Factor a general remote FS accessor out of BinaryCacheStore

src/libstore/remote-fs-accessor.hh

@@ -0,0 +1,29 @@
+#pragma once
+
+#include "fs-accessor.hh"
+#include "ref.hh"
+#include "store-api.hh"
+
+namespace nix {
+
+class RemoteFSAccessor : public FSAccessor
+{
+    ref<Store> store;
+
+    std::map<Path, ref<FSAccessor>> nars;
+
+    std::pair<ref<FSAccessor>, Path> fetch(const Path & path_);
+public:
+
+    RemoteFSAccessor(ref<Store> store);
+
+    Stat stat(const Path & path) override;
+
+    StringSet readDirectory(const Path & path) override;
+
+    std::string readFile(const Path & path) override;
+
+    std::string readLink(const Path & path) override;
+};
+
+}