core_model 0.1.0

Shared primitives with no Flutter dependency: a monotonic ownership lease, a cancellation token and a retry backoff.

core_model

Three primitives that a Dart application keeps re-deriving, extracted once and tested. No Flutter dependency: it runs under dart test, in an isolate, or in a CLI.

Lease: monotonic ownership over a shared resource

One lease guards one resource scope: a hardware session, a storage key, a composition of dependencies. An owner calls acquire() and keeps the handle; a new term invalidates every handle issued before it, so a stale owner's deferred work (a queued release, a late callback, a retry) becomes a no-op instead of tearing down the current owner's state.

final lease = Lease();

final handle = lease.acquire();
// ... later, on a path that may have been superseded:
lease.guard(handle, () => transport.close());

It is not a mutex: it serializes nothing, it decides whose completed work still counts.

CancelToken: cooperative cancellation

A token an operation checks, and a caller cancels. No timers, no zones, no Future wrapping.

retryBackoff: exponential backoff with jitter

The retry schedule as a function, so a client's retry policy is a value that can be tested rather than a loop that has to be read.

Also here

Guid, a UUID as a string with GuidX.nil and GuidX.empty; IDeviceInfo, the interface an application implements to describe the device and build it runs on; and a platform-neutral VoidCallback typedef, so a package that uses it stays free of dart:ui; RetryNotifier, the callback a retrying middleware reports each attempt through.

Install

dependencies:
  core_model:
    git:
      url: https://github.com/zs-dima/core_model.git
      ref: v0.1.0

Changelog

CHANGELOG.md

License

MIT