1 files changed, 30 insertions, 0 deletions
diff --git a/third_party/nix/src/libstore/nar-info-disk-cache.hh b/third_party/nix/src/libstore/nar-info-disk-cache.hh
new file mode 100644
index 000000000000..8eeab7635a4e
--- /dev/null
+++ b/third_party/nix/src/libstore/nar-info-disk-cache.hh
@@ -0,0 +1,30 @@
+#pragma once
+
+#include "libstore/nar-info.hh"
+#include "libutil/ref.hh"
+
+namespace nix {
+
+class NarInfoDiskCache {
+ public:
+  typedef enum { oValid, oInvalid, oUnknown } Outcome;
+
+  virtual void createCache(const std::string& uri, const Path& storeDir,
+                           bool wantMassQuery, int priority) = 0;
+
+  virtual bool cacheExists(const std::string& uri, bool& wantMassQuery,
+                           int& priority) = 0;
+
+  virtual std::pair<Outcome, std::shared_ptr<NarInfo>> lookupNarInfo(
+      const std::string& uri, const std::string& hashPart) = 0;
+
+  virtual void upsertNarInfo(const std::string& uri,
+                             const std::string& hashPart,
+                             std::shared_ptr<ValidPathInfo> info) = 0;
+};
+
+/* Return a singleton cache object that can be used concurrently by
+   multiple threads. */
+std::shared_ptr<NarInfoDiskCache> getNarInfoDiskCache();
+
+}  // namespace nix