feat: support context in breaker methods (#4088)

core/breaker/breaker.go

@@ -1,6 +1,7 @@
 package breaker
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"strings"
@@ -36,12 +37,16 @@ type (
 		// The caller needs to call promise.Accept() on success,
 		// or call promise.Reject() on failure.
 		Allow() (Promise, error)
+		// AllowCtx checks if the request is allowed when ctx isn't done.
+		AllowCtx(ctx context.Context) (Promise, error)
 
 		// Do runs the given request if the Breaker accepts it.
 		// Do returns an error instantly if the Breaker rejects the request.
 		// If a panic occurs in the request, the Breaker handles it as an error
 		// and causes the same panic again.
 		Do(req func() error) error
+		// DoCtx runs the given request if the Breaker accepts it when ctx isn't done.
+		DoCtx(ctx context.Context, req func() error) error
 
 		// DoWithAcceptable runs the given request if the Breaker accepts it.
 		// DoWithAcceptable returns an error instantly if the Breaker rejects the request.
@@ -49,12 +54,16 @@ type (
 		// and causes the same panic again.
 		// acceptable checks if it's a successful call, even if the error is not nil.
 		DoWithAcceptable(req func() error, acceptable Acceptable) error
+		// DoWithAcceptableCtx runs the given request if the Breaker accepts it when ctx isn't done.
+		DoWithAcceptableCtx(ctx context.Context, req func() error, acceptable Acceptable) error
 
 		// DoWithFallback runs the given request if the Breaker accepts it.
 		// DoWithFallback runs the fallback if the Breaker rejects the request.
 		// If a panic occurs in the request, the Breaker handles it as an error
 		// and causes the same panic again.
 		DoWithFallback(req func() error, fallback Fallback) error
+		// DoWithFallbackCtx runs the given request if the Breaker accepts it when ctx isn't done.
+		DoWithFallbackCtx(ctx context.Context, req func() error, fallback Fallback) error
 
 		// DoWithFallbackAcceptable runs the given request if the Breaker accepts it.
 		// DoWithFallbackAcceptable runs the fallback if the Breaker rejects the request.
@@ -62,6 +71,9 @@ type (
 		// and causes the same panic again.
 		// acceptable checks if it's a successful call, even if the error is not nil.
 		DoWithFallbackAcceptable(req func() error, fallback Fallback, acceptable Acceptable) error
+		// DoWithFallbackAcceptableCtx runs the given request if the Breaker accepts it when ctx isn't done.
+		DoWithFallbackAcceptableCtx(ctx context.Context, req func() error, fallback Fallback,
+			acceptable Acceptable) error
 	}
 
 	// Fallback is the func to be called if the request is rejected.
@@ -118,23 +130,71 @@ func (cb *circuitBreaker) Allow() (Promise, error) {
 	return cb.throttle.allow()
 }
 
+func (cb *circuitBreaker) AllowCtx(ctx context.Context) (Promise, error) {
+	select {
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	default:
+		return cb.Allow()
+	}
+}
+
 func (cb *circuitBreaker) Do(req func() error) error {
 	return cb.throttle.doReq(req, nil, defaultAcceptable)
 }
 
+func (cb *circuitBreaker) DoCtx(ctx context.Context, req func() error) error {
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	default:
+		return cb.Do(req)
+	}
+}
+
 func (cb *circuitBreaker) DoWithAcceptable(req func() error, acceptable Acceptable) error {
 	return cb.throttle.doReq(req, nil, acceptable)
 }
 
+func (cb *circuitBreaker) DoWithAcceptableCtx(ctx context.Context, req func() error,
+	acceptable Acceptable) error {
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	default:
+		return cb.DoWithAcceptable(req, acceptable)
+	}
+}
+
 func (cb *circuitBreaker) DoWithFallback(req func() error, fallback Fallback) error {
 	return cb.throttle.doReq(req, fallback, defaultAcceptable)
 }
 
+func (cb *circuitBreaker) DoWithFallbackCtx(ctx context.Context, req func() error,
+	fallback Fallback) error {
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	default:
+		return cb.DoWithFallback(req, fallback)
+	}
+}
+
 func (cb *circuitBreaker) DoWithFallbackAcceptable(req func() error, fallback Fallback,
 	acceptable Acceptable) error {
 	return cb.throttle.doReq(req, fallback, acceptable)
 }
 
+func (cb *circuitBreaker) DoWithFallbackAcceptableCtx(ctx context.Context, req func() error,
+	fallback Fallback, acceptable Acceptable) error {
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	default:
+		return cb.DoWithFallbackAcceptable(req, fallback, acceptable)
+	}
+}
+
 func (cb *circuitBreaker) Name() string {
 	return cb.name
 }