3 files changed, 65 insertions, 16 deletions

diff --git a/third_party/nix/src/libstore/rpc-store.cc b/third_party/nix/src/libstore/rpc-store.cc
index 92ad4e762bf9..bc1fcc73d818 100644
--- a/third_party/nix/src/libstore/rpc-store.cc
+++ b/third_party/nix/src/libstore/rpc-store.cc
@@ -5,6 +5,7 @@
 #include <memory>
 #include <optional>
 #include <ostream>
+#include <string_view>
 
 #include <absl/status/status.h>
 #include <absl/strings/str_cat.h>
@@ -36,6 +37,11 @@ namespace nix {
 
 namespace store {
 
+// Should be set to the bandwidth delay product between the client and the
+// daemon. The current value, which should eventually be determined dynamically,
+// has currently been set to a developer's deskop computer, rounded up
+constexpr size_t kChunkSize = 1024 * 64;
+
 using google::protobuf::util::TimeUtil;
 using grpc::ClientContext;
 using nix::proto::WorkerService;
@@ -308,14 +314,29 @@ Path RpcStore::addTextToStore(const std::string& name,
         "repairing is not supported when building through the Nix daemon");
   }
   ClientContext ctx;
-  proto::AddTextToStoreRequest request;
-  request.set_name(name);
-  request.set_content(content);
+  proto::StorePath result;
+  auto writer = stub_->AddTextToStore(&ctx, &result);
+
+  proto::AddTextToStoreRequest meta;
+  meta.mutable_meta()->set_name(name);
+  meta.mutable_meta()->set_size(content.size());
   for (const auto& ref : references) {
-    request.add_references(ref);
+    meta.mutable_meta()->add_references(ref);
   }
-  proto::StorePath result;
-  SuccessOrThrow(stub_->AddTextToStore(&ctx, request, &result), __FUNCTION__);
+  writer->Write(meta);
+
+  for (int i = 0; i <= content.size(); i += kChunkSize) {
+    auto len = std::min(kChunkSize, content.size() - i);
+    proto::AddTextToStoreRequest data;
+    data.set_data(content.data() + i, len);
+    if (!writer->Write(data)) {
+      // Finish() below will error
+      break;
+    }
+  }
+
+  writer->WritesDone();
+  SuccessOrThrow(writer->Finish(), __FUNCTION__);
   return result.path();
 }
 
diff --git a/third_party/nix/src/nix-daemon/nix-daemon-proto.cc b/third_party/nix/src/nix-daemon/nix-daemon-proto.cc
index 6d18fc40964f..ed859f584e39 100644
--- a/third_party/nix/src/nix-daemon/nix-daemon-proto.cc
+++ b/third_party/nix/src/nix-daemon/nix-daemon-proto.cc
@@ -271,17 +271,38 @@ class WorkerServiceImpl final : public WorkerService::Service {
         __FUNCTION__);
   }
 
-  Status AddTextToStore(grpc::ServerContext*,
-                        const nix::proto::AddTextToStoreRequest* request,
-                        nix::proto::StorePath* response) override {
+  Status AddTextToStore(
+      grpc::ServerContext*,
+      grpc::ServerReader<nix::proto::AddTextToStoreRequest>* reader,
+      nix::proto::StorePath* response) override {
     return HandleExceptions(
         [&]() -> Status {
+          proto::AddTextToStoreRequest request;
+          auto has_metadata = reader->Read(&request);
+          if (!has_metadata || !request.has_meta()) {
+            return Status(grpc::StatusCode::INVALID_ARGUMENT,
+                          "Metadata must be set before sending content");
+          }
+
+          proto::AddTextToStoreRequest_Metadata meta = request.meta();
+
           PathSet references;
-          for (const auto& ref : request->references()) {
+          for (const auto& ref : meta.references()) {
             references.insert(ref);
           }
-          auto path = store_->addTextToStore(request->name(),
-                                             request->content(), references);
+
+          std::string content;
+          content.reserve(meta.size());
+          while (reader->Read(&request)) {
+            if (request.add_oneof_case() != request.kData) {
+              return Status(grpc::StatusCode::INVALID_ARGUMENT,
+                            "All requests except the first must contain data");
+            }
+
+            content.append(request.data());
+          }
+
+          auto path = store_->addTextToStore(meta.name(), content, references);
           response->set_path(path);
           return Status::OK;
         },
diff --git a/third_party/nix/src/proto/worker.proto b/third_party/nix/src/proto/worker.proto
index 6a80b3e32b42..b0dc32afbe5f 100644
--- a/third_party/nix/src/proto/worker.proto
+++ b/third_party/nix/src/proto/worker.proto
@@ -23,7 +23,7 @@ service WorkerService {
   rpc AddToStore(stream AddToStoreRequest) returns (StorePath);
 
   // Adds the supplied string to the store, as a text file.
-  rpc AddTextToStore(AddTextToStoreRequest) returns (StorePath);
+  rpc AddTextToStore(stream AddTextToStoreRequest) returns (StorePath);
 
   // Build the specified derivations in one of the specified build
   // modes, defaulting to a normal build.
@@ -223,9 +223,16 @@ message AddToStoreRequest {
 }
 
 message AddTextToStoreRequest {
-  string name = 1;
-  string content = 2;
-  repeated string references = 3;
+  message Metadata {
+    string name = 1;
+    repeated string references = 2;
+    uint64 size = 3;
+  }
+
+  oneof add_oneof {
+    Metadata meta = 4;
+    bytes data = 5;
+  }
 }
 
 message BuildPathsRequest {