Add logging, fix devenv up

proto/buf.yaml

@@ -4,6 +4,9 @@ modules:
 lint:
   use:
     - STANDARD
+  except:
+    - RPC_RESPONSE_STANDARD_NAME
+    - RPC_REQUEST_RESPONSE_UNIQUE
 breaking:
   use:
     - FILE

proto/musicfs.proto

@@ -3,17 +3,27 @@ syntax = "proto3";
 package musicfs;
 
 // MusicFs service exposes a server-side music library to a remote musicfs
-// FUSE mount. Three RPCs, all server-streaming so the client can pull
-// incrementally and the server can keep large bodies off the heap.
+// FUSE mount.
 service MusicFs {
-  // Stream every file entry in the library. The client diffs each entry's
-  // hash against its DB to decide what changed.
+  // Hash-based reconciliation. Client sends the (inode, hash) pairs it
+  // currently has; server responds with the subset that changed (new or
+  // hash-different) plus the inodes the client has but the server no longer
+  // has. Cheap on the wire — no file metadata crosses until the client asks.
+  rpc Reconcile(ReconcileRequest) returns (ReconcileResponse);
+
+  // Fetch full metadata for a specific set of inodes. Called after Reconcile
+  // returns a non-empty `changed` list, for just those inodes.
+  rpc GetMetadata(GetMetadataRequest) returns (stream ManifestEntry);
+
+  // Stream every file entry in the library. Convenience RPC for first-run
+  // bootstrapping or full-refresh. The diff-based Reconcile path is the
+  // normal case.
   rpc GetManifest(GetManifestRequest) returns (stream ManifestEntry);
 
-  // Stream the bytes of one file. If `start` and `length` are both set on
-  // the request, only that byte range is sent; otherwise the whole file.
-  // The first chunk carries `total_size` and `offset`; subsequent chunks
-  // continue from there.
+  // Stream the bytes of one file. If `start` and `length` are both zero the
+  // server streams the entire file; otherwise just the requested range. The
+  // first chunk carries `total_size` and `offset`; subsequent chunks continue
+  // from there.
   rpc GetFile(GetFileRequest) returns (stream FileChunk);
 
   // Long-lived stream of filesystem change events. The client uses these as
@@ -22,6 +32,24 @@ service MusicFs {
   rpc SubscribeEvents(SubscribeEventsRequest) returns (stream ChangeEvent);
 }
 
+message ReconcileRequest {
+  repeated InodeHash entries = 1;
+}
+
+message ReconcileResponse {
+  repeated InodeHash changed = 1;
+  repeated uint64 deleted = 2;
+}
+
+message InodeHash {
+  uint64 inode = 1;
+  uint64 hash = 2;
+}
+
+message GetMetadataRequest {
+  repeated uint64 inodes = 1;
+}
+
 message GetManifestRequest {}
 
 message GetFileRequest {