Go

Sample code of multipart upload using Go:

package main

import (
	"bytes"
	"crypto/md5"
	"encoding/base64"
	"encoding/xml"
	"errors"
	"fmt"
	"github.com/huaweicloud/huaweicloud-sdk-go-v3/core/auth/basic"
	vod "github.com/huaweicloud/huaweicloud-sdk-go-v3/services/vod/v1"
	"github.com/huaweicloud/huaweicloud-sdk-go-v3/services/vod/v1/model"
	"github.com/huaweicloud/huaweicloud-sdk-go-v3/services/vod/v1/region"
	"io"
	"net/http"
	"os"
)

// Region
const regionNorth4 = "cn-north-4"
const regionNorth1 = "cn-north-1"
const regionEast2 = "cn-east-2"

// ak/sk
const ak = ""
const sk = ""

// Set the buffer size as needed, that is, the size of the file part read each time.
// 1M
const bufferSize = 1024 * 1024

/*
Example of multipart upload
*/
func main() {
	// Path of the local media asset to be uploaded
	filePath := ""

	// Upload the media asset.
	partUpload(filePath)
}

/*
Multipart upload
filePath: local path where the file to be uploaded is
*/
func partUpload(filePath string) {
	// Verify the file and its path.
	fileInfo := validFile(filePath)
	fileName := fileInfo.Name()
	fmt.Println(fileName)

	file, err := os.Open(filePath)
	if err != nil {
		fmt.Println("Error:", err)
		return
	}
	defer func(file *os.File) {
		err := file.Close()
		if err != nil {
			panic(err)
		}
	}(file)

	// An MP4 file is used as an example. For details about other formats, see the official website.
	fileType := "MP4"
	fileContentType := "video/mp4"

	// 1. Initialize authentication and obtain vodClient.
	client := createVodClient()
	// 2. Create a VOD media asset.
	fmt.Println("Start creating a media file: " + fileName)
	assetResponse := createAsset(client, fileName, fileName, fileType)

	// 3. Obtain authorization for initializing an upload task.
	initAuthResponse := initPartUploadAuthority(client, assetResponse, fileContentType)

	// 4. Initialize the upload task.
	uploadId := initPartUpload(initAuthResponse.SignStr, fileContentType)

	// Count the number of file parts.
	partNumber := 1

	// 7. Read the file content and repeat steps 5 and 6 to upload all parts.
	for {
		buf := make([]byte, bufferSize)
		n, err := file.Read(buf)
		if n == 0 || err != nil || err == io.EOF {
			break
		}
		// Perform MD5 encoding and then Base64 encoding.
		h := md5.New()
		h.Write(buf[:n])
		data := h.Sum(nil)
		contentMd5 := base64.StdEncoding.EncodeToString(data)
		fmt.Println("The MD5 value of the ", partNumber, " part of the file is :", contentMd5)

		// 5. Obtain authorization for multipart upload.
		partUploadAuthorityResponse := getPartUploadAuthority(client, fileContentType, assetResponse,
			contentMd5, uploadId, partNumber)

		// 6. Upload parts.
		uploadPartFile(partUploadAuthorityResponse.SignStr, buf[:n], contentMd5)

		// The part number automatically increments by one.
		partNumber++
	}

	// 8. Obtain authorization for obtaining uploaded parts.
	listPartUploadAuthorityResponse := listUploadedPartAuthority(client, assetResponse, uploadId)

	// 9. Obtain uploaded parts.
	partInfo := listUploadedPart(listPartUploadAuthorityResponse.SignStr)

	// 10. Obtain authorization for merging parts.
	mergePartUploadAuthorityResponse := mergeUploadedPartAuthority(client, assetResponse, uploadId)

	// 11. Merge uploaded parts.
	mergeUploadedPart(mergePartUploadAuthorityResponse.SignStr, partInfo)

	// 12. Confirm media asset upload.
	confirmUploaded(client, assetResponse)

	fmt.Println("Media asset created. assetId:", *assetResponse.AssetId)
}

/*
Verify the file and its path.
filePath: file path
*/
func validFile(filePath string) os.FileInfo {
	// Check whether the file exists.
	fileInfo, err := os.Stat(filePath)
	if os.IsNotExist(err) {
		fmt.Println("The file does not exist.")
		// Throw an error.
		panic(errors.New("The file does not exist."))
	}
	if err != nil {
		fmt.Println("Error:", err)
		panic(err)
	}
	return fileInfo
}

/*
1. Construct authentication.
*/
func createVodClient() *vod.VodClient {
	auth, _ := basic.NewCredentialsBuilder().
		WithAk(ak).
		WithSk(sk).
		SafeBuild()
	reg, _ := region.SafeValueOf(regionNorth4)

	build, _ := vod.VodClientBuilder().
		WithRegion(reg).
		WithCredential(auth).
		SafeBuild()

	client := vod.NewVodClient(build)
	return client
}

/*
2. Create a media asset.
videoName: name
title: title
videoType: file type
*/
func createAsset(client *vod.VodClient, videoName string, title string,
	videoType string) *model.CreateAssetByFileUploadResponse {
	request := &model.CreateAssetByFileUploadRequest{}
	request.Body = &model.CreateAssetByFileUploadReq{
		VideoName: videoName,
		Title:     title,
		VideoType: videoType,
	}
	response, err := client.CreateAssetByFileUpload(request)
	if err == nil {
		fmt.Println(response)
	} else {
		fmt.Println(err)
		panic(err)
	}
	return response
}

/*
3. Obtain authorization for initializing an upload task.
client
assetResponse
*/
func initPartUploadAuthority(client *vod.VodClient, assetResponse *model.CreateAssetByFileUploadResponse,
	fileContentType string) *model.ShowAssetTempAuthorityResponse {
	fmt.Println("Obtain authorization for initializing an upload task. initPartUploadAuthority start")
	// Configure parameters.
	request := &model.ShowAssetTempAuthorityRequest{}
	request.HttpVerb = "POST"
	request.Bucket = assetResponse.Target.Bucket
	request.ObjectKey = assetResponse.Target.Object
	request.ContentType = &fileContentType
	// Send an initialization request.
	response, err := client.ShowAssetTempAuthority(request)
	if err == nil {
		fmt.Print(response)
	} else {
		fmt.Println(err)
		panic(err)
	}
	fmt.Println("Obtain authorization for initializing an upload task. initPartUploadAuthority end\n")
	return response
}

/*
4. Initialize multipart upload.
signStr: signed URL for initialization returned in step 3
contentType: media file format
return uploadId
*/
func initPartUpload(signStr *string, contentType string) string {
	fmt.Println("Initialize multipart upload. initPartUpload start")
	// Create an HTTP client.
	client := &http.Client{}
	// Create a request.
	req, err := http.NewRequest("POST", *signStr, nil)

	req.Header.Set("Content-Type", contentType)
	// Send a request.
	resp, err := client.Do(req)
	if err != nil {
		fmt.Println("Error sending request:", err)
		panic(err)
	}
	defer func(Body io.ReadCloser) {
		err := Body.Close()
		if err != nil {
			panic(err)
		}
	}(resp.Body)

	// Read the response body.
	body, _ := io.ReadAll(resp.Body)
	// Print the response body.
	fmt.Println(string(body))

	// Parse the response body. The returned result is XML text, which is parsed based on the format.
	var initiateMultipartUploadResult InitiateMultipartUploadResult
	err = xml.Unmarshal(body, &initiateMultipartUploadResult)
	if err != nil {
		panic(err)
	}
	fmt.Printf("Bucket:%s, Key:%s, UploadId:%s\n", initiateMultipartUploadResult.Bucket,
		initiateMultipartUploadResult.Key, initiateMultipartUploadResult.UploadId)
	fmt.Println("Initialize multipart upload. initPartUpload end\n")
	return initiateMultipartUploadResult.UploadId
}

/*
5. Obtain authorization for multipart upload.
client
fileContentType: media file format
assetResponse: response to media asset creation
contentMd5: contentMd5 of the current part
uploadId
partNumber: part number
return: authorization result
*/
func getPartUploadAuthority(client *vod.VodClient, fileContentType string, assetResponse *model.CreateAssetByFileUploadResponse,
	contentMd5 string, uploadId string, partNumber int) *model.ShowAssetTempAuthorityResponse {
	fmt.Println("Obtain authorization for multipart upload. getPartUploadAuthority start; partNumber:", partNumber)
	// Configure parameters.
	request := &model.ShowAssetTempAuthorityRequest{}
	request.HttpVerb = "PUT"
	request.Bucket = assetResponse.Target.Bucket
	request.ObjectKey = assetResponse.Target.Object
	request.ContentType = &fileContentType
	request.ContentMd5 = &contentMd5
	request.UploadId = &uploadId
	partNumberRequest := int32(partNumber)
	request.PartNumber = &partNumberRequest
	// Send a request.
	response, err := client.ShowAssetTempAuthority(request)
	if err == nil {
		fmt.Print(response)
	} else {
		fmt.Println(err)
		panic(err)
	}
	fmt.Println("Obtain authorization for multipart upload. getPartUploadAuthority end; partNumber:", partNumber, "\n")
	return response
}

/*
6. Upload parts.
signStr: signed URL for upload returned in step 5
fileByte: data of the current part
contentMd5: contentMd5 of the current part
*/
func uploadPartFile(signStr *string, fileByte []byte, contentMd5 string) {
	fmt.Print("Upload parts. uploadPartFile start")

	// Create an HTTP client.
	client := &http.Client{}
	// Create a request.
	req, err := http.NewRequest("PUT", *signStr, bytes.NewBuffer(fileByte))
	req.Header.Set("Content-MD5", contentMd5)
	req.Header.Set("Content-Type", "application/octet-stream")

	// Send a request.
	resp, err := client.Do(req)
	if err != nil {
		fmt.Println("Error sending request:", err)
		panic(err)
	}
	defer func(Body io.ReadCloser) {
		err := Body.Close()
		if err != nil {
			panic(err)
		}
	}(resp.Body)
	// Read the response body.
	body, _ := io.ReadAll(resp.Body)
	// Print the response body.
	fmt.Println(string(body))
	if resp.StatusCode != 200 {
		panic("File upload failed.")
	}
	fmt.Println("Upload parts. uploadPartFile end \n")
}

/*
8. Obtain authorization for listing uploaded parts.
client
assetResponse: response to media asset creation
uploadId
return
*/
func listUploadedPartAuthority(client *vod.VodClient, assetResponse *model.CreateAssetByFileUploadResponse,
	uploadId string) *model.ShowAssetTempAuthorityResponse {
	fmt.Println("Obtain authorization for listing uploaded parts. listUploadedPartAuthority start")
	// Configure parameters.
	request := &model.ShowAssetTempAuthorityRequest{}
	request.HttpVerb = "GET"
	request.Bucket = assetResponse.Target.Bucket
	request.ObjectKey = assetResponse.Target.Object
	request.UploadId = &uploadId
	// Send a request.
	response, err := client.ShowAssetTempAuthority(request)
	if err == nil {
		fmt.Print(response)
	} else {
		fmt.Println(err)
		panic(err)
	}
	fmt.Println("Obtain authorization for listing uploaded parts. listUploadedPartAuthority end\n")
	return response
}

/*
9. Query uploaded parts.
signStr: signed URL for query returned in step 8
return
*/
func listUploadedPart(signStr *string) string {
	fmt.Println("Query uploaded parts. listUploadedPart start")
	// Query the start number of file parts.
	partNumberMarker := 0
	// Parameter (XML) for assembling merged parts
	result := "<CompleteMultipartUpload>"
	// Create an HTTP client.
	client := &http.Client{}
	for {
		// Create a request.
		url := *signStr + "&part-number-marker=" + fmt.Sprintf("%d", partNumberMarker)
		req, _ := http.NewRequest("GET", url, nil)
		// Send a request.
		resp, _ := client.Do(req)
		// Read the response body.
		body, _ := io.ReadAll(resp.Body)
		// Print the response body.
		fmt.Println(string(body))
		// Parse and convert the response result to XML text.
		var listPartsResult ListPartsResult
		_ = xml.Unmarshal(body, &listPartsResult)
		// parts is not displayed in the response result.
		if len(listPartsResult.Parts) < 1 {
			break
		}
		// Loop parts to assemble Part data.
		for _, part := range listPartsResult.Parts {
			num := part.PartNumber
			tag := part.Etag
			result += "<Part>" +
				"<PartNumber>" +
				fmt.Sprintf("%d", num) +
				"</PartNumber>" +
				"<ETag>" +
				tag +
				"</ETag>" +
				"</Part>"
		}
		// Set the next part number in the response to the start part number and send the request again.
		partNumberMarker = listPartsResult.NextPartNumberMarker
		if partNumberMarker%1000 != 0 {
			break
		}
	}
	result += "</CompleteMultipartUpload>"
	fmt.Println(result)
	fmt.Println("Query uploaded parts. listUploadedPart end\n")
	return result
}

/*
10. Obtain authorization for merging parts.
client
assetResponse
uploadId
return
*/
func mergeUploadedPartAuthority(client *vod.VodClient, assetResponse *model.CreateAssetByFileUploadResponse,
	uploadId string) *model.ShowAssetTempAuthorityResponse {
	fmt.Println("Obtain authorization for merging parts. mergeUploadedPartAuthority start")
	// Configure parameters.
	request := &model.ShowAssetTempAuthorityRequest{}
	request.HttpVerb = "POST"
	request.Bucket = assetResponse.Target.Bucket
	request.ObjectKey = assetResponse.Target.Object
	request.UploadId = &uploadId
	// Send a request.
	response, err := client.ShowAssetTempAuthority(request)
	if err == nil {
		fmt.Print(response)
	} else {
		fmt.Println(err)
		panic(err)
	}
	fmt.Println("Obtain authorization for merging parts. mergeUploadedPartAuthority end\n")
	return response
}

/*
11. Merge parts.
signStr: signed URL for merging parts returned in step 10
partInfo: data of the parts to be merged
*/
func mergeUploadedPart(signStr *string, partInfo string) {
	fmt.Println("Merge parts. mergeUploadedPart start")
	// Create an HTTP client.
	client := &http.Client{}
	// Create a request.
	//req, err := http.NewRequest("POST", *signStr, bytes.NewBuffer([]byte(partInfo)))
	req, err := http.NewRequest("POST", *signStr, bytes.NewBufferString(partInfo))
	// Add "Content-Type":"application/xml" to the request header.
	req.Header.Set("Content-Type", "application/xml")
	// Send a request.
	resp, err := client.Do(req)
	if err != nil {
		fmt.Println("Error sending request:", err)
		panic(err)
	}
	defer func(Body io.ReadCloser) {
		err := Body.Close()
		if err != nil {
			panic(err)
		}
	}(resp.Body)
	// Read the response body.
	body, _ := io.ReadAll(resp.Body)
	// Print the response body.
	fmt.Println(string(body))
	fmt.Println("Merge parts. mergeUploadedPart end\n")
}

/*
12. Confirm the upload completion.
*/
func confirmUploaded(client *vod.VodClient, assetResponse *model.CreateAssetByFileUploadResponse) {
	fmt.Println("Confirm the upload completion. confirmUploaded start")
	// Configure request parameters.
	request := &model.ConfirmAssetUploadRequest{}
	request.Body = &model.ConfirmAssetUploadReq{
		Status:  model.GetConfirmAssetUploadReqStatusEnum().CREATED,
		AssetId: *assetResponse.AssetId,
	}
	// Send a request.
	response, err := client.ConfirmAssetUpload(request)
	if err == nil {
		fmt.Print(response)
	} else {
		fmt.Println(err)
		panic(err)
	}
	fmt.Println("Uploaded, assetId:", *response.AssetId)
}

// InitiateMultipartUploadResult: XML structure returned after multipart upload initialization
type InitiateMultipartUploadResult struct {
	Bucket   string `xml:"Bucket"`
	Key      string `xml:"Key"`
	UploadId string `xml:"UploadId"`
}

// ListPartsResult: XML structure returned after querying uploaded parts
type ListPartsResult struct {
	Bucket               string `xml:"Bucket"`
	Key                  string `xml:"Key"`
	UploadId             string `xml:"UploadId"`
	NextPartNumberMarker int    `xml:"NextPartNumberMarker"`
	Parts                []Part `xml:"Part"`
}

// Part: part structure of the returned xml listPartsResult after querying uploaded parts
type Part struct {
	Etag       string `xml:"ETag"`
	PartNumber int    `xml:"PartNumber"`
}