From f02620b291b988848392c455a7719699f6b5c00f Mon Sep 17 00:00:00 2001
From: Harshavardhana <harsha@minio.io>
Date: Wed, 26 Oct 2016 05:21:07 -0700
Subject: Moving away from goamz to use minio-go instead. (#4193)

minio-go does fully managed way of handling S3 API requests

  - Automatic bucket location management across all s3 regions.
  - Transparently upload large files in multipart if file 64MB
    or larger.
  - Right GetObject() API provides compatibility with
    io.ReadWriteSeeker interface.
  - Various other APIs including bulk deletes, server side object
    copy, bucket policies and bucket notifications.

Fixes #4182
---
 vendor/github.com/minio/minio-go/retry.go | 138 ++++++++++++++++++++++++++++++
 1 file changed, 138 insertions(+)
 create mode 100644 vendor/github.com/minio/minio-go/retry.go

(limited to 'vendor/github.com/minio/minio-go/retry.go')

diff --git a/vendor/github.com/minio/minio-go/retry.go b/vendor/github.com/minio/minio-go/retry.go
new file mode 100644
index 000000000..41b70e474
--- /dev/null
+++ b/vendor/github.com/minio/minio-go/retry.go
@@ -0,0 +1,138 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage (C) 2015, 2016 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 (
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+)
+
+// MaxRetry is the maximum number of retries before stopping.
+var MaxRetry = 5
+
+// 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
+
+// newRetryTimer creates a timer with exponentially increasing delays
+// until the maximum retry attempts are reached.
+func (c Client) newRetryTimer(maxRetry int, unit time.Duration, cap time.Duration, jitter float64, doneCh chan struct{}) <-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 {
+			// Attempts start from 1.
+			case attemptCh <- i + 1:
+			case <-doneCh:
+				// Stop the routine.
+				return
+			}
+			time.Sleep(exponentialBackoffWait(i))
+		}
+	}()
+	return attemptCh
+}
+
+// isNetErrorRetryable - is network error retryable.
+func isNetErrorRetryable(err error) bool {
+	switch err.(type) {
+	case net.Error:
+		switch err.(type) {
+		case *net.DNSError, *net.OpError, net.UnknownNetworkError:
+			return true
+		case *url.Error:
+			// For a URL error, where it replies back "connection closed"
+			// retry again.
+			if strings.Contains(err.Error(), "Connection closed by foreign host") {
+				return true
+			}
+		default:
+			if strings.Contains(err.Error(), "net/http: TLS handshake timeout") {
+				// If error is - tlsHandshakeTimeoutError, retry.
+				return true
+			} else if strings.Contains(err.Error(), "i/o timeout") {
+				// If error is - tcp timeoutError, retry.
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// List of AWS S3 error codes which are retryable.
+var retryableS3Codes = map[string]struct{}{
+	"RequestError":          {},
+	"RequestTimeout":        {},
+	"Throttling":            {},
+	"ThrottlingException":   {},
+	"RequestLimitExceeded":  {},
+	"RequestThrottled":      {},
+	"InternalError":         {},
+	"ExpiredToken":          {},
+	"ExpiredTokenException": {},
+	// 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:  {},
+	// Add more HTTP status codes here.
+}
+
+// isHTTPStatusRetryable - is HTTP error code retryable.
+func isHTTPStatusRetryable(httpStatusCode int) (ok bool) {
+	_, ok = retryableHTTPStatusCodes[httpStatusCode]
+	return ok
+}
-- 
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