def testFallbackPrecedenceWhenServerRemoved(self):
mockHasher = MockHasher()
hashSpace = Flexihash(mockHasher, 1)
mockHasher.setHashValue(10)
hashSpace.addTarget("t1")
mockHasher.setHashValue(20)
hashSpace.addTarget("t2")
mockHasher.setHashValue(30)
hashSpace.addTarget("t3")
mockHasher.setHashValue(15)
self.assertEqual(hashSpace.lookup('resource'), 't2')
self.assertEqual(hashSpace.lookupList('resource', 3),
['t2', 't3', 't1'])
hashSpace.removeTarget('t2')
self.assertEqual(hashSpace.lookup('resource'), 't3')
self.assertEqual(hashSpace.lookupList('resource', 3), ['t3', 't1'])
hashSpace.removeTarget('t3')
self.assertEqual(hashSpace.lookup('resource'), 't1')
self.assertEqual(hashSpace.lookupList('resource', 3), ['t1'])
def testLookupListReturnsWithShortListIfAllTargetsUsed(self):
hashSpace = Flexihash()
# both have CRC32 of 1253617450
hashSpace.addTarget("x").addTarget("y") # make the list non-empty, non-one-value, to avoid shortcuts
hashSpace.addTarget("80726") # add a value
hashSpace.addTarget("14746907") # add a different value with the same hash, to clobber the first
hashSpace.removeTarget("14746907") # remove the fourth value; with the third clobbered, only X and Y are left
result = hashSpace.lookupList('test', 3) # try to get 3 results, our target list is X, Y, 80726
self.assertEqual(len(result), 2) # but 80726 isn't reachable since it was clobbered
self.assertIn("x", result) # all that's left is x
self.assertIn("y", result) # and y
def testLookupListReturnsWithShortListIfAllTargetsUsed(self):
hashSpace = Flexihash()
# both have CRC32 of 1253617450
hashSpace.addTarget("x").addTarget(
"y") # make the list non-empty, non-one-value, to avoid shortcuts
hashSpace.addTarget("80726") # add a value
hashSpace.addTarget(
"14746907"
) # add a different value with the same hash, to clobber the first
hashSpace.removeTarget(
"14746907"
) # remove the fourth value; with the third clobbered, only X and Y are left
result = hashSpace.lookupList(
'test', 3) # try to get 3 results, our target list is X, Y, 80726
self.assertEqual(len(result),
2) # but 80726 isn't reachable since it was clobbered
self.assertIn("x", result) # all that's left is x
self.assertIn("y", result) # and y
def testFallbackPrecedenceWhenServerRemoved(self):
mockHasher = MockHasher()
hashSpace = Flexihash(mockHasher, 1)
mockHasher.setHashValue(10)
hashSpace.addTarget("t1")
mockHasher.setHashValue(20)
hashSpace.addTarget("t2")
mockHasher.setHashValue(30)
hashSpace.addTarget("t3")
mockHasher.setHashValue(15)
self.assertEqual(hashSpace.lookup('resource'), 't2')
self.assertEqual(
hashSpace.lookupList('resource', 3),
['t2', 't3', 't1']
)
hashSpace.removeTarget('t2')
self.assertEqual(hashSpace.lookup('resource'), 't3')
self.assertEqual(
hashSpace.lookupList('resource', 3),
['t3', 't1']
)
hashSpace.removeTarget('t3')
self.assertEqual(hashSpace.lookup('resource'), 't1')
self.assertEqual(
hashSpace.lookupList('resource', 3),
['t1']
)
