mirror of
https://github.com/Mrs4s/go-cqhttp.git
synced 2025-05-04 19:17:37 +08:00
296 lines
6.4 KiB
Go
296 lines
6.4 KiB
Go
package download
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import (
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"bufio"
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"compress/gzip"
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"fmt"
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"io"
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"net/http"
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"net/url"
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"os"
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"strconv"
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"strings"
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"sync"
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"github.com/pkg/errors"
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"github.com/tidwall/gjson"
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"github.com/Mrs4s/go-cqhttp/internal/base"
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)
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var client = &http.Client{
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Transport: &http.Transport{
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Proxy: func(request *http.Request) (u *url.URL, e error) {
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if base.Proxy == "" {
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return http.ProxyFromEnvironment(request)
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}
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return url.Parse(base.Proxy)
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},
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ForceAttemptHTTP2: false,
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MaxConnsPerHost: 0,
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MaxIdleConns: 0,
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MaxIdleConnsPerHost: 999,
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},
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}
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// ErrOverSize 响应主体过大时返回此错误
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var ErrOverSize = errors.New("oversize")
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// UserAgent HTTP请求时使用的UA
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const UserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36 Edg/87.0.664.66"
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type Request struct {
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URL string
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Header map[string]string
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Limit int64
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}
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func (r Request) do() (*http.Response, error) {
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req, err := http.NewRequest(http.MethodGet, r.URL, nil)
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if err != nil {
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return nil, err
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}
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req.Header["User-Agent"] = []string{UserAgent}
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for k, v := range r.Header {
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req.Header.Set(k, v)
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}
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return client.Do(req)
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}
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func (r Request) body() (io.ReadCloser, error) {
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resp, err := r.do()
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if err != nil {
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return nil, err
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}
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limit := r.Limit // check file size limit
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if limit > 0 && resp.ContentLength > limit {
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_ = resp.Body.Close()
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return nil, ErrOverSize
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}
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if strings.Contains(resp.Header.Get("Content-Encoding"), "gzip") {
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return gzipReadCloser(resp.Body)
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}
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return resp.Body, err
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}
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// Bytes 对给定URL发送Get请求，返回响应主体
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func (r Request) Bytes() ([]byte, error) {
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rd, err := r.body()
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if err != nil {
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return nil, err
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}
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defer rd.Close()
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return io.ReadAll(rd)
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}
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func (r Request) JSON() (gjson.Result, error) {
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rd, err := r.body()
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if err != nil {
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return gjson.Result{}, err
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}
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defer rd.Close()
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var sb strings.Builder
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_, err = io.Copy(&sb, rd)
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if err != nil {
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return gjson.Result{}, err
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}
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return gjson.Parse(sb.String()), nil
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}
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func writeToFile(reader io.ReadCloser, path string) error {
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file, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE, 0o644)
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if err != nil {
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return err
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}
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_, err = file.ReadFrom(reader)
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return err
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}
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func (r Request) WriteToFile(path string) error {
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rd, err := r.body()
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if err != nil {
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return err
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}
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defer rd.Close()
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return writeToFile(rd, path)
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}
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func (r Request) WriteToFileMultiThreading(path string, thread int) error {
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if thread < 2 {
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return r.WriteToFile(path)
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}
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limit := r.Limit
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type BlockMetaData struct {
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BeginOffset int64
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EndOffset int64
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DownloadedSize int64
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}
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var blocks []*BlockMetaData
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var contentLength int64
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errUnsupportedMultiThreading := errors.New("unsupported multi-threading")
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// 初始化分块或直接下载
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initOrDownload := func() error {
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header := make(map[string]string, len(r.Header))
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for k, v := range r.Header { // copy headers
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header[k] = v
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}
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header["range"] = "bytes=0-"
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req := Request{
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URL: r.URL,
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Header: header,
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}
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resp, err := req.do()
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if err != nil {
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return err
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}
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defer resp.Body.Close()
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if resp.StatusCode < 200 || resp.StatusCode >= 300 {
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return errors.New("response status unsuccessful: " + strconv.FormatInt(int64(resp.StatusCode), 10))
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}
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if resp.StatusCode == http.StatusOK {
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if limit > 0 && resp.ContentLength > limit {
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return ErrOverSize
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}
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if err = writeToFile(resp.Body, path); err != nil {
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return err
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}
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return errUnsupportedMultiThreading
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}
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if resp.StatusCode == http.StatusPartialContent {
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contentLength = resp.ContentLength
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if limit > 0 && resp.ContentLength > limit {
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return ErrOverSize
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}
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blockSize := contentLength
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if contentLength > 1024*1024 {
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blockSize = (contentLength / int64(thread)) - 10
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}
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if blockSize == contentLength {
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return writeToFile(resp.Body, path)
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}
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var tmp int64
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for tmp+blockSize < contentLength {
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blocks = append(blocks, &BlockMetaData{
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BeginOffset: tmp,
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EndOffset: tmp + blockSize - 1,
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})
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tmp += blockSize
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}
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blocks = append(blocks, &BlockMetaData{
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BeginOffset: tmp,
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EndOffset: contentLength - 1,
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})
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return nil
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}
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return errors.New("unknown status code")
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}
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// 下载分块
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downloadBlock := func(block *BlockMetaData) error {
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file, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE, 0o666)
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if err != nil {
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return err
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}
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defer file.Close()
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_, _ = file.Seek(block.BeginOffset, io.SeekStart)
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writer := bufio.NewWriter(file)
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defer writer.Flush()
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header := make(map[string]string, len(r.Header))
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for k, v := range r.Header { // copy headers
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header[k] = v
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}
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header["range"] = fmt.Sprintf("bytes=%d-%d", block.BeginOffset, block.EndOffset)
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req := Request{
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URL: r.URL,
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Header: header,
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}
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resp, err := req.do()
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if err != nil {
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return err
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}
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defer resp.Body.Close()
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if resp.StatusCode < 200 || resp.StatusCode >= 300 {
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return errors.New("response status unsuccessful: " + strconv.FormatInt(int64(resp.StatusCode), 10))
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}
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buffer := make([]byte, 1024)
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i, err := resp.Body.Read(buffer)
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for {
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if err != nil && err != io.EOF {
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return err
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}
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i64 := int64(len(buffer[:i]))
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needSize := block.EndOffset + 1 - block.BeginOffset
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if i64 > needSize {
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i64 = needSize
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err = io.EOF
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}
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_, e := writer.Write(buffer[:i64])
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if e != nil {
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return e
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}
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block.BeginOffset += i64
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block.DownloadedSize += i64
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if err == io.EOF || block.BeginOffset > block.EndOffset {
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break
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}
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i, err = resp.Body.Read(buffer)
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}
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return nil
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}
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if err := initOrDownload(); err != nil {
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if err == errUnsupportedMultiThreading {
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return nil
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}
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return err
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}
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wg := sync.WaitGroup{}
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wg.Add(len(blocks))
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var lastErr error
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for i := range blocks {
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go func(b *BlockMetaData) {
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defer wg.Done()
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if err := downloadBlock(b); err != nil {
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lastErr = err
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}
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}(blocks[i])
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}
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wg.Wait()
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return lastErr
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}
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type gzipCloser struct {
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f io.Closer
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r *gzip.Reader
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}
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// gzipReadCloser 从 io.ReadCloser 创建 gunzip io.ReadCloser
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func gzipReadCloser(reader io.ReadCloser) (io.ReadCloser, error) {
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gzipReader, err := gzip.NewReader(reader)
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if err != nil {
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return nil, err
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}
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return &gzipCloser{
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f: reader,
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r: gzipReader,
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}, nil
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}
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// Read impls io.Reader
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func (g *gzipCloser) Read(p []byte) (n int, err error) {
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return g.r.Read(p)
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}
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// Close impls io.Closer
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func (g *gzipCloser) Close() error {
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_ = g.f.Close()
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return g.r.Close()
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}
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