mirror of
https://github.com/truewhile/MeBox.git
synced 2026-09-30 11:46:36 +08:00
truewhile
376 lines
11 KiB
Go
376 lines
11 KiB
Go
package service
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import (
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"context"
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"errors"
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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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"strconv"
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"strings"
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"sync"
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"time"
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"github.com/truewhile/MeBox/internal/service/cloud115"
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)
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var (
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ErrCloud115HLSSessionNotFound = errors.New("115 hls session not found")
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ErrCloud115HLSUpstreamExpired = errors.New("115 hls upstream expired")
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)
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const (
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cloud115HLSSessionTTL = 30 * time.Minute
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cloud115HLSMaxSessions = 256
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cloud115HLSMaxManifest = 8 << 20
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)
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type cloud115HLSSession struct {
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ID string
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MediaID string
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Definition int
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CreatedAt time.Time
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ExpiresAt time.Time
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mu sync.Mutex
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entries map[string]string
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next int
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}
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// Cloud115HLSProxy 把 115 云端 HLS 转成 MeBox 同源 HLS。
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//
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// 浏览器不能直接请求 115 的 m3u8：master/variant/分片的 CORS 只允许
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// https://115.com，且 master 还是 HTTP。代理在服务端拉取并重写播放列表，
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// 分片按 Range 流式转发。
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type Cloud115HLSProxy struct {
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service *Cloud115PlaybackService
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client *http.Client
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mu sync.Mutex
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sessions map[string]*cloud115HLSSession
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}
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func newCloud115HLSProxy(service *Cloud115PlaybackService) *Cloud115HLSProxy {
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return &Cloud115HLSProxy{
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service: service,
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client: &http.Client{
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Timeout: 0,
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CheckRedirect: func(req *http.Request, via []*http.Request) error {
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if len(via) >= 6 {
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return errors.New("stopped after 6 redirects")
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}
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return nil
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},
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},
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sessions: make(map[string]*cloud115HLSSession),
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}
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}
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// ServeMaster 解析指定清晰度并返回重写后的 master.m3u8。
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func (p *Cloud115HLSProxy) ServeMaster(ctx context.Context, w http.ResponseWriter, r *http.Request, mediaID string, definition int) error {
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if p == nil || p.service == nil {
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return ErrCloud115NotApplicable
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}
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upstream, _, err := p.service.ResolveCloud115URL(ctx, mediaID, definition)
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if err != nil {
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return err
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}
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session := p.newSession(mediaID, definition)
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fetchCtx, cancel := context.WithTimeout(ctx, 30*time.Second)
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defer cancel()
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resp, err := p.fetchUpstream(fetchCtx, upstream, "")
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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 fmt.Errorf("115 云端播放列表返回 HTTP %d", resp.StatusCode)
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}
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body, err := io.ReadAll(io.LimitReader(resp.Body, cloud115HLSMaxManifest))
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if err != nil {
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return err
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}
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baseURL := upstream
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if resp.Request != nil && resp.Request.URL != nil {
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baseURL = resp.Request.URL.String()
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}
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rewritten := p.rewriteManifest(session, string(body), baseURL, r.URL.RawQuery)
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p.storeSession(session)
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w.Header().Set("Content-Type", "application/vnd.apple.mpegurl")
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w.Header().Set("Cache-Control", "no-store, no-cache, must-revalidate, max-age=0")
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w.Header().Set("Content-Length", strconv.Itoa(len(rewritten)))
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if r.Method != http.MethodHead {
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_, err = io.WriteString(w, rewritten)
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}
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return err
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}
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// ServeChild 代理 variant/分片；variant 播放列表会继续重写为同源地址。
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func (p *Cloud115HLSProxy) ServeChild(ctx context.Context, w http.ResponseWriter, r *http.Request, sessionID, key string) error {
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session, upstream, ok := p.lookup(sessionID, key)
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if !ok {
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return ErrCloud115HLSSessionNotFound
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}
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resp, err := p.fetchUpstream(ctx, upstream, r.Header.Get("Range"))
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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 == http.StatusForbidden || resp.StatusCode == http.StatusGone {
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p.deleteSession(sessionID)
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return ErrCloud115HLSUpstreamExpired
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}
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contentType := strings.ToLower(strings.TrimSpace(resp.Header.Get("Content-Type")))
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isPlaylist := strings.Contains(contentType, "mpegurl") ||
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strings.Contains(contentType, "application/vnd.apple.mpegurl")
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if !isPlaylist {
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// Content-Type 缺失时用前 4KB 内容嗅探是否为播放列表；无论结果如何
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// 都要把已读前缀接回 body，避免分片/播放列表丢开头字节。
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body, readErr := io.ReadAll(io.LimitReader(resp.Body, 4096))
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if readErr != nil {
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return readErr
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}
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if strings.HasPrefix(strings.TrimSpace(string(body)), "#EXTM3U") {
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isPlaylist = true
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}
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resp.Body = io.NopCloser(io.MultiReader(strings.NewReader(string(body)), resp.Body))
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}
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copyUpstreamHeaders(w, resp, isPlaylist)
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if isPlaylist {
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body, err := io.ReadAll(io.LimitReader(resp.Body, cloud115HLSMaxManifest))
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if err != nil {
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return err
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}
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baseURL := upstream
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if resp.Request != nil && resp.Request.URL != nil {
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baseURL = resp.Request.URL.String()
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}
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rewritten := p.rewriteManifest(session, string(body), baseURL, r.URL.RawQuery)
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w.Header().Set("Content-Type", "application/vnd.apple.mpegurl")
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w.Header().Set("Cache-Control", "no-store, no-cache, must-revalidate, max-age=0")
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w.Header().Set("Content-Length", strconv.Itoa(len(rewritten)))
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w.WriteHeader(resp.StatusCode)
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if r.Method != http.MethodHead {
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_, err = io.WriteString(w, rewritten)
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}
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return err
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}
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w.WriteHeader(resp.StatusCode)
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if r.Method != http.MethodHead {
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_, err = io.Copy(w, resp.Body)
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}
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return err
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}
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func (p *Cloud115HLSProxy) newSession(mediaID string, definition int) *cloud115HLSSession {
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now := time.Now()
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return &cloud115HLSSession{
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ID: cloud115.RandomString(24),
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MediaID: mediaID,
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Definition: definition,
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CreatedAt: now,
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ExpiresAt: now.Add(cloud115HLSSessionTTL),
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entries: make(map[string]string),
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}
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}
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func (p *Cloud115HLSProxy) storeSession(session *cloud115HLSSession) {
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if p == nil || session == nil {
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return
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}
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p.mu.Lock()
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defer p.mu.Unlock()
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now := time.Now()
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if len(p.sessions) >= cloud115HLSMaxSessions {
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for id, existing := range p.sessions {
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if now.After(existing.ExpiresAt) {
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delete(p.sessions, id)
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}
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}
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}
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if len(p.sessions) >= cloud115HLSMaxSessions {
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// ExpiresAt 恒为「最近一次活跃时间 + TTL」（lookup 会滑动续期），
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// 因此最小者即最久未活跃的会话，淘汰它对正在播放的影响最小。
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evictID := ""
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var evictAt time.Time
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for id, existing := range p.sessions {
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if evictID == "" || existing.ExpiresAt.Before(evictAt) {
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evictID, evictAt = id, existing.ExpiresAt
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}
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}
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if evictID != "" {
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delete(p.sessions, evictID)
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}
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}
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session.ExpiresAt = now.Add(cloud115HLSSessionTTL)
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p.sessions[session.ID] = session
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}
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func (p *Cloud115HLSProxy) lookup(sessionID, key string) (*cloud115HLSSession, string, bool) {
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if p == nil {
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return nil, "", false
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}
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p.mu.Lock()
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session := p.sessions[sessionID]
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if session != nil {
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if time.Now().After(session.ExpiresAt) {
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delete(p.sessions, sessionID)
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session = nil
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} else {
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// 滑动续期：VOD 点播整个播放期间只有分片请求，master 只在起播时取
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// 一次，不续期的话会话会在 TTL 后被删，长视频播放到一半必然断流。
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session.ExpiresAt = time.Now().Add(cloud115HLSSessionTTL)
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}
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}
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p.mu.Unlock()
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if session == nil {
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return nil, "", false
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}
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session.mu.Lock()
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upstream, ok := session.entries[key]
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session.mu.Unlock()
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return session, upstream, ok
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}
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func (p *Cloud115HLSProxy) deleteSession(sessionID string) {
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if p == nil {
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return
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}
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p.mu.Lock()
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delete(p.sessions, sessionID)
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p.mu.Unlock()
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}
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func (p *Cloud115HLSProxy) fetchUpstream(ctx context.Context, rawURL, rangeHeader string) (*http.Response, error) {
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parsed, err := url.Parse(strings.TrimSpace(rawURL))
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if err != nil || parsed == nil || !isAllowed115UpstreamHost(parsed.Hostname()) {
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return nil, fmt.Errorf("115 hls upstream host not allowed: %s", rawURL)
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}
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req, err := http.NewRequestWithContext(ctx, http.MethodGet, rawURL, 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.Set("User-Agent", cloud115.DefaultUA)
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if strings.TrimSpace(rangeHeader) != "" {
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req.Header.Set("Range", rangeHeader)
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}
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return p.client.Do(req)
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}
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func isAllowed115UpstreamHost(host string) bool {
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host = strings.ToLower(strings.TrimSpace(host))
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if host == "" {
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return false
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}
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for _, suffix := range []string{".115.com", ".115cdn.com", ".115cdn.net"} {
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if strings.HasSuffix(host, suffix) {
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return true
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}
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}
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return host == "115.com" || host == "115cdn.com" || host == "115cdn.net"
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}
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func (p *Cloud115HLSProxy) rewriteManifest(session *cloud115HLSSession, text, baseURL, rawQuery string) string {
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if session == nil {
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return text
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}
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lines := strings.SplitAfter(text, "\n")
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for i, line := range lines {
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trimmed := strings.TrimSpace(line)
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if trimmed == "" {
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continue
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}
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if strings.HasPrefix(trimmed, "#") {
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if strings.HasPrefix(trimmed, "#EXT-X-MEDIA:") ||
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strings.HasPrefix(trimmed, "#EXT-X-KEY:") ||
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strings.HasPrefix(trimmed, "#EXT-X-MAP:") {
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lines[i] = replaceManifestURI(line, func(uri string) string {
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return p.proxyURL(session, resolveManifestURL(baseURL, uri), rawQuery)
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})
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}
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continue
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}
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lines[i] = p.proxyURL(session, resolveManifestURL(baseURL, trimmed), rawQuery) + lineEnding(line)
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}
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return strings.Join(lines, "")
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}
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func (p *Cloud115HLSProxy) proxyURL(session *cloud115HLSSession, upstream, rawQuery string) string {
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session.mu.Lock()
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session.next++
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key := "e" + strconv.Itoa(session.next)
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session.entries[key] = upstream
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mediaID := session.MediaID
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session.mu.Unlock()
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query := childProxyQuery(rawQuery, mediaID)
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return "/api/cloud115/hls/" + url.PathEscape(session.ID) + "/" + url.PathEscape(key) + "?" + query
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}
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func childProxyQuery(rawQuery, mediaID string) string {
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values, _ := url.ParseQuery(rawQuery)
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keep := url.Values{}
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for _, key := range []string{"token", "api_key", "apiKey", "ApiKey", "profile_id", "profile_pin_token"} {
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if value := strings.TrimSpace(values.Get(key)); value != "" {
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keep.Set(key, value)
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}
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}
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if strings.TrimSpace(mediaID) != "" {
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keep.Set("media_id", mediaID)
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}
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return keep.Encode()
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}
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func replaceManifestURI(line string, replace func(string) string) string {
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const marker = `URI="`
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idx := strings.Index(line, marker)
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if idx < 0 {
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return line
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}
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start := idx + len(marker)
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end := strings.Index(line[start:], `"`)
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if end < 0 {
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return line
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}
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end += start
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return line[:start] + replace(line[start:end]) + line[end:]
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}
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func resolveManifestURL(baseURL, raw string) string {
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base, baseErr := url.Parse(strings.TrimSpace(baseURL))
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ref, refErr := url.Parse(strings.TrimSpace(raw))
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if baseErr != nil || refErr != nil || base == nil || ref == nil {
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return raw
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}
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return base.ResolveReference(ref).String()
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}
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func lineEnding(line string) string {
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if strings.HasSuffix(line, "\r\n") {
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return "\r\n"
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}
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if strings.HasSuffix(line, "\n") {
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return "\n"
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}
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return ""
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}
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func copyUpstreamHeaders(w http.ResponseWriter, resp *http.Response, playlist bool) {
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for _, key := range []string{"Content-Type", "Content-Length", "Content-Range", "Accept-Ranges", "ETag", "Last-Modified"} {
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if value := resp.Header.Get(key); value != "" {
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w.Header().Set(key, value)
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}
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}
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if playlist {
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w.Header().Set("Cache-Control", "no-store, no-cache, must-revalidate, max-age=0")
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} else if w.Header().Get("Cache-Control") == "" {
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w.Header().Set("Cache-Control", "public, max-age=3600")
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}
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}
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