new file: examples/halving-calculator.py

MANIFEST.in

@@ -26,4 +26,6 @@ include scripts/create-token.py
 include scripts/traceback_run.py
 include scripts/uninstall-mmgen.py
 
+include examples/halving-calculator.py
+
 prune test/ref/__db*

examples/halving-calculator.py

@@ -0,0 +1,54 @@
+#!/usr/bin/env python3
+
+# Demonstrates use of the MMGen asyncio/aiohttp JSON-RPC interface
+# https://github.com/mmgen/mmgen
+# Requires a running Bitcoin Core node
+# If necessary, invoke with --rpc-host/--rpc-port/--rpc-user/--rpc-password
+# Specify aiohttp backend with --rpc-backend=aiohttp (Linux only)
+
+import time
+from decimal import Decimal
+from mmgen.common import *
+
+opts.init({ 'text': { 'desc':'', 'usage':'', 'options':'' }})
+
+HalvingInterval = 210000 # src/chainparams.cpp
+sample_size = 6 * 24     # about a day's worth of blocks
+
+def date(t):
+	return '{}-{:02}-{:02} {:02}:{:02}:{:02}'.format(*time.gmtime(t)[:6])
+
+def dhms(t):
+	return f'{t//60//60//24} days, {t//60//60%24:02}:{t//60%60:02}:{t%60:02} h/m/s'
+
+def time_diff_warning(t_diff):
+	if abs(t_diff) > 60*60:
+		print('Warning: block tip time is {} {} current time!'.format(
+			dhms(abs(t_diff)),
+			('behind','ahead of')[t_diff<0]))
+
+async def main():
+	from mmgen.rpc import rpc_init
+	c = await rpc_init()
+	tip = await c.call('getblockcount')
+
+	# aiohttp backend will perform these two calls concurrently:
+	cur,old = await c.gathered_call('getblockstats',((tip,),(tip - sample_size,)))
+
+	time_diff_warning(int(time.time() - cur['time']))
+
+	remaining = HalvingInterval - tip % HalvingInterval
+	bdr = (cur['time'] - old['time']) / sample_size
+	t_rem = remaining * int(bdr)
+	sub = cur['subsidy'] * Decimal("0.00000001")
+
+	print(f'Current block:      {tip}')
+	print(f'Next halving block: {tip + remaining}')
+	print(f'Blocks until halving: {remaining}')
+	print('Current block subsidy: {} BTC'.format(str(sub).rstrip('0')))
+	print(f'Current block discovery rate (over last {sample_size} blocks): {bdr/60:0.1f} minutes')
+	print(f'Current clock time (UTC): {date(time.time())}')
+	print(f'Est. halving date (UTC):  {date(cur["time"] + t_rem)}')
+	print(f'Est. time until halving:  {dhms(cur["time"] + t_rem - int(time.time()))}')
+
+run_session(main(),do_rpc_init=False)

mmgen/altcoins/eth/tw.py

@@ -276,9 +276,6 @@ Actions:         [q]uit view, [p]rint to file, pager [v]iew, [w]ide view,
 	def age_disp(self,o,age_fmt): # TODO
 		return None
 
-	def age_disp(self,o,age_fmt): # TODO
-		return None
-
 class EthereumTokenTwUnspentOutputs(EthereumTwUnspentOutputs):
 
 	disp_type = 'token'