get_scanner

获取scanner对象，用于指定范围的数据扫描。可以通过scan_options参数指定扫描的模式。

  1. def get_scanner(self, hash_key,
  2.                 start_sort_key, stop_sort_key,
  3.                 scan_options):
  4.     """
  5.     Get scanner for hash_key, start from start_sort_key, and stop at stop_sort_key.
  6.     Whether the scanner include the start_sort_key and stop_sort_key is configurable by scan_options
  8.     :param hash_key: (str) which hash key used for this API.
  9.     :param start_sort_key: (str) returned scanner is start from start_sort_key.
  10.     :param stop_sort_key: (str) returned scanner is stop at stop_sort_key.
  11.     :param scan_options: (ScanOptions) configurable scan options.
  12.     :return: (PegasusScanner) scanner, instance of PegasusScanner.
  13.     """

其中，ScanOptions可以指定是否包含边界、超时时间、一次从replica server批量获取的sortkey-value数量等，具体定义如下：

  1. class ScanOptions(object):
  2.     """
  3.     configurable options for scan.
  4.     """
  6.     def __init__(self):
  7.         self.timeout_millis = 5000
  8.         self.batch_size = 1000
  9.         self.start_inclusive = True
  10.         self.stop_inclusive = False
  11.         self.snapshot = None                   # for future use