diff options
Diffstat (limited to 'vendor/github.com/minio/minio-go/v7/retry.go')
-rw-r--r-- | vendor/github.com/minio/minio-go/v7/retry.go | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/vendor/github.com/minio/minio-go/v7/retry.go b/vendor/github.com/minio/minio-go/v7/retry.go new file mode 100644 index 00000000..598af297 --- /dev/null +++ b/vendor/github.com/minio/minio-go/v7/retry.go @@ -0,0 +1,124 @@ +/* + * MinIO Go Library for Amazon S3 Compatible Cloud Storage + * Copyright 2015-2017 MinIO, Inc. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package minio + +import ( + "context" + "net/http" + "time" +) + +// MaxRetry is the maximum number of retries before stopping. +var MaxRetry = 10 + +// MaxJitter will randomize over the full exponential backoff time +const MaxJitter = 1.0 + +// NoJitter disables the use of jitter for randomizing the exponential backoff time +const NoJitter = 0.0 + +// DefaultRetryUnit - default unit multiplicative per retry. +// defaults to 200 * time.Millisecond +var DefaultRetryUnit = 200 * time.Millisecond + +// DefaultRetryCap - Each retry attempt never waits no longer than +// this maximum time duration. +var DefaultRetryCap = time.Second + +// newRetryTimer creates a timer with exponentially increasing +// delays until the maximum retry attempts are reached. +func (c Client) newRetryTimer(ctx context.Context, maxRetry int, unit time.Duration, cap time.Duration, jitter float64) <-chan int { + attemptCh := make(chan int) + + // computes the exponential backoff duration according to + // https://www.awsarchitectureblog.com/2015/03/backoff.html + exponentialBackoffWait := func(attempt int) time.Duration { + // normalize jitter to the range [0, 1.0] + if jitter < NoJitter { + jitter = NoJitter + } + if jitter > MaxJitter { + jitter = MaxJitter + } + + //sleep = random_between(0, min(cap, base * 2 ** attempt)) + sleep := unit * time.Duration(1<<uint(attempt)) + if sleep > cap { + sleep = cap + } + if jitter != NoJitter { + sleep -= time.Duration(c.random.Float64() * float64(sleep) * jitter) + } + return sleep + } + + go func() { + defer close(attemptCh) + for i := 0; i < maxRetry; i++ { + select { + case attemptCh <- i + 1: + case <-ctx.Done(): + return + } + + select { + case <-time.After(exponentialBackoffWait(i)): + case <-ctx.Done(): + return + } + } + }() + return attemptCh +} + +// List of AWS S3 error codes which are retryable. +var retryableS3Codes = map[string]struct{}{ + "RequestError": {}, + "RequestTimeout": {}, + "Throttling": {}, + "ThrottlingException": {}, + "RequestLimitExceeded": {}, + "RequestThrottled": {}, + "InternalError": {}, + "ExpiredToken": {}, + "ExpiredTokenException": {}, + "SlowDown": {}, + // Add more AWS S3 codes here. +} + +// isS3CodeRetryable - is s3 error code retryable. +func isS3CodeRetryable(s3Code string) (ok bool) { + _, ok = retryableS3Codes[s3Code] + return ok +} + +// List of HTTP status codes which are retryable. +var retryableHTTPStatusCodes = map[int]struct{}{ + 429: {}, // http.StatusTooManyRequests is not part of the Go 1.5 library, yet + http.StatusInternalServerError: {}, + http.StatusBadGateway: {}, + http.StatusServiceUnavailable: {}, + http.StatusGatewayTimeout: {}, + // Add more HTTP status codes here. +} + +// isHTTPStatusRetryable - is HTTP error code retryable. +func isHTTPStatusRetryable(httpStatusCode int) (ok bool) { + _, ok = retryableHTTPStatusCodes[httpStatusCode] + return ok +} |