Use Nix's Machine type in a minimal way

src/hydra-queue-runner/build-remote.cc

@@ -48,7 +48,7 @@ static Strings extraStoreArgs(std::string & machine)
     return result;
 }
 
-static void openConnection(Machine::ptr machine, Path tmpDir, int stderrFD, SSHMaster::Connection & child)
+static void openConnection(::Machine::ptr machine, Path tmpDir, int stderrFD, SSHMaster::Connection & child)
 {
     std::string pgmName;
     Pipe to, from;
@@ -104,7 +104,7 @@ static void openConnection(Machine::ptr machine, Path tmpDir, int stderrFD, SSHM
 
 
 static void copyClosureTo(
-    Machine::Connection & conn,
+    ::Machine::Connection & conn,
     Store & destStore,
     const StorePathSet & paths,
     SubstituteFlag useSubstitutes = NoSubstitute)
@@ -195,7 +195,7 @@ static std::pair<Path, AutoCloseFD> openLogFile(const std::string & logDir, cons
  * Therefore, no `ServeProto::Serialize` functions can be used until
  * that field is set.
  */
-static void handshake(Machine::Connection & conn, unsigned int repeats)
+static void handshake(::Machine::Connection & conn, unsigned int repeats)
 {
     conn.to << SERVE_MAGIC_1 << 0x206;
     conn.to.flush();
@@ -216,7 +216,7 @@ static BasicDerivation sendInputs(
     Step & step,
     Store & localStore,
     Store & destStore,
-    Machine::Connection & conn,
+    ::Machine::Connection & conn,
     unsigned int & overhead,
     counter & nrStepsWaiting,
     counter & nrStepsCopyingTo
@@ -272,7 +272,7 @@ static BasicDerivation sendInputs(
 }
 
 static BuildResult performBuild(
-    Machine::Connection & conn,
+    ::Machine::Connection & conn,
     Store & localStore,
     StorePath drvPath,
     const BasicDerivation & drv,
@@ -317,7 +317,7 @@ static BuildResult performBuild(
 }
 
 static std::map<StorePath, ValidPathInfo> queryPathInfos(
-    Machine::Connection & conn,
+    ::Machine::Connection & conn,
     Store & localStore,
     StorePathSet & outputs,
     size_t & totalNarSize
@@ -355,7 +355,7 @@ static std::map<StorePath, ValidPathInfo> queryPathInfos(
 }
 
 static void copyPathFromRemote(
-    Machine::Connection & conn,
+    ::Machine::Connection & conn,
     NarMemberDatas & narMembers,
     Store & localStore,
     Store & destStore,
@@ -385,7 +385,7 @@ static void copyPathFromRemote(
 }
 
 static void copyPathsFromRemote(
-    Machine::Connection & conn,
+    ::Machine::Connection & conn,
     NarMemberDatas & narMembers,
     Store & localStore,
     Store & destStore,
@@ -462,7 +462,7 @@ void RemoteResult::updateWithBuildResult(const nix::BuildResult & buildResult)
 
 
 void State::buildRemote(ref<Store> destStore,
-    Machine::ptr machine, Step::ptr step,
+    ::Machine::ptr machine, Step::ptr step,
     const BuildOptions & buildOptions,
     RemoteResult & result, std::shared_ptr<ActiveStep> activeStep,
     std::function<void(StepState)> updateStep,
@@ -503,7 +503,7 @@ void State::buildRemote(ref<Store> destStore,
                process. Meh. */
         });
 
-        Machine::Connection conn {
+        ::Machine::Connection conn {
             .from = child.out.get(),
             .to = child.in.get(),
             .machine = machine,

src/hydra-queue-runner/builder.cc

@@ -400,7 +400,7 @@ void State::failStep(
     Step::ptr step,
     BuildID buildId,
     const RemoteResult & result,
-    Machine::ptr machine,
+    ::Machine::ptr machine,
     bool & stepFinished)
 {
     /* Register failure in the database for all Build objects that

src/hydra-queue-runner/dispatcher.cc

@@ -199,7 +199,7 @@ system_time State::doDispatch()
            filter out temporarily disabled machines. */
         struct MachineInfo
         {
-            Machine::ptr machine;
+            ::Machine::ptr machine;
             unsigned long currentJobs;
         };
         std::vector<MachineInfo> machinesSorted;
@@ -231,11 +231,11 @@ system_time State::doDispatch()
         sort(machinesSorted.begin(), machinesSorted.end(),
             [](const MachineInfo & a, const MachineInfo & b) -> bool
             {
-                float ta = std::round(a.currentJobs / a.machine->speedFactor);
-                float tb = std::round(b.currentJobs / b.machine->speedFactor);
+                float ta = std::round(a.currentJobs / a.machine->speedFactorFloat);
+                float tb = std::round(b.currentJobs / b.machine->speedFactorFloat);
                 return
                     ta != tb ? ta < tb :
-                    a.machine->speedFactor != b.machine->speedFactor ? a.machine->speedFactor > b.machine->speedFactor :
+                    a.machine->speedFactorFloat != b.machine->speedFactorFloat ? a.machine->speedFactorFloat > b.machine->speedFactorFloat :
                     a.currentJobs > b.currentJobs;
             });
 
@@ -435,7 +435,7 @@ void Jobset::pruneSteps()
 }
 
 
-State::MachineReservation::MachineReservation(State & state, Step::ptr step, Machine::ptr machine)
+State::MachineReservation::MachineReservation(State & state, Step::ptr step, ::Machine::ptr machine)
     : state(state), step(step), machine(machine)
 {
     machine->state->currentJobs++;

src/hydra-queue-runner/hydra-queue-runner.cc

@@ -1,6 +1,7 @@
 #include <iostream>
 #include <thread>
 #include <optional>
+#include <type_traits>
 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -140,23 +141,43 @@ void State::parseMachines(const std::string & contents)
         if (tokens.size() < 3) continue;
         tokens.resize(8);
 
-        auto machine = std::make_shared<Machine>();
-        machine->sshName = tokens[0];
-        machine->systemTypes = tokenizeString<StringSet>(tokens[1], ",");
-        machine->sshKey = tokens[2] == "-" ? std::string("") : tokens[2];
-        if (tokens[3] != "")
-            machine->maxJobs = string2Int<decltype(machine->maxJobs)>(tokens[3]).value();
-        else
-            machine->maxJobs = 1;
-        machine->speedFactor = atof(tokens[4].c_str());
         if (tokens[5] == "-") tokens[5] = "";
-        machine->supportedFeatures = tokenizeString<StringSet>(tokens[5], ",");
+        auto supportedFeatures = tokenizeString<StringSet>(tokens[5], ",");
+
         if (tokens[6] == "-") tokens[6] = "";
-        machine->mandatoryFeatures = tokenizeString<StringSet>(tokens[6], ",");
-        for (auto & f : machine->mandatoryFeatures)
-            machine->supportedFeatures.insert(f);
-        if (tokens[7] != "" && tokens[7] != "-")
-            machine->sshPublicHostKey = base64Decode(tokens[7]);
+        auto mandatoryFeatures = tokenizeString<StringSet>(tokens[6], ",");
+
+        for (auto & f : mandatoryFeatures)
+            supportedFeatures.insert(f);
+
+        using MaxJobs = std::remove_const<decltype(nix::Machine::maxJobs)>::type;
+
+        auto machine = std::make_shared<::Machine>(nix::Machine {
+            // `storeUri`, not yet used
+            "",
+            // `systemTypes`, not yet used
+            {},
+            // `sshKey`
+            tokens[2] == "-" ? "" : tokens[2],
+            // `maxJobs`
+            tokens[3] != ""
+                ? string2Int<MaxJobs>(tokens[3]).value()
+                : 1,
+            // `speedFactor`, not yet used
+            1,
+            // `supportedFeatures`
+            std::move(supportedFeatures),
+            // `mandatoryFeatures`
+            std::move(mandatoryFeatures),
+            // `sshPublicHostKey`
+            tokens[7] != "" && tokens[7] != "-"
+                ? base64Decode(tokens[7])
+                : "",
+        });
+
+        machine->sshName = tokens[0];
+        machine->systemTypesSet = tokenizeString<StringSet>(tokens[1], ",");
+        machine->speedFactorFloat = atof(tokens[4].c_str());
 
         /* Re-use the State object of the previous machine with the
            same name. */
@@ -166,7 +187,7 @@ void State::parseMachines(const std::string & contents)
         else
             printMsg(lvlChatty, "updating machine ‘%1%’", machine->sshName);
         machine->state = i == oldMachines.end()
-            ? std::make_shared<Machine::State>()
+            ? std::make_shared<::Machine::State>()
             : i->second->state;
         newMachines[machine->sshName] = machine;
     }
@@ -175,9 +196,9 @@ void State::parseMachines(const std::string & contents)
         if (newMachines.find(m.first) == newMachines.end()) {
             if (m.second->enabled)
                 printInfo("removing machine ‘%1%’", m.first);
-            /* Add a disabled Machine object to make sure stats are
+            /* Add a disabled ::Machine object to make sure stats are
                maintained. */
-            auto machine = std::make_shared<Machine>(*(m.second));
+            auto machine = std::make_shared<::Machine>(*(m.second));
             machine->enabled = false;
             newMachines[m.first] = machine;
         }
@@ -596,7 +617,7 @@ void State::dumpStatus(Connection & conn)
 
                 json machine = {
                     {"enabled",  m->enabled},
-                    {"systemTypes", m->systemTypes},
+                    {"systemTypes", m->systemTypesSet},
                     {"supportedFeatures", m->supportedFeatures},
                     {"mandatoryFeatures", m->mandatoryFeatures},
                     {"nrStepsDone", s->nrStepsDone.load()},

src/hydra-queue-runner/state.hh

@@ -22,6 +22,7 @@
 #include "sync.hh"
 #include "nar-extractor.hh"
 #include "serve-protocol.hh"
+#include "machines.hh"
 
 
 typedef unsigned int BuildID;
@@ -234,17 +235,21 @@ void getDependents(Step::ptr step, std::set<Build::ptr> & builds, std::set<Step:
 void visitDependencies(std::function<void(Step::ptr)> visitor, Step::ptr step);
 
 
-struct Machine
+struct Machine : nix::Machine
 {
     typedef std::shared_ptr<Machine> ptr;
 
-    bool enabled{true};
+    /* TODO Get rid of: `nix::Machine::storeUri` is normalized in a way
+       we are not yet used to, but once we are, we don't need this. */
+    std::string sshName;
 
-    std::string sshName, sshKey;
-    std::set<std::string> systemTypes, supportedFeatures, mandatoryFeatures;
-    unsigned int maxJobs = 1;
-    float speedFactor = 1.0;
-    std::string sshPublicHostKey;
+    /* TODO Get rid once `nix::Machine::systemTypes` is a set not
+       vector. */
+    std::set<std::string> systemTypesSet;
+
+    /* TODO Get rid once `nix::Machine::systemTypes` is a `float` not
+       an `int`. */
+    float speedFactorFloat = 1.0;
 
     struct State {
         typedef std::shared_ptr<State> ptr;
@@ -272,7 +277,7 @@ struct Machine
     {
         /* Check that this machine is of the type required by the
            step. */
-        if (!systemTypes.count(step->drv->platform == "builtin" ? nix::settings.thisSystem : step->drv->platform))
+        if (!systemTypesSet.count(step->drv->platform == "builtin" ? nix::settings.thisSystem : step->drv->platform))
             return false;
 
         /* Check that the step requires all mandatory features of this