text: #!/usr/bin/env python3
  # Copyright (c) 2014-2016 The Bitcoin Core developers
  # Copyright (c) 2017-2018 The STP Core developers
  # Distributed under the MIT software license, see the accompanying
  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  """Test the pruning code.
  
  WARNING:
  This test uses 4GB of disk space.
  This test takes 30 mins or more (up to 2 hours)
  """
  
  from test_framework.test_framework import STPTestFramework
  from test_framework.util import *
  import time
  import os
  
  MIN_BLOCKS_TO_KEEP = 288
  
  # Rescans start at the earliest block up to 2 hours before a key timestamp, so
  # the manual prune RPC avoids pruning blocks in the same window to be
  # compatible with pruning based on key creation time.
  TIMESTAMP_WINDOW = 2 * 60 * 60
  
  
  def calc_usage(blockdir):
      return sum(os.path.getsize(blockdir+f) for f in os.listdir(blockdir) if os.path.isfile(blockdir+f)) / (1024. * 1024.)
  
  class PruneTest(STPTestFramework):
      def set_test_params(self):
          self.setup_clean_chain = True
          self.num_nodes = 6
  
          # Create nodes 0 and 1 to mine.
          # Create node 2 to test pruning.
          self.full_node_default_args = ["-maxreceivebuffer=20000","-blockmaxsize=999000", "-checkblocks=5", "-limitdescendantcount=100", "-limitdescendantsize=5000", "-limitancestorcount=100", "-limitancestorsize=5000" ]
          # Create nodes 3 and 4 to test manual pruning (they will be re-started with manual pruning later)
          # Create nodes 5 to test wallet in prune mode, but do not connect
          self.extra_args = [self.full_node_default_args,
                             self.full_node_default_args,
                             ["-maxreceivebuffer=20000", "-prune=550"],
                             ["-maxreceivebuffer=20000", "-blockmaxsize=999000"],
                             ["-maxreceivebuffer=20000", "-blockmaxsize=999000"],
                             ["-prune=550"]]
  
      def setup_network(self):
          self.setup_nodes()
  
          self.prunedir = self.options.tmpdir + "/node2/regtest/blocks/"
  
          connect_nodes(self.nodes[0], 1)
          connect_nodes(self.nodes[1], 2)
          connect_nodes(self.nodes[2], 0)
          connect_nodes(self.nodes[0], 3)
          connect_nodes(self.nodes[0], 4)
          sync_blocks(self.nodes[0:5])
  
      def setup_nodes(self):
          self.add_nodes(self.num_nodes, self.extra_args, timewait=900)
          self.start_nodes()
  
      def create_big_chain(self):
          # Start by creating some coinbases we can spend later
          self.nodes[1].generate(200)
          sync_blocks(self.nodes[0:2])
          self.nodes[0].generate(150)
          # Then mine enough full blocks to create more than 550MiB of data
          for i in range(645):
              mine_large_block(self.nodes[0], self.utxo_cache_0)
  
          sync_blocks(self.nodes[0:5])
  
      def test_height_min(self):
          if not os.path.isfile(self.prunedir+"blk00000.dat"):
              raise AssertionError("blk00000.dat is missing, pruning too early")
          self.log.info("Success")
          self.log.info("Though we're already using more than 550MiB, current usage: %d" % calc_usage(self.prunedir))
          self.log.info("Mining 25 more blocks should cause the first block file to be pruned")
          # Pruning doesn't run until we're allocating another chunk, 20 full blocks past the height cutoff will ensure this
          for i in range(25):
              mine_large_block(self.nodes[0], self.utxo_cache_0)
  
          waitstart = time.time()
          while os.path.isfile(self.prunedir+"blk00000.dat"):
              time.sleep(0.1)
              if time.time() - waitstart > 30:
                  raise AssertionError("blk00000.dat not pruned when it should be")
  
          self.log.info("Success")
          usage = calc_usage(self.prunedir)
          self.log.info("Usage should be below target: %d" % usage)
          if (usage > 550):
              raise AssertionError("Pruning target not being met")
  
      def create_chain_with_staleblocks(self):
          # Create stale blocks in manageable sized chunks
          self.log.info("Mine 24 (stale) blocks on Node 1, followed by 25 (main chain) block reorg from Node 0, for 12 rounds")
  
          for j in range(12):
              # Disconnect node 0 so it can mine a longer reorg chain without knowing about node 1's soon-to-be-stale chain
              # Node 2 stays connected, so it hears about the stale blocks and then reorg's when node0 reconnects
              # Stopping node 0 also clears its mempool, so it doesn't have node1's transactions to accidentally mine
              self.stop_node(0)
              self.start_node(0, extra_args=self.full_node_default_args)
              # Mine 24 blocks in node 1
              for i in range(24):
                  if j == 0:
                      mine_large_block(self.nodes[1], self.utxo_cache_1)
                  else:
                      # Add node1's wallet transactions back to the mempool, to
                      # avoid the mined blocks from being too small.
                      self.nodes[1].resendwallettransactions()
                      self.nodes[1].generate(1) #tx's already in mempool from previous disconnects
  
              # Reorg back with 25 block chain from node 0
              for i in range(25):
                  mine_large_block(self.nodes[0], self.utxo_cache_0)
  
              # Create connections in the order so both nodes can see the reorg at the same time
              connect_nodes(self.nodes[1], 0)
              connect_nodes(self.nodes[2], 0)
              sync_blocks(self.nodes[0:3])
  
          self.log.info("Usage can be over target because of high stale rate: %d" % calc_usage(self.prunedir))
  
      def reorg_test(self):
          # Node 1 will mine a 300 block chain starting 287 blocks back from Node 0 and Node 2's tip
          # This will cause Node 2 to do a reorg requiring 288 blocks of undo data to the reorg_test chain
          # Reboot node 1 to clear its mempool (hopefully make the invalidate faster)
          # Lower the block max size so we don't keep mining all our big mempool transactions (from disconnected blocks)
          self.stop_node(1)
          self.start_node(1, extra_args=["-maxreceivebuffer=20000","-blockmaxsize=5000", "-checkblocks=5", "-disablesafemode"])
  
          height = self.nodes[1].getblockcount()
          self.log.info("Current block height: %d" % height)
  
          invalidheight = height-287
          badhash = self.nodes[1].getblockhash(invalidheight)
          self.log.info("Invalidating block %s at height %d" % (badhash,invalidheight))
          self.nodes[1].invalidateblock(badhash)
  
          # We've now switched to our previously mined-24 block fork on node 1, but that's not what we want
          # So invalidate that fork as well, until we're on the same chain as node 0/2 (but at an ancestor 288 blocks ago)
          mainchainhash = self.nodes[0].getblockhash(invalidheight - 1)
          curhash = self.nodes[1].getblockhash(invalidheight - 1)
          while curhash != mainchainhash:
              self.nodes[1].invalidateblock(curhash)
              curhash = self.nodes[1].getblockhash(invalidheight - 1)
  
          assert(self.nodes[1].getblockcount() == invalidheight - 1)
          self.log.info("New best height: %d" % self.nodes[1].getblockcount())
  
          # Reboot node1 to clear those giant tx's from mempool
          self.stop_node(1)
          self.start_node(1, extra_args=["-maxreceivebuffer=20000","-blockmaxsize=5000", "-checkblocks=5", "-disablesafemode"])
  
          self.log.info("Generating new longer chain of 300 more blocks")
          self.nodes[1].generate(300)
  
          self.log.info("Reconnect nodes")
          connect_nodes(self.nodes[0], 1)
          connect_nodes(self.nodes[2], 1)
          sync_blocks(self.nodes[0:3], timeout=120)
  
          self.log.info("Verify height on node 2: %d" % self.nodes[2].getblockcount())
          self.log.info("Usage possibly still high bc of stale blocks in block files: %d" % calc_usage(self.prunedir))
  
          self.log.info("Mine 220 more blocks so we have requisite history (some blocks will be big and cause pruning of previous chain)")
  
          # Get node0's wallet transactions back in its mempool, to avoid the
          # mined blocks from being too small.
          self.nodes[0].resendwallettransactions()
  
          for i in range(22):
              # This can be slow, so do this in multiple RPC calls to avoid
              # RPC timeouts.
              self.nodes[0].generate(10) #node 0 has many large tx's in its mempool from the disconnects
          sync_blocks(self.nodes[0:3], timeout=300)
  
          usage = calc_usage(self.prunedir)
          self.log.info("Usage should be below target: %d" % usage)
          if (usage > 550):
              raise AssertionError("Pruning target not being met")
  
          return invalidheight,badhash
  
      def reorg_back(self):
          # Verify that a block on the old main chain fork has been pruned away
          assert_raises_rpc_error(-1, "Block not available (pruned data)", self.nodes[2].getblock, self.forkhash)
          self.log.info("Will need to redownload block %d" % self.forkheight)
  
          # Verify that we have enough history to reorg back to the fork point
          # Although this is more than 288 blocks, because this chain was written more recently
          # and only its other 299 small and 220 large block are in the block files after it,
          # its expected to still be retained
          self.nodes[2].getblock(self.nodes[2].getblockhash(self.forkheight))
  
          first_reorg_height = self.nodes[2].getblockcount()
          curchainhash = self.nodes[2].getblockhash(self.mainchainheight)
          self.nodes[2].invalidateblock(curchainhash)
          goalbestheight = self.mainchainheight
          goalbesthash = self.mainchainhash2
  
          # As of 0.10 the current block download logic is not able to reorg to the original chain created in
          # create_chain_with_stale_blocks because it doesn't know of any peer that's on that chain from which to
          # redownload its missing blocks.
          # Invalidate the reorg_test chain in node 0 as well, it can successfully switch to the original chain
          # because it has all the block data.
          # However it must mine enough blocks to have a more work chain than the reorg_test chain in order
          # to trigger node 2's block download logic.
          # At this point node 2 is within 288 blocks of the fork point so it will preserve its ability to reorg
          if self.nodes[2].getblockcount() < self.mainchainheight:
              blocks_to_mine = first_reorg_height + 1 - self.mainchainheight
              self.log.info("Rewind node 0 to prev main chain to mine longer chain to trigger redownload. Blocks needed: %d" % blocks_to_mine)
              self.nodes[0].invalidateblock(curchainhash)
              assert(self.nodes[0].getblockcount() == self.mainchainheight)
              assert(self.nodes[0].getbestblockhash() == self.mainchainhash2)
              goalbesthash = self.nodes[0].generate(blocks_to_mine)[-1]
              goalbestheight = first_reorg_height + 1
  
          self.log.info("Verify node 2 reorged back to the main chain, some blocks of which it had to redownload")
          waitstart = time.time()
          while self.nodes[2].getblockcount() < goalbestheight:
              time.sleep(0.1)
              if time.time() - waitstart > 900:
                  raise AssertionError("Node 2 didn't reorg to proper height")
          assert(self.nodes[2].getbestblockhash() == goalbesthash)
          # Verify we can now have the data for a block previously pruned
          assert(self.nodes[2].getblock(self.forkhash)["height"] == self.forkheight)
  
      def manual_test(self, node_number, use_timestamp):
          # at this point, node has 995 blocks and has not yet run in prune mode
          self.start_node(node_number)
          node = self.nodes[node_number]
          assert_equal(node.getblockcount(), 995)
          assert_raises_rpc_error(-1, "not in prune mode", node.pruneblockchain, 500)
  
          # now re-start in manual pruning mode
          self.stop_node(node_number)
          self.start_node(node_number, extra_args=["-prune=1"])
          node = self.nodes[node_number]
          assert_equal(node.getblockcount(), 995)
  
          def height(index):
              if use_timestamp:
                  return node.getblockheader(node.getblockhash(index))["time"] + TIMESTAMP_WINDOW
              else:
                  return index
  
          def prune(index, expected_ret=None):
              ret = node.pruneblockchain(height(index))
              # Check the return value. When use_timestamp is True, just check
              # that the return value is less than or equal to the expected
              # value, because when more than one block is generated per second,
              # a timestamp will not be granular enough to uniquely identify an
              # individual block.
              if expected_ret is None:
                  expected_ret = index
              if use_timestamp:
                  assert_greater_than(ret, 0)
                  assert_greater_than(expected_ret + 1, ret)
              else:
                  assert_equal(ret, expected_ret)
  
          def has_block(index):
              return os.path.isfile(self.options.tmpdir + "/node{}/regtest/blocks/blk{:05}.dat".format(node_number, index))
  
          # should not prune because chain tip of node 3 (995) < PruneAfterHeight (1000)
          assert_raises_rpc_error(-1, "Blockchain is too short for pruning", node.pruneblockchain, height(500))
  
          # mine 6 blocks so we are at height 1001 (i.e., above PruneAfterHeight)
          node.generate(6)
          assert_equal(node.getblockchaininfo()["blocks"], 1001)
  
          # negative heights should raise an exception
          assert_raises_rpc_error(-8, "Negative", node.pruneblockchain, -10)
  
          # height=100 too low to prune first block file so this is a no-op
          prune(100)
          if not has_block(0):
              raise AssertionError("blk00000.dat is missing when should still be there")
  
          # Does nothing
          node.pruneblockchain(height(0))
          if not has_block(0):
              raise AssertionError("blk00000.dat is missing when should still be there")
  
          # height=500 should prune first file
          prune(500)
          if has_block(0):
              raise AssertionError("blk00000.dat is still there, should be pruned by now")
          if not has_block(1):
              raise AssertionError("blk00001.dat is missing when should still be there")
  
          # height=650 should prune second file
          prune(650)
          if has_block(1):
              raise AssertionError("blk00001.dat is still there, should be pruned by now")
  
          # height=1000 should not prune anything more, because tip-288 is in blk00002.dat.
          prune(1000, 1001 - MIN_BLOCKS_TO_KEEP)
          if not has_block(2):
              raise AssertionError("blk00002.dat is still there, should be pruned by now")
  
          # advance the tip so blk00002.dat and blk00003.dat can be pruned (the last 288 blocks should now be in blk00004.dat)
          node.generate(288)
          prune(1000)
          if has_block(2):
              raise AssertionError("blk00002.dat is still there, should be pruned by now")
          if has_block(3):
              raise AssertionError("blk00003.dat is still there, should be pruned by now")
  
          # stop node, start back up with auto-prune at 550MB, make sure still runs
          self.stop_node(node_number)
          self.start_node(node_number, extra_args=["-prune=550"])
  
          self.log.info("Success")
  
      def wallet_test(self):
          # check that the pruning node's wallet is still in good shape
          self.log.info("Stop and start pruning node to trigger wallet rescan")
          self.stop_node(2)
          self.start_node(2, extra_args=["-prune=550"])
          self.log.info("Success")
  
          # check that wallet loads successfully when restarting a pruned node after IBD.
          # this was reported to fail in #7494.
          self.log.info("Syncing node 5 to test wallet")
          connect_nodes(self.nodes[0], 5)
          nds = [self.nodes[0], self.nodes[5]]
          sync_blocks(nds, wait=5, timeout=300)
          self.stop_node(5) #stop and start to trigger rescan
          self.start_node(5, extra_args=["-prune=550"])
          self.log.info("Success")
  
      def run_test(self):
          self.log.info("Warning! This test requires 4GB of disk space and takes over 30 mins (up to 2 hours)")
          self.log.info("Mining a big blockchain of 995 blocks")
  
          # Determine default relay fee
          self.relayfee = self.nodes[0].getnetworkinfo()["relayfee"]
  
          # Cache for utxos, as the listunspent may take a long time later in the test
          self.utxo_cache_0 = []
          self.utxo_cache_1 = []
  
          self.create_big_chain()
          # Chain diagram key:
          # *   blocks on main chain
          # +,&,$,@ blocks on other forks
          # X   invalidated block
          # N1  Node 1
          #
          # Start by mining a simple chain that all nodes have
          # N0=N1=N2 **...*(995)
  
          # stop manual-pruning node with 995 blocks
          self.stop_node(3)
          self.stop_node(4)
  
          self.log.info("Check that we haven't started pruning yet because we're below PruneAfterHeight")
          self.test_height_min()
          # Extend this chain past the PruneAfterHeight
          # N0=N1=N2 **...*(1020)
  
          self.log.info("Check that we'll exceed disk space target if we have a very high stale block rate")
          self.create_chain_with_staleblocks()
          # Disconnect N0
          # And mine a 24 block chain on N1 and a separate 25 block chain on N0
          # N1=N2 **...*+...+(1044)
          # N0    **...**...**(1045)
          #
          # reconnect nodes causing reorg on N1 and N2
          # N1=N2 **...*(1020) *...**(1045)
          #                   \
          #                    +...+(1044)
          #
          # repeat this process until you have 12 stale forks hanging off the
          # main chain on N1 and N2
          # N0    *************************...***************************(1320)
          #
          # N1=N2 **...*(1020) *...**(1045) *..         ..**(1295) *...**(1320)
          #                   \            \                      \
          #                    +...+(1044)  &..                    $...$(1319)
  
          # Save some current chain state for later use
          self.mainchainheight = self.nodes[2].getblockcount()   #1320
          self.mainchainhash2 = self.nodes[2].getblockhash(self.mainchainheight)
  
          self.log.info("Check that we can survive a 288 block reorg still")
          (self.forkheight,self.forkhash) = self.reorg_test() #(1033, )
          # Now create a 288 block reorg by mining a longer chain on N1
          # First disconnect N1
          # Then invalidate 1033 on main chain and 1032 on fork so height is 1032 on main chain
          # N1   **...*(1020) **...**(1032)X..
          #                  \
          #                   ++...+(1031)X..
          #
          # Now mine 300 more blocks on N1
          # N1    **...*(1020) **...**(1032) @@...@(1332)
          #                 \               \
          #                  \               X...
          #                   \                 \
          #                    ++...+(1031)X..   ..
          #
          # Reconnect nodes and mine 220 more blocks on N1
          # N1    **...*(1020) **...**(1032) @@...@@@(1552)
          #                 \               \
          #                  \               X...
          #                   \                 \
          #                    ++...+(1031)X..   ..
          #
          # N2    **...*(1020) **...**(1032) @@...@@@(1552)
          #                 \               \
          #                  \               *...**(1320)
          #                   \                 \
          #                    ++...++(1044)     ..
          #
          # N0    ********************(1032) @@...@@@(1552)
          #                                 \
          #                                  *...**(1320)
  
          self.log.info("Test that we can rerequest a block we previously pruned if needed for a reorg")
          self.reorg_back()
          # Verify that N2 still has block 1033 on current chain (@), but not on main chain (*)
          # Invalidate 1033 on current chain (@) on N2 and we should be able to reorg to
          # original main chain (*), but will require redownload of some blocks
          # In order to have a peer we think we can download from, must also perform this invalidation
          # on N0 and mine a new longest chain to trigger.
          # Final result:
          # N0    ********************(1032) **...****(1553)
          #                                 \
          #                                  X@...@@@(1552)
          #
          # N2    **...*(1020) **...**(1032) **...****(1553)
          #                 \               \
          #                  \               X@...@@@(1552)
          #                   \
          #                    +..
          #
          # N1 doesn't change because 1033 on main chain (*) is invalid
  
          self.log.info("Test manual pruning with block indices")
          self.manual_test(3, use_timestamp=False)
  
          self.log.info("Test manual pruning with timestamps")
          self.manual_test(4, use_timestamp=True)
  
          self.log.info("Test wallet re-scan")
          self.wallet_test()
  
          self.log.info("Done")
  
  if __name__ == '__main__':
      PruneTest().main()
  