UmadbClient

An Elixir gRPC client for UmaDB's DCB (Dynamic Consistency Boundary) event store service. It wraps the generated UmaDb.V1.DCB.Stub with a small, ergonomic API for appending events, reading and subscribing to event streams, querying by type and tags, tracking consumer positions, and optimistic concurrency control — plus UmaDbClient.Builder convenience constructors for the underlying proto message structs.

Installation

If available in Hex, the package can be installed by adding umadb_client to your list of dependencies in mix.exs:

def deps do
  [
    {:umadb_client, "~> 0.6.4"}
  ]
end

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/umadb_client.

Regenerating uma_db.pb.ex from the proto

lib/uma_db/v1/uma_db.pb.ex is generated from the umadb.proto definition published in the umadb-proto crate. When that proto changes, regenerate the module as follows.

Prerequisites (one-time)

• protoc — the Protocol Buffers compiler.

• The Elixir protobuf plugin, installed as an escript on your PATH:

  mix escript.install hex protobuf
  # ensure ~/.mix/escripts is on your PATH
  

Steps

1. Fetch the target proto version. The source of truth is the umadb-proto crate; grab the version you want from crates.io and extract it:

   VERSION=0.6.4
   curl -sSL "https://crates.io/api/v1/crates/umadb-proto/${VERSION}/download" \
     -H "User-Agent: umadb-client-dev" -o "/tmp/umadb-proto-${VERSION}.crate"
   tar xzf "/tmp/umadb-proto-${VERSION}.crate" -C /tmp
   # proto now at /tmp/umadb-proto-${VERSION}/proto/v1/umadb.proto
   

   (If you already have the crate locally, e.g. via a Rust build, it lives under ~/.cargo/registry/src/*/umadb-proto-${VERSION}/proto/v1/umadb.proto.)

2. Run protoc to generate the Elixir module:

   protoc --elixir_out=plugins=grpc:./lib \
          --proto_path="/tmp/umadb-proto-${VERSION}/proto" \
          v1/umadb.proto
   

3. protoc writes to lib/v1/umadb.pb.ex (following the proto path). Move it into this project's layout and update the header comment with the proto version:

   mv lib/v1/umadb.pb.ex lib/uma_db/v1/uma_db.pb.ex
   rmdir lib/v1 2>/dev/null || true
   

4. Format and verify:

   mix format
   mix compile
   mix test
   

If the proto adds or changes fields, also update the hand-written convenience constructors in lib/uma_db_client/builder.ex and the public API in lib/uma_db_client.ex to surface them.