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[SPARK-10642][PySpark] Fix crash when calling rdd.lookup() on tuple keys #8796

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[SPARK-10642][PySpark] Fix crash when calling rdd.lookup() on tuple keys #8796

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1eac461
Fix hash value for tuple.
viirya Sep 17, 2015
d5bfb01
Add test.
viirya Sep 17, 2015
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5 changes: 4 additions & 1 deletion python/pyspark/rdd.py
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Original file line number Diff line number Diff line change
Expand Up @@ -84,7 +84,7 @@ def portable_hash(x):
h ^= len(x)
if h == -1:
h = -2
return h
return int(h)
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Just asking the dumb question here, but is this intended to return an int? sys.maxsize does not appear to be the max positive 32-bit int.

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Should it use sys.maxint instead?

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CC @davies the real question is whether this hash is intended to be 32-bit or 64-bit, and my Python knowledge is too limited to reason about this. It appears that it's computing a 64-bit hash given the size of sys.maxsize but maybe that's platform dependent or something. Anyway: I kind of suspect you're right that it's 32-bit, but I think that has to be verified first.

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The h become a long when h *= 1000003, even after h &= sys.maxsize or (maxint).

The fix looks good to me.

return hash(x)


Expand Down Expand Up @@ -2192,6 +2192,9 @@ def lookup(self, key):
[42]
>>> sorted.lookup(1024)
[]
>>> rdd2 = sc.parallelize([(('a', 'b'), 'c')]).groupByKey()
>>> list(rdd2.lookup(('a', 'b'))[0])
['c']
"""
values = self.filter(lambda kv: kv[0] == key).values()

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