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, 17 insertions, 0 deletions

diff --git a/third_party/nix/src/libutil/hash.cc b/third_party/nix/src/libutil/hash.cc
index 0d5a1de07c..4a8904b4e0 100644
--- a/third_party/nix/src/libutil/hash.cc
+++ b/third_party/nix/src/libutil/hash.cc
@@ -18,6 +18,23 @@
 
 namespace nix {
 
+std::optional<HashType> hash_type_from(nix::proto::HashType hash_type) {
+  switch (hash_type) {
+    case nix::proto::HashType::UNKNOWN:
+      return HashType::htUnknown;
+    case nix::proto::HashType::MD5:
+      return HashType::htMD5;
+    case nix::proto::HashType::SHA1:
+      return HashType::htSHA1;
+    case nix::proto::HashType::SHA256:
+      return HashType::htSHA256;
+    case nix::proto::HashType::SHA512:
+      return HashType::htSHA512;
+    default:
+      return {};
+  }
+}
+
 void Hash::init() {
   if (type == htMD5) {
     hashSize = md5HashSize;