StorePath: Rewrite in C++

On nix-env -qa -f '<nixpkgs>', this reduces maximum RSS by 20970 KiB
and runtime by 0.8%. This is mostly because we're not parsing the hash
part as a hash anymore (just validating that it consists of base-32
characters).

Also, replace storePathToHash() by StorePath::hashPart().

1 files changed, 1 insertions, 1 deletions

diff --git a/src/nix/verify.cc b/src/nix/verify.cc
index 001401ac2..ab83637dc 100644
--- a/src/nix/verify.cc
+++ b/src/nix/verify.cc
@@ -90,7 +90,7 @@ struct CmdVerify : StorePathsCommand
                     if (info->ca == "")
                         hashSink = std::make_unique<HashSink>(info->narHash.type);
                     else
-                        hashSink = std::make_unique<HashModuloSink>(info->narHash.type, storePathToHash(store->printStorePath(info->path)));
+                        hashSink = std::make_unique<HashModuloSink>(info->narHash.type, std::string(info->path.hashPart()));
 
                     store->narFromPath(info->path, *hashSink);