README
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guard
guard guards external resources (and your application) from your application.
Documentation
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Overview ¶
Package guard wraps context based process and manage it.
Index ¶
- type Backoff
- type ExponentialBackoffOption
- func WithInitialInterval(d time.Duration) ExponentialBackoffOption
- func WithMaxInterval(d time.Duration) ExponentialBackoffOption
- func WithMultiplier(f float64) ExponentialBackoffOption
- func WithRandomizationFactor(f float64) ExponentialBackoffOption
- func WithRandomizer(r Randomizer) ExponentialBackoffOption
- type Guard
- type GuardFunc
- type Randomizer
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Backoff ¶
type Backoff interface {
// NextInterval returns the next interval.
NextInterval() time.Duration
// Reset creates the clone of the current strategy with an initialized state.
Reset() Backoff
}
Backoff is a strategy of backoff interval.
func NewConstantBackoff ¶
ConstantBackoff creates Backoff with a constant interval. NextInterval() always returns given parameter d.
func NewExponentialBackoff ¶
func NewExponentialBackoff(options ...ExponentialBackoffOption) Backoff
ExponentialBackoff creates Backoff with an exponential backoff.
Let N be a retry count of the process, the value of NextInterval(N) is calculated by following formula.
NextInterval(N) = BaseInterval(N) * [1-RandomizationFactor, 1+RandomizationFactor) BaseInterval(N) = min(BaseInterval(N-1) * Multiplier, MaxInterval) BaseInterval(1) = min(InitialInterval, MaxInterval)
The default parameters.
InitialInterval: 200 (ms) MaxInterval: 1 (min) Multiplier: 2 RandomizationFactor: 0.2 Randomizer: rand.New(rand.NewSource(time.Now().Unix()))
Example intervals.
+----+----------------------+----------------------+ | N | BaseInterval(N) (ms) | NextInterval(N) (ms) | +----+----------------------+----------------------+ | 1 | 200 | [160, 240) | | 2 | 400 | [320, 480) | | 3 | 800 | [640, 960) | | 4 | 1600 | [1280, 1920) | | 5 | 3200 | [2560, 3840) | | 6 | 6400 | [5120, 7680) | | 7 | 12800 | [10240, 15360) | | 8 | 25600 | [20480, 30720) | | 9 | 51200 | [40960, 61440) | | 10 | 60000 | [48000, 72000) | | 11 | 60000 | [48000, 72000) | +----+----------------------+----------------------+
Note: MaxInterval effects only the base interval. The actual interval may exceed MaxInterval depending on RandomizationFactor.
func NewNoBackoff ¶
func NewNoBackoff() Backoff
NoBackoff creates Backoff without an interval. NextInterval() always returns 0.
type ExponentialBackoffOption ¶
type ExponentialBackoffOption func(*exponentialBackoff)
ExponentialBackoffOption is the optional parameter for ExponentialBackoff.
func WithInitialInterval ¶
func WithInitialInterval(d time.Duration) ExponentialBackoffOption
WithInitialInterval set the initial interval of ExponentialBackoff.
func WithMaxInterval ¶
func WithMaxInterval(d time.Duration) ExponentialBackoffOption
WithMaxInterval set the maximum interval of ExponentialBackoff.
func WithMultiplier ¶
func WithMultiplier(f float64) ExponentialBackoffOption
WithMultiplier set the multiplier of ExponentialBackoff.
func WithRandomizationFactor ¶
func WithRandomizationFactor(f float64) ExponentialBackoffOption
WithRandomizationFactor set the randomization factor of ExponentialBackoff.
func WithRandomizer ¶
func WithRandomizer(r Randomizer) ExponentialBackoffOption
WithRandomizer set the randomizer of ExponentialBackoff.
type Guard ¶
type Guard interface {
// Run runs the function with its own capability.
Run(ctx context.Context, f func(context.Context) error) error
}
Guard is a process manager that runs and manages the process.
type Randomizer ¶
type Randomizer interface {
// Float64 returns random floating point number in [0.0,1.0).
Float64() float64
}
Randomizer generates random numbers.
Source Files
Directories
¶
| Path | Synopsis |
|---|---|
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Package circuitbreaker provide a circuitbreaker pattern failure management.
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Package circuitbreaker provide a circuitbreaker pattern failure management. |
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Package panicguard provide a panic-safe process management.
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Package panicguard provide a panic-safe process management. |
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Package rate limit provides a manager to control the execution rate of the process.
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Package rate limit provides a manager to control the execution rate of the process. |
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Package retry provides a failure management with retry for the process.
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Package retry provides a failure management with retry for the process. |
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Package semaphore provides a semaphore that limits a number of concurrent processes.
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Package semaphore provides a semaphore that limits a number of concurrent processes. |