lbry-rocksdb/rocksdb/merge_operators.py
2017-04-25 19:33:42 +08:00

22 lines
714 B
Python

import struct as py_struct
from interfaces import AssociativeMergeOperator
class UintAddOperator(AssociativeMergeOperator):
def merge(self, key, existing_value, value):
if existing_value:
s = py_struct.unpack('Q', existing_value)[0] + py_struct.unpack('Q', value)[0]
return (True, py_struct.pack('Q', s))
return (True, value)
def name(self):
return b'uint64add'
class StringAppendOperator(AssociativeMergeOperator):
def merge(self, key, existing_value, value):
if existing_value:
s = existing_value + ',' + value
return (True, s)
return (True, value)
def name(self):
return b'StringAppendOperator'