152 lines
3.5 KiB
Go
152 lines
3.5 KiB
Go
package retry
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import (
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"math/rand"
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"time"
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)
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// Function signature of retry if function
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type RetryIfFunc func(error) bool
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// Function signature of OnRetry function
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// n = count of attempts
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type OnRetryFunc func(n uint, err error)
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type DelayTypeFunc func(n uint, config *Config) time.Duration
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type Config struct {
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attempts uint
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delay time.Duration
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maxDelay time.Duration
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maxJitter time.Duration
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onRetry OnRetryFunc
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retryIf RetryIfFunc
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delayType DelayTypeFunc
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lastErrorOnly bool
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}
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// Option represents an option for retry.
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type Option func(*Config)
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// return the direct last error that came from the retried function
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// default is false (return wrapped errors with everything)
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func LastErrorOnly(lastErrorOnly bool) Option {
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return func(c *Config) {
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c.lastErrorOnly = lastErrorOnly
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}
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}
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// Attempts set count of retry
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// default is 10
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func Attempts(attempts uint) Option {
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return func(c *Config) {
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c.attempts = attempts
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}
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}
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// Delay set delay between retry
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// default is 100ms
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func Delay(delay time.Duration) Option {
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return func(c *Config) {
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c.delay = delay
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}
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}
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// MaxDelay set maximum delay between retry
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// does not apply by default
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func MaxDelay(maxDelay time.Duration) Option {
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return func(c *Config) {
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c.maxDelay = maxDelay
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}
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}
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// MaxJitter sets the maximum random Jitter between retries for RandomDelay
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func MaxJitter(maxJitter time.Duration) Option {
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return func(c *Config) {
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c.maxJitter = maxJitter
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}
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}
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// DelayType set type of the delay between retries
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// default is BackOff
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func DelayType(delayType DelayTypeFunc) Option {
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return func(c *Config) {
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c.delayType = delayType
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}
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}
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// BackOffDelay is a DelayType which increases delay between consecutive retries
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func BackOffDelay(n uint, config *Config) time.Duration {
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return config.delay * (1 << n)
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}
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// FixedDelay is a DelayType which keeps delay the same through all iterations
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func FixedDelay(_ uint, config *Config) time.Duration {
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return config.delay
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}
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// RandomDelay is a DelayType which picks a random delay up to config.maxJitter
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func RandomDelay(_ uint, config *Config) time.Duration {
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return time.Duration(rand.Int63n(int64(config.maxJitter)))
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}
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// CombineDelay is a DelayType the combines all of the specified delays into a new DelayTypeFunc
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func CombineDelay(delays ...DelayTypeFunc) DelayTypeFunc {
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return func(n uint, config *Config) time.Duration {
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var total time.Duration
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for _, delay := range delays {
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total += delay(n, config)
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}
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return total
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}
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}
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// OnRetry function callback are called each retry
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//
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// log each retry example:
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//
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// retry.Do(
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// func() error {
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// return errors.New("some error")
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// },
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// retry.OnRetry(func(n uint, err error) {
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// log.Printf("#%d: %s\n", n, err)
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// }),
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// )
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func OnRetry(onRetry OnRetryFunc) Option {
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return func(c *Config) {
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c.onRetry = onRetry
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}
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}
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// RetryIf controls whether a retry should be attempted after an error
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// (assuming there are any retry attempts remaining)
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//
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// skip retry if special error example:
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//
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// retry.Do(
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// func() error {
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// return errors.New("special error")
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// },
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// retry.RetryIf(func(err error) bool {
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// if err.Error() == "special error" {
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// return false
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// }
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// return true
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// })
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// )
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//
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// By default RetryIf stops execution if the error is wrapped using `retry.Unrecoverable`,
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// so above example may also be shortened to:
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//
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// retry.Do(
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// func() error {
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// return retry.Unrecoverable(errors.New("special error"))
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// }
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// )
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func RetryIf(retryIf RetryIfFunc) Option {
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return func(c *Config) {
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c.retryIf = retryIf
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}
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}
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