Add NAR / Store accessor abstraction

This is primary to allow hydra-queue-runner to extract files like
"nix-support/hydra-build-products" from NARs in binary caches.

1 files changed, 11 insertions, 0 deletions

diff --git a/src/libstore/nar-accessor.hh b/src/libstore/nar-accessor.hh
new file mode 100644
index 000000000000..83c570be4c7b
--- /dev/null
+++ b/src/libstore/nar-accessor.hh
@@ -0,0 +1,11 @@
+#pragma once
+
+#include "fs-accessor.hh"
+
+namespace nix {
+
+/* Return an object that provides access to the contents of a NAR
+   file. */
+ref<FSAccessor> makeNarAccessor(ref<const std::string> nar);
+
+}