Fix race condition gphoto2 : verrou camera sur preview et capture

backend/camera.py

@@ -1,6 +1,7 @@
 import io
 import logging
 import subprocess
+import threading
 import time
 from datetime import datetime
 
@@ -66,6 +67,7 @@ class Camera:
         self.webcam = None
         self.webcam_index = -1
         self.preview_dslr_ok = True  # True si le dernier preview DSLR a reussi
+        self._lock = threading.Lock()  # Verrou pour eviter acces gphoto2 concurrent
 
     def connecter(self, source=None) -> bool:
         """Connecte la camera. source: 'gphoto2', 'webcam:0', 'webcam:2', etc."""
@@ -145,34 +147,33 @@ class Camera:
     def _capture_gphoto2(self, chemin_dest: Path) -> Path | None:
         from PIL import Image as PILImage
 
-        for attempt in range(3):
-            try:
-                chemin_camera = self.camera.capture(gp.GP_CAPTURE_IMAGE)
-                fichier_camera = gp.CameraFile()
-                self.camera.file_get(
-                    chemin_camera.folder, chemin_camera.name, gp.GP_FILE_TYPE_NORMAL, fichier_camera
-                )
-                # Sauvegarder le fichier brut temporairement
-                tmp_path = str(chemin_dest) + ".tmp"
-                fichier_camera.save(tmp_path)
+        with self._lock:
+            for attempt in range(3):
+                try:
+                    chemin_camera = self.camera.capture(gp.GP_CAPTURE_IMAGE)
+                    fichier_camera = gp.CameraFile()
+                    self.camera.file_get(
+                        chemin_camera.folder, chemin_camera.name, gp.GP_FILE_TYPE_NORMAL, fichier_camera
+                    )
+                    tmp_path = str(chemin_dest) + ".tmp"
+                    fichier_camera.save(tmp_path)
 
-                # Redimensionner (max 4000px de large, JPEG 92%)
-                img = PILImage.open(tmp_path)
-                if img.width > 4000:
-                    ratio = 4000 / img.width
-                    img = img.resize((4000, int(img.height * ratio)), PILImage.LANCZOS)
-                img.save(str(chemin_dest), "JPEG", quality=92)
-                Path(tmp_path).unlink(missing_ok=True)
+                    img = PILImage.open(tmp_path)
+                    if img.width > 4000:
+                        ratio = 4000 / img.width
+                        img = img.resize((4000, int(img.height * ratio)), PILImage.LANCZOS)
+                    img.save(str(chemin_dest), "JPEG", quality=92)
+                    Path(tmp_path).unlink(missing_ok=True)
 
-                log.info(f"Photo capturee (DSLR) : {chemin_dest} ({img.width}x{img.height})")
-                return chemin_dest
-            except gp.GPhoto2Error as e:
-                if "I/O in progress" in str(e) and attempt < 2:
-                    log.warning(f"DSLR occupe, retry {attempt + 1}/3...")
-                    time.sleep(0.5)
-                    continue
-                log.error(f"Erreur capture DSLR : {e}")
-                return None
+                    log.info(f"Photo capturee (DSLR) : {chemin_dest} ({img.width}x{img.height})")
+                    return chemin_dest
+                except gp.GPhoto2Error as e:
+                    if "I/O in progress" in str(e) and attempt < 2:
+                        log.warning(f"DSLR occupe, retry {attempt + 1}/3...")
+                        time.sleep(0.5)
+                        continue
+                    log.error(f"Erreur capture DSLR : {e}")
+                    return None
 
     def _capture_webcam(self, chemin_dest: Path) -> Path | None:
         if not self.webcam or not self.webcam.isOpened():
@@ -203,47 +204,46 @@ class Camera:
         """Active le LiveView sur les Canon (nécessaire avant capture_preview)."""
         if self.mode != "gphoto2" or not self.connectee:
             return
-        try:
-            cfg = self.camera.get_config()
-            vf = cfg.get_child_by_name("viewfinder")
-            vf.set_value(1)
-            self.camera.set_config(cfg)
-            log.info("Viewfinder activé")
-        except Exception as e:
-            log.warning(f"Viewfinder non supporté : {e}")
+        with self._lock:
+            try:
+                cfg = self.camera.get_config()
+                vf = cfg.get_child_by_name("viewfinder")
+                vf.set_value(1)
+                self.camera.set_config(cfg)
+                log.info("Viewfinder activé")
+            except Exception as e:
+                log.warning(f"Viewfinder non supporté : {e}")
 
     def desactiver_viewfinder(self):
         """Désactive le LiveView."""
         if self.mode != "gphoto2" or not self.connectee:
             return
-        try:
-            cfg = self.camera.get_config()
-            vf = cfg.get_child_by_name("viewfinder")
-            vf.set_value(0)
-            self.camera.set_config(cfg)
-            log.info("Viewfinder désactivé")
-        except Exception as e:
-            log.warning(f"Viewfinder non supporté : {e}")
+        with self._lock:
+            try:
+                cfg = self.camera.get_config()
+                vf = cfg.get_child_by_name("viewfinder")
+                vf.set_value(0)
+                self.camera.set_config(cfg)
+                log.info("Viewfinder désactivé")
+            except Exception as e:
+                log.warning(f"Viewfinder non supporté : {e}")
 
     def _preview_gphoto2(self) -> bytes | None:
-        try:
-            fichier = self.camera.capture_preview()
-            donnees = bytes(fichier.get_data_and_size())
-            # Redimensionner pour alléger le WebSocket
-            img = cv2.imdecode(
-                np.frombuffer(donnees, dtype=np.uint8),
-                cv2.IMREAD_COLOR,
-            )
-            if img is not None:
-                h, w = img.shape[:2]
-                if w > 960:
-                    img = cv2.resize(img, (960, int(h * 960 / w)), interpolation=cv2.INTER_LINEAR)
-                _, buf = cv2.imencode(".jpg", img, [cv2.IMWRITE_JPEG_QUALITY, 75])
-                return buf.tobytes()
-            return donnees
-        except gp.GPhoto2Error as e:
-            log.error(f"Erreur preview DSLR : {e}")
-            return None
+        with self._lock:
+            try:
+                fichier = self.camera.capture_preview()
+                donnees = bytes(fichier.get_data_and_size())
+                img = cv2.imdecode(np.frombuffer(donnees, dtype=np.uint8), cv2.IMREAD_COLOR)
+                if img is not None:
+                    h, w = img.shape[:2]
+                    if w > 960:
+                        img = cv2.resize(img, (960, int(h * 960 / w)), interpolation=cv2.INTER_LINEAR)
+                    _, buf = cv2.imencode(".jpg", img, [cv2.IMWRITE_JPEG_QUALITY, 75])
+                    return buf.tobytes()
+                return donnees
+            except gp.GPhoto2Error as e:
+                log.error(f"Erreur preview DSLR : {e}")
+                return None
 
     def _preview_webcam(self) -> bytes | None:
         if not self.webcam or not self.webcam.isOpened():