feat: add gblob scheme support for extension (#1358)

pkg/download/extension_engine_session.go

@@ -0,0 +1,117 @@
+package download
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/GopeedLab/gopeed/pkg/download/engine"
+	"github.com/GopeedLab/gopeed/pkg/download/engine/inject/stream"
+	"github.com/dop251/goja"
+)
+
+type engineSession struct {
+	engine *engine.Engine
+
+	mu     sync.Mutex
+	refs   int
+	closed bool
+}
+
+func newEngineSession(e *engine.Engine) *engineSession {
+	return &engineSession{engine: e}
+}
+
+func (s *engineSession) SetEngine(e *engine.Engine) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.engine = e
+}
+
+func (s *engineSession) Retain() {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if s.closed {
+		return
+	}
+	s.refs++
+}
+
+func (s *engineSession) Release() {
+	s.mu.Lock()
+	if s.refs > 0 {
+		s.refs--
+	}
+	shouldClose := s.refs == 0 && !s.closed
+	if shouldClose {
+		s.closed = true
+	}
+	s.mu.Unlock()
+	if shouldClose {
+		if s.engine != nil {
+			go s.engine.Close()
+		}
+	}
+}
+
+func (s *engineSession) CloseIfIdle() {
+	s.mu.Lock()
+	shouldClose := s.refs == 0 && !s.closed
+	if shouldClose {
+		s.closed = true
+	}
+	s.mu.Unlock()
+	if shouldClose {
+		if s.engine != nil {
+			s.engine.Close()
+		}
+	}
+}
+
+func normalizeStreamChunk(data any) ([]byte, error) {
+	switch v := data.(type) {
+	case nil:
+		return nil, nil
+	case string:
+		return []byte(v), nil
+	case []byte:
+		return v, nil
+	case goja.ArrayBuffer:
+		return v.Bytes(), nil
+	default:
+		return nil, fmt.Errorf("unsupported stream chunk type: %T", data)
+	}
+}
+
+func (d *Downloader) newExtensionEngine() (*engine.Engine, *engineSession) {
+	session := newEngineSession(nil)
+	engineCfg := &stream.Config{
+		CreateBlobObjectURL: func(data []byte, contentType string) (string, error) {
+			return d.gblob.CreateBlob(data, contentType)
+		},
+		CreateWritableStreamObjectURL: func() (string, error) {
+			return d.gblob.CreateWritableStream(session)
+		},
+		WriteWritableStreamObjectURL: func(url string, data any) error {
+			chunk, err := normalizeStreamChunk(data)
+			if err != nil {
+				return err
+			}
+			return d.gblob.Write(url, chunk)
+		},
+		CloseWritableStreamObjectURL: func(url string) error {
+			return d.gblob.CloseSource(url)
+		},
+		AbortWritableStreamObjectURL: func(url string, reason string) error {
+			return d.gblob.AbortSource(url, fmt.Errorf("%s", reason))
+		},
+		RevokeObjectURL: func(url string) error {
+			return d.gblob.Revoke(url)
+		},
+	}
+	e := engine.NewEngine(&engine.Config{
+		ProxyConfig:  d.cfg.Proxy,
+		StreamConfig: engineCfg,
+	})
+	session.SetEngine(e)
+	return e, session
+}