#!/usr/bin/env python3 # Copyright (c) 2014-2016 The Bitcoin Core developers # Distributed under the MIT software license, see the accompanying # file COPYING or http://www.opensource.org/licenses/mit-license.php. """Test fee estimation code.""" from collections import OrderedDict from test_framework.test_framework import BitcoinTestFramework from test_framework.util import * # Construct 2 trivial P2SH's and the ScriptSigs that spend them # So we can create many many transactions without needing to spend # time signing. P2SH_1 = "2MySexEGVzZpRgNQ1JdjdP5bRETznm3roQ2" # P2SH of "OP_1 OP_DROP" P2SH_2 = "2NBdpwq8Aoo1EEKEXPNrKvr5xQr3M9UfcZA" # P2SH of "OP_2 OP_DROP" # Associated ScriptSig's to spend satisfy P2SH_1 and P2SH_2 # 4 bytes of OP_TRUE and push 2-byte redeem script of "OP_1 OP_DROP" or "OP_2 OP_DROP" SCRIPT_SIG = ["0451025175", "0451025275"] def small_txpuzzle_randfee(from_node, conflist, unconflist, amount, min_fee, fee_increment): """ Create and send a transaction with a random fee. The transaction pays to a trivial P2SH script, and assumes that its inputs are of the same form. The function takes a list of confirmed outputs and unconfirmed outputs and attempts to use the confirmed list first for its inputs. It adds the newly created outputs to the unconfirmed list. Returns (raw transaction, fee) """ # It's best to exponentially distribute our random fees # because the buckets are exponentially spaced. # Exponentially distributed from 1-128 * fee_increment rand_fee = float(fee_increment)*(1.1892**random.randint(0,28)) # Total fee ranges from min_fee to min_fee + 127*fee_increment fee = min_fee - fee_increment + satoshi_round(rand_fee) inputs = [] total_in = Decimal("0.00000000") while total_in <= (amount + fee) and len(conflist) > 0: t = conflist.pop(0) total_in += t["amount"] inputs.append({ "txid" : t["txid"], "vout" : t["vout"]} ) if total_in <= amount + fee: while total_in <= (amount + fee) and len(unconflist) > 0: t = unconflist.pop(0) total_in += t["amount"] inputs.append({ "txid" : t["txid"], "vout" : t["vout"]} ) if total_in <= amount + fee: raise RuntimeError("Insufficient funds: need %d, have %d"%(amount+fee, total_in)) outputs = {} outputs = OrderedDict([(P2SH_1, total_in - amount - fee), (P2SH_2, amount)]) rawtx = from_node.createrawtransaction(inputs, outputs) # createrawtransaction constructs a transaction that is ready to be signed. # These transactions don't need to be signed, but we still have to insert the ScriptSig # that will satisfy the ScriptPubKey. completetx = rawtx[0:10] inputnum = 0 for inp in inputs: completetx += rawtx[10+82*inputnum:82+82*inputnum] completetx += SCRIPT_SIG[inp["vout"]] completetx += rawtx[84+82*inputnum:92+82*inputnum] inputnum += 1 completetx += rawtx[10+82*inputnum:] txid = from_node.sendrawtransaction(completetx, True) unconflist.append({ "txid" : txid, "vout" : 0 , "amount" : total_in - amount - fee}) unconflist.append({ "txid" : txid, "vout" : 1 , "amount" : amount}) return (completetx, fee) def split_inputs(from_node, txins, txouts, initial_split = False): """ We need to generate a lot of very small inputs so we can generate a ton of transactions and they will have low priority. This function takes an input from txins, and creates and sends a transaction which splits the value into 2 outputs which are appended to txouts. """ prevtxout = txins.pop() inputs = [] inputs.append({ "txid" : prevtxout["txid"], "vout" : prevtxout["vout"] }) half_change = satoshi_round(prevtxout["amount"]/2) rem_change = prevtxout["amount"] - half_change - Decimal("0.00001000") outputs = OrderedDict([(P2SH_1, half_change), (P2SH_2, rem_change)]) rawtx = from_node.createrawtransaction(inputs, outputs) # If this is the initial split we actually need to sign the transaction # Otherwise we just need to insert the property ScriptSig if (initial_split) : completetx = from_node.signrawtransaction(rawtx)["hex"] else : completetx = rawtx[0:82] + SCRIPT_SIG[prevtxout["vout"]] + rawtx[84:] txid = from_node.sendrawtransaction(completetx, True) txouts.append({ "txid" : txid, "vout" : 0 , "amount" : half_change}) txouts.append({ "txid" : txid, "vout" : 1 , "amount" : rem_change}) def check_estimates(node, fees_seen, max_invalid, print_estimates = True): """ This function calls estimatefee and verifies that the estimates meet certain invariants. """ all_estimates = [ node.estimatefee(i) for i in range(1,26) ] if print_estimates: print([str(all_estimates[e-1]) for e in [1,2,3,6,15,25]]) delta = 1.0e-6 # account for rounding error last_e = max(fees_seen) for e in [x for x in all_estimates if x >= 0]: # Estimates should be within the bounds of what transactions fees actually were: if float(e)+delta < min(fees_seen) or float(e)-delta > max(fees_seen): raise AssertionError("Estimated fee (%f) out of range (%f,%f)" %(float(e), min(fees_seen), max(fees_seen))) # Estimates should be monotonically decreasing if float(e)-delta > last_e: raise AssertionError("Estimated fee (%f) larger than last fee (%f) for lower number of confirms" %(float(e),float(last_e))) last_e = e valid_estimate = False invalid_estimates = 0 for i,e in enumerate(all_estimates): # estimate is for i+1 if e >= 0: valid_estimate = True # estimatesmartfee should return the same result assert_equal(node.estimatesmartfee(i+1)["feerate"], e) else: invalid_estimates += 1 # estimatesmartfee should still be valid approx_estimate = node.estimatesmartfee(i+1)["feerate"] answer_found = node.estimatesmartfee(i+1)["blocks"] assert(approx_estimate > 0) assert(answer_found > i+1) # Once we're at a high enough confirmation count that we can give an estimate # We should have estimates for all higher confirmation counts if valid_estimate: raise AssertionError("Invalid estimate appears at higher confirm count than valid estimate") # Check on the expected number of different confirmation counts # that we might not have valid estimates for if invalid_estimates > max_invalid: raise AssertionError("More than (%d) invalid estimates"%(max_invalid)) return all_estimates class EstimateFeeTest(BitcoinTestFramework): def __init__(self): super().__init__() self.num_nodes = 3 self.setup_clean_chain = False def setup_network(self): """ We'll setup the network to have 3 nodes that all mine with different parameters. But first we need to use one node to create a lot of small low priority outputs which we will use to generate our transactions. """ self.nodes = [] # Use node0 to mine blocks for input splitting self.nodes.append(start_node(0, self.options.tmpdir, ["-maxorphantx=1000", "-whitelist=127.0.0.1"])) print("This test is time consuming, please be patient") print("Splitting inputs to small size so we can generate low priority tx's") self.txouts = [] self.txouts2 = [] # Split a coinbase into two transaction puzzle outputs split_inputs(self.nodes[0], self.nodes[0].listunspent(0), self.txouts, True) # Mine while (len(self.nodes[0].getrawmempool()) > 0): self.nodes[0].generate(1) # Repeatedly split those 2 outputs, doubling twice for each rep # Use txouts to monitor the available utxo, since these won't be tracked in wallet reps = 0 while (reps < 5): #Double txouts to txouts2 while (len(self.txouts)>0): split_inputs(self.nodes[0], self.txouts, self.txouts2) while (len(self.nodes[0].getrawmempool()) > 0): self.nodes[0].generate(1) #Double txouts2 to txouts while (len(self.txouts2)>0): split_inputs(self.nodes[0], self.txouts2, self.txouts) while (len(self.nodes[0].getrawmempool()) > 0): self.nodes[0].generate(1) reps += 1 print("Finished splitting") # Now we can connect the other nodes, didn't want to connect them earlier # so the estimates would not be affected by the splitting transactions # Node1 mines small blocks but that are bigger than the expected transaction rate. # NOTE: the CreateNewBlock code starts counting block size at 1,000 bytes, # (17k is room enough for 110 or so transactions) self.nodes.append(start_node(1, self.options.tmpdir, ["-blockmaxsize=17000", "-maxorphantx=1000", "-debug=estimatefee"])) connect_nodes(self.nodes[1], 0) # Node2 is a stingy miner, that # produces too small blocks (room for only 55 or so transactions) node2args = ["-blockmaxsize=8000", "-maxorphantx=1000"] self.nodes.append(start_node(2, self.options.tmpdir, node2args)) connect_nodes(self.nodes[0], 2) connect_nodes(self.nodes[2], 1) self.is_network_split = False self.sync_all() def transact_and_mine(self, numblocks, mining_node): min_fee = Decimal("0.00001") # We will now mine numblocks blocks generating on average 100 transactions between each block # We shuffle our confirmed txout set before each set of transactions # small_txpuzzle_randfee will use the transactions that have inputs already in the chain when possible # resorting to tx's that depend on the mempool when those run out for i in range(numblocks): random.shuffle(self.confutxo) for j in range(random.randrange(100-50,100+50)): from_index = random.randint(1,2) (txhex, fee) = small_txpuzzle_randfee(self.nodes[from_index], self.confutxo, self.memutxo, Decimal("0.005"), min_fee, min_fee) tx_kbytes = (len(txhex) // 2) / 1000.0 self.fees_per_kb.append(float(fee)/tx_kbytes) sync_mempools(self.nodes[0:3], wait=.1) mined = mining_node.getblock(mining_node.generate(1)[0],True)["tx"] sync_blocks(self.nodes[0:3], wait=.1) # update which txouts are confirmed newmem = [] for utx in self.memutxo: if utx["txid"] in mined: self.confutxo.append(utx) else: newmem.append(utx) self.memutxo = newmem def run_test(self): self.fees_per_kb = [] self.memutxo = [] self.confutxo = self.txouts # Start with the set of confirmed txouts after splitting print("Will output estimates for 1/2/3/6/15/25 blocks") for i in range(2): print("Creating transactions and mining them with a block size that can't keep up") # Create transactions and mine 10 small blocks with node 2, but create txs faster than we can mine self.transact_and_mine(10, self.nodes[2]) check_estimates(self.nodes[1], self.fees_per_kb, 14) print("Creating transactions and mining them at a block size that is just big enough") # Generate transactions while mining 10 more blocks, this time with node1 # which mines blocks with capacity just above the rate that transactions are being created self.transact_and_mine(10, self.nodes[1]) check_estimates(self.nodes[1], self.fees_per_kb, 2) # Finish by mining a normal-sized block: while len(self.nodes[1].getrawmempool()) > 0: self.nodes[1].generate(1) sync_blocks(self.nodes[0:3], wait=.1) print("Final estimates after emptying mempools") check_estimates(self.nodes[1], self.fees_per_kb, 2) if __name__ == '__main__': EstimateFeeTest().main()