,
     QueryValidPaths = 31,