basic backup added

Repetitions of code and lack of tests
Next step add tests

Author: UrszulaNeuman

dls_barcode/data_store/backup.py

@@ -0,0 +1,53 @@
+import time
+
+from dls_barcode.data_store.record import Record
+from dls_util.file import FileManager
+
+
+class Backup:
+
+    def __init__(self, backup_file):
+        self._backup_file = backup_file
+        self._file_manager = FileManager()
+        self._load_records_from_file()
+
+    def _load_records_from_file(self):
+        """ Clear the current record store and load a new set of records from the specified file. """
+        self.records = []
+
+        if not self._file_manager.is_file(self._backup_file):
+            return
+
+        lines = self._file_manager.read_lines(self._backup_file)
+        for line in lines:
+            try:
+                record = Record.from_string(line)
+                self.records.append(record)
+            except Exception:
+                print("Failed to parse store Record: {}".format(line))
+
+        #self._truncate_record_list()
+
+    def _to_backup_file(self):
+        """ Save the contents of the store to the backing file
+        """
+        record_lines = [rec.to_string() + "\n" for rec in self.records]
+        self._file_manager.write_lines(self._backup_file, record_lines)
+
+    def _truncate_record_list(self):
+        for record in self.records:
+            if self._is_old(record):
+                self.records.remove(record)
+
+    def backup_records(self, to_back):
+        self.records.extend(to_back)
+        self._truncate_record_list()
+        self._to_backup_file()
+
+    def _is_old(self,record):
+        tm = time.time()
+        record_time = record.timestamp
+        delta = tm - record_time
+        weeks = 3 * 604800 #3 weeks in seconds
+        return delta > weeks
+

dls_barcode/data_store/record.py

@@ -162,3 +162,4 @@ def _formatted_date(self):
         """
         return datetime.datetime.fromtimestamp(self.timestamp).strftime(Record.DATE_FORMAT)
 
+

dls_barcode/data_store/store.py

@@ -1,22 +1,24 @@
 import uuid
 import os
 
+from dls_barcode.data_store.backup import Backup
+from dls_util.file import FileManager
 from .record import Record
 
 
 class Store:
     """ Maintains a list of records of previous barcodes scans. Any changes (additions
     or deletions) are automatically written to the backing file.
     """
-    def __init__(self, directory, store_capacity, file_manager):
+    def __init__(self, directory, store_capacity):
         """ Initializes a new instance of Store.
         """
         self._store_capacity = store_capacity
         self._directory = directory
-        self._file_manager = file_manager
+        self._file_manager = FileManager()
         self._file = os.path.join(directory, "store.txt")
         self._csv_file = os.path.join(directory, "store.csv")
-        self._backup_csv_file = os.path.join(directory, "backup.csv")
+        self._backup = Backup(os.path.join(directory, "backup.txt"))
         self._img_dir = os.path.join(directory, "img_dir")
 
         if not self._file_manager.is_dir(self._img_dir):
@@ -85,8 +87,8 @@ def delete_records(self, records_to_delete):
 
         self._process_change()
 
-    def backup_records(self, records_to_back_up):
-        self._to_backup_csv_file(records_to_back_up)
+    def backup_records(self, records_to_backup):
+        self._backup.backup_records(records_to_backup)
 
     def _truncate_record_list(self):
         min_store_capacity = 2
@@ -122,11 +124,6 @@ def _to_csv_file(self):
         record_lines = [rec.to_csv_string() + "\n" for rec in self.records]
         self._file_manager.write_lines(self._csv_file, record_lines)
 
-    def _to_backup_csv_file(self, records):
-        """ Save the contents of the store to the backup csv file
-        """
-        record_lines = [rec.to_csv_string() + "\n" for rec in records]
-        self._file_manager.write_lines(self._backup_csv_file, record_lines)
 
     def _merge_holder_image_into_pins_image(self, holder_img, pins_img):
         factor = 0.22 * pins_img.width / holder_img.width

dls_barcode/gui/image_widget.py

@@ -15,5 +15,6 @@ def __init__(self, parent=None):
     def eventFilter(self, source, event):
         if source is self and event.type() == QtCore.QEvent.Resize:
             ma = self.pixmap()
-            self.setPixmap(ma.scaled(self.size(), QtCore.Qt.KeepAspectRatio, QtCore.Qt.SmoothTransformation))
+            if ma is not None:
+                self.setPixmap(ma.scaled(self.size(), QtCore.Qt.KeepAspectRatio, QtCore.Qt.SmoothTransformation))
         return QtWidgets.QWidget.eventFilter(self, source, event)

dls_barcode/gui/record_table.py

@@ -22,7 +22,7 @@ def __init__(self, barcode_table, image_frame, options):
         super(ScanRecordTable, self).__init__()
 
         # Read the store from file
-        self._store = Store(options.store_directory.value(), options.store_capacity, FileManager())
+        self._store = Store(options.store_directory.value(), options.store_capacity)
         self._options = options
 
         self._barcodeTable = barcode_table
@@ -115,7 +115,7 @@ def _record_selected(self):
             self._imageFrame.display_puck_image(marked_image)
         except IndexError:
             self._barcodeTable.clear()
-            self._imageFrame.clear_frame("Record table empty\nNothing to display")
+#            self._imageFrame.clear_frame("Record table empty\nNothing to display")
 
     def _delete_selected_records(self):
         """ Called when the 'Delete' button is pressed. Deletes all of the selected records

dls_util/file/file_manager.py

@@ -14,6 +14,11 @@ def write_lines(self, file_path, lines):
         with open(file_path, 'w') as file:
             file.writelines(lines)
 
+    def append_lines(self, file_path, lines):
+        """Calls file.writelines, so doesn't append any new line characters"""
+        with open(file_path, 'a') as file:
+            file.writelines(lines)
+
     def is_file(self, path):
         return os.path.isfile(path)