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Write your durable execution

Define your durable execution name, contract, and business logic.

Tourbillon durable executions require:

  • A definition - the name of your durable execution and the input/output schema
  • An implementation - the business logic of your durable execution
  • A contracts file - required by Tourbillon to enable durable executions to be triggered

Definition​

Definitions are written in protobuf.

echo/echo.proto
syntax = "proto3";

package echo;

import "tourbillon/annotations/v1/durable_service.proto";

option (tourbillon.annotations.v1.durable_services) = true;

service EchoService {
  rpc Echo(EchoRequest) returns (EchoResponse);
}

message EchoRequest {
  string message = 1;
}

message EchoResponse {
  string message = 1;
}

Implementation​

Implementations are written in Starlark.

echo/EchoService.star
load("time", "time")


def Echo(ctx, req)!:
  pkg = proto.package("echo", contracts = ctx.contracts)
  time.sleep(time.SECOND * 5)
  return pkg.EchoResponse(message = req.message)

Test​

echo/EchoService_test.star
load("//echo/EchoService.star", "Echo")
load("assert", "assert")

def test_echo(ctx)!:
  """Simple echo test"""
  pkg = proto.package("echo", contracts = ctx.contracts)
  res = Echo(ctx, pkg.EchoRequest(message = "durable"))
  assert.eq(res.message, req.message)

Contracts​

A contracts.binpb file is required by Tourbillon to read each available durable execution definition.

buf.yaml
version: "v2"
deps:
  - buf.build/bckground/tourbillon-starlark
buf build -o contracts.binpb

Repository​

The repository that Tourbillon will fetch periodically and implement in your Tourbillon runtime. These are connected to Tourbillon namespaces (see next step).

git init .
git checkout -b main
git add .
git commit -m "echo service"
git remote add origin git@github.com/my-org/durable-executions
git push -u origin main