text: #!/usr/bin/env python3
  # Copyright (c) 2010 ArtForz -- public domain half-a-node
  # Copyright (c) 2012 Jeff Garzik
  # Copyright (c) 2010-2016 The Bitcoin Core developers
  # Distributed under the MIT software license, see the accompanying
  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  """eBitcash P2P network half-a-node.
  
  This python code was modified from ArtForz' public domain  half-a-node, as
  found in the mini-node branch of http://github.com/jgarzik/pynode.
  
  NodeConn: an object which manages p2p connectivity to a ebitcash node
  NodeConnCB: a base class that describes the interface for receiving
              callbacks with network messages from a NodeConn
  CBlock, CTransaction, CBlockHeader, CTxIn, CTxOut, etc....:
      data structures that should map to corresponding structures in
      ebitcash/primitives
  msg_block, msg_tx, msg_headers, etc.:
      data structures that represent network messages
  ser_*, deser_*: functions that handle serialization/deserialization
  """
  
  import asyncore
  from codecs import encode
  from collections import defaultdict
  import copy
  import hashlib
  from io import BytesIO
  import logging
  import random
  import socket
  import struct
  import sys
  import time
  from threading import RLock, Thread
  
  from test_framework.siphash import siphash256
  from test_framework.util import hex_str_to_bytes, bytes_to_hex_str
  
  BIP0031_VERSION = 60000
  MY_VERSION = 70014  # past bip-31 for ping/pong
  MY_SUBVERSION = b"/python-mininode-tester:0.0.3/"
  MY_RELAY = 1 # from version 70001 onwards, fRelay should be appended to version messages (BIP37)
  
  MAX_INV_SZ = 50000
  MAX_BLOCK_BASE_SIZE = 1000000
  
  COIN = 100000000 # 1 ebc in satoshis
  
  NODE_NETWORK = (1 << 0)
  NODE_GETUTXO = (1 << 1)
  NODE_BLOOM = (1 << 2)
  NODE_WITNESS = (1 << 3)
  
  logger = logging.getLogger("TestFramework.mininode")
  
  # Keep our own socket map for asyncore, so that we can track disconnects
  # ourselves (to workaround an issue with closing an asyncore socket when
  # using select)
  mininode_socket_map = dict()
  
  # One lock for synchronizing all data access between the networking thread (see
  # NetworkThread below) and the thread running the test logic.  For simplicity,
  # NodeConn acquires this lock whenever delivering a message to a NodeConnCB,
  # and whenever adding anything to the send buffer (in send_message()).  This
  # lock should be acquired in the thread running the test logic to synchronize
  # access to any data shared with the NodeConnCB or NodeConn.
  mininode_lock = RLock()
  
  # Serialization/deserialization tools
  def sha256(s):
      return hashlib.new('sha256', s).digest()
  
  def ripemd160(s):
      return hashlib.new('ripemd160', s).digest()
  
  def hash256(s):
      return sha256(sha256(s))
  
  def ser_compact_size(l):
      r = b""
      if l < 253:
          r = struct.pack("B", l)
      elif l < 0x10000:
          r = struct.pack("<BH", 253, l)
      elif l < 0x100000000:
          r = struct.pack("<BI", 254, l)
      else:
          r = struct.pack("<BQ", 255, l)
      return r
  
  def deser_compact_size(f):
      nit = struct.unpack("<B", f.read(1))[0]
      if nit == 253:
          nit = struct.unpack("<H", f.read(2))[0]
      elif nit == 254:
          nit = struct.unpack("<I", f.read(4))[0]
      elif nit == 255:
          nit = struct.unpack("<Q", f.read(8))[0]
      return nit
  
  def deser_string(f):
      nit = deser_compact_size(f)
      return f.read(nit)
  
  def ser_string(s):
      return ser_compact_size(len(s)) + s
  
  def deser_uint256(f):
      r = 0
      for i in range(8):
          t = struct.unpack("<I", f.read(4))[0]
          r += t << (i * 32)
      return r
  
  
  def ser_uint256(u):
      rs = b""
      for i in range(8):
          rs += struct.pack("<I", u & 0xFFFFFFFF)
          u >>= 32
      return rs
  
  
  def uint256_from_str(s):
      r = 0
      t = struct.unpack("<IIIIIIII", s[:32])
      for i in range(8):
          r += t[i] << (i * 32)
      return r
  
  
  def uint256_from_compact(c):
      nbytes = (c >> 24) & 0xFF
      v = (c & 0xFFFFFF) << (8 * (nbytes - 3))
      return v
  
  
  def deser_vector(f, c):
      nit = deser_compact_size(f)
      r = []
      for i in range(nit):
          t = c()
          t.deserialize(f)
          r.append(t)
      return r
  
  
  # ser_function_name: Allow for an alternate serialization function on the
  # entries in the vector (we use this for serializing the vector of transactions
  # for a witness block).
  def ser_vector(l, ser_function_name=None):
      r = ser_compact_size(len(l))
      for i in l:
          if ser_function_name:
              r += getattr(i, ser_function_name)()
          else:
              r += i.serialize()
      return r
  
  
  def deser_uint256_vector(f):
      nit = deser_compact_size(f)
      r = []
      for i in range(nit):
          t = deser_uint256(f)
          r.append(t)
      return r
  
  
  def ser_uint256_vector(l):
      r = ser_compact_size(len(l))
      for i in l:
          r += ser_uint256(i)
      return r
  
  
  def deser_string_vector(f):
      nit = deser_compact_size(f)
      r = []
      for i in range(nit):
          t = deser_string(f)
          r.append(t)
      return r
  
  
  def ser_string_vector(l):
      r = ser_compact_size(len(l))
      for sv in l:
          r += ser_string(sv)
      return r
  
  
  def deser_int_vector(f):
      nit = deser_compact_size(f)
      r = []
      for i in range(nit):
          t = struct.unpack("<i", f.read(4))[0]
          r.append(t)
      return r
  
  
  def ser_int_vector(l):
      r = ser_compact_size(len(l))
      for i in l:
          r += struct.pack("<i", i)
      return r
  
  # Deserialize from a hex string representation (eg from RPC)
  def FromHex(obj, hex_string):
      obj.deserialize(BytesIO(hex_str_to_bytes(hex_string)))
      return obj
  
  # Convert a binary-serializable object to hex (eg for submission via RPC)
  def ToHex(obj):
      return bytes_to_hex_str(obj.serialize())
  
  # Objects that map to ebitcashd objects, which can be serialized/deserialized
  
  class CAddress(object):
      def __init__(self):
          self.nServices = 1
          self.pchReserved = b"\x00" * 10 + b"\xff" * 2
          self.ip = "0.0.0.0"
          self.port = 0
  
      def deserialize(self, f):
          self.nServices = struct.unpack("<Q", f.read(8))[0]
          self.pchReserved = f.read(12)
          self.ip = socket.inet_ntoa(f.read(4))
          self.port = struct.unpack(">H", f.read(2))[0]
  
      def serialize(self):
          r = b""
          r += struct.pack("<Q", self.nServices)
          r += self.pchReserved
          r += socket.inet_aton(self.ip)
          r += struct.pack(">H", self.port)
          return r
  
      def __repr__(self):
          return "CAddress(nServices=%i ip=%s port=%i)" % (self.nServices,
                                                           self.ip, self.port)
  
  MSG_WITNESS_FLAG = 1<<30
  
  class CInv(object):
      typemap = {
          0: "Error",
          1: "TX",
          2: "Block",
          1|MSG_WITNESS_FLAG: "WitnessTx",
          2|MSG_WITNESS_FLAG : "WitnessBlock",
          4: "CompactBlock"
      }
  
      def __init__(self, t=0, h=0):
          self.type = t
          self.hash = h
  
      def deserialize(self, f):
          self.type = struct.unpack("<i", f.read(4))[0]
          self.hash = deser_uint256(f)
  
      def serialize(self):
          r = b""
          r += struct.pack("<i", self.type)
          r += ser_uint256(self.hash)
          return r
  
      def __repr__(self):
          return "CInv(type=%s hash=%064x)" \
              % (self.typemap[self.type], self.hash)
  
  
  class CBlockLocator(object):
      def __init__(self):
          self.nVersion = MY_VERSION
          self.vHave = []
  
      def deserialize(self, f):
          self.nVersion = struct.unpack("<i", f.read(4))[0]
          self.vHave = deser_uint256_vector(f)
  
      def serialize(self):
          r = b""
          r += struct.pack("<i", self.nVersion)
          r += ser_uint256_vector(self.vHave)
          return r
  
      def __repr__(self):
          return "CBlockLocator(nVersion=%i vHave=%s)" \
              % (self.nVersion, repr(self.vHave))
  
  
  class COutPoint(object):
      def __init__(self, hash=0, n=0):
          self.hash = hash
          self.n = n
  
      def deserialize(self, f):
          self.hash = deser_uint256(f)
          self.n = struct.unpack("<I", f.read(4))[0]
  
      def serialize(self):
          r = b""
          r += ser_uint256(self.hash)
          r += struct.pack("<I", self.n)
          return r
  
      def __repr__(self):
          return "COutPoint(hash=%064x n=%i)" % (self.hash, self.n)
  
  
  class CTxIn(object):
      def __init__(self, outpoint=None, scriptSig=b"", nSequence=0):
          if outpoint is None:
              self.prevout = COutPoint()
          else:
              self.prevout = outpoint
          self.scriptSig = scriptSig
          self.nSequence = nSequence
  
      def deserialize(self, f):
          self.prevout = COutPoint()
          self.prevout.deserialize(f)
          self.scriptSig = deser_string(f)
          self.nSequence = struct.unpack("<I", f.read(4))[0]
  
      def serialize(self):
          r = b""
          r += self.prevout.serialize()
          r += ser_string(self.scriptSig)
          r += struct.pack("<I", self.nSequence)
          return r
  
      def __repr__(self):
          return "CTxIn(prevout=%s scriptSig=%s nSequence=%i)" \
              % (repr(self.prevout), bytes_to_hex_str(self.scriptSig),
                 self.nSequence)
  
  
  class CTxOut(object):
      def __init__(self, nValue=0, scriptPubKey=b""):
          self.nValue = nValue
          self.scriptPubKey = scriptPubKey
  
      def deserialize(self, f):
          self.nValue = struct.unpack("<q", f.read(8))[0]
          self.scriptPubKey = deser_string(f)
  
      def serialize(self):
          r = b""
          r += struct.pack("<q", self.nValue)
          r += ser_string(self.scriptPubKey)
          return r
  
      def __repr__(self):
          return "CTxOut(nValue=%i.%08i scriptPubKey=%s)" \
              % (self.nValue // COIN, self.nValue % COIN,
                 bytes_to_hex_str(self.scriptPubKey))
  
  
  class CScriptWitness(object):
      def __init__(self):
          # stack is a vector of strings
          self.stack = []
  
      def __repr__(self):
          return "CScriptWitness(%s)" % \
                 (",".join([bytes_to_hex_str(x) for x in self.stack]))
  
      def is_null(self):
          if self.stack:
              return False
          return True
  
  
  class CTxInWitness(object):
      def __init__(self):
          self.scriptWitness = CScriptWitness()
  
      def deserialize(self, f):
          self.scriptWitness.stack = deser_string_vector(f)
  
      def serialize(self):
          return ser_string_vector(self.scriptWitness.stack)
  
      def __repr__(self):
          return repr(self.scriptWitness)
  
      def is_null(self):
          return self.scriptWitness.is_null()
  
  
  class CTxWitness(object):
      def __init__(self):
          self.vtxinwit = []
  
      def deserialize(self, f):
          for i in range(len(self.vtxinwit)):
              self.vtxinwit[i].deserialize(f)
  
      def serialize(self):
          r = b""
          # This is different than the usual vector serialization --
          # we omit the length of the vector, which is required to be
          # the same length as the transaction's vin vector.
          for x in self.vtxinwit:
              r += x.serialize()
          return r
  
      def __repr__(self):
          return "CTxWitness(%s)" % \
                 (';'.join([repr(x) for x in self.vtxinwit]))
  
      def is_null(self):
          for x in self.vtxinwit:
              if not x.is_null():
                  return False
          return True
  
  
  class CTransaction(object):
      def __init__(self, tx=None):
          if tx is None:
              self.nVersion = 1
              self.vin = []
              self.vout = []
              self.wit = CTxWitness()
              self.nLockTime = 0
              self.sha256 = None
              self.hash = None
          else:
              self.nVersion = tx.nVersion
              self.vin = copy.deepcopy(tx.vin)
              self.vout = copy.deepcopy(tx.vout)
              self.nLockTime = tx.nLockTime
              self.sha256 = tx.sha256
              self.hash = tx.hash
              self.wit = copy.deepcopy(tx.wit)
  
      def deserialize(self, f):
          self.nVersion = struct.unpack("<i", f.read(4))[0]
          self.vin = deser_vector(f, CTxIn)
          flags = 0
          if len(self.vin) == 0:
              flags = struct.unpack("<B", f.read(1))[0]
              # Not sure why flags can't be zero, but this
              # matches the implementation in ebitcashd
              if (flags != 0):
                  self.vin = deser_vector(f, CTxIn)
                  self.vout = deser_vector(f, CTxOut)
          else:
              self.vout = deser_vector(f, CTxOut)
          if flags != 0:
              self.wit.vtxinwit = [CTxInWitness() for i in range(len(self.vin))]
              self.wit.deserialize(f)
          self.nLockTime = struct.unpack("<I", f.read(4))[0]
          self.sha256 = None
          self.hash = None
  
      def serialize_without_witness(self):
          r = b""
          r += struct.pack("<i", self.nVersion)
          r += ser_vector(self.vin)
          r += ser_vector(self.vout)
          r += struct.pack("<I", self.nLockTime)
          return r
  
      # Only serialize with witness when explicitly called for
      def serialize_with_witness(self):
          flags = 0
          if not self.wit.is_null():
              flags |= 1
          r = b""
          r += struct.pack("<i", self.nVersion)
          if flags:
              dummy = []
              r += ser_vector(dummy)
              r += struct.pack("<B", flags)
          r += ser_vector(self.vin)
          r += ser_vector(self.vout)
          if flags & 1:
              if (len(self.wit.vtxinwit) != len(self.vin)):
                  # vtxinwit must have the same length as vin
                  self.wit.vtxinwit = self.wit.vtxinwit[:len(self.vin)]
                  for i in range(len(self.wit.vtxinwit), len(self.vin)):
                      self.wit.vtxinwit.append(CTxInWitness())
              r += self.wit.serialize()
          r += struct.pack("<I", self.nLockTime)
          return r
  
      # Regular serialization is without witness -- must explicitly
      # call serialize_with_witness to include witness data.
      def serialize(self):
          return self.serialize_without_witness()
  
      # Recalculate the txid (transaction hash without witness)
      def rehash(self):
          self.sha256 = None
          self.calc_sha256()
  
      # We will only cache the serialization without witness in
      # self.sha256 and self.hash -- those are expected to be the txid.
      def calc_sha256(self, with_witness=False):
          if with_witness:
              # Don't cache the result, just return it
              return uint256_from_str(hash256(self.serialize_with_witness()))
  
          if self.sha256 is None:
              self.sha256 = uint256_from_str(hash256(self.serialize_without_witness()))
          self.hash = encode(hash256(self.serialize())[::-1], 'hex_codec').decode('ascii')
  
      def is_valid(self):
          self.calc_sha256()
          for tout in self.vout:
              if tout.nValue < 0 or tout.nValue > 21000000 * COIN:
                  return False
          return True
  
      def __repr__(self):
          return "CTransaction(nVersion=%i vin=%s vout=%s wit=%s nLockTime=%i)" \
              % (self.nVersion, repr(self.vin), repr(self.vout), repr(self.wit), self.nLockTime)
  
  
  class CBlockHeader(object):
      def __init__(self, header=None):
          if header is None:
              self.set_null()
          else:
              self.nVersion = header.nVersion
              self.hashPrevBlock = header.hashPrevBlock
              self.hashMerkleRoot = header.hashMerkleRoot
              self.nTime = header.nTime
              self.nBits = header.nBits
              self.nNonce = header.nNonce
              self.sha256 = header.sha256
              self.hash = header.hash
              self.calc_sha256()
  
      def set_null(self):
          self.nVersion = 1
          self.hashPrevBlock = 0
          self.hashMerkleRoot = 0
          self.nTime = 0
          self.nBits = 0
          self.nNonce = 0
          self.sha256 = None
          self.hash = None
  
      def deserialize(self, f):
          self.nVersion = struct.unpack("<i", f.read(4))[0]
          self.hashPrevBlock = deser_uint256(f)
          self.hashMerkleRoot = deser_uint256(f)
          self.nTime = struct.unpack("<I", f.read(4))[0]
          self.nBits = struct.unpack("<I", f.read(4))[0]
          self.nNonce = struct.unpack("<I", f.read(4))[0]
          self.sha256 = None
          self.hash = None
  
      def serialize(self):
          r = b""
          r += struct.pack("<i", self.nVersion)
          r += ser_uint256(self.hashPrevBlock)
          r += ser_uint256(self.hashMerkleRoot)
          r += struct.pack("<I", self.nTime)
          r += struct.pack("<I", self.nBits)
          r += struct.pack("<I", self.nNonce)
          return r
  
      def calc_sha256(self):
          if self.sha256 is None:
              r = b""
              r += struct.pack("<i", self.nVersion)
              r += ser_uint256(self.hashPrevBlock)
              r += ser_uint256(self.hashMerkleRoot)
              r += struct.pack("<I", self.nTime)
              r += struct.pack("<I", self.nBits)
              r += struct.pack("<I", self.nNonce)
              self.sha256 = uint256_from_str(hash256(r))
              self.hash = encode(hash256(r)[::-1], 'hex_codec').decode('ascii')
  
      def rehash(self):
          self.sha256 = None
          self.calc_sha256()
          return self.sha256
  
      def __repr__(self):
          return "CBlockHeader(nVersion=%i hashPrevBlock=%064x hashMerkleRoot=%064x nTime=%s nBits=%08x nNonce=%08x)" \
              % (self.nVersion, self.hashPrevBlock, self.hashMerkleRoot,
                 time.ctime(self.nTime), self.nBits, self.nNonce)
  
  
  class CBlock(CBlockHeader):
      def __init__(self, header=None):
          super(CBlock, self).__init__(header)
          self.vtx = []
  
      def deserialize(self, f):
          super(CBlock, self).deserialize(f)
          self.vtx = deser_vector(f, CTransaction)
  
      def serialize(self, with_witness=False):
          r = b""
          r += super(CBlock, self).serialize()
          if with_witness:
              r += ser_vector(self.vtx, "serialize_with_witness")
          else:
              r += ser_vector(self.vtx)
          return r
  
      # Calculate the merkle root given a vector of transaction hashes
      @classmethod
      def get_merkle_root(cls, hashes):
          while len(hashes) > 1:
              newhashes = []
              for i in range(0, len(hashes), 2):
                  i2 = min(i+1, len(hashes)-1)
                  newhashes.append(hash256(hashes[i] + hashes[i2]))
              hashes = newhashes
          return uint256_from_str(hashes[0])
  
      def calc_merkle_root(self):
          hashes = []
          for tx in self.vtx:
              tx.calc_sha256()
              hashes.append(ser_uint256(tx.sha256))
          return self.get_merkle_root(hashes)
  
      def calc_witness_merkle_root(self):
          # For witness root purposes, the hash of the
          # coinbase, with witness, is defined to be 0...0
          hashes = [ser_uint256(0)]
  
          for tx in self.vtx[1:]:
              # Calculate the hashes with witness data
              hashes.append(ser_uint256(tx.calc_sha256(True)))
  
          return self.get_merkle_root(hashes)
  
      def is_valid(self):
          self.calc_sha256()
          target = uint256_from_compact(self.nBits)
          if self.sha256 > target:
              return False
          for tx in self.vtx:
              if not tx.is_valid():
                  return False
          if self.calc_merkle_root() != self.hashMerkleRoot:
              return False
          return True
  
      def solve(self):
          self.rehash()
          target = uint256_from_compact(self.nBits)
          while self.sha256 > target:
              self.nNonce += 1
              self.rehash()
  
      def __repr__(self):
          return "CBlock(nVersion=%i hashPrevBlock=%064x hashMerkleRoot=%064x nTime=%s nBits=%08x nNonce=%08x vtx=%s)" \
              % (self.nVersion, self.hashPrevBlock, self.hashMerkleRoot,
                 time.ctime(self.nTime), self.nBits, self.nNonce, repr(self.vtx))
  
  
  class CUnsignedAlert(object):
      def __init__(self):
          self.nVersion = 1
          self.nRelayUntil = 0
          self.nExpiration = 0
          self.nID = 0
          self.nCancel = 0
          self.setCancel = []
          self.nMinVer = 0
          self.nMaxVer = 0
          self.setSubVer = []
          self.nPriority = 0
          self.strComment = b""
          self.strStatusBar = b""
          self.strReserved = b""
  
      def deserialize(self, f):
          self.nVersion = struct.unpack("<i", f.read(4))[0]
          self.nRelayUntil = struct.unpack("<q", f.read(8))[0]
          self.nExpiration = struct.unpack("<q", f.read(8))[0]
          self.nID = struct.unpack("<i", f.read(4))[0]
          self.nCancel = struct.unpack("<i", f.read(4))[0]
          self.setCancel = deser_int_vector(f)
          self.nMinVer = struct.unpack("<i", f.read(4))[0]
          self.nMaxVer = struct.unpack("<i", f.read(4))[0]
          self.setSubVer = deser_string_vector(f)
          self.nPriority = struct.unpack("<i", f.read(4))[0]
          self.strComment = deser_string(f)
          self.strStatusBar = deser_string(f)
          self.strReserved = deser_string(f)
  
      def serialize(self):
          r = b""
          r += struct.pack("<i", self.nVersion)
          r += struct.pack("<q", self.nRelayUntil)
          r += struct.pack("<q", self.nExpiration)
          r += struct.pack("<i", self.nID)
          r += struct.pack("<i", self.nCancel)
          r += ser_int_vector(self.setCancel)
          r += struct.pack("<i", self.nMinVer)
          r += struct.pack("<i", self.nMaxVer)
          r += ser_string_vector(self.setSubVer)
          r += struct.pack("<i", self.nPriority)
          r += ser_string(self.strComment)
          r += ser_string(self.strStatusBar)
          r += ser_string(self.strReserved)
          return r
  
      def __repr__(self):
          return "CUnsignedAlert(nVersion %d, nRelayUntil %d, nExpiration %d, nID %d, nCancel %d, nMinVer %d, nMaxVer %d, nPriority %d, strComment %s, strStatusBar %s, strReserved %s)" \
              % (self.nVersion, self.nRelayUntil, self.nExpiration, self.nID,
                 self.nCancel, self.nMinVer, self.nMaxVer, self.nPriority,
                 self.strComment, self.strStatusBar, self.strReserved)
  
  
  class CAlert(object):
      def __init__(self):
          self.vchMsg = b""
          self.vchSig = b""
  
      def deserialize(self, f):
          self.vchMsg = deser_string(f)
          self.vchSig = deser_string(f)
  
      def serialize(self):
          r = b""
          r += ser_string(self.vchMsg)
          r += ser_string(self.vchSig)
          return r
  
      def __repr__(self):
          return "CAlert(vchMsg.sz %d, vchSig.sz %d)" \
              % (len(self.vchMsg), len(self.vchSig))
  
  
  class PrefilledTransaction(object):
      def __init__(self, index=0, tx = None):
          self.index = index
          self.tx = tx
  
      def deserialize(self, f):
          self.index = deser_compact_size(f)
          self.tx = CTransaction()
          self.tx.deserialize(f)
  
      def serialize(self, with_witness=False):
          r = b""
          r += ser_compact_size(self.index)
          if with_witness:
              r += self.tx.serialize_with_witness()
          else:
              r += self.tx.serialize_without_witness()
          return r
  
      def serialize_with_witness(self):
          return self.serialize(with_witness=True)
  
      def __repr__(self):
          return "PrefilledTransaction(index=%d, tx=%s)" % (self.index, repr(self.tx))
  
  # This is what we send on the wire, in a cmpctblock message.
  class P2PHeaderAndShortIDs(object):
      def __init__(self):
          self.header = CBlockHeader()
          self.nonce = 0
          self.shortids_length = 0
          self.shortids = []
          self.prefilled_txn_length = 0
          self.prefilled_txn = []
  
      def deserialize(self, f):
          self.header.deserialize(f)
          self.nonce = struct.unpack("<Q", f.read(8))[0]
          self.shortids_length = deser_compact_size(f)
          for i in range(self.shortids_length):
              # shortids are defined to be 6 bytes in the spec, so append
              # two zero bytes and read it in as an 8-byte number
              self.shortids.append(struct.unpack("<Q", f.read(6) + b'\x00\x00')[0])
          self.prefilled_txn = deser_vector(f, PrefilledTransaction)
          self.prefilled_txn_length = len(self.prefilled_txn)
  
      # When using version 2 compact blocks, we must serialize with_witness.
      def serialize(self, with_witness=False):
          r = b""
          r += self.header.serialize()
          r += struct.pack("<Q", self.nonce)
          r += ser_compact_size(self.shortids_length)
          for x in self.shortids:
              # We only want the first 6 bytes
              r += struct.pack("<Q", x)[0:6]
          if with_witness:
              r += ser_vector(self.prefilled_txn, "serialize_with_witness")
          else:
              r += ser_vector(self.prefilled_txn)
          return r
  
      def __repr__(self):
          return "P2PHeaderAndShortIDs(header=%s, nonce=%d, shortids_length=%d, shortids=%s, prefilled_txn_length=%d, prefilledtxn=%s" % (repr(self.header), self.nonce, self.shortids_length, repr(self.shortids), self.prefilled_txn_length, repr(self.prefilled_txn))
  
  # P2P version of the above that will use witness serialization (for compact
  # block version 2)
  class P2PHeaderAndShortWitnessIDs(P2PHeaderAndShortIDs):
      def serialize(self):
          return super(P2PHeaderAndShortWitnessIDs, self).serialize(with_witness=True)
  
  # Calculate the BIP 152-compact blocks shortid for a given transaction hash
  def calculate_shortid(k0, k1, tx_hash):
      expected_shortid = siphash256(k0, k1, tx_hash)
      expected_shortid &= 0x0000ffffffffffff
      return expected_shortid
  
  # This version gets rid of the array lengths, and reinterprets the differential
  # encoding into indices that can be used for lookup.
  class HeaderAndShortIDs(object):
      def __init__(self, p2pheaders_and_shortids = None):
          self.header = CBlockHeader()
          self.nonce = 0
          self.shortids = []
          self.prefilled_txn = []
          self.use_witness = False
  
          if p2pheaders_and_shortids != None:
              self.header = p2pheaders_and_shortids.header
              self.nonce = p2pheaders_and_shortids.nonce
              self.shortids = p2pheaders_and_shortids.shortids
              last_index = -1
              for x in p2pheaders_and_shortids.prefilled_txn:
                  self.prefilled_txn.append(PrefilledTransaction(x.index + last_index + 1, x.tx))
                  last_index = self.prefilled_txn[-1].index
  
      def to_p2p(self):
          if self.use_witness:
              ret = P2PHeaderAndShortWitnessIDs()
          else:
              ret = P2PHeaderAndShortIDs()
          ret.header = self.header
          ret.nonce = self.nonce
          ret.shortids_length = len(self.shortids)
          ret.shortids = self.shortids
          ret.prefilled_txn_length = len(self.prefilled_txn)
          ret.prefilled_txn = []
          last_index = -1
          for x in self.prefilled_txn:
              ret.prefilled_txn.append(PrefilledTransaction(x.index - last_index - 1, x.tx))
              last_index = x.index
          return ret
  
      def get_siphash_keys(self):
          header_nonce = self.header.serialize()
          header_nonce += struct.pack("<Q", self.nonce)
          hash_header_nonce_as_str = sha256(header_nonce)
          key0 = struct.unpack("<Q", hash_header_nonce_as_str[0:8])[0]
          key1 = struct.unpack("<Q", hash_header_nonce_as_str[8:16])[0]
          return [ key0, key1 ]
  
      # Version 2 compact blocks use wtxid in shortids (rather than txid)
      def initialize_from_block(self, block, nonce=0, prefill_list = [0], use_witness = False):
          self.header = CBlockHeader(block)
          self.nonce = nonce
          self.prefilled_txn = [ PrefilledTransaction(i, block.vtx[i]) for i in prefill_list ]
          self.shortids = []
          self.use_witness = use_witness
          [k0, k1] = self.get_siphash_keys()
          for i in range(len(block.vtx)):
              if i not in prefill_list:
                  tx_hash = block.vtx[i].sha256
                  if use_witness:
                      tx_hash = block.vtx[i].calc_sha256(with_witness=True)
                  self.shortids.append(calculate_shortid(k0, k1, tx_hash))
  
      def __repr__(self):
          return "HeaderAndShortIDs(header=%s, nonce=%d, shortids=%s, prefilledtxn=%s" % (repr(self.header), self.nonce, repr(self.shortids), repr(self.prefilled_txn))
  
  
  class BlockTransactionsRequest(object):
  
      def __init__(self, blockhash=0, indexes = None):
          self.blockhash = blockhash
          self.indexes = indexes if indexes != None else []
  
      def deserialize(self, f):
          self.blockhash = deser_uint256(f)
          indexes_length = deser_compact_size(f)
          for i in range(indexes_length):
              self.indexes.append(deser_compact_size(f))
  
      def serialize(self):
          r = b""
          r += ser_uint256(self.blockhash)
          r += ser_compact_size(len(self.indexes))
          for x in self.indexes:
              r += ser_compact_size(x)
          return r
  
      # helper to set the differentially encoded indexes from absolute ones
      def from_absolute(self, absolute_indexes):
          self.indexes = []
          last_index = -1
          for x in absolute_indexes:
              self.indexes.append(x-last_index-1)
              last_index = x
  
      def to_absolute(self):
          absolute_indexes = []
          last_index = -1
          for x in self.indexes:
              absolute_indexes.append(x+last_index+1)
              last_index = absolute_indexes[-1]
          return absolute_indexes
  
      def __repr__(self):
          return "BlockTransactionsRequest(hash=%064x indexes=%s)" % (self.blockhash, repr(self.indexes))
  
  
  class BlockTransactions(object):
  
      def __init__(self, blockhash=0, transactions = None):
          self.blockhash = blockhash
          self.transactions = transactions if transactions != None else []
  
      def deserialize(self, f):
          self.blockhash = deser_uint256(f)
          self.transactions = deser_vector(f, CTransaction)
  
      def serialize(self, with_witness=False):
          r = b""
          r += ser_uint256(self.blockhash)
          if with_witness:
              r += ser_vector(self.transactions, "serialize_with_witness")
          else:
              r += ser_vector(self.transactions)
          return r
  
      def __repr__(self):
          return "BlockTransactions(hash=%064x transactions=%s)" % (self.blockhash, repr(self.transactions))
  
  
  # Objects that correspond to messages on the wire
  class msg_version(object):
      command = b"version"
  
      def __init__(self):
          self.nVersion = MY_VERSION
          self.nServices = 1
          self.nTime = int(time.time())
          self.addrTo = CAddress()
          self.addrFrom = CAddress()
          self.nNonce = random.getrandbits(64)
          self.strSubVer = MY_SUBVERSION
          self.nStartingHeight = -1
          self.nRelay = MY_RELAY
  
      def deserialize(self, f):
          self.nVersion = struct.unpack("<i", f.read(4))[0]
          if self.nVersion == 10300:
              self.nVersion = 300
          self.nServices = struct.unpack("<Q", f.read(8))[0]
          self.nTime = struct.unpack("<q", f.read(8))[0]
          self.addrTo = CAddress()
          self.addrTo.deserialize(f)
  
          if self.nVersion >= 106:
              self.addrFrom = CAddress()
              self.addrFrom.deserialize(f)
              self.nNonce = struct.unpack("<Q", f.read(8))[0]
              self.strSubVer = deser_string(f)
          else:
              self.addrFrom = None
              self.nNonce = None
              self.strSubVer = None
              self.nStartingHeight = None
  
          if self.nVersion >= 209:
              self.nStartingHeight = struct.unpack("<i", f.read(4))[0]
          else:
              self.nStartingHeight = None
  
          if self.nVersion >= 70001:
              # Relay field is optional for version 70001 onwards
              try:
                  self.nRelay = struct.unpack("<b", f.read(1))[0]
              except:
                  self.nRelay = 0
          else:
              self.nRelay = 0
  
      def serialize(self):
          r = b""
          r += struct.pack("<i", self.nVersion)
          r += struct.pack("<Q", self.nServices)
          r += struct.pack("<q", self.nTime)
          r += self.addrTo.serialize()
          r += self.addrFrom.serialize()
          r += struct.pack("<Q", self.nNonce)
          r += ser_string(self.strSubVer)
          r += struct.pack("<i", self.nStartingHeight)
          r += struct.pack("<b", self.nRelay)
          return r
  
      def __repr__(self):
          return 'msg_version(nVersion=%i nServices=%i nTime=%s addrTo=%s addrFrom=%s nNonce=0x%016X strSubVer=%s nStartingHeight=%i nRelay=%i)' \
              % (self.nVersion, self.nServices, time.ctime(self.nTime),
                 repr(self.addrTo), repr(self.addrFrom), self.nNonce,
                 self.strSubVer, self.nStartingHeight, self.nRelay)
  
  
  class msg_verack(object):
      command = b"verack"
  
      def __init__(self):
          pass
  
      def deserialize(self, f):
          pass
  
      def serialize(self):
          return b""
  
      def __repr__(self):
          return "msg_verack()"
  
  
  class msg_addr(object):
      command = b"addr"
  
      def __init__(self):
          self.addrs = []
  
      def deserialize(self, f):
          self.addrs = deser_vector(f, CAddress)
  
      def serialize(self):
          return ser_vector(self.addrs)
  
      def __repr__(self):
          return "msg_addr(addrs=%s)" % (repr(self.addrs))
  
  
  class msg_alert(object):
      command = b"alert"
  
      def __init__(self):
          self.alert = CAlert()
  
      def deserialize(self, f):
          self.alert = CAlert()
          self.alert.deserialize(f)
  
      def serialize(self):
          r = b""
          r += self.alert.serialize()
          return r
  
      def __repr__(self):
          return "msg_alert(alert=%s)" % (repr(self.alert), )
  
  
  class msg_inv(object):
      command = b"inv"
  
      def __init__(self, inv=None):
          if inv is None:
              self.inv = []
          else:
              self.inv = inv
  
      def deserialize(self, f):
          self.inv = deser_vector(f, CInv)
  
      def serialize(self):
          return ser_vector(self.inv)
  
      def __repr__(self):
          return "msg_inv(inv=%s)" % (repr(self.inv))
  
  
  class msg_getdata(object):
      command = b"getdata"
  
      def __init__(self, inv=None):
          self.inv = inv if inv != None else []
  
      def deserialize(self, f):
          self.inv = deser_vector(f, CInv)
  
      def serialize(self):
          return ser_vector(self.inv)
  
      def __repr__(self):
          return "msg_getdata(inv=%s)" % (repr(self.inv))
  
  
  class msg_getblocks(object):
      command = b"getblocks"
  
      def __init__(self):
          self.locator = CBlockLocator()
          self.hashstop = 0
  
      def deserialize(self, f):
          self.locator = CBlockLocator()
          self.locator.deserialize(f)
          self.hashstop = deser_uint256(f)
  
      def serialize(self):
          r = b""
          r += self.locator.serialize()
          r += ser_uint256(self.hashstop)
          return r
  
      def __repr__(self):
          return "msg_getblocks(locator=%s hashstop=%064x)" \
              % (repr(self.locator), self.hashstop)
  
  
  class msg_tx(object):
      command = b"tx"
  
      def __init__(self, tx=CTransaction()):
          self.tx = tx
  
      def deserialize(self, f):
          self.tx.deserialize(f)
  
      def serialize(self):
          return self.tx.serialize_without_witness()
  
      def __repr__(self):
          return "msg_tx(tx=%s)" % (repr(self.tx))
  
  class msg_witness_tx(msg_tx):
  
      def serialize(self):
          return self.tx.serialize_with_witness()
  
  
  class msg_block(object):
      command = b"block"
  
      def __init__(self, block=None):
          if block is None:
              self.block = CBlock()
          else:
              self.block = block
  
      def deserialize(self, f):
          self.block.deserialize(f)
  
      def serialize(self):
          return self.block.serialize()
  
      def __repr__(self):
          return "msg_block(block=%s)" % (repr(self.block))
  
  # for cases where a user needs tighter control over what is sent over the wire
  # note that the user must supply the name of the command, and the data
  class msg_generic(object):
      def __init__(self, command, data=None):
          self.command = command
          self.data = data
  
      def serialize(self):
          return self.data
  
      def __repr__(self):
          return "msg_generic()"
  
  class msg_witness_block(msg_block):
  
      def serialize(self):
          r = self.block.serialize(with_witness=True)
          return r
  
  class msg_getaddr(object):
      command = b"getaddr"
  
      def __init__(self):
          pass
  
      def deserialize(self, f):
          pass
  
      def serialize(self):
          return b""
  
      def __repr__(self):
          return "msg_getaddr()"
  
  
  class msg_ping_prebip31(object):
      command = b"ping"
  
      def __init__(self):
          pass
  
      def deserialize(self, f):
          pass
  
      def serialize(self):
          return b""
  
      def __repr__(self):
          return "msg_ping() (pre-bip31)"
  
  
  class msg_ping(object):
      command = b"ping"
  
      def __init__(self, nonce=0):
          self.nonce = nonce
  
      def deserialize(self, f):
          self.nonce = struct.unpack("<Q", f.read(8))[0]
  
      def serialize(self):
          r = b""
          r += struct.pack("<Q", self.nonce)
          return r
  
      def __repr__(self):
          return "msg_ping(nonce=%08x)" % self.nonce
  
  
  class msg_pong(object):
      command = b"pong"
  
      def __init__(self, nonce=0):
          self.nonce = nonce
  
      def deserialize(self, f):
          self.nonce = struct.unpack("<Q", f.read(8))[0]
  
      def serialize(self):
          r = b""
          r += struct.pack("<Q", self.nonce)
          return r
  
      def __repr__(self):
          return "msg_pong(nonce=%08x)" % self.nonce
  
  
  class msg_mempool(object):
      command = b"mempool"
  
      def __init__(self):
          pass
  
      def deserialize(self, f):
          pass
  
      def serialize(self):
          return b""
  
      def __repr__(self):
          return "msg_mempool()"
  
  class msg_sendheaders(object):
      command = b"sendheaders"
  
      def __init__(self):
          pass
  
      def deserialize(self, f):
          pass
  
      def serialize(self):
          return b""
  
      def __repr__(self):
          return "msg_sendheaders()"
  
  
  # getheaders message has
  # number of entries
  # vector of hashes
  # hash_stop (hash of last desired block header, 0 to get as many as possible)
  class msg_getheaders(object):
      command = b"getheaders"
  
      def __init__(self):
          self.locator = CBlockLocator()
          self.hashstop = 0
  
      def deserialize(self, f):
          self.locator = CBlockLocator()
          self.locator.deserialize(f)
          self.hashstop = deser_uint256(f)
  
      def serialize(self):
          r = b""
          r += self.locator.serialize()
          r += ser_uint256(self.hashstop)
          return r
  
      def __repr__(self):
          return "msg_getheaders(locator=%s, stop=%064x)" \
              % (repr(self.locator), self.hashstop)
  
  
  # headers message has
  # <count> <vector of block headers>
  class msg_headers(object):
      command = b"headers"
  
      def __init__(self):
          self.headers = []
  
      def deserialize(self, f):
          # comment in ebitcashd indicates these should be deserialized as blocks
          blocks = deser_vector(f, CBlock)
          for x in blocks:
              self.headers.append(CBlockHeader(x))
  
      def serialize(self):
          blocks = [CBlock(x) for x in self.headers]
          return ser_vector(blocks)
  
      def __repr__(self):
          return "msg_headers(headers=%s)" % repr(self.headers)
  
  
  class msg_reject(object):
      command = b"reject"
      REJECT_MALFORMED = 1
  
      def __init__(self):
          self.message = b""
          self.code = 0
          self.reason = b""
          self.data = 0
  
      def deserialize(self, f):
          self.message = deser_string(f)
          self.code = struct.unpack("<B", f.read(1))[0]
          self.reason = deser_string(f)
          if (self.code != self.REJECT_MALFORMED and
                  (self.message == b"block" or self.message == b"tx")):
              self.data = deser_uint256(f)
  
      def serialize(self):
          r = ser_string(self.message)
          r += struct.pack("<B", self.code)
          r += ser_string(self.reason)
          if (self.code != self.REJECT_MALFORMED and
                  (self.message == b"block" or self.message == b"tx")):
              r += ser_uint256(self.data)
          return r
  
      def __repr__(self):
          return "msg_reject: %s %d %s [%064x]" \
              % (self.message, self.code, self.reason, self.data)
  
  # Helper function
  def wait_until(predicate, *, attempts=float('inf'), timeout=float('inf')):
      if attempts == float('inf') and timeout == float('inf'):
          timeout = 60
      attempt = 0
      elapsed = 0
  
      while attempt < attempts and elapsed < timeout:
          with mininode_lock:
              if predicate():
                  return True
          attempt += 1
          elapsed += 0.05
          time.sleep(0.05)
  
      return False
  
  class msg_feefilter(object):
      command = b"feefilter"
  
      def __init__(self, feerate=0):
          self.feerate = feerate
  
      def deserialize(self, f):
          self.feerate = struct.unpack("<Q", f.read(8))[0]
  
      def serialize(self):
          r = b""
          r += struct.pack("<Q", self.feerate)
          return r
  
      def __repr__(self):
          return "msg_feefilter(feerate=%08x)" % self.feerate
  
  class msg_sendcmpct(object):
      command = b"sendcmpct"
  
      def __init__(self):
          self.announce = False
          self.version = 1
  
      def deserialize(self, f):
          self.announce = struct.unpack("<?", f.read(1))[0]
          self.version = struct.unpack("<Q", f.read(8))[0]
  
      def serialize(self):
          r = b""
          r += struct.pack("<?", self.announce)
          r += struct.pack("<Q", self.version)
          return r
  
      def __repr__(self):
          return "msg_sendcmpct(announce=%s, version=%lu)" % (self.announce, self.version)
  
  class msg_cmpctblock(object):
      command = b"cmpctblock"
  
      def __init__(self, header_and_shortids = None):
          self.header_and_shortids = header_and_shortids
  
      def deserialize(self, f):
          self.header_and_shortids = P2PHeaderAndShortIDs()
          self.header_and_shortids.deserialize(f)
  
      def serialize(self):
          r = b""
          r += self.header_and_shortids.serialize()
          return r
  
      def __repr__(self):
          return "msg_cmpctblock(HeaderAndShortIDs=%s)" % repr(self.header_and_shortids)
  
  class msg_getblocktxn(object):
      command = b"getblocktxn"
  
      def __init__(self):
          self.block_txn_request = None
  
      def deserialize(self, f):
          self.block_txn_request = BlockTransactionsRequest()
          self.block_txn_request.deserialize(f)
  
      def serialize(self):
          r = b""
          r += self.block_txn_request.serialize()
          return r
  
      def __repr__(self):
          return "msg_getblocktxn(block_txn_request=%s)" % (repr(self.block_txn_request))
  
  class msg_blocktxn(object):
      command = b"blocktxn"
  
      def __init__(self):
          self.block_transactions = BlockTransactions()
  
      def deserialize(self, f):
          self.block_transactions.deserialize(f)
  
      def serialize(self):
          r = b""
          r += self.block_transactions.serialize()
          return r
  
      def __repr__(self):
          return "msg_blocktxn(block_transactions=%s)" % (repr(self.block_transactions))
  
  class msg_witness_blocktxn(msg_blocktxn):
      def serialize(self):
          r = b""
          r += self.block_transactions.serialize(with_witness=True)
          return r
  
  class NodeConnCB(object):
      """Callback and helper functions for P2P connection to a ebitcashd node.
  
      Individual testcases should subclass this and override the on_* methods
      if they want to alter message handling behaviour.
      """
  
      def __init__(self):
          # Track whether we have a P2P connection open to the node
          self.connected = False
          self.connection = None
  
          # Track number of messages of each type received and the most recent
          # message of each type
          self.message_count = defaultdict(int)
          self.last_message = {}
  
          # A count of the number of ping messages we've sent to the node
          self.ping_counter = 1
  
          # deliver_sleep_time is helpful for debugging race conditions in p2p
          # tests; it causes message delivery to sleep for the specified time
          # before acquiring the global lock and delivering the next message.
          self.deliver_sleep_time = None
  
          # Remember the services our peer has advertised
          self.peer_services = None
  
      # Message receiving methods
  
      def deliver(self, conn, message):
          """Receive message and dispatch message to appropriate callback.
  
          We keep a count of how many of each message type has been received
          and the most recent message of each type.
  
          Optionally waits for deliver_sleep_time before dispatching message.
          """
  
          deliver_sleep = self.get_deliver_sleep_time()
          if deliver_sleep is not None:
              time.sleep(deliver_sleep)
          with mininode_lock:
              try:
                  command = message.command.decode('ascii')
                  self.message_count[command] += 1
                  self.last_message[command] = message
                  getattr(self, 'on_' + command)(conn, message)
              except:
                  print("ERROR delivering %s (%s)" % (repr(message),
                                                      sys.exc_info()[0]))
  
      def set_deliver_sleep_time(self, value):
          with mininode_lock:
              self.deliver_sleep_time = value
  
      def get_deliver_sleep_time(self):
          with mininode_lock:
              return self.deliver_sleep_time
  
      # Callback methods. Can be overridden by subclasses in individual test
      # cases to provide custom message handling behaviour.
  
      def on_open(self, conn):
          self.connected = True
  
      def on_close(self, conn):
          self.connected = False
          self.connection = None
  
      def on_addr(self, conn, message): pass
      def on_alert(self, conn, message): pass
      def on_block(self, conn, message): pass
      def on_blocktxn(self, conn, message): pass
      def on_cmpctblock(self, conn, message): pass
      def on_feefilter(self, conn, message): pass
      def on_getaddr(self, conn, message): pass
      def on_getblocks(self, conn, message): pass
      def on_getblocktxn(self, conn, message): pass
      def on_getdata(self, conn, message): pass
      def on_getheaders(self, conn, message): pass
      def on_headers(self, conn, message): pass
      def on_mempool(self, conn): pass
      def on_pong(self, conn, message): pass
      def on_reject(self, conn, message): pass
      def on_sendcmpct(self, conn, message): pass
      def on_sendheaders(self, conn, message): pass
      def on_tx(self, conn, message): pass
  
      def on_inv(self, conn, message):
          want = msg_getdata()
          for i in message.inv:
              if i.type != 0:
                  want.inv.append(i)
          if len(want.inv):
              conn.send_message(want)
  
      def on_ping(self, conn, message):
          if conn.ver_send > BIP0031_VERSION:
              conn.send_message(msg_pong(message.nonce))
  
      def on_verack(self, conn, message):
          conn.ver_recv = conn.ver_send
          self.verack_received = True
  
      def on_version(self, conn, message):
          if message.nVersion >= 209:
              conn.send_message(msg_verack())
          conn.ver_send = min(MY_VERSION, message.nVersion)
          if message.nVersion < 209:
              conn.ver_recv = conn.ver_send
          conn.nServices = message.nServices
  
      # Connection helper methods
  
      def add_connection(self, conn):
          self.connection = conn
  
      def wait_for_disconnect(self, timeout=60):
          test_function = lambda: not self.connected
          assert wait_until(test_function, timeout=timeout)
  
      # Message receiving helper methods
  
      def wait_for_block(self, blockhash, timeout=60):
          test_function = lambda: self.last_message.get("block") and self.last_message["block"].block.rehash() == blockhash
          assert wait_until(test_function, timeout=timeout)
  
      def wait_for_getdata(self, timeout=60):
          test_function = lambda: self.last_message.get("getdata")
          assert wait_until(test_function, timeout=timeout)
  
      def wait_for_getheaders(self, timeout=60):
          test_function = lambda: self.last_message.get("getheaders")
          assert wait_until(test_function, timeout=timeout)
  
      def wait_for_inv(self, expected_inv, timeout=60):
          """Waits for an INV message and checks that the first inv object in the message was as expected."""
          if len(expected_inv) > 1:
              raise NotImplementedError("wait_for_inv() will only verify the first inv object")
          test_function = lambda: self.last_message.get("inv") and \
                                  self.last_message["inv"].inv[0].type == expected_inv[0].type and \
                                  self.last_message["inv"].inv[0].hash == expected_inv[0].hash
          assert wait_until(test_function, timeout=timeout)
  
      def wait_for_verack(self, timeout=60):
          test_function = lambda: self.message_count["verack"]
          assert wait_until(test_function, timeout=timeout)
  
      # Message sending helper functions
  
      def send_message(self, message):
          if self.connection:
              self.connection.send_message(message)
          else:
              logger.error("Cannot send message. No connection to node!")
  
      def send_and_ping(self, message):
          self.send_message(message)
          self.sync_with_ping()
  
      # Sync up with the node
      def sync_with_ping(self, timeout=60):
          self.send_message(msg_ping(nonce=self.ping_counter))
          test_function = lambda: self.last_message.get("pong") and self.last_message["pong"].nonce == self.ping_counter
          assert wait_until(test_function, timeout=timeout)
          self.ping_counter += 1
          return True
  
  # The actual NodeConn class
  # This class provides an interface for a p2p connection to a specified node
  class NodeConn(asyncore.dispatcher):
      messagemap = {
          b"version": msg_version,
          b"verack": msg_verack,
          b"addr": msg_addr,
          b"alert": msg_alert,
          b"inv": msg_inv,
          b"getdata": msg_getdata,
          b"getblocks": msg_getblocks,
          b"tx": msg_tx,
          b"block": msg_block,
          b"getaddr": msg_getaddr,
          b"ping": msg_ping,
          b"pong": msg_pong,
          b"headers": msg_headers,
          b"getheaders": msg_getheaders,
          b"reject": msg_reject,
          b"mempool": msg_mempool,
          b"feefilter": msg_feefilter,
          b"sendheaders": msg_sendheaders,
          b"sendcmpct": msg_sendcmpct,
          b"cmpctblock": msg_cmpctblock,
          b"getblocktxn": msg_getblocktxn,
          b"blocktxn": msg_blocktxn
      }
      MAGIC_BYTES = {
          "mainnet": b"\xf9\xbe\xb4\xd9",   # mainnet
          "testnet3": b"\x0b\x11\x09\x07",  # testnet3
          "regtest": b"\xfa\xbf\xb5\xda",   # regtest
      }
  
      def __init__(self, dstaddr, dstport, rpc, callback, net="regtest", services=NODE_NETWORK, send_version=True):
          asyncore.dispatcher.__init__(self, map=mininode_socket_map)
          self.dstaddr = dstaddr
          self.dstport = dstport
          self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
          self.sendbuf = b""
          self.recvbuf = b""
          self.ver_send = 209
          self.ver_recv = 209
          self.last_sent = 0
          self.state = "connecting"
          self.network = net
          self.cb = callback
          self.disconnect = False
          self.nServices = 0
  
          if send_version:
              # stuff version msg into sendbuf
              vt = msg_version()
              vt.nServices = services
              vt.addrTo.ip = self.dstaddr
              vt.addrTo.port = self.dstport
              vt.addrFrom.ip = "0.0.0.0"
              vt.addrFrom.port = 0
              self.send_message(vt, True)
  
          logger.info('Connecting to eBitcash Node: %s:%d' % (self.dstaddr, self.dstport))
  
          try:
              self.connect((dstaddr, dstport))
          except:
              self.handle_close()
          self.rpc = rpc
  
      def handle_connect(self):
          if self.state != "connected":
              logger.debug("Connected & Listening: %s:%d" % (self.dstaddr, self.dstport))
              self.state = "connected"
              self.cb.on_open(self)
  
      def handle_close(self):
          logger.debug("Closing connection to: %s:%d" % (self.dstaddr, self.dstport))
          self.state = "closed"
          self.recvbuf = b""
          self.sendbuf = b""
          try:
              self.close()
          except:
              pass
          self.cb.on_close(self)
  
      def handle_read(self):
          try:
              t = self.recv(8192)
              if len(t) > 0:
                  self.recvbuf += t
                  self.got_data()
          except:
              pass
  
      def readable(self):
          return True
  
      def writable(self):
          with mininode_lock:
              pre_connection = self.state == "connecting"
              length = len(self.sendbuf)
          return (length > 0 or pre_connection)
  
      def handle_write(self):
          with mininode_lock:
              # asyncore does not expose socket connection, only the first read/write
              # event, thus we must check connection manually here to know when we
              # actually connect
              if self.state == "connecting":
                  self.handle_connect()
              if not self.writable():
                  return
  
              try:
                  sent = self.send(self.sendbuf)
              except:
                  self.handle_close()
                  return
              self.sendbuf = self.sendbuf[sent:]
  
      def got_data(self):
          try:
              while True:
                  if len(self.recvbuf) < 4:
                      return
                  if self.recvbuf[:4] != self.MAGIC_BYTES[self.network]:
                      raise ValueError("got garbage %s" % repr(self.recvbuf))
                  if self.ver_recv < 209:
                      if len(self.recvbuf) < 4 + 12 + 4:
                          return
                      command = self.recvbuf[4:4+12].split(b"\x00", 1)[0]
                      msglen = struct.unpack("<i", self.recvbuf[4+12:4+12+4])[0]
                      checksum = None
                      if len(self.recvbuf) < 4 + 12 + 4 + msglen:
                          return
                      msg = self.recvbuf[4+12+4:4+12+4+msglen]
                      self.recvbuf = self.recvbuf[4+12+4+msglen:]
                  else:
                      if len(self.recvbuf) < 4 + 12 + 4 + 4:
                          return
                      command = self.recvbuf[4:4+12].split(b"\x00", 1)[0]
                      msglen = struct.unpack("<i", self.recvbuf[4+12:4+12+4])[0]
                      checksum = self.recvbuf[4+12+4:4+12+4+4]
                      if len(self.recvbuf) < 4 + 12 + 4 + 4 + msglen:
                          return
                      msg = self.recvbuf[4+12+4+4:4+12+4+4+msglen]
                      th = sha256(msg)
                      h = sha256(th)
                      if checksum != h[:4]:
                          raise ValueError("got bad checksum " + repr(self.recvbuf))
                      self.recvbuf = self.recvbuf[4+12+4+4+msglen:]
                  if command in self.messagemap:
                      f = BytesIO(msg)
                      t = self.messagemap[command]()
                      t.deserialize(f)
                      self.got_message(t)
                  else:
                      logger.warning("Received unknown command from %s:%d: '%s' %s" % (self.dstaddr, self.dstport, command, repr(msg)))
          except Exception as e:
              logger.exception('got_data:', repr(e))
  
      def send_message(self, message, pushbuf=False):
          if self.state != "connected" and not pushbuf:
              raise IOError('Not connected, no pushbuf')
          self._log_message("send", message)
          command = message.command
          data = message.serialize()
          tmsg = self.MAGIC_BYTES[self.network]
          tmsg += command
          tmsg += b"\x00" * (12 - len(command))
          tmsg += struct.pack("<I", len(data))
          if self.ver_send >= 209:
              th = sha256(data)
              h = sha256(th)
              tmsg += h[:4]
          tmsg += data
          with mininode_lock:
              self.sendbuf += tmsg
              self.last_sent = time.time()
  
      def got_message(self, message):
          if message.command == b"version":
              if message.nVersion <= BIP0031_VERSION:
                  self.messagemap[b'ping'] = msg_ping_prebip31
          if self.last_sent + 30 * 60 < time.time():
              self.send_message(self.messagemap[b'ping']())
          self._log_message("receive", message)
          self.cb.deliver(self, message)
  
      def _log_message(self, direction, msg):
          if direction == "send":
              log_message = "Send message to "
          elif direction == "receive":
              log_message = "Received message from "
          log_message += "%s:%d: %s" % (self.dstaddr, self.dstport, repr(msg)[:500])
          if len(log_message) > 500:
              log_message += "... (msg truncated)"
          logger.debug(log_message)
  
      def disconnect_node(self):
          self.disconnect = True
  
  
  class NetworkThread(Thread):
      def run(self):
          while mininode_socket_map:
              # We check for whether to disconnect outside of the asyncore
              # loop to workaround the behavior of asyncore when using
              # select
              disconnected = []
              for fd, obj in mininode_socket_map.items():
                  if obj.disconnect:
                      disconnected.append(obj)
              [ obj.handle_close() for obj in disconnected ]
              asyncore.loop(0.1, use_poll=True, map=mininode_socket_map, count=1)
  
  
  # An exception we can raise if we detect a potential disconnect
  # (p2p or rpc) before the test is complete
  class EarlyDisconnectError(Exception):
      def __init__(self, value):
          self.value = value
  
      def __str__(self):
          return repr(self.value)
  