Vendor dependencies with dep

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

@@ -0,0 +1,801 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage
+ * (C) 2015, 2016, 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 (
+	"bytes"
+	"crypto/md5"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"hash"
+	"io"
+	"io/ioutil"
+	"math/rand"
+	"net"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"os"
+	"runtime"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/minio/minio-go/pkg/credentials"
+	"github.com/minio/minio-go/pkg/s3signer"
+	"github.com/minio/minio-go/pkg/s3utils"
+)
+
+// Client implements Amazon S3 compatible methods.
+type Client struct {
+	///  Standard options.
+
+	// Parsed endpoint url provided by the user.
+	endpointURL url.URL
+
+	// Holds various credential providers.
+	credsProvider *credentials.Credentials
+
+	// Custom signerType value overrides all credentials.
+	overrideSignerType credentials.SignatureType
+
+	// User supplied.
+	appInfo struct {
+		appName    string
+		appVersion string
+	}
+
+	// Indicate whether we are using https or not
+	secure bool
+
+	// Needs allocation.
+	httpClient     *http.Client
+	bucketLocCache *bucketLocationCache
+
+	// Advanced functionality.
+	isTraceEnabled bool
+	traceOutput    io.Writer
+
+	// S3 specific accelerated endpoint.
+	s3AccelerateEndpoint string
+
+	// Region endpoint
+	region string
+
+	// Random seed.
+	random *rand.Rand
+}
+
+// Global constants.
+const (
+	libraryName    = "minio-go"
+	libraryVersion = "3.0.0"
+)
+
+// User Agent should always following the below style.
+// Please open an issue to discuss any new changes here.
+//
+//       Minio (OS; ARCH) LIB/VER APP/VER
+const (
+	libraryUserAgentPrefix = "Minio (" + runtime.GOOS + "; " + runtime.GOARCH + ") "
+	libraryUserAgent       = libraryUserAgentPrefix + libraryName + "/" + libraryVersion
+)
+
+// NewV2 - instantiate minio client with Amazon S3 signature version
+// '2' compatibility.
+func NewV2(endpoint string, accessKeyID, secretAccessKey string, secure bool) (*Client, error) {
+	creds := credentials.NewStaticV2(accessKeyID, secretAccessKey, "")
+	clnt, err := privateNew(endpoint, creds, secure, "")
+	if err != nil {
+		return nil, err
+	}
+	clnt.overrideSignerType = credentials.SignatureV2
+	return clnt, nil
+}
+
+// NewV4 - instantiate minio client with Amazon S3 signature version
+// '4' compatibility.
+func NewV4(endpoint string, accessKeyID, secretAccessKey string, secure bool) (*Client, error) {
+	creds := credentials.NewStaticV4(accessKeyID, secretAccessKey, "")
+	clnt, err := privateNew(endpoint, creds, secure, "")
+	if err != nil {
+		return nil, err
+	}
+	clnt.overrideSignerType = credentials.SignatureV4
+	return clnt, nil
+}
+
+// New - instantiate minio client, adds automatic verification of signature.
+func New(endpoint, accessKeyID, secretAccessKey string, secure bool) (*Client, error) {
+	creds := credentials.NewStaticV4(accessKeyID, secretAccessKey, "")
+	clnt, err := privateNew(endpoint, creds, secure, "")
+	if err != nil {
+		return nil, err
+	}
+	// Google cloud storage should be set to signature V2, force it if not.
+	if s3utils.IsGoogleEndpoint(clnt.endpointURL) {
+		clnt.overrideSignerType = credentials.SignatureV2
+	}
+	// If Amazon S3 set to signature v4.
+	if s3utils.IsAmazonEndpoint(clnt.endpointURL) {
+		clnt.overrideSignerType = credentials.SignatureV4
+	}
+	return clnt, nil
+}
+
+// NewWithCredentials - instantiate minio client with credentials provider
+// for retrieving credentials from various credentials provider such as
+// IAM, File, Env etc.
+func NewWithCredentials(endpoint string, creds *credentials.Credentials, secure bool, region string) (*Client, error) {
+	return privateNew(endpoint, creds, secure, region)
+}
+
+// NewWithRegion - instantiate minio client, with region configured. Unlike New(),
+// NewWithRegion avoids bucket-location lookup operations and it is slightly faster.
+// Use this function when if your application deals with single region.
+func NewWithRegion(endpoint, accessKeyID, secretAccessKey string, secure bool, region string) (*Client, error) {
+	creds := credentials.NewStaticV4(accessKeyID, secretAccessKey, "")
+	return privateNew(endpoint, creds, secure, region)
+}
+
+// lockedRandSource provides protected rand source, implements rand.Source interface.
+type lockedRandSource struct {
+	lk  sync.Mutex
+	src rand.Source
+}
+
+// Int63 returns a non-negative pseudo-random 63-bit integer as an int64.
+func (r *lockedRandSource) Int63() (n int64) {
+	r.lk.Lock()
+	n = r.src.Int63()
+	r.lk.Unlock()
+	return
+}
+
+// Seed uses the provided seed value to initialize the generator to a
+// deterministic state.
+func (r *lockedRandSource) Seed(seed int64) {
+	r.lk.Lock()
+	r.src.Seed(seed)
+	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
+}
+
+func privateNew(endpoint string, creds *credentials.Credentials, secure bool, region string) (*Client, error) {
+	// construct endpoint.
+	endpointURL, err := getEndpointURL(endpoint, secure)
+	if err != nil {
+		return nil, err
+	}
+
+	// instantiate new Client.
+	clnt := new(Client)
+
+	// Save the credentials.
+	clnt.credsProvider = creds
+
+	// Remember whether we are using https or not
+	clnt.secure = secure
+
+	// Save endpoint URL, user agent for future uses.
+	clnt.endpointURL = *endpointURL
+
+	// Instantiate http client and bucket location cache.
+	clnt.httpClient = &http.Client{
+		Transport:     http.DefaultTransport,
+		CheckRedirect: redirectHeaders,
+	}
+
+	// Sets custom region, if region is empty bucket location cache is used automatically.
+	clnt.region = region
+
+	// Instantiate bucket location cache.
+	clnt.bucketLocCache = newBucketLocationCache()
+
+	// Introduce a new locked random seed.
+	clnt.random = rand.New(&lockedRandSource{src: rand.NewSource(time.Now().UTC().UnixNano())})
+
+	// Return.
+	return clnt, nil
+}
+
+// SetAppInfo - add application details to user agent.
+func (c *Client) SetAppInfo(appName string, appVersion string) {
+	// if app name and version not set, we do not set a new user agent.
+	if appName != "" && appVersion != "" {
+		c.appInfo = struct {
+			appName    string
+			appVersion string
+		}{}
+		c.appInfo.appName = appName
+		c.appInfo.appVersion = appVersion
+	}
+}
+
+// SetCustomTransport - set new custom transport.
+func (c *Client) SetCustomTransport(customHTTPTransport http.RoundTripper) {
+	// Set this to override default transport
+	// ``http.DefaultTransport``.
+	//
+	// This transport is usually needed for debugging OR to add your
+	// own custom TLS certificates on the client transport, for custom
+	// CA's and certs which are not part of standard certificate
+	// authority follow this example :-
+	//
+	//   tr := &http.Transport{
+	//           TLSClientConfig:    &tls.Config{RootCAs: pool},
+	//           DisableCompression: true,
+	//   }
+	//   api.SetTransport(tr)
+	//
+	if c.httpClient != nil {
+		c.httpClient.Transport = customHTTPTransport
+	}
+}
+
+// TraceOn - enable HTTP tracing.
+func (c *Client) TraceOn(outputStream io.Writer) {
+	// if outputStream is nil then default to os.Stdout.
+	if outputStream == nil {
+		outputStream = os.Stdout
+	}
+	// Sets a new output stream.
+	c.traceOutput = outputStream
+
+	// Enable tracing.
+	c.isTraceEnabled = true
+}
+
+// TraceOff - disable HTTP tracing.
+func (c *Client) TraceOff() {
+	// Disable tracing.
+	c.isTraceEnabled = false
+}
+
+// SetS3TransferAccelerate - turns s3 accelerated endpoint on or off for all your
+// requests. This feature is only specific to S3 for all other endpoints this
+// function does nothing. To read further details on s3 transfer acceleration
+// please vist -
+// http://docs.aws.amazon.com/AmazonS3/latest/dev/transfer-acceleration.html
+func (c *Client) SetS3TransferAccelerate(accelerateEndpoint string) {
+	if s3utils.IsAmazonEndpoint(c.endpointURL) {
+		c.s3AccelerateEndpoint = accelerateEndpoint
+	}
+}
+
+// Hash materials provides relevant initialized hash algo writers
+// based on the expected signature type.
+//
+//  - For signature v4 request if the connection is insecure compute only sha256.
+//  - For signature v4 request if the connection is secure compute only md5.
+//  - For anonymous request compute md5.
+func (c *Client) hashMaterials() (hashAlgos map[string]hash.Hash, hashSums map[string][]byte) {
+	hashSums = make(map[string][]byte)
+	hashAlgos = make(map[string]hash.Hash)
+	if c.overrideSignerType.IsV4() {
+		if c.secure {
+			hashAlgos["md5"] = md5.New()
+		} else {
+			hashAlgos["sha256"] = sha256.New()
+		}
+	} else {
+		if c.overrideSignerType.IsAnonymous() {
+			hashAlgos["md5"] = md5.New()
+		}
+	}
+	return hashAlgos, hashSums
+}
+
+// requestMetadata - is container for all the values to make a request.
+type requestMetadata struct {
+	// If set newRequest presigns the URL.
+	presignURL bool
+
+	// User supplied.
+	bucketName   string
+	objectName   string
+	queryValues  url.Values
+	customHeader http.Header
+	expires      int64
+
+	// Generated by our internal code.
+	bucketLocation     string
+	contentBody        io.Reader
+	contentLength      int64
+	contentSHA256Bytes []byte
+	contentMD5Bytes    []byte
+}
+
+// dumpHTTP - dump HTTP request and response.
+func (c Client) dumpHTTP(req *http.Request, resp *http.Response) error {
+	// Starts http dump.
+	_, err := fmt.Fprintln(c.traceOutput, "---------START-HTTP---------")
+	if err != nil {
+		return err
+	}
+
+	// Filter out Signature field from Authorization header.
+	origAuth := req.Header.Get("Authorization")
+	if origAuth != "" {
+		req.Header.Set("Authorization", redactSignature(origAuth))
+	}
+
+	// Only display request header.
+	reqTrace, err := httputil.DumpRequestOut(req, false)
+	if err != nil {
+		return err
+	}
+
+	// Write request to trace output.
+	_, err = fmt.Fprint(c.traceOutput, string(reqTrace))
+	if err != nil {
+		return err
+	}
+
+	// Only display response header.
+	var respTrace []byte
+
+	// For errors we make sure to dump response body as well.
+	if resp.StatusCode != http.StatusOK &&
+		resp.StatusCode != http.StatusPartialContent &&
+		resp.StatusCode != http.StatusNoContent {
+		respTrace, err = httputil.DumpResponse(resp, true)
+		if err != nil {
+			return err
+		}
+	} else {
+		// WORKAROUND for https://github.com/golang/go/issues/13942.
+		// httputil.DumpResponse does not print response headers for
+		// all successful calls which have response ContentLength set
+		// to zero. Keep this workaround until the above bug is fixed.
+		if resp.ContentLength == 0 {
+			var buffer bytes.Buffer
+			if err = resp.Header.Write(&buffer); err != nil {
+				return err
+			}
+			respTrace = buffer.Bytes()
+			respTrace = append(respTrace, []byte("\r\n")...)
+		} else {
+			respTrace, err = httputil.DumpResponse(resp, false)
+			if err != nil {
+				return err
+			}
+		}
+	}
+	// Write response to trace output.
+	_, err = fmt.Fprint(c.traceOutput, strings.TrimSuffix(string(respTrace), "\r\n"))
+	if err != nil {
+		return err
+	}
+
+	// Ends the http dump.
+	_, err = fmt.Fprintln(c.traceOutput, "---------END-HTTP---------")
+	if err != nil {
+		return err
+	}
+
+	// Returns success.
+	return nil
+}
+
+// do - execute http request.
+func (c Client) do(req *http.Request) (*http.Response, error) {
+	var resp *http.Response
+	var err error
+	// Do the request in a loop in case of 307 http is met since golang still doesn't
+	// handle properly this situation (https://github.com/golang/go/issues/7912)
+	for {
+		resp, err = c.httpClient.Do(req)
+		if err != nil {
+			// Handle this specifically for now until future Golang
+			// versions fix this issue properly.
+			urlErr, ok := err.(*url.Error)
+			if ok && strings.Contains(urlErr.Err.Error(), "EOF") {
+				return nil, &url.Error{
+					Op:  urlErr.Op,
+					URL: urlErr.URL,
+					Err: errors.New("Connection closed by foreign host " + urlErr.URL + ". Retry again."),
+				}
+			}
+			return nil, err
+		}
+		// Redo the request with the new redirect url if http 307 is returned, quit the loop otherwise
+		if resp != nil && resp.StatusCode == http.StatusTemporaryRedirect {
+			newURL, err := url.Parse(resp.Header.Get("Location"))
+			if err != nil {
+				break
+			}
+			req.URL = newURL
+		} else {
+			break
+		}
+	}
+
+	// Response cannot be non-nil, report if its the case.
+	if resp == nil {
+		msg := "Response is empty. " + reportIssue
+		return nil, ErrInvalidArgument(msg)
+	}
+
+	// If trace is enabled, dump http request and response.
+	if c.isTraceEnabled {
+		err = c.dumpHTTP(req, resp)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return resp, nil
+}
+
+// List of success status.
+var successStatus = []int{
+	http.StatusOK,
+	http.StatusNoContent,
+	http.StatusPartialContent,
+}
+
+// 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) {
+	var isRetryable bool     // Indicates if request can be retried.
+	var bodySeeker io.Seeker // Extracted seeker from io.Reader.
+	if metadata.contentBody != nil {
+		// Check if body is seekable then it is retryable.
+		bodySeeker, isRetryable = metadata.contentBody.(io.Seeker)
+		switch bodySeeker {
+		case os.Stdin, os.Stdout, os.Stderr:
+			isRetryable = false
+		}
+		// Figure out if the body can be closed - if yes
+		// we will definitely close it upon the function
+		// return.
+		bodyCloser, ok := metadata.contentBody.(io.Closer)
+		if ok {
+			defer bodyCloser.Close()
+		}
+	}
+
+	// Create a done channel to control 'newRetryTimer' go routine.
+	doneCh := make(chan struct{}, 1)
+
+	// Indicate to our routine to exit cleanly upon return.
+	defer close(doneCh)
+
+	// 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) {
+		// 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
+		// binomial fashion.
+		if isRetryable {
+			// Seek back to beginning for each attempt.
+			if _, err = bodySeeker.Seek(0, 0); err != nil {
+				// If seek failed, no need to retry.
+				return nil, err
+			}
+		}
+
+		// Instantiate a new request.
+		var req *http.Request
+		req, err = c.newRequest(method, metadata)
+		if err != nil {
+			errResponse := ToErrorResponse(err)
+			if isS3CodeRetryable(errResponse.Code) {
+				continue // Retry.
+			}
+			return nil, err
+		}
+
+		// Initiate the request.
+		res, err = c.do(req)
+		if err != nil {
+			// For supported network errors verify.
+			if isNetErrorRetryable(err) {
+				continue // Retry.
+			}
+			// For other errors, return here no need to retry.
+			return nil, err
+		}
+
+		// For any known successful http status, return quickly.
+		for _, httpStatus := range successStatus {
+			if httpStatus == res.StatusCode {
+				return res, nil
+			}
+		}
+
+		// Read the body to be saved later.
+		errBodyBytes, err := ioutil.ReadAll(res.Body)
+		// res.Body should be closed
+		closeResponse(res)
+		if err != nil {
+			return nil, err
+		}
+
+		// Save the body.
+		errBodySeeker := bytes.NewReader(errBodyBytes)
+		res.Body = ioutil.NopCloser(errBodySeeker)
+
+		// For errors verify if its retryable otherwise fail quickly.
+		errResponse := ToErrorResponse(httpRespToErrorResponse(res, metadata.bucketName, metadata.objectName))
+
+		// Save the body back again.
+		errBodySeeker.Seek(0, 0) // Seek back to starting point.
+		res.Body = ioutil.NopCloser(errBodySeeker)
+
+		// Bucket region if set in error response and the error
+		// code dictates invalid region, we can retry the request
+		// with the new region.
+		//
+		// Additionally we should only retry if bucketLocation and custom
+		// region is empty.
+		if metadata.bucketLocation == "" && c.region == "" {
+			if res.StatusCode == http.StatusBadRequest && errResponse.Region != "" {
+				c.bucketLocCache.Set(metadata.bucketName, errResponse.Region)
+				continue // Retry.
+			}
+		}
+
+		// Verify if error response code is retryable.
+		if isS3CodeRetryable(errResponse.Code) {
+			continue // Retry.
+		}
+
+		// Verify if http status code is retryable.
+		if isHTTPStatusRetryable(res.StatusCode) {
+			continue // Retry.
+		}
+
+		// For all other cases break out of the retry loop.
+		break
+	}
+	return res, err
+}
+
+// newRequest - instantiate a new HTTP request for a given method.
+func (c Client) newRequest(method string, metadata requestMetadata) (req *http.Request, err error) {
+	// If no method is supplied default to 'POST'.
+	if method == "" {
+		method = "POST"
+	}
+
+	location := metadata.bucketLocation
+	if location == "" {
+		if metadata.bucketName != "" {
+			// Gather location only if bucketName is present.
+			location, err = c.getBucketLocation(metadata.bucketName)
+			if err != nil {
+				if ToErrorResponse(err).Code != "AccessDenied" {
+					return nil, err
+				}
+			}
+			// Upon AccessDenied error on fetching bucket location, default
+			// to possible locations based on endpoint URL. This can usually
+			// happen when GetBucketLocation() is disabled using IAM policies.
+		}
+		if location == "" {
+			location = getDefaultLocation(c.endpointURL, c.region)
+		}
+	}
+
+	// Construct a new target URL.
+	targetURL, err := c.makeTargetURL(metadata.bucketName, metadata.objectName, location, metadata.queryValues)
+	if err != nil {
+		return nil, err
+	}
+
+	// Initialize a new HTTP request for the method.
+	req, err = http.NewRequest(method, targetURL.String(), nil)
+	if err != nil {
+		return nil, err
+	}
+
+	// Get credentials from the configured credentials provider.
+	value, err := c.credsProvider.Get()
+	if err != nil {
+		return nil, err
+	}
+
+	var (
+		signerType      = value.SignerType
+		accessKeyID     = value.AccessKeyID
+		secretAccessKey = value.SecretAccessKey
+		sessionToken    = value.SessionToken
+	)
+
+	// Custom signer set then override the behavior.
+	if c.overrideSignerType != credentials.SignatureDefault {
+		signerType = c.overrideSignerType
+	}
+
+	// If signerType returned by credentials helper is anonymous,
+	// then do not sign regardless of signerType override.
+	if value.SignerType == credentials.SignatureAnonymous {
+		signerType = credentials.SignatureAnonymous
+	}
+
+	// Generate presign url if needed, return right here.
+	if metadata.expires != 0 && metadata.presignURL {
+		if signerType.IsAnonymous() {
+			return nil, ErrInvalidArgument("Presigned URLs cannot be generated with anonymous credentials.")
+		}
+		if signerType.IsV2() {
+			// Presign URL with signature v2.
+			req = s3signer.PreSignV2(*req, accessKeyID, secretAccessKey, metadata.expires)
+		} else if signerType.IsV4() {
+			// Presign URL with signature v4.
+			req = s3signer.PreSignV4(*req, accessKeyID, secretAccessKey, sessionToken, location, metadata.expires)
+		}
+		return req, nil
+	}
+
+	// Set 'User-Agent' header for the request.
+	c.setUserAgent(req)
+
+	// Set all headers.
+	for k, v := range metadata.customHeader {
+		req.Header.Set(k, v[0])
+	}
+
+	// Go net/http notoriously closes the request body.
+	// - The request Body, if non-nil, will be closed by the underlying Transport, even on errors.
+	// This can cause underlying *os.File seekers to fail, avoid that
+	// by making sure to wrap the closer as a nop.
+	if metadata.contentLength == 0 {
+		req.Body = nil
+	} else {
+		req.Body = ioutil.NopCloser(metadata.contentBody)
+	}
+
+	// Set incoming content-length.
+	req.ContentLength = metadata.contentLength
+	if req.ContentLength <= -1 {
+		// For unknown content length, we upload using transfer-encoding: chunked.
+		req.TransferEncoding = []string{"chunked"}
+	}
+
+	// set md5Sum for content protection.
+	if metadata.contentMD5Bytes != nil {
+		req.Header.Set("Content-Md5", base64.StdEncoding.EncodeToString(metadata.contentMD5Bytes))
+	}
+
+	// For anonymous requests just return.
+	if signerType.IsAnonymous() {
+		return req, nil
+	}
+
+	switch {
+	case signerType.IsV2():
+		// Add signature version '2' authorization header.
+		req = s3signer.SignV2(*req, accessKeyID, secretAccessKey)
+	case signerType.IsStreamingV4() && method == "PUT":
+		req = s3signer.StreamingSignV4(req, accessKeyID,
+			secretAccessKey, sessionToken, location, metadata.contentLength, time.Now().UTC())
+	default:
+		// Set sha256 sum for signature calculation only with signature version '4'.
+		shaHeader := unsignedPayload
+		if len(metadata.contentSHA256Bytes) > 0 {
+			shaHeader = hex.EncodeToString(metadata.contentSHA256Bytes)
+		}
+		req.Header.Set("X-Amz-Content-Sha256", shaHeader)
+
+		// Add signature version '4' authorization header.
+		req = s3signer.SignV4(*req, accessKeyID, secretAccessKey, sessionToken, location)
+	}
+
+	// Return request.
+	return req, nil
+}
+
+// set User agent.
+func (c Client) setUserAgent(req *http.Request) {
+	req.Header.Set("User-Agent", libraryUserAgent)
+	if c.appInfo.appName != "" && c.appInfo.appVersion != "" {
+		req.Header.Set("User-Agent", libraryUserAgent+" "+c.appInfo.appName+"/"+c.appInfo.appVersion)
+	}
+}
+
+// makeTargetURL make a new target url.
+func (c Client) makeTargetURL(bucketName, objectName, bucketLocation string, queryValues url.Values) (*url.URL, error) {
+	host := c.endpointURL.Host
+	// For Amazon S3 endpoint, try to fetch location based endpoint.
+	if s3utils.IsAmazonEndpoint(c.endpointURL) {
+		if c.s3AccelerateEndpoint != "" && bucketName != "" {
+			// http://docs.aws.amazon.com/AmazonS3/latest/dev/transfer-acceleration.html
+			// Disable transfer acceleration for non-compliant bucket names.
+			if strings.Contains(bucketName, ".") {
+				return nil, ErrTransferAccelerationBucket(bucketName)
+			}
+			// If transfer acceleration is requested set new host.
+			// For more details about enabling transfer acceleration read here.
+			// http://docs.aws.amazon.com/AmazonS3/latest/dev/transfer-acceleration.html
+			host = c.s3AccelerateEndpoint
+		} else {
+			// Do not change the host if the endpoint URL is a FIPS S3 endpoint.
+			if !s3utils.IsAmazonFIPSGovCloudEndpoint(c.endpointURL) {
+				// Fetch new host based on the bucket location.
+				host = getS3Endpoint(bucketLocation)
+			}
+		}
+	}
+
+	// Save scheme.
+	scheme := c.endpointURL.Scheme
+
+	// Strip port 80 and 443 so we won't send these ports in Host header.
+	// The reason is that browsers and curl automatically remove :80 and :443
+	// with the generated presigned urls, then a signature mismatch error.
+	if h, p, err := net.SplitHostPort(host); err == nil {
+		if scheme == "http" && p == "80" || scheme == "https" && p == "443" {
+			host = h
+		}
+	}
+
+	urlStr := scheme + "://" + host + "/"
+	// Make URL only if bucketName is available, otherwise use the
+	// endpoint URL.
+	if bucketName != "" {
+		// Save if target url will have buckets which suppport virtual host.
+		isVirtualHostStyle := s3utils.IsVirtualHostSupported(c.endpointURL, bucketName)
+
+		// If endpoint supports virtual host style use that always.
+		// Currently only S3 and Google Cloud Storage would support
+		// virtual host style.
+		if isVirtualHostStyle {
+			urlStr = scheme + "://" + bucketName + "." + host + "/"
+			if objectName != "" {
+				urlStr = urlStr + s3utils.EncodePath(objectName)
+			}
+		} else {
+			// If not fall back to using path style.
+			urlStr = urlStr + bucketName + "/"
+			if objectName != "" {
+				urlStr = urlStr + s3utils.EncodePath(objectName)
+			}
+		}
+	}
+
+	// If there are any query values, add them to the end.
+	if len(queryValues) > 0 {
+		urlStr = urlStr + "?" + s3utils.QueryEncode(queryValues)
+	}
+
+	u, err := url.Parse(urlStr)
+	if err != nil {
+		return nil, err
+	}
+
+	return u, nil
+}