From 19b2ce68dab741a6277ec804785848b632152094 Mon Sep 17 00:00:00 2001
From: "xiaobo.chen" <xiaobo.chen@ucloud.cn>
Date: Mon, 19 Jun 2023 18:15:34 +0800
Subject: [PATCH] [feature]add UploadPartCopy

---
 file_mutipart_upload.go | 42 +++++++++++++++++++++++++++++++++++++++++
 utils.go                | 35 ++++++++++++++++++++++++++++++++++
 2 files changed, 77 insertions(+)

diff --git a/file_mutipart_upload.go b/file_mutipart_upload.go
index 4190dac..7c46cfd 100644
--- a/file_mutipart_upload.go
+++ b/file_mutipart_upload.go
@@ -266,6 +266,48 @@ func (u *UFileRequest) UploadPart(buf *bytes.Buffer, state *MultipartState, part
 	return nil
 }
 
+//UploadPartCopy 实现从一个已存在的Object中拷贝数据来上传一个Part。
+func (u *UFileRequest) UploadPartCopy(state *MultipartState, partNumber int, sourceBucketName, sourceObject string, offset, size int64) error {
+	query := &url.Values{}
+	query.Add("uploadId", state.uploadID)
+	query.Add("partNumber", strconv.Itoa(partNumber))
+
+	reqURL := u.genFileURL(state.keyName) + "?" + query.Encode()
+	req, err := http.NewRequest("PUT", reqURL, nil)
+	if err != nil {
+		return err
+	}
+	req.Header.Add("X-Ufile-Copy-Source", fmt.Sprintf("/%s/%s", sourceBucketName, sourceObject))
+	req.Header.Add("X-Ufile-Copy-Source-Range", fmt.Sprintf("bytes=%d-%d", offset, offset+size-1))
+	req.Header.Add("Content-Type", state.mimeType)
+	authorization := u.Auth.Authorization("PUT", u.BucketName, state.keyName, req.Header)
+	req.Header.Add("Authorization", authorization)
+
+	resp, err := u.requestWithResp(req)
+	if err != nil {
+		return err
+	}
+
+	if !VerifyHTTPCode(resp.StatusCode) {
+		err = u.responseParse(resp)
+		if err != nil {
+			return err
+		}
+		return fmt.Errorf("Remote response code is %d - %s not 2xx call DumpResponse(true) show details",
+			resp.StatusCode, http.StatusText(resp.StatusCode))
+	}
+	defer resp.Body.Close()
+
+	etag := strings.Trim(resp.Header.Get("Etag"), "\"") //为保证线程安全，这里就不保留 lastResponse
+	if etag == "" {
+		etag = strings.Trim(resp.Header.Get("ETag"), "\"") //为保证线程安全，这里就不保留 lastResponse
+	}
+	state.mux.Lock()
+	state.etags[partNumber] = etag
+	state.mux.Unlock()
+	return nil
+}
+
 //FinishMultipartUpload 完成分片上传。分片上传必须要调用的接口。
 //state 参数是 InitiateMultipartUpload 返回的
 func (u *UFileRequest) FinishMultipartUpload(state *MultipartState) error {
diff --git a/utils.go b/utils.go
index ee3a90b..52034da 100644
--- a/utils.go
+++ b/utils.go
@@ -7,6 +7,7 @@ import (
 	"encoding/base64"
 	"encoding/binary"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -188,3 +189,37 @@ func structPrettyStr(data interface{}) string {
 	}
 	return ""
 }
+
+// FilePart is the file part definition
+type FilePart struct {
+	Number int   // Part number
+	Offset int64 // Part offset
+	Size   int64 // Part size
+}
+
+// SplitFileByPartSize splits big file into parts by the size of parts.
+// Splits the file by the part size. Returns the FilePart when error is nil.
+func SplitFileByPartSize(fileSize, partSize int64) ([]FilePart, error) {
+	if fileSize <= 0 || partSize <= 0 {
+		return nil, errors.New("fileSize or partSize invalid")
+	}
+
+	var partN = fileSize / partSize
+	var parts []FilePart
+	var part = FilePart{}
+	for i := int64(0); i < partN; i++ {
+		part.Number = int(i + 1)
+		part.Offset = i * partSize
+		part.Size = partSize
+		parts = append(parts, part)
+	}
+
+	if fileSize%partSize > 0 {
+		part.Number = len(parts) + 1
+		part.Offset = int64(len(parts)) * partSize
+		part.Size = fileSize % partSize
+		parts = append(parts, part)
+	}
+
+	return parts, nil
+}