Merge #18485: test: Add mempool_updatefromblock.py

8098dea06944f9de8b285f44958eb98761f133ee test: Add mempool_updatefromblock.py (Hennadii Stepanov)

Pull request description:

  This PR adds a new test for mempool update of transaction descendants/ancestors information (count, size) when transactions have been re-added from a disconnected block to the mempool.

  It could be helpful for working on PRs like #17925, #18191.

ACKs for top commit:
  ariard:
    ACK 8098dea

Tree-SHA512: 7e808fa8df8d7d7a7dbdc3f79361049b49c7bce9b58fd5539b28c9636bedac747695537e500d7ed68dc8bdb80167ad3f1c01086f7551691405d2ba2e38ef1d06

2 files changed, 124 insertions, 0 deletions

diff --git a/test/functional/mempool_updatefromblock.py b/test/functional/mempool_updatefromblock.py
new file mode 100755
index 0000000000..8a703ef009
--- /dev/null
+++ b/test/functional/mempool_updatefromblock.py
@@ -0,0 +1,123 @@
+#!/usr/bin/env python3
+# Copyright (c) 2020 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 mempool descendants/ancestors information update.
+
+Test mempool update of transaction descendants/ancestors information (count, size)
+when transactions have been re-added from a disconnected block to the mempool.
+"""
+import time
+
+from decimal import Decimal
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import assert_equal
+
+
+class MempoolUpdateFromBlockTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.num_nodes = 1
+        self.extra_args = [['-limitdescendantsize=1000', '-limitancestorsize=1000']]
+
+    def skip_test_if_missing_module(self):
+        self.skip_if_no_wallet()
+
+    def transaction_graph_test(self, size, n_tx_to_mine=None, start_input_txid='', end_address='', fee=Decimal(0.00100000)):
+        """Create an acyclic tournament (a type of directed graph) of transactions and use it for testing.
+
+        Keyword arguments:
+        size -- the order N of the tournament which is equal to the number of the created transactions
+        n_tx_to_mine -- the number of transaction that should be mined into a block
+
+        If all of the N created transactions tx[0]..tx[N-1] reside in the mempool,
+        the following holds:
+            the tx[K] transaction:
+            - has N-K descendants (including this one), and
+            - has K+1 ancestors (including this one)
+
+        More details: https://en.wikipedia.org/wiki/Tournament_(graph_theory)
+        """
+
+        if not start_input_txid:
+            start_input_txid = self.nodes[0].getblock(self.nodes[0].getblockhash(1))['tx'][0]
+
+        if not end_address:
+            end_address = self.nodes[0].getnewaddress()
+
+        first_block_hash = ''
+        tx_id = []
+        tx_size = []
+        self.log.info('Creating {} transactions...'.format(size))
+        for i in range(0, size):
+            self.log.debug('Preparing transaction #{}...'.format(i))
+            # Prepare inputs.
+            if i == 0:
+                inputs = [{'txid': start_input_txid, 'vout': 0}]
+                inputs_value = self.nodes[0].gettxout(start_input_txid, 0)['value']
+            else:
+                inputs = []
+                inputs_value = 0
+                for j, tx in enumerate(tx_id[0:i]):
+                    # Transaction tx[K] is a child of each of previous transactions tx[0]..tx[K-1] at their output K-1.
+                    vout = i - j - 1
+                    inputs.append({'txid': tx_id[j], 'vout': vout})
+                    inputs_value += self.nodes[0].gettxout(tx, vout)['value']
+
+            self.log.debug('inputs={}'.format(inputs))
+            self.log.debug('inputs_value={}'.format(inputs_value))
+
+            # Prepare outputs.
+            tx_count = i + 1
+            if tx_count < size:
+                # Transaction tx[K] is an ancestor of each of subsequent transactions tx[K+1]..tx[N-1].
+                n_outputs = size - tx_count
+                output_value = ((inputs_value - fee) / Decimal(n_outputs)).quantize(Decimal('0.00000001'))
+                outputs = {}
+                for n in range(0, n_outputs):
+                    outputs[self.nodes[0].getnewaddress()] = output_value
+            else:
+                output_value = (inputs_value - fee).quantize(Decimal('0.00000001'))
+                outputs = {end_address: output_value}
+
+            self.log.debug('output_value={}'.format(output_value))
+            self.log.debug('outputs={}'.format(outputs))
+
+            # Create a new transaction.
+            unsigned_raw_tx = self.nodes[0].createrawtransaction(inputs, outputs)
+            signed_raw_tx = self.nodes[0].signrawtransactionwithwallet(unsigned_raw_tx)
+            tx_id.append(self.nodes[0].sendrawtransaction(signed_raw_tx['hex']))
+            tx_size.append(self.nodes[0].getrawmempool(True)[tx_id[-1]]['vsize'])
+
+            if tx_count in n_tx_to_mine:
+                # The created transactions are mined into blocks by batches.
+                self.log.info('The batch of {} transactions has been accepted into the mempool.'.format(len(self.nodes[0].getrawmempool())))
+                block_hash = self.nodes[0].generate(1)[0]
+                if not first_block_hash:
+                    first_block_hash = block_hash
+                assert_equal(len(self.nodes[0].getrawmempool()), 0)
+                self.log.info('All of the transactions from the current batch have been mined into a block.')
+            elif tx_count == size:
+                # At the end all of the mined blocks are invalidated, and all of the created
+                # transactions should be re-added from disconnected blocks to the mempool.
+                self.log.info('The last batch of {} transactions has been accepted into the mempool.'.format(len(self.nodes[0].getrawmempool())))
+                start = time.time()
+                self.nodes[0].invalidateblock(first_block_hash)
+                end = time.time()
+                assert_equal(len(self.nodes[0].getrawmempool()), size)
+                self.log.info('All of the recently mined transactions have been re-added into the mempool in {} seconds.'.format(end - start))
+
+        self.log.info('Checking descendants/ancestors properties of all of the in-mempool transactions...')
+        for k, tx in enumerate(tx_id):
+            self.log.debug('Check transaction #{}.'.format(k))
+            assert_equal(self.nodes[0].getrawmempool(True)[tx]['descendantcount'], size - k)
+            assert_equal(self.nodes[0].getrawmempool(True)[tx]['descendantsize'], sum(tx_size[k:size]))
+            assert_equal(self.nodes[0].getrawmempool(True)[tx]['ancestorcount'], k + 1)
+            assert_equal(self.nodes[0].getrawmempool(True)[tx]['ancestorsize'], sum(tx_size[0:(k + 1)]))
+
+    def run_test(self):
+        # Use batch size limited by DEFAULT_ANCESTOR_LIMIT = 25 to not fire "too many unconfirmed parents" error.
+        self.transaction_graph_test(size=100, n_tx_to_mine=[25, 50, 75])
+
+
+if __name__ == '__main__':
+    MempoolUpdateFromBlockTest().main()
diff --git a/test/functional/test_runner.py b/test/functional/test_runner.py
index 344df368a8..6f5f61de2c 100755
--- a/test/functional/test_runner.py
+++ b/test/functional/test_runner.py
@@ -93,6 +93,7 @@ BASE_SCRIPTS = [
     'p2p_segwit.py',
     'p2p_timeouts.py',
     'p2p_tx_download.py',
+    'mempool_updatefromblock.py',
     'wallet_dump.py',
     'wallet_listtransactions.py',
     # vv Tests less than 60s vv