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Fee rates under
mempool pressure simulation
import sys, random, math
def hours(hrs):
return hrs * minutes(60)
def minutes(mins):
return 60 * mins
def megabytes(mega):
return mega * 1024 * 1024
def get_next_block_elapsed_time():
return int(random.gauss(minutes(10), minutes(1.5)))
# parameters
days = 1
txs_per_second = 8
block_size_mb = megabytes(1.1)
mempool_max_size_mb = megabytes(300)
tip = 0
time = 0;
next_block_time = get_next_block_elapsed_time()
mempool = []
mempool_size = 0
buckets = int(days * 20) * [1]
while time < days * hours(24):
target = int(random.gauss(3, 1))
estimated_fee_rate = buckets[target];
fee_rate = random.uniform(0.75 * estimated_fee_rate, 1.5 * estimated_fee_rate)
tx_size = int(random.gauss(500, 100))
fee = int(tx_size * fee_rate)
amount = int(random.uniform(0.0005, 10) * 100_000_000)
if fee < (amount / 100):
# if mempool_size > mempool_max_size_mb:
# mempool.sort(key=lambda tx: tx["paid_fee"], reverse=True)
# mempool = mempool[:(len(mempool) // 10) * 8]
# mempool_size = sum(tx["size"] for tx in mempool)
if mempool_size < mempool_max_size_mb:
mempool.append({"paid_fee": fee_rate, "broadcasted_block_time": tip, "size": tx_size})
mempool_size = mempool_size + tx_size
if int(time) == next_block_time:
cur_mempool = len(mempool)
mempool.sort(key=lambda tx: tx["paid_fee"], reverse=True)
tx_index = 0
block_size = 0
while tx_index < len(mempool) and (block_size < block_size_mb):
block_size = block_size + mempool[tx_index]["size"]
tx_index = tx_index + 1
block, mempool = mempool[:tx_index], mempool[tx_index:]
buckets_t = len(buckets) * [[]]
for tx in block:
mempool_size = mempool_size - tx["size"]
past_blocks = tip - tx["broadcasted_block_time"]
buckets_t[past_blocks] = buckets_t[past_blocks] + [tx["paid_fee"]]
buckets[past_blocks] = sum(buckets_t[past_blocks]) / len(buckets_t[past_blocks])
print(tip+1, block_size, cur_mempool, len(mempool))
tip = tip + 1
next_block_time = next_block_time + get_next_block_elapsed_time()
time = time + (1 / txs_per_second)
print(buckets)
#for fee in iter(buckets):
# print("{:.8f}".format(fee))