Separate the instantiation and initialisation of the stores

Add a new `init()` method to the `Store` class that is supposed to
handle all the effectful initialisation needed to set-up the store.
The constructor should remain side-effect free and just initialize the
c++ data structure.

The goal behind that is that we can create “dummy” instances of each
store to query static properties about it (the parameters it accepts for
example)

1 files changed, 6 insertions, 0 deletions

diff --git a/src/libstore/local-binary-cache-store.cc b/src/libstore/local-binary-cache-store.cc
index 808a1338f..bcd23eb82 100644
--- a/src/libstore/local-binary-cache-store.cc
+++ b/src/libstore/local-binary-cache-store.cc
@@ -13,6 +13,12 @@ private:
 public:
 
     LocalBinaryCacheStore(
+        const Params & params)
+        : LocalBinaryCacheStore("dummy", params)
+    {
+    }
+
+    LocalBinaryCacheStore(
         const Path & binaryCacheDir,
         const Params & params)
         : BinaryCacheStore(params)