410 lines
8.9 KiB
Go
410 lines
8.9 KiB
Go
package http
|
||
|
||
import (
|
||
"bytes"
|
||
"context"
|
||
"fmt"
|
||
"gitea.bvbej.com/bvbej/base-golang/pkg/downloader/base"
|
||
"gitea.bvbej.com/bvbej/base-golang/pkg/downloader/fetcher"
|
||
"golang.org/x/sync/errgroup"
|
||
"io"
|
||
"mime"
|
||
"net"
|
||
"net/http"
|
||
"net/url"
|
||
"path"
|
||
"path/filepath"
|
||
"strconv"
|
||
"strings"
|
||
"time"
|
||
)
|
||
|
||
type RequestError struct {
|
||
Code int
|
||
Msg string
|
||
}
|
||
|
||
func NewRequestError(code int, msg string) *RequestError {
|
||
return &RequestError{Code: code, Msg: msg}
|
||
}
|
||
|
||
func (re *RequestError) Error() string {
|
||
return fmt.Sprintf("http request fail,code:%d", re.Code)
|
||
}
|
||
|
||
type Fetcher struct {
|
||
*fetcher.DefaultFetcher
|
||
|
||
res *base.Resource
|
||
opts *base.Options
|
||
status base.Status
|
||
clients []*http.Response
|
||
chunks []*Chunk
|
||
|
||
ctx context.Context
|
||
cancel context.CancelFunc
|
||
pauseCh chan any
|
||
}
|
||
|
||
func NewFetcher() *Fetcher {
|
||
return &Fetcher{
|
||
DefaultFetcher: new(fetcher.DefaultFetcher),
|
||
pauseCh: make(chan any),
|
||
}
|
||
}
|
||
|
||
var protocols = []string{"HTTP", "HTTPS"}
|
||
|
||
func FetcherBuilder() ([]string, func() fetcher.Fetcher) {
|
||
return protocols, func() fetcher.Fetcher {
|
||
return NewFetcher()
|
||
}
|
||
}
|
||
|
||
func (f *Fetcher) Resolve(req *base.Request) (*base.Resource, error) {
|
||
httpReq, err := f.buildRequest(nil, req)
|
||
if err != nil {
|
||
return nil, err
|
||
}
|
||
client, err := f.buildClient()
|
||
if err != nil {
|
||
return nil, err
|
||
}
|
||
// 只访问一个字节，测试资源是否支持Range请求
|
||
httpReq.Header.Set(base.HttpHeaderRange, fmt.Sprintf(base.HttpHeaderRangeFormat, 0, 0))
|
||
httpResp, err := client.Do(httpReq)
|
||
if err != nil {
|
||
return nil, err
|
||
}
|
||
// 拿到响应头就关闭，不用加defer
|
||
_ = httpResp.Body.Close()
|
||
res := &base.Resource{
|
||
Req: req,
|
||
Range: false,
|
||
Files: []*base.FileInfo{},
|
||
}
|
||
if base.HttpCodePartialContent == httpResp.StatusCode {
|
||
// 返回206响应码表示支持断点下载
|
||
res.Range = true
|
||
// 解析资源大小: bytes 0-1000/1001 => 1001
|
||
contentTotal := path.Base(httpResp.Header.Get(base.HttpHeaderContentRange))
|
||
if contentTotal != "" {
|
||
parse, err := strconv.ParseInt(contentTotal, 10, 64)
|
||
if err != nil {
|
||
return nil, err
|
||
}
|
||
res.TotalSize = parse
|
||
}
|
||
} else if base.HttpCodeOK == httpResp.StatusCode {
|
||
// 返回200响应码，不支持断点下载，通过Content-Length头获取文件大小，获取不到的话可能是chunked编码
|
||
contentLength := httpResp.Header.Get(base.HttpHeaderContentLength)
|
||
if contentLength != "" {
|
||
parse, err := strconv.ParseInt(contentLength, 10, 64)
|
||
if err != nil {
|
||
return nil, err
|
||
}
|
||
res.TotalSize = parse
|
||
}
|
||
} else {
|
||
return nil, NewRequestError(httpResp.StatusCode, httpResp.Status)
|
||
}
|
||
file := &base.FileInfo{
|
||
Size: res.TotalSize,
|
||
}
|
||
contentDisposition := httpResp.Header.Get(base.HttpHeaderContentDisposition)
|
||
if contentDisposition != "" {
|
||
_, params, _ := mime.ParseMediaType(contentDisposition)
|
||
filename := params["filename"]
|
||
if filename != "" {
|
||
file.Name = filename
|
||
}
|
||
}
|
||
// Get file filename by URL
|
||
if file.Name == "" && strings.Count(req.URL, "/") > 2 {
|
||
file.Name = filepath.Base(req.URL)
|
||
}
|
||
// unknown file filename
|
||
if file.Name == "" {
|
||
file.Name = "unknown"
|
||
}
|
||
res.Files = append(res.Files, file)
|
||
return res, nil
|
||
}
|
||
|
||
func (f *Fetcher) Create(res *base.Resource, opts *base.Options) error {
|
||
f.res = res
|
||
f.opts = opts
|
||
f.status = base.DownloadStatusReady
|
||
return nil
|
||
}
|
||
|
||
func (f *Fetcher) Start() (err error) {
|
||
// 创建文件
|
||
name := f.filename()
|
||
_, err = f.Ctl.Touch(name, f.res.TotalSize)
|
||
if err != nil {
|
||
return err
|
||
}
|
||
f.status = base.DownloadStatusStart
|
||
if f.res.Range {
|
||
// 每个连接平均需要下载的分块大小
|
||
chunkSize := f.res.TotalSize / int64(f.opts.Connections)
|
||
f.chunks = make([]*Chunk, f.opts.Connections)
|
||
f.clients = make([]*http.Response, f.opts.Connections)
|
||
for i := 0; i < f.opts.Connections; i++ {
|
||
var (
|
||
begin = chunkSize * int64(i)
|
||
end int64
|
||
)
|
||
if i == f.opts.Connections-1 {
|
||
// 最后一个分块需要保证把文件下载完
|
||
end = f.res.TotalSize - 1
|
||
} else {
|
||
end = begin + chunkSize - 1
|
||
}
|
||
chunk := NewChunk(begin, end)
|
||
f.chunks[i] = chunk
|
||
}
|
||
} else {
|
||
// 只支持单连接下载
|
||
f.chunks = make([]*Chunk, 1)
|
||
f.clients = make([]*http.Response, 1)
|
||
f.chunks[0] = NewChunk(0, 0)
|
||
}
|
||
f.fetch()
|
||
return
|
||
}
|
||
|
||
func (f *Fetcher) Pause() (err error) {
|
||
if base.DownloadStatusStart != f.status {
|
||
return
|
||
}
|
||
f.status = base.DownloadStatusPause
|
||
f.cancel()
|
||
<-f.pauseCh
|
||
return
|
||
}
|
||
|
||
func (f *Fetcher) Continue() (err error) {
|
||
if base.DownloadStatusStart == f.status || base.DownloadStatusDone == f.status {
|
||
return
|
||
}
|
||
f.status = base.DownloadStatusStart
|
||
var name = f.filename()
|
||
_, err = f.Ctl.Open(name)
|
||
if err != nil {
|
||
return err
|
||
}
|
||
f.fetch()
|
||
return
|
||
}
|
||
|
||
func (f *Fetcher) Progress() fetcher.Progress {
|
||
p := make(fetcher.Progress, 0)
|
||
if len(f.chunks) > 0 {
|
||
total := int64(0)
|
||
for _, chunk := range f.chunks {
|
||
total += chunk.Downloaded
|
||
}
|
||
p = append(p, total)
|
||
}
|
||
return p
|
||
}
|
||
|
||
func (f *Fetcher) filename() string {
|
||
// 创建文件
|
||
var filename = f.opts.Name
|
||
if filename == "" {
|
||
filename = f.res.Files[0].Name
|
||
}
|
||
return filepath.Join(f.opts.Path, filename)
|
||
}
|
||
|
||
func (f *Fetcher) fetch() {
|
||
f.ctx, f.cancel = context.WithCancel(context.Background())
|
||
eg, _ := errgroup.WithContext(f.ctx)
|
||
for i := 0; i < f.opts.Connections; i++ {
|
||
eg.Go(func() error {
|
||
return f.fetchChunk(i)
|
||
})
|
||
}
|
||
|
||
go func() {
|
||
err := eg.Wait()
|
||
// 下载停止，关闭文件句柄
|
||
_ = f.Ctl.Close(f.filename())
|
||
if f.status == base.DownloadStatusPause {
|
||
f.pauseCh <- nil
|
||
} else {
|
||
if err != nil {
|
||
f.status = base.DownloadStatusError
|
||
} else {
|
||
f.status = base.DownloadStatusDone
|
||
}
|
||
f.DoneCh <- err
|
||
}
|
||
}()
|
||
}
|
||
|
||
func (f *Fetcher) fetchChunk(index int) (err error) {
|
||
filename := f.filename()
|
||
chunk := f.chunks[index]
|
||
|
||
httpReq, err := f.buildRequest(f.ctx, f.res.Req)
|
||
if err != nil {
|
||
return err
|
||
}
|
||
|
||
client, err := f.buildClient()
|
||
if err != nil {
|
||
return err
|
||
}
|
||
|
||
var buf = make([]byte, 8192)
|
||
|
||
// 重试10次
|
||
for i := 0; i < 10; i++ {
|
||
// 如果下载完成直接返回
|
||
if chunk.Status == base.DownloadStatusDone {
|
||
return
|
||
}
|
||
// 如果已暂停直接跳出
|
||
if f.status == base.DownloadStatusPause {
|
||
break
|
||
}
|
||
var (
|
||
resp *http.Response
|
||
retry bool
|
||
)
|
||
if f.res.Range {
|
||
httpReq.Header.Set(base.HttpHeaderRange,
|
||
fmt.Sprintf(base.HttpHeaderRangeFormat, chunk.Begin+chunk.Downloaded, chunk.End))
|
||
} else {
|
||
chunk.Downloaded = 0
|
||
}
|
||
err = func() error {
|
||
resp, err = client.Do(httpReq)
|
||
if err != nil {
|
||
return err
|
||
}
|
||
f.clients[index] = resp
|
||
if resp.StatusCode != base.HttpCodeOK && resp.StatusCode != base.HttpCodePartialContent {
|
||
err = NewRequestError(resp.StatusCode, resp.Status)
|
||
return err
|
||
}
|
||
return nil
|
||
}()
|
||
if err != nil {
|
||
//请求失败3s后重试
|
||
time.Sleep(time.Second * 3)
|
||
continue
|
||
}
|
||
|
||
// 请求成功就重置错误次数，连续失败10次才终止
|
||
i = 0
|
||
|
||
retry, err = func() (bool, error) {
|
||
defer func() {
|
||
_ = resp.Body.Close()
|
||
}()
|
||
var n int
|
||
for {
|
||
n, err = resp.Body.Read(buf)
|
||
if n > 0 {
|
||
_, err = f.Ctl.Write(filename, chunk.Begin+chunk.Downloaded, buf[:n])
|
||
if err != nil {
|
||
return false, err
|
||
}
|
||
chunk.Downloaded += int64(n)
|
||
}
|
||
if err != nil {
|
||
if err != io.EOF {
|
||
return true, err
|
||
}
|
||
break
|
||
}
|
||
}
|
||
return false, nil
|
||
}()
|
||
if !retry {
|
||
// 下载成功，跳出重试
|
||
break
|
||
}
|
||
}
|
||
|
||
if f.status == base.DownloadStatusPause {
|
||
chunk.Status = base.DownloadStatusPause
|
||
} else if chunk.Downloaded >= chunk.End-chunk.Begin+1 {
|
||
chunk.Status = base.DownloadStatusDone
|
||
} else {
|
||
if err != nil {
|
||
chunk.Status = base.DownloadStatusError
|
||
} else {
|
||
chunk.Status = base.DownloadStatusDone
|
||
}
|
||
}
|
||
return
|
||
}
|
||
|
||
func (f *Fetcher) buildClient() (*http.Client, error) {
|
||
dialer, err := f.Ctl.ContextDialer()
|
||
if err != nil {
|
||
return nil, err
|
||
}
|
||
transport := &http.Transport{
|
||
DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
|
||
return dialer.Dial(network, addr)
|
||
},
|
||
}
|
||
if f.Ctl.ContextProxy() != nil {
|
||
transport.Proxy = f.Ctl.ContextProxy()
|
||
}
|
||
return &http.Client{
|
||
Jar: f.Ctl.ContextCookie(),
|
||
Timeout: f.Ctl.ContextTimeout(),
|
||
Transport: transport,
|
||
}, nil
|
||
}
|
||
|
||
func (f *Fetcher) buildRequest(ctx context.Context, req *base.Request) (httpReq *http.Request, err error) {
|
||
reqUrl, err := url.Parse(req.URL)
|
||
if err != nil {
|
||
return
|
||
}
|
||
|
||
var (
|
||
method string
|
||
body io.Reader
|
||
)
|
||
headers := make(map[string][]string)
|
||
if req.Extra == nil {
|
||
method = http.MethodGet
|
||
} else {
|
||
extra := req.Extra.(Extra)
|
||
if extra.Method != "" {
|
||
method = extra.Method
|
||
} else {
|
||
method = http.MethodGet
|
||
}
|
||
if len(extra.Header) > 0 {
|
||
for k, v := range extra.Header {
|
||
headers[k] = []string{v}
|
||
}
|
||
}
|
||
if extra.Body != "" {
|
||
body = io.NopCloser(bytes.NewBufferString(extra.Body))
|
||
}
|
||
}
|
||
|
||
if ctx != nil {
|
||
httpReq, err = http.NewRequestWithContext(ctx, method, reqUrl.String(), body)
|
||
} else {
|
||
httpReq, err = http.NewRequest(method, reqUrl.String(), body)
|
||
}
|
||
if err != nil {
|
||
return
|
||
}
|
||
httpReq.Header = headers
|
||
return httpReq, nil
|
||
}
|