save selection to file if above threshold

logFileModel.py

@@ -56,6 +56,18 @@ class LogFileModel:
                 bytes = f.read(end_byte - start_byte)
                 return bytes.decode("utf8", errors="ignore")
 
+    def write_range(self, start_byte: int, end_byte: int, file: str):
+        print("write range: %d - %d -> %s" % (start_byte, end_byte, file))
+        with self._lock, open(self._file, 'rb') as source, open(file, "w+b") as target:
+            offset = start_byte
+            source.seek(offset)
+            while offset < end_byte:
+                new_offset = min(offset + 1024 * 1024, end_byte)
+                buffer_size = new_offset - offset
+                buffer = source.read(buffer_size)
+                target.write(buffer)
+                offset = new_offset
+
     def data(self, byte_offset, scroll_lines, lines) -> List[Line]:
         # print("data(%s, %s, %s)" % (byte_offset, scroll_lines, lines))
         lines_before_offset: List[Line] = []