CounterStore

CounterStore is a software component or pattern designed to track and manage numeric counters within an application. It provides centralized access to one or more counters, allowing components to increment, decrement, reset, or read values in a controlled way. The term is often used to describe lightweight store modules that focus specifically on counters rather than a full application state.

Its typical API includes operations such as getCounter(name), setCounter(name, value), increment(name, amount=1), decrement(name, amount=1), reset(name, value=0), and resetAll(). Many implementations offer a publish/subscribe mechanism so that observers can react to counter changes. Some variants expose a derived view or allow grouping counters under namespaces or keys.

Counter stores can be in-memory for fast access, or backed by persistent storage such as localStorage, a database, or a distributed cache like Redis. When used in multi-client or multi-instance environments, atomic operations or transactions are employed to avoid race conditions. Immutability and event-sourcing patterns can be used to simplify reasoning about updates.

Common use cases include UI counters (clicks, views), rate limiting, quotas, or progress tracking across processes. They are often implemented as part of larger state management strategies, or as standalone modules in microservices or client applications. In testing, counter stores help simulate system activity and verify correct decrement-and-reset behavior.

Related concepts include state stores, event emitters, and reactive data flows. Variants may support advanced features such as persistence, time-based counters, or counters scoped to user sessions or resources.