refactor(tvix): Factor-out proto utilities r/1621

Factor out the shared utilities for interacting with protobufs/grpc from
libstore to a proto.hh header in libproto.

Change-Id: I1cb8d94867d5d4b63a9994be0b53f8f612eb8e3a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1691
Tested-by: BuildkiteCI
Reviewed-by: kanepyork <rikingcoding@gmail.com>

3 files changed, 162 insertions, 136 deletions

diff --git a/third_party/nix/src/libstore/rpc-store.cc b/third_party/nix/src/libstore/rpc-store.cc
index 27f64150a1e9..05f4f7968ed3 100644
--- a/third_party/nix/src/libstore/rpc-store.cc
+++ b/third_party/nix/src/libstore/rpc-store.cc
@@ -7,6 +7,8 @@
 #include <absl/status/status.h>
 #include <absl/strings/str_cat.h>
 #include <absl/strings/str_format.h>
+#include <absl/strings/string_view.h>
+#include <glog/logging.h>
 #include <google/protobuf/empty.pb.h>
 #include <google/protobuf/util/time_util.h>
 #include <grpcpp/create_channel.h>
@@ -23,6 +25,7 @@
 #include "libstore/store-api.hh"
 #include "libutil/archive.hh"
 #include "libutil/hash.hh"
+#include "libutil/proto.hh"
 #include "libutil/types.hh"
 
 namespace nix {
@@ -35,27 +38,6 @@ using nix::proto::WorkerService;
 
 static google::protobuf::Empty kEmpty;
 
-proto::StorePath StorePath(const Path& path) {
-  proto::StorePath store_path;
-  store_path.set_path(path);
-  return store_path;
-}
-
-proto::StorePaths StorePaths(const PathSet& paths) {
-  proto::StorePaths result;
-  for (const auto& path : paths) {
-    result.add_paths(path);
-  }
-  return result;
-}
-
-template <typename T, typename U>
-T FillFrom(const U& src) {
-  T result;
-  result.insert(src.begin(), src.end());
-  return result;
-}
-
 template <typename Request>
 class RPCSink : public BufferedSink {
  public:
@@ -85,88 +67,6 @@ class RPCSink : public BufferedSink {
   bool good_;
 };
 
-constexpr absl::StatusCode GRPCStatusCodeToAbsl(grpc::StatusCode code) {
-  switch (code) {
-    case grpc::StatusCode::OK:
-      return absl::StatusCode::kOk;
-    case grpc::StatusCode::CANCELLED:
-      return absl::StatusCode::kCancelled;
-    case grpc::StatusCode::UNKNOWN:
-      return absl::StatusCode::kUnknown;
-    case grpc::StatusCode::INVALID_ARGUMENT:
-      return absl::StatusCode::kInvalidArgument;
-    case grpc::StatusCode::DEADLINE_EXCEEDED:
-      return absl::StatusCode::kDeadlineExceeded;
-    case grpc::StatusCode::NOT_FOUND:
-      return absl::StatusCode::kNotFound;
-    case grpc::StatusCode::ALREADY_EXISTS:
-      return absl::StatusCode::kAlreadyExists;
-    case grpc::StatusCode::PERMISSION_DENIED:
-      return absl::StatusCode::kPermissionDenied;
-    case grpc::StatusCode::UNAUTHENTICATED:
-      return absl::StatusCode::kUnauthenticated;
-    case grpc::StatusCode::RESOURCE_EXHAUSTED:
-      return absl::StatusCode::kResourceExhausted;
-    case grpc::StatusCode::FAILED_PRECONDITION:
-      return absl::StatusCode::kFailedPrecondition;
-    case grpc::StatusCode::ABORTED:
-      return absl::StatusCode::kAborted;
-    case grpc::StatusCode::OUT_OF_RANGE:
-      return absl::StatusCode::kOutOfRange;
-    case grpc::StatusCode::UNIMPLEMENTED:
-      return absl::StatusCode::kUnimplemented;
-    case grpc::StatusCode::INTERNAL:
-      return absl::StatusCode::kInternal;
-    case grpc::StatusCode::UNAVAILABLE:
-      return absl::StatusCode::kUnavailable;
-    case grpc::StatusCode::DATA_LOSS:
-      return absl::StatusCode::kDataLoss;
-    default:
-      return absl::StatusCode::kInternal;
-  }
-}
-
-constexpr absl::string_view GRPCStatusCodeDescription(grpc::StatusCode code) {
-  switch (code) {
-    case grpc::StatusCode::OK:
-      return "OK";
-    case grpc::StatusCode::CANCELLED:
-      return "CANCELLED";
-    case grpc::StatusCode::UNKNOWN:
-      return "UNKNOWN";
-    case grpc::StatusCode::INVALID_ARGUMENT:
-      return "INVALID_ARGUMENT";
-    case grpc::StatusCode::DEADLINE_EXCEEDED:
-      return "DEADLINE_EXCEEDED";
-    case grpc::StatusCode::NOT_FOUND:
-      return "NOT_FOUND";
-    case grpc::StatusCode::ALREADY_EXISTS:
-      return "ALREADY_EXISTS";
-    case grpc::StatusCode::PERMISSION_DENIED:
-      return "PERMISSION_DENIED";
-    case grpc::StatusCode::UNAUTHENTICATED:
-      return "UNAUTHENTICATED";
-    case grpc::StatusCode::RESOURCE_EXHAUSTED:
-      return "RESOURCE_EXHAUSTED";
-    case grpc::StatusCode::FAILED_PRECONDITION:
-      return "FAILED_PRECONDITION";
-    case grpc::StatusCode::ABORTED:
-      return "ABORTED";
-    case grpc::StatusCode::OUT_OF_RANGE:
-      return "OUT_OF_RANGE";
-    case grpc::StatusCode::UNIMPLEMENTED:
-      return "UNIMPLEMENTED";
-    case grpc::StatusCode::INTERNAL:
-      return "INTERNAL";
-    case grpc::StatusCode::UNAVAILABLE:
-      return "UNAVAILABLE";
-    case grpc::StatusCode::DATA_LOSS:
-      return "DATA_LOSS";
-    default:
-      return "<BAD ERROR CODE>";
-  };
-}
-
 // TODO(grfn): Obviously this should go away and be replaced by StatusOr... but
 // that would require refactoring the entire store api, which we don't feel like
 // doing right now. We should at some point though
@@ -177,13 +77,13 @@ void const RpcStore::SuccessOrThrow(const grpc::Status& status,
     switch (status.error_code()) {
       case grpc::StatusCode::UNIMPLEMENTED:
         throw Unsupported(
-            absl::StrFormat("operation is not supported by store at %s: %s",
-                            uri, status.error_message()));
+            absl::StrFormat("operation %s is not supported by store at %s: %s",
+                            call, uri, status.error_message()));
       default:
-        throw Error(
-            absl::StrFormat("Rpc call to %s failed (%s): %s ", uri,
-                            GRPCStatusCodeDescription(status.error_code()),
-                            status.error_message()));
+        throw Error(absl::StrFormat(
+            "Rpc call %s to %s failed (%s): %s ", call, uri,
+            util::proto::GRPCStatusCodeDescription(status.error_code()),
+            status.error_message()));
     }
   }
 }
@@ -191,7 +91,7 @@ void const RpcStore::SuccessOrThrow(const grpc::Status& status,
 bool RpcStore::isValidPathUncached(const Path& path) {
   ClientContext ctx;
   proto::IsValidPathResponse resp;
-  SuccessOrThrow(stub_->IsValidPath(&ctx, StorePath(path), &resp),
+  SuccessOrThrow(stub_->IsValidPath(&ctx, util::proto::StorePath(path), &resp),
                  __FUNCTION__);
   return resp.is_valid();
 }
@@ -200,7 +100,7 @@ PathSet RpcStore::queryAllValidPaths() {
   ClientContext ctx;
   proto::StorePaths paths;
   SuccessOrThrow(stub_->QueryAllValidPaths(&ctx, kEmpty, &paths), __FUNCTION__);
-  return FillFrom<PathSet>(paths.paths());
+  return util::proto::FillFrom<PathSet>(paths.paths());
 }
 
 PathSet RpcStore::queryValidPaths(const PathSet& paths,
@@ -213,7 +113,7 @@ PathSet RpcStore::queryValidPaths(const PathSet& paths,
   proto::StorePaths result_paths;
   SuccessOrThrow(stub_->QueryValidPaths(&ctx, store_paths, &result_paths),
                  __FUNCTION__);
-  return FillFrom<PathSet>(result_paths.paths());
+  return util::proto::FillFrom<PathSet>(result_paths.paths());
 }
 
 void RpcStore::queryPathInfoUncached(
@@ -260,33 +160,36 @@ void RpcStore::queryPathInfoUncached(
 void RpcStore::queryReferrers(const Path& path, PathSet& referrers) {
   ClientContext ctx;
   proto::StorePaths paths;
-  SuccessOrThrow(stub_->QueryReferrers(&ctx, StorePath(path), &paths),
-                 __FUNCTION__);
+  SuccessOrThrow(
+      stub_->QueryReferrers(&ctx, util::proto::StorePath(path), &paths),
+      __FUNCTION__);
   referrers.insert(paths.paths().begin(), paths.paths().end());
 }
 
 PathSet RpcStore::queryValidDerivers(const Path& path) {
   ClientContext ctx;
   proto::StorePaths paths;
-  SuccessOrThrow(stub_->QueryValidDerivers(&ctx, StorePath(path), &paths),
-                 __FUNCTION__);
-  return FillFrom<PathSet>(paths.paths());
+  SuccessOrThrow(
+      stub_->QueryValidDerivers(&ctx, util::proto::StorePath(path), &paths),
+      __FUNCTION__);
+  return util::proto::FillFrom<PathSet>(paths.paths());
 }
 
 PathSet RpcStore::queryDerivationOutputs(const Path& path) {
   ClientContext ctx;
   proto::StorePaths paths;
-  SuccessOrThrow(stub_->QueryDerivationOutputs(&ctx, StorePath(path), &paths),
-                 __FUNCTION__);
-  return FillFrom<PathSet>(paths.paths());
+  SuccessOrThrow(
+      stub_->QueryDerivationOutputs(&ctx, util::proto::StorePath(path), &paths),
+      __FUNCTION__);
+  return util::proto::FillFrom<PathSet>(paths.paths());
 }
 
 StringSet RpcStore::queryDerivationOutputNames(const Path& path) {
   ClientContext ctx;
   proto::DerivationOutputNames output_names;
-  SuccessOrThrow(
-      stub_->QueryDerivationOutputNames(&ctx, StorePath(path), &output_names));
-  return FillFrom<StringSet>(output_names.names());
+  SuccessOrThrow(stub_->QueryDerivationOutputNames(
+      &ctx, util::proto::StorePath(path), &output_names));
+  return util::proto::FillFrom<StringSet>(output_names.names());
 }
 
 Path RpcStore::queryPathFromHashPart(const std::string& hashPart) {
@@ -302,17 +205,17 @@ Path RpcStore::queryPathFromHashPart(const std::string& hashPart) {
 PathSet RpcStore::querySubstitutablePaths(const PathSet& paths) {
   ClientContext ctx;
   proto::StorePaths result;
-  SuccessOrThrow(
-      stub_->QuerySubstitutablePaths(&ctx, StorePaths(paths), &result));
-  return FillFrom<PathSet>(result.paths());
+  SuccessOrThrow(stub_->QuerySubstitutablePaths(
+      &ctx, util::proto::StorePaths(paths), &result));
+  return util::proto::FillFrom<PathSet>(result.paths());
 }
 
 void RpcStore::querySubstitutablePathInfos(const PathSet& paths,
                                            SubstitutablePathInfos& infos) {
   ClientContext ctx;
   proto::SubstitutablePathInfos result;
-  SuccessOrThrow(
-      stub_->QuerySubstitutablePathInfos(&ctx, StorePaths(paths), &result));
+  SuccessOrThrow(stub_->QuerySubstitutablePathInfos(
+      &ctx, util::proto::StorePaths(paths), &result));
 
   for (const auto& path_info : result.path_infos()) {
     auto path = path_info.path().path();
@@ -321,7 +224,7 @@ void RpcStore::querySubstitutablePathInfos(const PathSet& paths,
     if (!info.deriver.empty()) {
       assertStorePath(info.deriver);
     }
-    info.references = FillFrom<PathSet>(path_info.references());
+    info.references = util::proto::FillFrom<PathSet>(path_info.references());
     info.downloadSize = path_info.download_size();
     info.narSize = path_info.nar_size();
   }
@@ -353,7 +256,9 @@ void RpcStore::addToStore(const ValidPathInfo& info, Source& narSource,
   path_info_req.mutable_path_info()->set_repair(repair);
   path_info_req.mutable_path_info()->set_check_sigs(checkSigs);
 
-  writer->Write(path_info_req);
+  if (!writer->Write(path_info_req)) {
+    throw Error("Could not write to nix daemon");
+  }
 
   RPCSink sink(std::move(writer));
   copyNAR(narSource, sink);
@@ -378,7 +283,10 @@ Path RpcStore::addToStore(const std::string& name, const Path& srcPath,
   metadata_req.mutable_meta()->set_fixed(!(hashAlgo == htSHA256 && recursive));
   metadata_req.mutable_meta()->set_recursive(recursive);
   metadata_req.mutable_meta()->set_hash_type(HashTypeToProto(hashAlgo));
-  writer->Write(metadata_req);
+
+  if (!writer->Write(metadata_req)) {
+    throw Error("Could not write to nix daemon");
+  }
 
   RPCSink sink(std::move(writer));
   dumpPath(std::filesystem::absolute(srcPath), sink);
@@ -435,15 +343,17 @@ void RpcStore::ensurePath(const Path& path) {
 void RpcStore::addTempRoot(const Path& path) {
   ClientContext ctx;
   google::protobuf::Empty response;
-  SuccessOrThrow(stub_->AddTempRoot(&ctx, StorePath(path), &response),
-                 __FUNCTION__);
+  SuccessOrThrow(
+      stub_->AddTempRoot(&ctx, util::proto::StorePath(path), &response),
+      __FUNCTION__);
 }
 
 void RpcStore::addIndirectRoot(const Path& path) {
   ClientContext ctx;
   google::protobuf::Empty response;
-  SuccessOrThrow(stub_->AddIndirectRoot(&ctx, StorePath(path), &response),
-                 __FUNCTION__);
+  SuccessOrThrow(
+      stub_->AddIndirectRoot(&ctx, util::proto::StorePath(path), &response),
+      __FUNCTION__);
 }
 
 void RpcStore::syncWithGC() {
@@ -459,7 +369,8 @@ Roots RpcStore::findRoots(bool censor) {
   Roots result;
 
   for (const auto& [target, links] : response.roots()) {
-    auto link_paths = FillFrom<std::unordered_set<std::string>>(links.paths());
+    auto link_paths =
+        util::proto::FillFrom<std::unordered_set<std::string>>(links.paths());
     result.insert({target, link_paths});
   }
 
diff --git a/third_party/nix/src/libutil/CMakeLists.txt b/third_party/nix/src/libutil/CMakeLists.txt
index ca60dd7a6ec8..cdf4655c4007 100644
--- a/third_party/nix/src/libutil/CMakeLists.txt
+++ b/third_party/nix/src/libutil/CMakeLists.txt
@@ -18,6 +18,7 @@ set(HEADER_FILES
     lru-cache.hh
     monitor-fd.hh
     pool.hh
+    proto.hh
     ref.hh
     serialise.hh
     sync.hh
diff --git a/third_party/nix/src/libutil/proto.hh b/third_party/nix/src/libutil/proto.hh
new file mode 100644
index 000000000000..484a10a82ac0
--- /dev/null
+++ b/third_party/nix/src/libutil/proto.hh
@@ -0,0 +1,114 @@
+#pragma once
+
+#include <absl/status/status.h>
+#include <grpcpp/impl/codegen/status.h>
+
+#include "libproto/worker.pb.h"
+#include "libutil/types.hh"
+
+namespace nix::util::proto {
+
+::nix::proto::StorePath StorePath(const Path& path) {
+  ::nix::proto::StorePath store_path;
+  store_path.set_path(path);
+  return store_path;
+}
+
+::nix::proto::StorePaths StorePaths(const PathSet& paths) {
+  ::nix::proto::StorePaths result;
+  for (const auto& path : paths) {
+    result.add_paths(path);
+  }
+  return result;
+}
+
+template <typename T, typename U>
+T FillFrom(const U& src) {
+  T result;
+  result.insert(src.begin(), src.end());
+  return result;
+}
+
+constexpr absl::StatusCode GRPCStatusCodeToAbsl(grpc::StatusCode code) {
+  switch (code) {
+    case grpc::StatusCode::OK:
+      return absl::StatusCode::kOk;
+    case grpc::StatusCode::CANCELLED:
+      return absl::StatusCode::kCancelled;
+    case grpc::StatusCode::UNKNOWN:
+      return absl::StatusCode::kUnknown;
+    case grpc::StatusCode::INVALID_ARGUMENT:
+      return absl::StatusCode::kInvalidArgument;
+    case grpc::StatusCode::DEADLINE_EXCEEDED:
+      return absl::StatusCode::kDeadlineExceeded;
+    case grpc::StatusCode::NOT_FOUND:
+      return absl::StatusCode::kNotFound;
+    case grpc::StatusCode::ALREADY_EXISTS:
+      return absl::StatusCode::kAlreadyExists;
+    case grpc::StatusCode::PERMISSION_DENIED:
+      return absl::StatusCode::kPermissionDenied;
+    case grpc::StatusCode::UNAUTHENTICATED:
+      return absl::StatusCode::kUnauthenticated;
+    case grpc::StatusCode::RESOURCE_EXHAUSTED:
+      return absl::StatusCode::kResourceExhausted;
+    case grpc::StatusCode::FAILED_PRECONDITION:
+      return absl::StatusCode::kFailedPrecondition;
+    case grpc::StatusCode::ABORTED:
+      return absl::StatusCode::kAborted;
+    case grpc::StatusCode::OUT_OF_RANGE:
+      return absl::StatusCode::kOutOfRange;
+    case grpc::StatusCode::UNIMPLEMENTED:
+      return absl::StatusCode::kUnimplemented;
+    case grpc::StatusCode::INTERNAL:
+      return absl::StatusCode::kInternal;
+    case grpc::StatusCode::UNAVAILABLE:
+      return absl::StatusCode::kUnavailable;
+    case grpc::StatusCode::DATA_LOSS:
+      return absl::StatusCode::kDataLoss;
+    default:
+      return absl::StatusCode::kInternal;
+  }
+}
+
+constexpr absl::string_view GRPCStatusCodeDescription(grpc::StatusCode code) {
+  switch (code) {
+    case grpc::StatusCode::OK:
+      return "OK";
+    case grpc::StatusCode::CANCELLED:
+      return "CANCELLED";
+    case grpc::StatusCode::UNKNOWN:
+      return "UNKNOWN";
+    case grpc::StatusCode::INVALID_ARGUMENT:
+      return "INVALID_ARGUMENT";
+    case grpc::StatusCode::DEADLINE_EXCEEDED:
+      return "DEADLINE_EXCEEDED";
+    case grpc::StatusCode::NOT_FOUND:
+      return "NOT_FOUND";
+    case grpc::StatusCode::ALREADY_EXISTS:
+      return "ALREADY_EXISTS";
+    case grpc::StatusCode::PERMISSION_DENIED:
+      return "PERMISSION_DENIED";
+    case grpc::StatusCode::UNAUTHENTICATED:
+      return "UNAUTHENTICATED";
+    case grpc::StatusCode::RESOURCE_EXHAUSTED:
+      return "RESOURCE_EXHAUSTED";
+    case grpc::StatusCode::FAILED_PRECONDITION:
+      return "FAILED_PRECONDITION";
+    case grpc::StatusCode::ABORTED:
+      return "ABORTED";
+    case grpc::StatusCode::OUT_OF_RANGE:
+      return "OUT_OF_RANGE";
+    case grpc::StatusCode::UNIMPLEMENTED:
+      return "UNIMPLEMENTED";
+    case grpc::StatusCode::INTERNAL:
+      return "INTERNAL";
+    case grpc::StatusCode::UNAVAILABLE:
+      return "UNAVAILABLE";
+    case grpc::StatusCode::DATA_LOSS:
+      return "DATA_LOSS";
+    default:
+      return "<BAD ERROR CODE>";
+  };
+}
+
+}  // namespace nix::util::proto