text: #!/usr/bin/env python3
  # Copyright (c) 2015-2016 The C-Bit Core developers
  # Distributed under the MIT software license, see the accompanying
  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #
  # Test PrioritiseTransaction code
  #
  
  from test_framework.test_framework import BitcoinTestFramework
  from test_framework.util import *
  from test_framework.mininode import COIN, MAX_BLOCK_SIZE
  
  class PrioritiseTransactionTest(BitcoinTestFramework):
  
      def __init__(self):
          super().__init__()
          self.setup_clean_chain = True
          self.num_nodes = 1
  
          self.txouts = gen_return_txouts()
  
      def setup_network(self):
          self.nodes = []
          self.is_network_split = False
  
          self.nodes.append(start_node(0, self.options.tmpdir, ["-debug", "-printpriority=1"]))
          self.relayfee = self.nodes[0].getnetworkinfo()['relayfee']
  
      def run_test(self):
          utxo_count = 90
          utxos = create_confirmed_utxos(self.relayfee, self.nodes[0], utxo_count)
          base_fee = self.relayfee*100 # our transactions are smaller than 100kb
          txids = []
  
          # Create 3 batches of transactions at 3 different fee rate levels
  		range_size = utxo_count // 3
          for i in range(3):
              txids.append([])
              start_range = i * range_size
              end_range = start_range + range_size
              txids[i] = create_lots_of_big_transactions(self.nodes[0], self.txouts, utxos[start_range:end_range], (i+1)*base_fee)
  
          # Make sure that the size of each group of transactions exceeds
          # MAX_BLOCK_SIZE -- otherwise the test needs to be revised to create
          # more transactions.
          mempool = self.nodes[0].getrawmempool(True)
          sizes = [0, 0, 0]
          for i in range(3):
              for j in txids[i]:
                  assert(j in mempool)
                  sizes[i] += mempool[j]['size']
              assert(sizes[i] > MAX_BLOCK_SIZE) # Fail => raise utxo_count
  
          # add a fee delta to something in the cheapest bucket and make sure it gets mined
          # also check that a different entry in the cheapest bucket is NOT mined (lower
          # the priority to ensure its not mined due to priority)
          self.nodes[0].prioritisetransaction(txids[0][0], 0, int(3*base_fee*COIN))
          self.nodes[0].prioritisetransaction(txids[0][1], -1e15, 0)
  
          self.nodes[0].generate(1)
  
          mempool = self.nodes[0].getrawmempool()
          print("Assert that prioritised transaction was mined")
          assert(txids[0][0] not in mempool)
          assert(txids[0][1] in mempool)
  
          high_fee_tx = None
          for x in txids[2]:
              if x not in mempool:
                  high_fee_tx = x
  
          # Something high-fee should have been mined!
          assert(high_fee_tx != None)
  
          # Add a prioritisation before a tx is in the mempool (de-prioritising a
          # high-fee transaction so that it's now low fee).
          self.nodes[0].prioritisetransaction(high_fee_tx, -1e15, -int(2*base_fee*COIN))
  
          # Add everything back to mempool
          self.nodes[0].invalidateblock(self.nodes[0].getbestblockhash())
  
          # Check to make sure our high fee rate tx is back in the mempool
          mempool = self.nodes[0].getrawmempool()
          assert(high_fee_tx in mempool)
  
          # Now verify the modified-high feerate transaction isn't mined before
          # the other high fee transactions. Keep mining until our mempool has
          # decreased by all the high fee size that we calculated above.
          while (self.nodes[0].getmempoolinfo()['bytes'] > sizes[0] + sizes[1]):
              self.nodes[0].generate(1)
  
          # High fee transaction should not have been mined, but other high fee rate
          # transactions should have been.
          mempool = self.nodes[0].getrawmempool()
          print("Assert that de-prioritised transaction is still in mempool")
          assert(high_fee_tx in mempool)
          for x in txids[2]:
              if (x != high_fee_tx):
                  assert(x not in mempool)
  
          # Create a free, low priority transaction.  Should be rejected.
          utxo_list = self.nodes[0].listunspent()
          assert(len(utxo_list) > 0)
          utxo = utxo_list[0]
  
          inputs = []
          outputs = {}
          inputs.append({"txid" : utxo["txid"], "vout" : utxo["vout"]})
          outputs[self.nodes[0].getnewaddress()] = utxo["amount"] - self.relayfee
          raw_tx = self.nodes[0].createrawtransaction(inputs, outputs)
          tx_hex = self.nodes[0].signrawtransaction(raw_tx)["hex"]
          txid = self.nodes[0].sendrawtransaction(tx_hex)
  
          # A tx that spends an in-mempool tx has 0 priority, so we can use it to
          # test the effect of using prioritise transaction for mempool acceptance
          inputs = []
          inputs.append({"txid": txid, "vout": 0})
          outputs = {}
          outputs[self.nodes[0].getnewaddress()] = utxo["amount"] - self.relayfee
          raw_tx2 = self.nodes[0].createrawtransaction(inputs, outputs)
          tx2_hex = self.nodes[0].signrawtransaction(raw_tx2)["hex"]
          tx2_id = self.nodes[0].decoderawtransaction(tx2_hex)["txid"]
  
          try:
              self.nodes[0].sendrawtransaction(tx2_hex)
          except JSONRPCException as exp:
              assert_equal(exp.error['code'], -26) # insufficient fee
              assert(tx2_id not in self.nodes[0].getrawmempool())
          else:
              assert(False)
  
          # This is a less than 1000-byte transaction, so just set the fee
          # to be the minimum for a 1000 byte transaction and check that it is
          # accepted.
          self.nodes[0].prioritisetransaction(tx2_id, 0, int(self.relayfee*COIN))
  
          print("Assert that prioritised free transaction is accepted to mempool")
          assert_equal(self.nodes[0].sendrawtransaction(tx2_hex), tx2_id)
          assert(tx2_id in self.nodes[0].getrawmempool())
  
  if __name__ == '__main__':
      PrioritiseTransactionTest().main()
  