feat(3p/nix): Implement AddToStore proto handler r/1519

Implement the proto handler for AddToStore, which adds a nix path to the
store. This is implemented by adding a new (probably
soon-to-be-generalized) Source concretion that wraps a grpc ServerReader
for the stream of data we're receiving from the client - this is less
than ideal, as it's perpetuating the source/sink thing that's going on
and storing entire nars in memory, but is at the very worst an
incremental step towards a functioning nix that we can refactor in the
future.

Paired-With: Perry Lorier <isomer@tvl.fyi>
Paired-With: Vincent Ambo <mail@tazj.in>
Change-Id: I48db734e7460a47aee4a85dd5137b690980859e3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1441
Tested-by: BuildkiteCI
Reviewed-by: kanepyork <rikingcoding@gmail.com>
Reviewed-by: tazjin <mail@tazj.in>

1 files changed, 4 insertions, 4 deletions

diff --git a/third_party/nix/src/nix-daemon/nix-daemon.cc b/third_party/nix/src/nix-daemon/nix-daemon.cc
index caff57851f93..fdb539d6628c 100644
--- a/third_party/nix/src/nix-daemon/nix-daemon.cc
+++ b/third_party/nix/src/nix-daemon/nix-daemon.cc
@@ -298,15 +298,15 @@ static void performOp(TunnelLogger* logger, const ref<Store>& store,
     case wopAddToStore: {
       bool fixed = 0;
       bool recursive = 0;
-      std::string s;
+      std::string hashType;
       std::string baseName;
-      from >> baseName >> fixed /* obsolete */ >> recursive >> s;
+      from >> baseName >> fixed /* obsolete */ >> recursive >> hashType;
       /* Compatibility hack. */
       if (!fixed) {
-        s = "sha256";
+        hashType = "sha256";
         recursive = true;
       }
-      HashType hashAlgo = parseHashType(s);
+      HashType hashAlgo = parseHashType(hashType);
 
       TeeSource savedNAR(from);
       RetrieveRegularNARSink savedRegular;