README
¶
retry
Golang retry library.
About The Project
Retry - small library, that provides api for easy function retry and error handling. Package has some benefits unlike known implementations:
- laconic api
- rich retry strategy set
- easy customization
- context package support
Usage
Retry function until success:
_ = retry.Exec(func(retryNumber int) (err error) {
// your logic here
return err
})
Limit attempts:
err := retry.Exec(func(retryNumber int) (err error) {
// your logic here
return err
}, retry.MaxAttempts(10))
Delay between retries:
err := retry.Exec(func(retryNumber int) (err error) {
// your logic here
return err
}, retry.FixedDelay(time.Second))
Combine few retry strategies:
err := retry.Exec(func(retryNumber int) (err error) {
// your logic here
return err
}, retry.MaxAttempts(10), retry.FixedDelay(time.Second))
Breaking retry loop directly from function:
err := retry.Exec(func(retryNumber int) (err error) {
// your logic here
if !canRetry {
return retry.Unrecoverable(err)
}
return err
})
Using context:
err := retry.ExecContext(ctx, func(ctx context.Context, retryNumber int) (err error) {
// your logic here
return err
})
Context cancellation:
ctx, cancel := context.WithCancel(context.Background())
go func() {
// wait some event
cancel()
}()
err := retry.ExecContext(ctx, func(ctx context.Context, retryNumber int) (err error) {
// your logic here
return err
})
Underwater rocks
Arguments order
Be careful:
err := retry.Exec(func(retryNumber int) (err error) {
// your logic here
return err
}, retry.MaxAttempts(2), retry.FixedDelay(time.Second))
not similar to
err := retry.Exec(func(retryNumber int) (err error) {
// your logic here
return err
}, retry.FixedDelay(time.Second), retry.MaxAttempts(2))
Trace steps in the first case are:
- Function call
- Max attempts check
- Delay
- Function call
- Max attempts check
- Break loop
Trace steps in the second case are:
- Function call
- Delay
- Max attempts check
- Function call
- Delay
- Max attempts check
- Break loop
So, we can see, that second block of code will have unnecessary delay. It is highly recommended to store strategies, that limit attempts, before strategies, that do delays.
Strategy reusing
Some strategies have internal state, so it is highly recommended not to share strategies between several Exec calls.
Incorrect:
strategy := retry.MaxAttempts(2)
err := retry.Exec(func(retryNumber int) (err error) {
// your logic here
return err
}, strategy)
err := retry.Exec(func(retryNumber int) (err error) {
// your logic here
return err
}, strategy)
Correct:
err := retry.Exec(func(retryNumber int) (err error) {
// your logic here
return err
}, retry.MaxAttempts(2))
err := retry.Exec(func(retryNumber int) (err error) {
// your logic here
return err
}, retry.MaxAttempts(2))
Similar projects
License
Retry is licensed under the Apache License, Version 2.0. See LICENSE for the full license text.
Contact
- Email:
cherkashin.evgeny.viktorovich@gmail.com - Telegram:
@evgeny_cherkashin
Documentation
¶
Index ¶
- func Exec(retryableFunc RetryableFunc, strategies ...Strategy) (err error)
- func ExecContext(ctx context.Context, retryableFunc RetryableContextFunc, ...) (err error)
- func Sleep(ctx context.Context, delay time.Duration) (ok bool)
- func Unrecoverable(err error) error
- type AndStrategy
- type DelayedStrategy
- type FixedDelayStrategy
- type FuncStrategy
- type InfiniteAttemptsStrategy
- type IsStrategy
- type LinearDelayStrategy
- type MaxRetriesStrategy
- type NotStrategy
- type OrStrategy
- type PowDelayStrategy
- type RandomDelayStrategy
- type RetryableContextFunc
- type RetryableFunc
- type Strategy
- type StrategyFunc
- type TypeStrategy
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Exec ¶
func Exec( retryableFunc RetryableFunc, strategies ...Strategy, ) (err error)
func ExecContext ¶
func ExecContext( ctx context.Context, retryableFunc RetryableContextFunc, strategies ...Strategy, ) (err error)
func Unrecoverable ¶
Types ¶
type AndStrategy ¶
type AndStrategy struct {
// contains filtered or unexported fields
}
func And ¶
func And(strategies ...Strategy) (strategy AndStrategy)
type DelayedStrategy ¶
type DelayedStrategy struct {
// contains filtered or unexported fields
}
func Delays ¶
func Delays(delays ...time.Duration) (strategy *DelayedStrategy)
type FixedDelayStrategy ¶
type FixedDelayStrategy struct {
// contains filtered or unexported fields
}
func FixedDelay ¶
func FixedDelay(delay time.Duration) (strategy FixedDelayStrategy)
type FuncStrategy ¶
type FuncStrategy struct {
// contains filtered or unexported fields
}
func Function ¶
func Function(retryFunc StrategyFunc) (strategy FuncStrategy)
type InfiniteAttemptsStrategy ¶
type InfiniteAttemptsStrategy struct {
}
func Infinite ¶
func Infinite() (strategy *InfiniteAttemptsStrategy)
type IsStrategy ¶
type IsStrategy struct {
// contains filtered or unexported fields
}
func Is ¶
func Is(err error) (strategy IsStrategy)
type LinearDelayStrategy ¶
type LinearDelayStrategy struct {
// contains filtered or unexported fields
}
func LinearDelay ¶
func LinearDelay(seed time.Duration, delta time.Duration) (strategy *LinearDelayStrategy)
type MaxRetriesStrategy ¶
type MaxRetriesStrategy struct {
// contains filtered or unexported fields
}
func MaxAttempts ¶
func MaxAttempts(attempts int) (strategy *MaxRetriesStrategy)
type NotStrategy ¶
type NotStrategy struct {
// contains filtered or unexported fields
}
func Not ¶
func Not(originStrategy Strategy) (strategy NotStrategy)
type OrStrategy ¶
type OrStrategy struct {
// contains filtered or unexported fields
}
func Or ¶
func Or(strategies ...Strategy) (strategy OrStrategy)
type PowDelayStrategy ¶
type PowDelayStrategy struct {
// contains filtered or unexported fields
}
type RandomDelayStrategy ¶
type RandomDelayStrategy struct {
// contains filtered or unexported fields
}
func RandomDelay ¶
func RandomDelay(minDelay time.Duration, maxDelay time.Duration) (strategy RandomDelayStrategy)
type RetryableContextFunc ¶
type RetryableFunc ¶
type StrategyFunc ¶
type TypeStrategy ¶
type TypeStrategy struct {
// contains filtered or unexported fields
}
func Type ¶
func Type(err error) (strategy TypeStrategy)
Source Files
Click to show internal directories.
Click to hide internal directories.