1 files changed, 40 insertions, 0 deletions
diff --git a/src/libexpr/flake/eval-cache.hh b/src/libexpr/flake/eval-cache.hh
new file mode 100644
index 000000000..f81d48ba5
--- /dev/null
+++ b/src/libexpr/flake/eval-cache.hh
@@ -0,0 +1,40 @@
+#pragma once
+
+#include "sync.hh"
+#include "flake.hh"
+#include "path.hh"
+
+namespace nix { struct SQLite; struct SQLiteStmt; }
+
+namespace nix::flake {
+
+class EvalCache
+{
+    struct State;
+
+    std::unique_ptr<Sync<State>> _state;
+
+    EvalCache();
+
+public:
+
+    struct Derivation
+    {
+        StorePath drvPath;
+        StorePath outPath;
+        std::string outputName;
+    };
+
+    void addDerivation(
+        const Fingerprint & fingerprint,
+        const std::string & attrPath,
+        const Derivation & drv);
+
+    std::optional<Derivation> getDerivation(
+        const Fingerprint & fingerprint,
+        const std::string & attrPath);
+
+    static EvalCache & singleton();
+};
+
+}