Catch and handle corrupted json files

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+* Handle corrupted json files by @bleykauf in https://github.com/linien-org/linien/pull/399
+
 ## [2.0.2] - 2024-05-14
 
 ### Fixed

linien-common/linien_common/config.py

@@ -15,11 +15,14 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with Linien.  If not, see <http://www.gnu.org/licenses/>.
-
+import logging
 from pathlib import Path
 
 from appdirs import AppDirs
 
+logger = logging.getLogger(__name__)
+logger.setLevel(logging.DEBUG)
+
 ACQUISITION_PORT = 19321
 SERVER_PORT = 18862
 DEFAULT_SWEEP_SPEED = (125 * 2048) << 6
@@ -29,3 +32,16 @@
 
 LOG_FILE_PATH = USER_DATA_PATH / "linien.log"
 LOG_FILE_PATH.parent.mkdir(parents=True, exist_ok=True)
+
+
+def create_backup_file(filename: Path) -> None:
+    """Rename the file to a unique filename."""
+    i = 0
+    while True:
+        backup_filename = filename.parent / f"{filename.stem}.backup{i}"
+        if not backup_filename.exists():
+            break
+        i += 1
+
+    filename.rename(backup_filename)
+    logger.info(f"{filename} has been saved as {backup_filename}.")

linien-common/linien_common/influxdb.py

@@ -19,7 +19,7 @@
 import logging
 from dataclasses import dataclass
 
-from .config import USER_DATA_PATH
+from .config import USER_DATA_PATH, create_backup_file
 
 CREDENTIAL_STORE_FILENAME = "influxdb_credentials.json"
 
@@ -69,3 +69,7 @@ def restore_credentials() -> InfluxDBCredentials:
         )
     except FileNotFoundError:
         return InfluxDBCredentials()
+    except json.JSONDecodeError:
+        logger.error(f"Credentials file {filename} was corrupted.")
+        create_backup_file(filename)
+        return InfluxDBCredentials()

linien-gui/linien_gui/config.py

@@ -23,13 +23,13 @@
 from pathlib import Path
 from typing import Callable, Iterator, Tuple
 
-from linien_common.config import USER_DATA_PATH
+from linien_common.config import USER_DATA_PATH, create_backup_file
 
 logger = logging.getLogger(__name__)
 logger.setLevel(logging.DEBUG)
 
 UI_PATH = Path(__file__).parents[0].resolve() / "ui"
-
+SETTINGS_STORE_FILENAME = "settings.json"
 # don't plot more often than once per `DEFAULT_PLOT_RATE_LIMIT` seconds
 DEFAULT_PLOT_RATE_LIMIT = 0.1
 
@@ -118,19 +118,22 @@ def __iter__(self) -> Iterator[Tuple[str, Setting]]:
 
 def save_settings(settings: Settings) -> None:
     data = {name: setting.value for name, setting in settings}
-    with open(USER_DATA_PATH / "settings.json", "w") as f:
+    with open(USER_DATA_PATH / SETTINGS_STORE_FILENAME, "w") as f:
         json.dump(data, f, indent=0)
 
 
 def load_settings() -> Settings:
     settings = Settings()
+    filename = USER_DATA_PATH / SETTINGS_STORE_FILENAME
     try:
-        with open(USER_DATA_PATH / "settings.json", "r") as f:
+        with open(filename, "r") as f:
             data = json.load(f)
             for name, value in data.items():
                 if name in settings.__dict__:
                     getattr(settings, name).value = value
     except FileNotFoundError:
         save_settings(settings)
-
+    except json.JSONDecodeError:
+        logger.error(f"Settings file {filename} was corrupted.")
+        create_backup_file(filename)
     return settings

linien-server/linien_server/parameters.py

@@ -24,7 +24,7 @@
 
 import linien_server
 from linien_common.common import AutolockMode, MHz, PSDAlgorithm, Vpp
-from linien_common.config import USER_DATA_PATH
+from linien_common.config import USER_DATA_PATH, create_backup_file
 
 PARAMETER_STORE_FILENAME = "parameters.json"
 
@@ -667,6 +667,10 @@ def restore_parameters(parameters: Parameters) -> Parameters:
     except FileNotFoundError:
         logger.info(f"Couldn't find {filename}. Using default parameters.")
         return parameters
+    except json.JSONDecodeError:
+        logger.error(f"Parameters file {filename} was corrupted.")
+        create_backup_file(filename)
+        return parameters
 
     for name, attributes in data["parameters"].items():
         try: