a playground for bitcoin Core's fee estimation buckets

buckets.py

#!/usr/bin/python

# last bucket with more than 2^14 sat/byte
BUCKETCOUNT = 200

# defines a 5% increase per bucket
# https://github.com/bitcoin/bitcoin/commit/e5007bae35ce22036a816505038277d99c84e3f7#diff-8c0941572d1cdf184d1751f7b7f1db4eR109
FEE_SPACING = 1.05

# list of fee buckets
BUCKETS = []

# fills the bucket list
bucketFillIndex = 0
BUCKETS.append(1) # initial bucket with 1 sat / byte
for bucketFillIndex in range(1,BUCKETCOUNT):
    BUCKETS.append(BUCKETS[bucketFillIndex-1] * FEE_SPACING) # append bucket with 5% more than the previous


# binary find bucket by Fee in BUCKETS
def findBucketByFee(feerate):
    posFirst = 0
    posLast = len(BUCKETS)-1

    if feerate >= BUCKETS[posLast]:
        return posLast
    if feerate <= BUCKETS[posFirst]:
        return posFirst

    while posFirst<=posLast:
        posMid = (posFirst+posLast)//2
        if BUCKETS[posMid] <= feerate and BUCKETS[posMid+1] > feerate:
            return posMid
        if BUCKETS[posMid] > feerate:
            posLast = posMid - 1
        if BUCKETS[posMid] < feerate:
            posFirst = posMid + 1

# function to manually verify a feerate for a bucket
def test(feerate):
    print str(feerate) + " is in bucket " + str(findBucketByFee(feerate))

# example tests for 1, 1.5, 2 sat/byte
test(1)
test(1.5)
test(2)

# print all buckets
counter = 0
for bucket in BUCKETS:
    print str(counter) + " - " + str(bucket)
    counter+=1