1 files changed, 76 insertions, 0 deletions
diff --git a/tvix/store/protos/rpc_pathinfo.proto b/tvix/store/protos/rpc_pathinfo.proto
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+++ b/tvix/store/protos/rpc_pathinfo.proto
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: MIT
+// Copyright © 2022 The Tvix Authors
+syntax = "proto3";
+
+package tvix.store.v1;
+
+import "tvix/castore/protos/castore.proto";
+import "tvix/store/protos/pathinfo.proto";
+
+option go_package = "code.tvl.fyi/tvix/store-go;storev1";
+
+service PathInfoService {
+  // Return a PathInfo message matching the criteria specified in the
+  // GetPathInfoRequest message.
+  rpc Get(GetPathInfoRequest) returns (PathInfo);
+
+  // Upload a PathInfo object to the remote end. It MUST not return until the
+  // PathInfo object has been written on the the remote end.
+  //
+  // The remote end MAY check if a potential DirectoryNode has already been
+  // uploaded.
+  //
+  // Uploading clients SHOULD obviously not steer other machines to try to
+  // substitute before from the remote end before having finished uploading
+  // PathInfo, Directories and Blobs.
+  // The returned PathInfo object MAY contain additional narinfo signatures, but
+  // is otherwise left untouched.
+  rpc Put(PathInfo) returns (PathInfo);
+
+  // Calculate the NAR representation of the contents specified by the
+  // root_node. The calculation SHOULD be cached server-side for subsequent
+  // requests.
+  //
+  // All references (to blobs or Directory messages) MUST already exist in the
+  // store.
+  //
+  // The method can be used to produce a Nix fixed-output path, which contains
+  // the (compressed) sha256 of the NAR content representation in the root_node
+  // name (suffixed with the name).
+  //
+  // It can also be used to calculate arbitrary NAR hashes of output paths, in
+  // case a legacy Nix Binary Cache frontend is provided.
+  rpc CalculateNAR(tvix.castore.v1.Node) returns (CalculateNARResponse);
+
+  // Return a stream of PathInfo messages matching the criteria specified in
+  // ListPathInfoRequest.
+  rpc List(ListPathInfoRequest) returns (stream PathInfo);
+}
+
+// The parameters that can be used to lookup a (single) PathInfo object.
+// Currently, only a lookup by output hash is supported.
+message GetPathInfoRequest {
+  oneof by_what {
+    // The output hash of a nix path (20 bytes).
+    // This is the nixbase32-decoded portion of a Nix output path, so to substitute
+    // /nix/store/xm35nga2g20mz5sm5l6n8v3bdm86yj83-cowsay-3.04
+    // this field would contain nixbase32dec("xm35nga2g20mz5sm5l6n8v3bdm86yj83").
+    bytes by_output_hash = 1;
+  }
+}
+
+// The parameters that can be used to lookup (multiple) PathInfo objects.
+// Currently no filtering is possible, all objects are returned.
+message ListPathInfoRequest {}
+
+// CalculateNARResponse is the response returned by the CalculateNAR request.
+//
+// It contains the size of the NAR representation (in bytes), and the sha56
+// digest.
+message CalculateNARResponse {
+  // This size of the NAR file, in bytes.
+  uint64 nar_size = 1;
+
+  // The sha256 of the NAR file representation.
+  bytes nar_sha256 = 2;
+}