Update minio-go

vendor/github.com/minio/minio-go/api.go

@@ -1,6 +1,6 @@
 /*
  * Minio Go Library for Amazon S3 Compatible Cloud Storage
- * (C) 2015, 2016, 2017 Minio, Inc.
+ * 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.
@@ -19,10 +19,9 @@ package minio
 
 import (
 	"bytes"
+	"context"
 	"crypto/md5"
 	"crypto/sha256"
-	"encoding/base64"
-	"encoding/hex"
 	"errors"
 	"fmt"
 	"hash"
@@ -87,7 +86,7 @@ type Client struct {
 // Global constants.
 const (
 	libraryName    = "minio-go"
-	libraryVersion = "3.0.3"
+	libraryVersion = "4.0.3"
 )
 
 // User Agent should always following the below style.
@@ -178,18 +177,6 @@ func (r *lockedRandSource) Seed(seed int64) {
 	r.lk.Unlock()
 }
 
-// redirectHeaders copies all headers when following a redirect URL.
-// This won't be needed anymore from go 1.8 (https://github.com/golang/go/issues/4800)
-func redirectHeaders(req *http.Request, via []*http.Request) error {
-	if len(via) == 0 {
-		return nil
-	}
-	for key, val := range via[0].Header {
-		req.Header[key] = val
-	}
-	return nil
-}
-
 // getRegionFromURL - parse region from URL if present.
 func getRegionFromURL(u url.URL) (region string) {
 	region = ""
@@ -236,8 +223,7 @@ func privateNew(endpoint string, creds *credentials.Credentials, secure bool, re
 
 	// Instantiate http client and bucket location cache.
 	clnt.httpClient = &http.Client{
-		Transport:     defaultMinioTransport,
-		CheckRedirect: redirectHeaders,
+		Transport: defaultMinioTransport,
 	}
 
 	// Sets custom region, if region is empty bucket location cache is used automatically.
@@ -356,11 +342,11 @@ type requestMetadata struct {
 	expires      int64
 
 	// Generated by our internal code.
-	bucketLocation     string
-	contentBody        io.Reader
-	contentLength      int64
-	contentSHA256Bytes []byte
-	contentMD5Bytes    []byte
+	bucketLocation   string
+	contentBody      io.Reader
+	contentLength    int64
+	contentMD5Base64 string // carries base64 encoded md5sum
+	contentSHA256Hex string // carries hex encoded sha256sum
 }
 
 // dumpHTTP - dump HTTP request and response.
@@ -494,9 +480,11 @@ var successStatus = []int{
 // executeMethod - instantiates a given method, and retries the
 // request upon any error up to maxRetries attempts in a binomially
 // delayed manner using a standard back off algorithm.
-func (c Client) executeMethod(method string, metadata requestMetadata) (res *http.Response, err error) {
+func (c Client) executeMethod(ctx context.Context, method string, metadata requestMetadata) (res *http.Response, err error) {
 	var isRetryable bool     // Indicates if request can be retried.
 	var bodySeeker io.Seeker // Extracted seeker from io.Reader.
+	var reqRetry = MaxRetry  // Indicates how many times we can retry the request
+
 	if metadata.contentBody != nil {
 		// Check if body is seekable then it is retryable.
 		bodySeeker, isRetryable = metadata.contentBody.(io.Seeker)
@@ -504,6 +492,11 @@ func (c Client) executeMethod(method string, metadata requestMetadata) (res *htt
 		case os.Stdin, os.Stdout, os.Stderr:
 			isRetryable = false
 		}
+		// Retry only when reader is seekable
+		if !isRetryable {
+			reqRetry = 1
+		}
+
 		// Figure out if the body can be closed - if yes
 		// we will definitely close it upon the function
 		// return.
@@ -522,7 +515,7 @@ func (c Client) executeMethod(method string, metadata requestMetadata) (res *htt
 	// Blank indentifier is kept here on purpose since 'range' without
 	// blank identifiers is only supported since go1.4
 	// https://golang.org/doc/go1.4#forrange.
-	for range c.newRetryTimer(MaxRetry, DefaultRetryUnit, DefaultRetryCap, MaxJitter, doneCh) {
+	for range c.newRetryTimer(reqRetry, DefaultRetryUnit, DefaultRetryCap, MaxJitter, doneCh) {
 		// Retry executes the following function body if request has an
 		// error until maxRetries have been exhausted, retry attempts are
 		// performed after waiting for a given period of time in a
@@ -545,6 +538,8 @@ func (c Client) executeMethod(method string, metadata requestMetadata) (res *htt
 			}
 			return nil, err
 		}
+		// Add context to request
+		req = req.WithContext(ctx)
 
 		// Initiate the request.
 		res, err = c.do(req)
@@ -720,8 +715,8 @@ func (c Client) newRequest(method string, metadata requestMetadata) (req *http.R
 	}
 
 	// set md5Sum for content protection.
-	if metadata.contentMD5Bytes != nil {
-		req.Header.Set("Content-Md5", base64.StdEncoding.EncodeToString(metadata.contentMD5Bytes))
+	if len(metadata.contentMD5Base64) > 0 {
+		req.Header.Set("Content-Md5", metadata.contentMD5Base64)
 	}
 
 	// For anonymous requests just return.
@@ -742,8 +737,8 @@ func (c Client) newRequest(method string, metadata requestMetadata) (req *http.R
 	default:
 		// Set sha256 sum for signature calculation only with signature version '4'.
 		shaHeader := unsignedPayload
-		if len(metadata.contentSHA256Bytes) > 0 {
-			shaHeader = hex.EncodeToString(metadata.contentSHA256Bytes)
+		if metadata.contentSHA256Hex != "" {
+			shaHeader = metadata.contentSHA256Hex
 		}
 		req.Header.Set("X-Amz-Content-Sha256", shaHeader)