Add "nix add-to-store" command

src/nix/add-to-store.cc

@@ -0,0 +1,61 @@
+#include "command.hh"
+#include "common-args.hh"
+#include "store-api.hh"
+#include "archive.hh"
+
+using namespace nix;
+
+struct CmdAddToStore : MixDryRun, StoreCommand
+{
+    Path path;
+    std::experimental::optional<std::string> namePart;
+
+    CmdAddToStore()
+    {
+        expectArg("path", &path);
+
+        mkFlag()
+            .longName("name")
+            .shortName('n')
+            .description("name component of the store path")
+            .labels({"name"})
+            .dest(&namePart);
+    }
+
+    std::string name() override
+    {
+        return "add-to-store";
+    }
+
+    std::string description() override
+    {
+        return "add a path to the Nix store";
+    }
+
+    Examples examples() override
+    {
+        return {
+        };
+    }
+
+    void run(ref<Store> store) override
+    {
+        if (!namePart) namePart = baseNameOf(path);
+
+        StringSink sink;
+        dumpPath(path, sink);
+
+        ValidPathInfo info;
+        info.narHash = hashString(htSHA256, *sink.s);
+        info.narSize = sink.s->size();
+        info.path = store->makeFixedOutputPath(true, info.narHash, *namePart);
+        info.ca = makeFixedOutputCA(true, info.narHash);
+
+        if (!dryRun)
+            store->addToStore(info, sink.s);
+
+        std::cout << fmt("%s\n", info.path);
+    }
+};
+
+static RegisterCommand r1(make_ref<CmdAddToStore>());