[THRIFT-3388] hash doesn't work on set/list

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.9.3
• Fix Version/s: 0.10.0
• Component/s: Python - Compiler

Environment

ubuntu 14.04 python 2.6.9

• Assignee: Jens Geyer
• Reporter: Michi Mutsuzaki
• Created: 16/Oct/15 00:05
• Updated: 18/Mar/16 17:54
• Resolved: 18/Mar/16 17:54

Description

THRIFT-2621 added hash function to thrift generated classes, but certain types like set or list cannot be hashed. One solution is to convert them to immutable types (fronzenset, tuple) before calling hash() on them.

$ thrift -version
Thrift version 0.9.3

$ cat test.thrift
struct Test {
  1: required set<string> test
}

$ thrift --gen py -out . test.thrift

$ cat test.py    
from test.ttypes import Test
from thrift.protocol import TBinaryProtocol
from thrift.transport import TTransport

# serialize
t = Test(test=set(["a"]))
tout = TTransport.TMemoryBuffer()
pout = TBinaryProtocol.TBinaryProtocol(tout)
t.write(pout)

# deserialize
tin = TTransport.TMemoryBuffer(tout.getvalue())
pin = TBinaryProtocol.TBinaryProtocol(tin)
t2 = Test()
t2.read(pin)

# put the deserialized object to a set
a = set([t2])

$ python test.py
Traceback (most recent call last):
  File "test.py", line 18, in <module>
    a = set([t2])
  File "/tmp/test/test/ttypes.py", line 81, in __hash__
    value = (value * 31) ^ hash(self.test)
TypeError: unhashable type: 'set'

Issue Links

• is broken by: THRIFT-2621 Add basic default hash code method to python
• is related to: THRIFT-162 Thrift structures are unhashable, preventing them from being used as set elements
• is related to: THRIFT-2621 Add basic default hash code method to python
• is related to: AURORA-1083 Upgrade to thrift 0.9.2