Changelog

All notable changes to phil/circuit-breaker will be documented in this file.

Updates should follow the Keep a CHANGELOG principles.

NEXT - YYYY-MM-DD

Added

• CircuitKey: what one breaker guards, lowercase ASCII segments separated by ., _ or -, at most 87 bytes.
• CircuitPolicy: a failure rate threshold from 1 to 100 %, a minimum of calls that is the denominator, a fixed window, an open duration and the half-open successes that close the circuit; an optional slowness threshold in milliseconds and a slow call rate, so that calls lasting longer than the threshold open the circuit too; trips() in integer arithmetic, isSlow().
• CallOutcome: how one call went, succeeded() or failed(), with its duration in milliseconds when the caller measured it.
• CircuitState and CircuitSnapshot: the closed/open/half-open state machine as pure transitions of a policy and an instant — at(), record(), recordSuccess(), recordFailure(), permitsCalls() —, closed() and restore(); the slow calls counted with the calls and failures of the window, a slow trial call opening the circuit again.
• CircuitStateStore, the port of the states shared by the processes; a state never stored or lost is closed.
• CircuitOverride, the port of the operator who forces a circuit open; CircuitOverrides, several overrides asked together, none forcing anything when empty.
• CircuitBreaker: isAvailable(), state(), record(), recordSuccess() and recordFailure() over a store, an override and a PSR-20 clock, the time-driven transitions saved only when they change something, nothing recorded while forced open; CircuitBreakers, the breakers by key, each key declared once.
• CircuitBreakerException, implemented by InvalidCircuit and UnknownCircuit.
• The benchmark of a breaker's ask and report, timed or not, a transition and a key.
• The documentation in doc/, one file per topic, indexed by the README.
• CONTRIBUTING.md, SECURITY.md and CODE_OF_CONDUCT.md.