hush some unreachable-code errors found by lgtm.com

This comments out some "if 0: debug()" stuff I keep around to investigate
problems, since lgtm thinks of it as accidentally-unreachable code.

I also deleted a server usage command
entirely (src/wormhole/server/cmd_usage.py show_usage) which was disabled
while I rewrote that schema: the new plan is to move the server into a new
repository altogether, and use a completely different approach to the
usage database.

misc/dump-timing.py

@@ -43,9 +43,8 @@ def web():
     root.putChild("lib", static.File(lib_root))
     class Shutdown(resource.Resource):
         def render_GET(self, request):
-            if 0:
-                print("timeline ready, server shutting down")
-                reactor.stop()
+            #print("timeline ready, server shutting down")
+            #reactor.stop()
             return "shutting down"
     root.putChild("done", Shutdown())
     site = server.Site(root)

src/wormhole/_rlcompleter.py

@@ -1,5 +1,5 @@
 from __future__ import print_function, unicode_literals
-import os, traceback
+import traceback
 from sys import stderr
 try:
     import readline
@@ -12,8 +12,8 @@ from twisted.internet.threads import deferToThread, blockingCallFromThread
 from .errors import KeyFormatError, AlreadyInputNameplateError
 
 errf = None
-if 0:
-    errf = open("err", "w") if os.path.exists("err") else None
+# uncomment this to enable tab-completion debugging
+#import os ; errf = open("err", "w") if os.path.exists("err") else None
 def debug(*args, **kwargs):
     if errf:
         print(*args, file=errf, **kwargs)
@@ -150,7 +150,6 @@ def _input_code_with_completion(prompt, input_helper, reactor):
         debug("==== readline-based completion is prepared")
     else:
         debug("==== unable to import readline, disabling completion")
-        pass
     code = input(prompt)
     # Code is str(bytes) on py2, and str(unicode) on py3. We want unicode.
     if isinstance(code, bytes):

src/wormhole/server/cmd_usage.py

@@ -1,6 +1,5 @@
 from __future__ import print_function, unicode_literals
 import os, time, json
-from collections import defaultdict
 import click
 from humanize import naturalsize
 from .database import get_db
@@ -32,65 +31,6 @@ def print_event(event):
 def show_usage(args):
     print("closed for renovation")
     return 0
-    if not os.path.exists("relay.sqlite"):
-        raise click.UsageError(
-            "cannot find relay.sqlite, please run from the server directory"
-        )
-    oldest = None
-    newest = None
-    rendezvous_counters = defaultdict(int)
-    transit_counters = defaultdict(int)
-    total_transit_bytes = 0
-    db = get_db("relay.sqlite")
-    c = db.execute("SELECT * FROM `usage`"
-                   " ORDER BY `started` ASC LIMIT ?",
-                   (args.n,))
-    for row in c.fetchall():
-        if row["type"] == "rendezvous":
-            counters = rendezvous_counters
-        elif row["type"] == "transit":
-            counters = transit_counters
-            total_transit_bytes += row["total_bytes"]
-        else:
-            continue
-        counters["total"] += 1
-        counters[row["result"]] += 1
-        if oldest is None or row["started"] < oldest:
-            oldest = row["started"]
-        if newest is None or row["started"] > newest:
-            newest = row["started"]
-        event = (row["type"], row["started"], row["result"],
-                 row["total_bytes"], row["waiting_time"], row["total_time"])
-        print_event(event)
-    if rendezvous_counters["total"] or transit_counters["total"]:
-        print("---")
-        print("(most recent started %s ago)" % abbrev(time.time() - newest))
-    if rendezvous_counters["total"]:
-        print("rendezvous events:")
-        counters = rendezvous_counters
-        elapsed = time.time() - oldest
-        total = counters["total"]
-        print(" %d events in %s (%.2f per hour)" % (total, abbrev(elapsed),
-                                                    (3600 * total / elapsed)))
-        print("", ", ".join(["%s=%d (%d%%)" %
-                             (k, counters[k], (100.0 * counters[k] / total))
-                             for k in sorted(counters)
-                             if k != "total"]))
-    if transit_counters["total"]:
-        print("transit events:")
-        counters = transit_counters
-        elapsed = time.time() - oldest
-        total = counters["total"]
-        print(" %d events in %s (%.2f per hour)" % (total, abbrev(elapsed),
-                                                    (3600 * total / elapsed)))
-        rate = total_transit_bytes / elapsed
-        print(" %s total bytes, %sps" % (naturalsize(total_transit_bytes),
-                                         naturalsize(rate)))
-        print("", ", ".join(["%s=%d (%d%%)" %
-                             (k, counters[k], (100.0 * counters[k] / total))
-                             for k in sorted(counters)
-                             if k != "total"]))
-    return 0
 
 def tail_usage(args):
     if not os.path.exists("relay.sqlite"):
@@ -117,7 +57,6 @@ def tail_usage(args):
             time.sleep(2)
     except KeyboardInterrupt:
         return 0
-    return 0
 
 def count_channels(args):
     if not os.path.exists("relay.sqlite"):

src/wormhole/transit.py

@@ -510,7 +510,6 @@ class InboundConnectionFactory(protocol.ClientFactory):
     def _proto_failed(self, f):
         # ignore these two, let Twisted log everything else
         f.trap(BadHandshake, defer.CancelledError)
-        pass
 
 def allocate_tcp_port():
     """Return an (integer) available TCP port on localhost. This briefly