Abstract out topo sorting logic

1 files changed, 16 insertions, 35 deletions

diff --git a/src/libstore/misc.cc b/src/libstore/misc.cc
index c4d22a634..34a14d30d 100644
--- a/src/libstore/misc.cc
+++ b/src/libstore/misc.cc
@@ -4,6 +4,7 @@
 #include "local-store.hh"
 #include "store-api.hh"
 #include "thread-pool.hh"
+#include "topo-sort.hh"
 
 
 namespace nix {
@@ -246,41 +247,21 @@ void Store::queryMissing(const std::vector<StorePathWithOutputs> & targets,
 
 StorePaths Store::topoSortPaths(const StorePathSet & paths)
 {
-    StorePaths sorted;
-    StorePathSet visited, parents;
-
-    std::function<void(const StorePath & path, const StorePath * parent)> dfsVisit;
-
-    dfsVisit = [&](const StorePath & path, const StorePath * parent) {
-        if (parents.count(path))
-            throw BuildError("cycle detected in the references of '%s' from '%s'",
-                printStorePath(path), printStorePath(*parent));
-
-        if (!visited.insert(path).second) return;
-        parents.insert(path);
-
-        StorePathSet references;
-        try {
-            references = queryPathInfo(path)->references;
-        } catch (InvalidPath &) {
-        }
-
-        for (auto & i : references)
-            /* Don't traverse into paths that don't exist.  That can
-               happen due to substitutes for non-existent paths. */
-            if (i != path && paths.count(i))
-                dfsVisit(i, &path);
-
-        sorted.push_back(path);
-        parents.erase(path);
-    };
-
-    for (auto & i : paths)
-        dfsVisit(i, nullptr);
-
-    std::reverse(sorted.begin(), sorted.end());
-
-    return sorted;
+    return topoSort(paths,
+        {[&](const StorePath & path) {
+            StorePathSet references;
+            try {
+                references = queryPathInfo(path)->references;
+            } catch (InvalidPath &) {
+            }
+            return references;
+        }},
+        {[&](const StorePath & path, const StorePath & parent) {
+            return BuildError(
+                "cycle detected in the references of '%s' from '%s'",
+                printStorePath(path),
+                printStorePath(parent));
+        }});
 }