move server to server directory.

server/internal/webrtc/cursor/image.go

@@ -0,0 +1,168 @@
+package cursor
+
+import (
+	"reflect"
+	"sync"
+
+	"github.com/rs/zerolog"
+
+	"github.com/demodesk/neko/pkg/types"
+	"github.com/demodesk/neko/pkg/utils"
+)
+
+type ImageListener interface {
+	SendCursorImage(cur *types.CursorImage, img []byte) error
+}
+
+type Image interface {
+	Start()
+	Shutdown()
+	GetCurrent() (cur *types.CursorImage, img []byte, err error)
+	AddListener(listener ImageListener)
+	RemoveListener(listener ImageListener)
+}
+
+type imageEntry struct {
+	*types.CursorImage
+	ImagePNG []byte
+}
+
+type image struct {
+	logger  zerolog.Logger
+	desktop types.DesktopManager
+
+	listeners   map[uintptr]ImageListener
+	listenersMu sync.RWMutex
+
+	cache     map[uint64]*imageEntry
+	cacheMu   sync.RWMutex
+	current   *imageEntry
+	maxSerial uint64
+}
+
+func NewImage(logger zerolog.Logger, desktop types.DesktopManager) *image {
+	return &image{
+		logger:    logger.With().Str("submodule", "cursor-image").Logger(),
+		desktop:   desktop,
+		listeners: map[uintptr]ImageListener{},
+		cache:     map[uint64]*imageEntry{},
+		maxSerial: 300, // TODO: Cleanup?
+	}
+}
+
+func (manager *image) Start() {
+	manager.desktop.OnCursorChanged(func(serial uint64) {
+		entry, err := manager.getCached(serial)
+		if err != nil {
+			manager.logger.Err(err).Msg("failed to get cursor image")
+			return
+		}
+
+		manager.current = entry
+
+		manager.listenersMu.RLock()
+		for _, l := range manager.listeners {
+			if err := l.SendCursorImage(entry.CursorImage, entry.ImagePNG); err != nil {
+				manager.logger.Err(err).Msg("failed to set cursor image")
+			}
+		}
+		manager.listenersMu.RUnlock()
+	})
+
+	manager.logger.Info().Msg("starting")
+}
+
+func (manager *image) Shutdown() {
+	manager.logger.Info().Msg("shutdown")
+
+	manager.listenersMu.Lock()
+	for key := range manager.listeners {
+		delete(manager.listeners, key)
+	}
+	manager.listenersMu.Unlock()
+}
+
+func (manager *image) getCached(serial uint64) (*imageEntry, error) {
+	// zero means no serial available
+	if serial == 0 || serial > manager.maxSerial {
+		manager.logger.Debug().Uint64("serial", serial).Msg("cache bypass")
+		return manager.fetchEntry()
+	}
+
+	manager.cacheMu.RLock()
+	entry, ok := manager.cache[serial]
+	manager.cacheMu.RUnlock()
+
+	if ok {
+		return entry, nil
+	}
+
+	manager.logger.Debug().Uint64("serial", serial).Msg("cache miss")
+
+	entry, err := manager.fetchEntry()
+	if err != nil {
+		return nil, err
+	}
+
+	manager.cacheMu.Lock()
+	manager.cache[entry.Serial] = entry
+	manager.cacheMu.Unlock()
+
+	if entry.Serial != serial {
+		manager.logger.Warn().
+			Uint64("expected-serial", serial).
+			Uint64("received-serial", entry.Serial).
+			Msg("serial mismatch")
+	}
+
+	return entry, nil
+}
+
+func (manager *image) GetCurrent() (cur *types.CursorImage, img []byte, err error) {
+	if manager.current != nil {
+		return manager.current.CursorImage, manager.current.ImagePNG, nil
+	}
+
+	entry, err := manager.fetchEntry()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	manager.current = entry
+	return entry.CursorImage, entry.ImagePNG, nil
+}
+
+func (manager *image) AddListener(listener ImageListener) {
+	manager.listenersMu.Lock()
+	defer manager.listenersMu.Unlock()
+
+	if listener != nil {
+		ptr := reflect.ValueOf(listener).Pointer()
+		manager.listeners[ptr] = listener
+	}
+}
+
+func (manager *image) RemoveListener(listener ImageListener) {
+	manager.listenersMu.Lock()
+	defer manager.listenersMu.Unlock()
+
+	if listener != nil {
+		ptr := reflect.ValueOf(listener).Pointer()
+		delete(manager.listeners, ptr)
+	}
+}
+
+func (manager *image) fetchEntry() (*imageEntry, error) {
+	cur := manager.desktop.GetCursorImage()
+
+	img, err := utils.CreatePNGImage(cur.Image)
+	if err != nil {
+		return nil, err
+	}
+	cur.Image = nil // free memory
+
+	return &imageEntry{
+		CursorImage: cur,
+		ImagePNG:    img,
+	}, nil
+}