Stream Jupyter workspace file downloads

src/jupyter_runtime.py

@@ -647,6 +647,50 @@ print(json.dumps(entries, ensure_ascii=False))
         name = str(payload.get('name') or PurePosixPath(target).name or 'remote-file')
         return data, name
 
+    def file_info(self, path: str) -> dict[str, Any]:
+        target = self.resolve_workspace_path(path)
+        api_path = api_path_for_absolute_path(target)
+        url = f'{self.binding.base_url}/api/contents/{quote(api_path, safe="/")}'
+        response = self._session.get(
+            url,
+            params={'content': 0},
+            headers={'X-XSRFToken': self._xsrf_token},
+            timeout=30,
+        )
+        if response.status_code >= 400:
+            raise JupyterRuntimeError(
+                f'Unable to inspect remote file: HTTP {response.status_code} {response.text[:500]}'
+            )
+        payload = response.json()
+        if payload.get('type') != 'file':
+            raise JupyterRuntimeError('Remote path is not a file.')
+        name = str(payload.get('name') or PurePosixPath(target).name or 'remote-file')
+        size = payload.get('size')
+        return {
+            'name': name,
+            'path': target,
+            'size': int(size) if isinstance(size, int) and size >= 0 else None,
+        }
+
+    def open_file_stream(self, path: str) -> tuple[Any, str]:
+        """打开远端文件流，由调用方负责关闭 response。"""
+
+        target = self.resolve_workspace_path(path)
+        api_path = api_path_for_absolute_path(target)
+        url = f'{self.binding.base_url}/files/{quote(api_path, safe="/")}'
+        response = self._session.get(
+            url,
+            headers={'X-XSRFToken': self._xsrf_token},
+            stream=True,
+            timeout=(10, 300),
+        )
+        if response.status_code >= 400:
+            response.close()
+            raise JupyterRuntimeError(
+                f'Unable to stream remote file: HTTP {response.status_code} {response.text[:500]}'
+            )
+        return response, str(PurePosixPath(target).name or 'remote-file')
+
     def read_text(
         self,
         path: str,