Eliminate the "store" global variable

Also, move a few free-standing functions into StoreAPI and Derivation.

Also, introduce a non-nullable smart pointer, ref<T>, which is just a
wrapper around std::shared_ptr ensuring that the pointer is never
null. (For reference-counted values, this is better than passing a
"T&", because the latter doesn't maintain the refcount. Usually, the
caller will have a shared_ptr keeping the value alive, but that's not
always the case, e.g., when passing a reference to a std::thread via
std::bind.)

1 files changed, 5 insertions, 8 deletions

diff --git a/src/libstore/store-api.cc b/src/libstore/store-api.cc
index f5035d323..98399cc48 100644
--- a/src/libstore/store-api.cc
+++ b/src/libstore/store-api.cc
@@ -284,12 +284,12 @@ string showPaths(const PathSet & paths)
 }
 
 
-void exportPaths(StoreAPI & store, const Paths & paths,
+void StoreAPI::exportPaths(const Paths & paths,
     bool sign, Sink & sink)
 {
     for (auto & i : paths) {
         sink << 1;
-        store.exportPath(i, sign, sink);
+        exportPath(i, sign, sink);
     }
     sink << 0;
 }
@@ -306,10 +306,7 @@ void exportPaths(StoreAPI & store, const Paths & paths,
 namespace nix {
 
 
-std::shared_ptr<StoreAPI> store;
-
-
-std::shared_ptr<StoreAPI> openStore(bool reserveSpace)
+ref<StoreAPI> openStore(bool reserveSpace)
 {
     enum { mDaemon, mLocal, mAuto } mode;
 
@@ -325,8 +322,8 @@ std::shared_ptr<StoreAPI> openStore(bool reserveSpace)
     }
 
     return mode == mDaemon
-        ? (std::shared_ptr<StoreAPI>) std::make_shared<RemoteStore>()
-        : std::make_shared<LocalStore>(reserveSpace);
+        ? make_ref<StoreAPI, RemoteStore>()
+        : make_ref<StoreAPI, LocalStore>(reserveSpace);
 }