Bloom filter problem when number of elements are low and FPRate is high
MBakhshi96 opened this issue · comments
The length of bloom filter as determined in this line
python-bitcoinlib/bitcoin/bloom.py
Line 116 in b5540e8
becomes
0
when number of elements nElements
is 1
and nFPRate
is more than 0.03
. This causes every pubkeyhash to return True
when checked using contains
method.
The way the length of the filter is determined using bytearray
also causes some problems, for example for some values, say 0.0005 < nFPRate < 0.01
and nElements = 1
when you change nFPRate
the length of the filter doesn't change. This means that regardless of the false positive rate, filter length and its construction is the same. This leads to a wrong false positive rate, different than the parameter passed for filter construction.
A possible fix could be to use bitarray
instead of bytearray
.