4 files changed, 130 insertions, 109 deletions

diff --git a/src/consensus/.gitignore b/src/consensus/.gitignore
index d49147d17..8050d760e 100644
--- a/src/consensus/.gitignore
+++ b/src/consensus/.gitignore
@@ -3,3 +3,4 @@ gnunet-consensus-profiler
 gnunet-service-consensus
 test_consensus_api
 resource.log.master
+consensus-simulation.py
diff --git a/src/consensus/Makefile.am b/src/consensus/Makefile.am
index c0205ee5d..991e36a95 100644
--- a/src/consensus/Makefile.am
+++ b/src/consensus/Makefile.am
@@ -27,6 +27,17 @@ libexec_PROGRAMS += \
  gnunet-service-evil-consensus
 endif
 
+do_subst = $(SED) -e 's,[@]PYTHON[@],$(PYTHON),g'
+
+SUFFIXES = .py.in .py
+
+.py.in.py:
+        $(do_subst) < $< > $@
+        chmod +x $@
+
+check-python-style:
+        flake8 consensus-simulation.py.in
+
 lib_LTLIBRARIES = \
   libgnunetconsensus.la
 
@@ -103,5 +114,12 @@ test_consensus_api_LDADD = \
   $(top_builddir)/src/testing/libgnunettesting.la \
   libgnunetconsensus.la
 
+noinst_SCRIPTS = \
+        consensus-simulation.py
+
+CLEANFILES = \
+        $(noinst_SCRIPTS)
+
 EXTRA_DIST = \
-  test_consensus.conf
+  test_consensus.conf \
+  consensus-simulation.py.in
diff --git a/src/consensus/consensus-simulation.py b/src/consensus/consensus-simulation.py
deleted file mode 100644
index 542fe0dac..000000000
--- a/src/consensus/consensus-simulation.py
+++ /dev/null
@@ -1,108 +0,0 @@
-#!/usr/bin/python
-# This file is part of GNUnet
-# (C) 2013 Christian Grothoff (and other contributing authors)
-#
-# GNUnet is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published
-# by the Free Software Foundation; either version 2, or (at your
-# option) any later version.
-#
-# GNUnet is distributed in the hope that it will be useful, but
-# WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-# General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with GNUnet; see the file COPYING.  If not, write to the
-# Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
-# Boston, MA 02110-1301, USA.
-
-from __future__ import absolute_import
-from __future__ import print_function
-import argparse
-import random
-from math import ceil,log,floor
-
-
-def bsc(n):
-  """ count the bits set in n"""
-  l = n.bit_length()
-  c = 0
-  x = 1
-  for _ in range(0, l):
-    if n & x:
-      c = c + 1
-    x = x << 1
-  return c
-
-
-def simulate(k, n, verbose):
-  assert k < n
-  largest_arc = int(2**ceil(log(n, 2))) / 2
-  num_ghosts = (2 * largest_arc) - n
-  if verbose:
-    print "we have", num_ghosts, "ghost peers"
-  # n.b. all peers with idx<k are evil
-  peers = range(n)
-  info = [1 << x for x in xrange(n)]
-  def done_p():
-    for x in xrange(k, n):
-      if bsc(info[x]) < n-k:
-        return False
-    return True
-  rounds = 0
-  while not done_p():
-    if verbose:
-      print "-- round --"
-    arc = 1
-    while arc <= largest_arc:
-      if verbose:
-        print "-- subround --"
-      new_info = [x for x in info]
-      for peer_physical in xrange(n):
-        peer_logical = peers[peer_physical]
-        peer_type = None
-        partner_logical = (peer_logical + arc) % n
-        partner_physical = peers.index(partner_logical)
-        if peer_physical < k or partner_physical < k:
-          if verbose:
-            print "bad peer in connection", peer_physical, "--", partner_physical
-          continue
-        if peer_logical & arc == 0:
-          # we are outgoing
-          if verbose:
-            print peer_physical, "connects to", partner_physical
-          peer_type = "outgoing"
-          if peer_logical < num_ghosts:
-            # we have a ghost, check if the peer who connects
-            # to our ghost is actually outgoing
-            ghost_partner_logical = (peer_logical - arc) % n
-            if ghost_partner_logical & arc == 0:
-              peer_type = peer_type + ", ghost incoming"
-          new_info[peer_physical] = new_info[peer_physical] | info[peer_physical] | info[partner_physical]
-          new_info[partner_physical] = new_info[partner_physical] | info[peer_physical] | info[partner_physical]
-        else:
-          peer_type = "incoming"
-        if verbose > 1:
-          print "type of", str(peer_physical) + ":", peer_type
-      info = new_info
-      arc = arc << 1;
-    rounds = rounds + 1
-    random.shuffle(peers)
-  return rounds
-
-
-if __name__ == "__main__":
-  parser = argparse.ArgumentParser()
-  parser.add_argument("k", metavar="k", type=int, help="#(bad peers)")
-  parser.add_argument("n", metavar="n", type=int, help="#(all peers)")
-  parser.add_argument("r", metavar="r", type=int, help="#(rounds)")
-  parser.add_argument('--verbose', '-v', action='count')
-
-  args = parser.parse_args()
-  sum = 0.0;
-  for n in xrange (0, args.r):
-    sum += simulate(args.k, args.n, args.verbose)
-  printsum / args.r;
-
-
diff --git a/src/consensus/consensus-simulation.py.in b/src/consensus/consensus-simulation.py.in
new file mode 100644
index 000000000..6629ffaa8
--- /dev/null
+++ b/src/consensus/consensus-simulation.py.in
@@ -0,0 +1,110 @@
+#!@PYTHON@
+# This file is part of GNUnet
+# (C) 2013, 2018 Christian Grothoff (and other contributing authors)
+#
+# GNUnet is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published
+# by the Free Software Foundation; either version 2, or (at your
+# option) any later version.
+#
+# GNUnet is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GNUnet; see the file COPYING.  If not, write to the
+# Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+# Boston, MA 02110-1301, USA.
+
+from __future__ import absolute_import
+from __future__ import print_function
+import argparse
+import random
+from math import ceil, log, floor
+from past.builtins import xrange
+
+
+def bsc(n):
+    """ count the bits set in n"""
+    l = n.bit_length()
+    c = 0
+    x = 1
+    for _ in range(0, l):
+        if n & x:
+            c = c + 1
+        x = x << 1
+    return c
+
+
+def simulate(k, n, verbose):
+    assert k < n
+    largest_arc = int(2**ceil(log(n, 2))) / 2
+    num_ghosts = (2 * largest_arc) - n
+    if verbose:
+        print("we have", num_ghosts, "ghost peers")
+        # n.b. all peers with idx<k are evil
+    peers = range(n)
+    # py2-3 compatible, backwards.
+    # refer to http://python-future.org/compatible_idioms.html#xrange
+    info = [1 << x for x in xrange(n)]
+
+    def done_p():
+        for x in xrange(k, n):
+            if bsc(info[x]) < n-k:
+                return False
+        return True
+    rounds = 0
+    while not done_p():
+        if verbose:
+            print("-- round --")
+        arc = 1
+        while arc <= largest_arc:
+            if verbose:
+                print("-- subround --")
+            new_info = [x for x in info]
+            for peer_physical in xrange(n):
+                peer_logical = peers[peer_physical]
+                peer_type = None
+                partner_logical = (peer_logical + arc) % n
+                partner_physical = peers.index(partner_logical)
+                if peer_physical < k or partner_physical < k:
+                    if verbose:
+                        print("bad peer in connection", peer_physical, "--", partner_physical)
+                    continue
+                if peer_logical & arc == 0:
+                    # we are outgoing
+                    if verbose:
+                        print(peer_physical, "connects to", partner_physical)
+                    peer_type = "outgoing"
+                    if peer_logical < num_ghosts:
+                        # we have a ghost, check if the peer who connects
+                        # to our ghost is actually outgoing
+                        ghost_partner_logical = (peer_logical - arc) % n
+                        if ghost_partner_logical & arc == 0:
+                            peer_type = peer_type + ", ghost incoming"
+                    new_info[peer_physical] = new_info[peer_physical] | info[peer_physical] | info[partner_physical]
+                    new_info[partner_physical] = new_info[partner_physical] | info[peer_physical] | info[partner_physical]
+                else:
+                    peer_type = "incoming"
+                if verbose > 1:
+                    print("type of", str(peer_physical) + ":", peer_type)
+            info = new_info
+            arc = arc << 1
+        rounds = rounds + 1
+        random.shuffle(peers)
+    return rounds
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser()
+    parser.add_argument("k", metavar="k", type=int, help="#(bad peers)")
+    parser.add_argument("n", metavar="n", type=int, help="#(all peers)")
+    parser.add_argument("r", metavar="r", type=int, help="#(rounds)")
+    parser.add_argument('--verbose', '-v', action='count')
+
+    args = parser.parse_args()
+    sum = 0.0
+    for n in xrange(0, args.r):
+        sum += simulate(args.k, args.n, args.verbose)
+    print(sum / args.r)