2026-05-03-23-22-10 修复阅览切换和下载触发

web_backend.py

@@ -41,6 +41,9 @@ PORT = 8787
 JOBS = {}
 JOBS_LOCK = threading.Lock()
 DICOM_FILE_CACHE = {}
+DICOM_VOLUME_CACHE = {}
+DICOM_VOLUME_CACHE_LOCK = threading.Lock()
+DICOM_VOLUME_CACHE_LIMIT = 2
 LIBRARY_DIR = APP_DIR / "web_library"
 LIBRARY_META = LIBRARY_DIR / "library.json"
 RESULT_DIR = APP_DIR / "web_results"
@@ -178,6 +181,56 @@ def sorted_dicom_files(dicom_dir):
     return sorted_files
 
 
+def dicom_dir_signature(dicom_dir):
+    dicom_dir = Path(dicom_dir).resolve()
+    files = list(dicom_dir.glob("*.dcm"))
+    return (
+        str(dicom_dir),
+        len(files),
+        max((file_path.stat().st_mtime for file_path in files), default=0),
+    )
+
+
+def load_cached_dicom_volume(dicom_dir):
+    dicom_dir = Path(dicom_dir).resolve()
+    signature = dicom_dir_signature(dicom_dir)
+    cache_key = str(dicom_dir)
+    with DICOM_VOLUME_CACHE_LOCK:
+        cached = DICOM_VOLUME_CACHE.get(cache_key)
+        if cached and cached["signature"] == signature:
+            cached["last_access"] = time.time()
+            return cached["volume"]
+
+        volume = load_dicom_volume(dicom_dir)
+        DICOM_VOLUME_CACHE[cache_key] = {
+            "signature": signature,
+            "volume": volume,
+            "last_access": time.time(),
+        }
+        while len(DICOM_VOLUME_CACHE) > DICOM_VOLUME_CACHE_LIMIT:
+            oldest_key = min(
+                DICOM_VOLUME_CACHE,
+                key=lambda key: DICOM_VOLUME_CACHE[key].get("last_access", 0),
+            )
+            if oldest_key == cache_key:
+                break
+            DICOM_VOLUME_CACHE.pop(oldest_key, None)
+        return volume
+
+
+def clear_dicom_caches(dicom_dir=None):
+    if dicom_dir is None:
+        DICOM_FILE_CACHE.clear()
+        with DICOM_VOLUME_CACHE_LOCK:
+            DICOM_VOLUME_CACHE.clear()
+        return
+
+    cache_key = str(Path(dicom_dir).resolve())
+    DICOM_FILE_CACHE.pop(cache_key, None)
+    with DICOM_VOLUME_CACHE_LOCK:
+        DICOM_VOLUME_CACHE.pop(cache_key, None)
+
+
 def find_library_item(item_id):
     return next((item for item in list_library() if item["id"] == item_id), None)
 
@@ -227,7 +280,7 @@ def make_library_reformat_preview(item_id, plane, index, window):
 
     plane = plane if plane in {"coronal", "sagittal"} else "coronal"
     window = window if window in VIEWER_WINDOWS else "default"
-    volume = load_dicom_volume(item["dicomPath"])
+    volume = load_cached_dicom_volume(item["dicomPath"])
 
     def normalize_reformat_index(raw_index, count):
         if str(raw_index) == "middle":
@@ -1156,7 +1209,7 @@ class Handler(BaseHTTPRequestHandler):
         write_library_meta(remaining)
         upload_root = Path(target["dicomPath"]).resolve().parent
         if upload_root.exists() and upload_root.is_relative_to(LIBRARY_DIR.resolve()):
-            DICOM_FILE_CACHE.pop(str(Path(target["dicomPath"]).resolve()), None)
+            clear_dicom_caches(target["dicomPath"])
             shutil.rmtree(upload_root)
         preview_cache = PREVIEW_CACHE_DIR / item_id
         if preview_cache.exists():
@@ -1188,8 +1241,11 @@ class Handler(BaseHTTPRequestHandler):
             self.send_header("Content-Disposition", f'attachment; filename="{file_path.name}"')
         self.send_header("Content-Length", str(file_path.stat().st_size))
         self.end_headers()
-        with file_path.open("rb") as file_handle:
-            shutil.copyfileobj(file_handle, self.wfile)
+        try:
+            with file_path.open("rb") as file_handle:
+                shutil.copyfileobj(file_handle, self.wfile)
+        except (BrokenPipeError, ConnectionResetError, ConnectionAbortedError):
+            return
 
     def send_cors_headers(self):
         self.send_header("Access-Control-Allow-Origin", "*")