mmnode-blocks-info: support JSON output

mmgen/node_tools/BlocksInfo.py

@@ -20,7 +20,7 @@
 mmgen.node_tools.BlocksInfo: Display information about a block or range of blocks
 """
 
-import re
+import re,json
 from collections import namedtuple
 from time import strftime,gmtime
 from decimal import Decimal
@@ -494,3 +494,33 @@ class BlocksInfo:
 		'utxo_increase': 1,
 		'utxo_size_inc': 117
 	}
+
+class JSONBlocksInfo(BlocksInfo):
+
+	def __init__(self,cmd_args,opt,rpc):
+		super().__init__(cmd_args,opt,rpc)
+		Msg_r('{')
+
+	async def process_blocks(self):
+		Msg_r('"block_data": [')
+		await super().process_blocks()
+		Msg_r(']')
+
+	def output_block(self,data,n):
+		Msg_r( (', ','')[n==0] + json.dumps(data._asdict()) )
+
+	async def output_stats(self,res):
+		name,data = await res
+		def gen(data):
+			for d in data:
+				if len(d) == 2:
+					for k,v in d[1].items():
+						yield (k,v)
+				else:
+					yield (d[1],d[2])
+		Msg_r(', "{}_data": {}'.format(name,json.dumps(dict(gen(data)))))
+
+	def process_stats_pre(self,i): pass
+
+	def finalize_output(self):
+		Msg('}')

mmnode-blocks-info

@@ -21,7 +21,7 @@ mmnode-blocks-info: Display information about a block or range of blocks
 """
 
 from mmgen.common import *
-from mmgen.node_tools.BlocksInfo import BlocksInfo
+from mmgen.node_tools.BlocksInfo import BlocksInfo,JSONBlocksInfo
 
 opts_data = {
 	'sets': [
@@ -29,6 +29,7 @@ opts_data = {
 		('hashes',     True,   'stats',      'none'),
 		('stats',      'none', 'stats_only', False),
 		('stats_only', True,   'no_header',  True),
+		('json',       True,   'no_header',  True),
 	],
 	'text': {
 		'desc':    'Display information about a block or range of blocks',
@@ -42,6 +43,7 @@ opts_data = {
 -h, --help            Print this help message
 --, --longhelp        Print help message for long options (common options)
 -H, --hashes          Display only block numbers and hashes
+-j, --json            Produce JSON output
 -m, --miner-info      Display miner info in coinbase transaction
 -M, --raw-miner-info  Display miner info in uninterpreted form
 -n, --no-header       Don’t print the column header
@@ -122,7 +124,9 @@ async def main():
 
 	proto = init_proto_from_opts()
 
-	m = BlocksInfo( cmd_args, opt, await rpc_init(proto) )
+	cls = JSONBlocksInfo if opt.json else BlocksInfo
+
+	m = cls( cmd_args, opt, await rpc_init(proto) )
 
 	if not opt.no_header:
 		m.print_header()