Move path info caching from BinaryCacheStore to Store

Caching path info is generally useful. For instance, it speeds up "nix
path-info -rS /run/current-system" (i.e. showing the closure sizes of
all paths in the closure of the current system) from 5.6s to 0.15s.

This also eliminates some APIs like Store::queryDeriver() and
Store::queryReferences().

1 files changed, 4 insertions, 9 deletions

diff --git a/src/nix-store/xmlgraph.cc b/src/nix-store/xmlgraph.cc
index b6e1c1c4b..0f7be7f7a 100644
--- a/src/nix-store/xmlgraph.cc
+++ b/src/nix-store/xmlgraph.cc
@@ -50,15 +50,10 @@ void printXmlGraph(ref<Store> store, const PathSet & roots)
 
         cout << makeNode(path);
 
-        PathSet references;
-        store->queryReferences(path, references);
-
-        for (PathSet::iterator i = references.begin();
-             i != references.end(); ++i)
-        {
-            if (*i != path) {
-                workList.insert(*i);
-                cout << makeEdge(*i, path);
+        for (auto & p : store->queryPathInfo(path)->references) {
+            if (p != path) {
+                workList.insert(p);
+                cout << makeEdge(p, path);
             }
         }