feat: support context in breaker methods (#4088)

This commit is contained in:
Kevin Wan 2024-04-18 18:00:17 +08:00 committed by GitHub
parent 4b0bacc9c6
commit 815a4f7eed
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5 changed files with 361 additions and 4 deletions

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@ -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
}

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@ -1,11 +1,13 @@
package breaker
import (
"context"
"errors"
"fmt"
"strconv"
"strings"
"testing"
"time"
"github.com/stretchr/testify/assert"
"github.com/zeromicro/go-zero/core/stat"
@ -16,10 +18,242 @@ func init() {
}
func TestCircuitBreaker_Allow(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
_, err := b.Allow()
assert.Nil(t, err)
t.Run("allow", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
_, err := b.Allow()
assert.Nil(t, err)
})
t.Run("allow with ctx", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
_, err := b.AllowCtx(context.Background())
assert.Nil(t, err)
})
t.Run("allow with ctx timeout", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
ctx, cancel := context.WithTimeout(context.Background(), time.Microsecond)
defer cancel()
time.Sleep(time.Millisecond)
_, err := b.AllowCtx(ctx)
assert.ErrorIs(t, err, context.DeadlineExceeded)
})
t.Run("allow with ctx cancel", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
ctx, cancel := context.WithTimeout(context.Background(), time.Second)
cancel()
_, err := b.AllowCtx(ctx)
assert.ErrorIs(t, err, context.Canceled)
})
}
func TestCircuitBreaker_Do(t *testing.T) {
t.Run("do", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
err := b.Do(func() error {
return nil
})
assert.Nil(t, err)
})
t.Run("do with ctx", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
err := b.DoCtx(context.Background(), func() error {
return nil
})
assert.Nil(t, err)
})
t.Run("do with ctx timeout", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
ctx, cancel := context.WithTimeout(context.Background(), time.Microsecond)
defer cancel()
time.Sleep(time.Millisecond)
err := b.DoCtx(ctx, func() error {
return nil
})
assert.ErrorIs(t, err, context.DeadlineExceeded)
})
t.Run("do with ctx cancel", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
ctx, cancel := context.WithTimeout(context.Background(), time.Second)
cancel()
err := b.DoCtx(ctx, func() error {
return nil
})
assert.ErrorIs(t, err, context.Canceled)
})
}
func TestCircuitBreaker_DoWithAcceptable(t *testing.T) {
t.Run("doWithAcceptable", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
err := b.DoWithAcceptable(func() error {
return nil
}, func(err error) bool {
return true
})
assert.Nil(t, err)
})
t.Run("doWithAcceptable with ctx", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
err := b.DoWithAcceptableCtx(context.Background(), func() error {
return nil
}, func(err error) bool {
return true
})
assert.Nil(t, err)
})
t.Run("doWithAcceptable with ctx timeout", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
ctx, cancel := context.WithTimeout(context.Background(), time.Microsecond)
defer cancel()
time.Sleep(time.Millisecond)
err := b.DoWithAcceptableCtx(ctx, func() error {
return nil
}, func(err error) bool {
return true
})
assert.ErrorIs(t, err, context.DeadlineExceeded)
})
t.Run("doWithAcceptable with ctx cancel", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
ctx, cancel := context.WithTimeout(context.Background(), time.Second)
cancel()
err := b.DoWithAcceptableCtx(ctx, func() error {
return nil
}, func(err error) bool {
return true
})
assert.ErrorIs(t, err, context.Canceled)
})
}
func TestCircuitBreaker_DoWithFallback(t *testing.T) {
t.Run("doWithFallback", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
err := b.DoWithFallback(func() error {
return nil
}, func(err error) error {
return err
})
assert.Nil(t, err)
})
t.Run("doWithFallback with ctx", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
err := b.DoWithFallbackCtx(context.Background(), func() error {
return nil
}, func(err error) error {
return err
})
assert.Nil(t, err)
})
t.Run("doWithFallback with ctx timeout", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
ctx, cancel := context.WithTimeout(context.Background(), time.Microsecond)
defer cancel()
time.Sleep(time.Millisecond)
err := b.DoWithFallbackCtx(ctx, func() error {
return nil
}, func(err error) error {
return err
})
assert.ErrorIs(t, err, context.DeadlineExceeded)
})
t.Run("doWithFallback with ctx cancel", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
ctx, cancel := context.WithTimeout(context.Background(), time.Second)
cancel()
err := b.DoWithFallbackCtx(ctx, func() error {
return nil
}, func(err error) error {
return err
})
assert.ErrorIs(t, err, context.Canceled)
})
}
func TestCircuitBreaker_DoWithFallbackAcceptable(t *testing.T) {
t.Run("doWithFallbackAcceptable", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
err := b.DoWithFallbackAcceptable(func() error {
return nil
}, func(err error) error {
return err
}, func(err error) bool {
return true
})
assert.Nil(t, err)
})
t.Run("doWithFallbackAcceptable with ctx", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
err := b.DoWithFallbackAcceptableCtx(context.Background(), func() error {
return nil
}, func(err error) error {
return err
}, func(err error) bool {
return true
})
assert.Nil(t, err)
})
t.Run("doWithFallbackAcceptable with ctx timeout", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
ctx, cancel := context.WithTimeout(context.Background(), time.Microsecond)
defer cancel()
time.Sleep(time.Millisecond)
err := b.DoWithFallbackAcceptableCtx(ctx, func() error {
return nil
}, func(err error) error {
return err
}, func(err error) bool {
return true
})
assert.ErrorIs(t, err, context.DeadlineExceeded)
})
t.Run("doWithFallbackAcceptable with ctx cancel", func(t *testing.T) {
b := NewBreaker()
assert.True(t, len(b.Name()) > 0)
ctx, cancel := context.WithTimeout(context.Background(), time.Second)
cancel()
err := b.DoWithFallbackAcceptableCtx(ctx, func() error {
return nil
}, func(err error) error {
return err
}, func(err error) bool {
return true
})
assert.ErrorIs(t, err, context.Canceled)
})
}
func TestLogReason(t *testing.T) {

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@ -1,5 +1,7 @@
package breaker
import "context"
const nopBreakerName = "nopBreaker"
type nopBreaker struct{}
@ -17,22 +19,43 @@ func (b nopBreaker) Allow() (Promise, error) {
return nopPromise{}, nil
}
func (b nopBreaker) AllowCtx(_ context.Context) (Promise, error) {
return nopPromise{}, nil
}
func (b nopBreaker) Do(req func() error) error {
return req()
}
func (b nopBreaker) DoCtx(_ context.Context, req func() error) error {
return req()
}
func (b nopBreaker) DoWithAcceptable(req func() error, _ Acceptable) error {
return req()
}
func (b nopBreaker) DoWithAcceptableCtx(_ context.Context, req func() error, _ Acceptable) error {
return req()
}
func (b nopBreaker) DoWithFallback(req func() error, _ Fallback) error {
return req()
}
func (b nopBreaker) DoWithFallbackCtx(_ context.Context, req func() error, _ Fallback) error {
return req()
}
func (b nopBreaker) DoWithFallbackAcceptable(req func() error, _ Fallback, _ Acceptable) error {
return req()
}
func (b nopBreaker) DoWithFallbackAcceptableCtx(_ context.Context, req func() error,
_ Fallback, _ Acceptable) error {
return req()
}
type nopPromise struct{}
func (p nopPromise) Accept() {

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@ -1,6 +1,7 @@
package breaker
import (
"context"
"errors"
"testing"
@ -12,6 +13,8 @@ func TestNopBreaker(t *testing.T) {
assert.Equal(t, nopBreakerName, b.Name())
p, err := b.Allow()
assert.Nil(t, err)
p, err = b.AllowCtx(context.Background())
assert.Nil(t, err)
p.Accept()
for i := 0; i < 1000; i++ {
p, err := b.Allow()
@ -21,18 +24,34 @@ func TestNopBreaker(t *testing.T) {
assert.Nil(t, b.Do(func() error {
return nil
}))
assert.Nil(t, b.DoCtx(context.Background(), func() error {
return nil
}))
assert.Nil(t, b.DoWithAcceptable(func() error {
return nil
}, defaultAcceptable))
assert.Nil(t, b.DoWithAcceptableCtx(context.Background(), func() error {
return nil
}, defaultAcceptable))
errDummy := errors.New("any")
assert.Equal(t, errDummy, b.DoWithFallback(func() error {
return errDummy
}, func(err error) error {
return nil
}))
assert.Equal(t, errDummy, b.DoWithFallbackCtx(context.Background(), func() error {
return errDummy
}, func(err error) error {
return nil
}))
assert.Equal(t, errDummy, b.DoWithFallbackAcceptable(func() error {
return errDummy
}, func(err error) error {
return nil
}, defaultAcceptable))
assert.Equal(t, errDummy, b.DoWithFallbackAcceptableCtx(context.Background(), func() error {
return errDummy
}, func(err error) error {
return nil
}, defaultAcceptable))
}

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@ -595,19 +595,40 @@ func (d *dropBreaker) Allow() (breaker.Promise, error) {
return nil, errDummy
}
func (d *dropBreaker) AllowCtx(_ context.Context) (breaker.Promise, error) {
return nil, errDummy
}
func (d *dropBreaker) Do(_ func() error) error {
return nil
}
func (d *dropBreaker) DoCtx(_ context.Context, _ func() error) error {
return nil
}
func (d *dropBreaker) DoWithAcceptable(_ func() error, _ breaker.Acceptable) error {
return errDummy
}
func (d *dropBreaker) DoWithAcceptableCtx(_ context.Context, _ func() error, _ breaker.Acceptable) error {
return errDummy
}
func (d *dropBreaker) DoWithFallback(_ func() error, _ breaker.Fallback) error {
return nil
}
func (d *dropBreaker) DoWithFallbackCtx(_ context.Context, _ func() error, _ breaker.Fallback) error {
return nil
}
func (d *dropBreaker) DoWithFallbackAcceptable(_ func() error, _ breaker.Fallback,
_ breaker.Acceptable) error {
return nil
}
func (d *dropBreaker) DoWithFallbackAcceptableCtx(_ context.Context, _ func() error,
_ breaker.Fallback, _ breaker.Acceptable) error {
return nil
}