text: #!/usr/bin/env python3
  # Copyright (c) 2017 The Bitcoin Core developers
  # Distributed under the MIT software license, see the accompanying
  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  """Class for safecashd node under test"""
  
  import decimal
  import errno
  import http.client
  import json
  import logging
  import os
  import re
  import subprocess
  import time
  
  from .authproxy import JSONRPCException
  from .util import (
      assert_equal,
      delete_cookie_file,
      get_rpc_proxy,
      rpc_url,
      wait_until,
      p2p_port,
  )
  
  # For Python 3.4 compatibility
  JSONDecodeError = getattr(json, "JSONDecodeError", ValueError)
  
  SAFECASHD_PROC_WAIT_TIMEOUT = 60
  
  class TestNode():
      """A class for representing a safecashd node under test.
  
      This class contains:
  
      - state about the node (whether it's running, etc)
      - a Python subprocess.Popen object representing the running process
      - an RPC connection to the node
      - one or more P2P connections to the node
  
  
      To make things easier for the test writer, any unrecognised messages will
      be dispatched to the RPC connection."""
  
      def __init__(self, i, dirname, extra_args, rpchost, timewait, binary, stderr, mocktime, coverage_dir, use_cli=False):
          self.index = i
          self.datadir = os.path.join(dirname, "node" + str(i))
          self.rpchost = rpchost
          if timewait:
              self.rpc_timeout = timewait
          else:
              # Wait for up to 60 seconds for the RPC server to respond
              self.rpc_timeout = 60
          if binary is None:
              self.binary = os.getenv("SAFECASHD", "safecashd")
          else:
              self.binary = binary
          self.stderr = stderr
          self.coverage_dir = coverage_dir
          # Most callers will just need to add extra args to the standard list below. For those callers that need more flexibity, they can just set the args property directly.
          self.extra_args = extra_args
          self.args = [self.binary, "-datadir=" + self.datadir, "-server", "-keypool=1", "-discover=0", "-rest", "-logtimemicros", "-debug", "-debugexclude=libevent", "-debugexclude=leveldb", "-mocktime=" + str(mocktime), "-uacomment=testnode%d" % i]
  
          self.cli = TestNodeCLI(os.getenv("SAFECASHCLI", "safecash-cli"), self.datadir)
          self.use_cli = use_cli
  
          self.running = False
          self.process = None
          self.rpc_connected = False
          self.rpc = None
          self.url = None
          self.log = logging.getLogger('TestFramework.node%d' % i)
          self.cleanup_on_exit = True # Whether to kill the node when this object goes away
  
          self.p2ps = []
  
      def __del__(self):
          # Ensure that we don't leave any bitcoind processes lying around after
          # the test ends
          if self.process and self.cleanup_on_exit:
              # Should only happen on test failure
              # Avoid using logger, as that may have already been shutdown when
              # this destructor is called.
              print("Cleaning up leftover process")
              self.process.kill()
  
      def __getattr__(self, name):
          """Dispatches any unrecognised messages to the RPC connection or a CLI instance."""
          if self.use_cli:
              return getattr(self.cli, name)
          else:
              assert self.rpc_connected and self.rpc is not None, "Error: no RPC connection"
              return getattr(self.rpc, name)
  
      def start(self, extra_args=None, stderr=None, *args, **kwargs):
          """Start the node."""
          if extra_args is None:
              extra_args = self.extra_args
          if stderr is None:
              stderr = self.stderr
          # Delete any existing cookie file -- if such a file exists (eg due to
          # unclean shutdown), it will get overwritten anyway by bitcoind, and
          # potentially interfere with our attempt to authenticate
          delete_cookie_file(self.datadir)
          self.process = subprocess.Popen(self.args + extra_args, stderr=stderr, *args, **kwargs)
          self.running = True
          self.log.debug("safecashd started, waiting for RPC to come up")
  
      def wait_for_rpc_connection(self):
          """Sets up an RPC connection to the safecashd process. Returns False if unable to connect."""
          # Poll at a rate of four times per second
          poll_per_s = 4
          for _ in range(poll_per_s * self.rpc_timeout):
              assert self.process.poll() is None, "safecashd exited with status %i during initialization" % self.process.returncode
              try:
                  self.rpc = get_rpc_proxy(rpc_url(self.datadir, self.index, self.rpchost), self.index, timeout=self.rpc_timeout, coveragedir=self.coverage_dir)
                  self.rpc.getblockcount()
                  # If the call to getblockcount() succeeds then the RPC connection is up
                  self.rpc_connected = True
                  self.url = self.rpc.url
                  self.log.debug("RPC successfully started")
                  return
              except IOError as e:
                  if e.errno != errno.ECONNREFUSED:  # Port not yet open?
                      raise  # unknown IO error
              except JSONRPCException as e:  # Initialization phase
                  if e.error['code'] != -28:  # RPC in warmup?
                      raise  # unknown JSON RPC exception
              except ValueError as e:  # cookie file not found and no rpcuser or rpcassword. safecashd still starting
                  if "No RPC credentials" not in str(e):
                      raise
              time.sleep(1.0 / poll_per_s)
          raise AssertionError("Unable to connect to safecashd")
  
      def get_wallet_rpc(self, wallet_name):
          if self.use_cli:
              return self.cli("-rpcwallet={}".format(wallet_name))
          else:
              assert self.rpc_connected
              assert self.rpc
              wallet_path = "wallet/%s" % wallet_name
              return self.rpc / wallet_path
  
      def stop_node(self):
          """Stop the node."""
          if not self.running:
              return
          self.log.debug("Stopping node")
          try:
              self.stop()
          except http.client.CannotSendRequest:
              self.log.exception("Unable to stop node.")
          del self.p2ps[:]
  
      def is_node_stopped(self):
          """Checks whether the node has stopped.
  
          Returns True if the node has stopped. False otherwise.
          This method is responsible for freeing resources (self.process)."""
          if not self.running:
              return True
          return_code = self.process.poll()
          if return_code is None:
              return False
  
          # process has stopped. Assert that it didn't return an error code.
          assert_equal(return_code, 0)
          self.running = False
          self.process = None
          self.rpc_connected = False
          self.rpc = None
          self.log.debug("Node stopped")
          return True
  
      def wait_until_stopped(self, timeout=SAFECASHD_PROC_WAIT_TIMEOUT):
          wait_until(self.is_node_stopped, timeout=timeout)
  
      def node_encrypt_wallet(self, passphrase):
          """"Encrypts the wallet.
  
          This causes safecashd to shutdown, so this method takes
          care of cleaning up resources."""
          self.encryptwallet(passphrase)
          self.wait_until_stopped()
  
      def add_p2p_connection(self, p2p_conn, *args, **kwargs):
          """Add a p2p connection to the node.
  
          This method adds the p2p connection to the self.p2ps list and also
          returns the connection to the caller."""
          if 'dstport' not in kwargs:
              kwargs['dstport'] = p2p_port(self.index)
          if 'dstaddr' not in kwargs:
              kwargs['dstaddr'] = '127.0.0.1'
  
          p2p_conn.peer_connect(*args, **kwargs)
          self.p2ps.append(p2p_conn)
  
          return p2p_conn
  
      @property
      def p2p(self):
          """Return the first p2p connection
  
          Convenience property - most tests only use a single p2p connection to each
          node, so this saves having to write node.p2ps[0] many times."""
          assert self.p2ps, "No p2p connection"
          return self.p2ps[0]
  
      def disconnect_p2ps(self):
          """Close all p2p connections to the node."""
          for p in self.p2ps:
              p.peer_disconnect()
          del self.p2ps[:]
  
  class TestNodeCLIAttr:
      def __init__(self, cli, command):
          self.cli = cli
          self.command = command
  
      def __call__(self, *args, **kwargs):
          return self.cli.send_cli(self.command, *args, **kwargs)
  
      def get_request(self, *args, **kwargs):
          return lambda: self(*args, **kwargs)
  
  class TestNodeCLI():
      """Interface to safecash-cli for an individual node"""
  
      def __init__(self, binary, datadir):
          self.options = []
          self.binary = binary
          self.datadir = datadir
          self.input = None
          self.log = logging.getLogger('TestFramework.safecashcli')
  
      def __call__(self, *options, input=None):
          # TestNodeCLI is callable with safecash-cli command-line options
          cli = TestNodeCLI(self.binary, self.datadir)
          cli.options = [str(o) for o in options]
          cli.input = input
          return cli
  
      def __getattr__(self, command):
          return TestNodeCLIAttr(self, command)
  
      def batch(self, requests):
          results = []
          for request in requests:
             try:
                 results.append(dict(result=request()))
             except JSONRPCException as e:
                 results.append(dict(error=e))
          return results
  
      def send_cli(self, command=None, *args, **kwargs):
          """Run safecash-cli command. Deserializes returned string as python object."""
  
          pos_args = [str(arg) for arg in args]
          named_args = [str(key) + "=" + str(value) for (key, value) in kwargs.items()]
          assert not (pos_args and named_args), "Cannot use positional arguments and named arguments in the same safecash-cli call"
          p_args = [self.binary, "-datadir=" + self.datadir] + self.options
          if named_args:
              p_args += ["-named"]
          if command is not None:
              p_args += [command]
          p_args += pos_args + named_args
          self.log.debug("Running safecash-cli command: %s" % command)
          process = subprocess.Popen(p_args, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
          cli_stdout, cli_stderr = process.communicate(input=self.input)
          returncode = process.poll()
          if returncode:
              match = re.match(r'error code: ([-0-9]+)\nerror message:\n(.*)', cli_stderr)
              if match:
                  code, message = match.groups()
                  raise JSONRPCException(dict(code=int(code), message=message))
              # Ignore cli_stdout, raise with cli_stderr
              raise subprocess.CalledProcessError(returncode, self.binary, output=cli_stderr)
          try:
              return json.loads(cli_stdout, parse_float=decimal.Decimal)
          except JSONDecodeError:
              return cli_stdout.rstrip("\n")
  