pyminer: Fix memory leak, refactor to be more pythonic, maintainable, and possibly faster

Pull #4483.

Note that pyminer is not currently functional due to the removal of
getwork in cf0c47b.

contrib/pyminer/pyminer.py

@@ -5,62 +5,66 @@
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 #
 
+import sys
+from multiprocessing import Process
 import time
-import json
-import pprint
-import hashlib
 import struct
-import re
+import hashlib
 import base64
+import re
 import httplib
-import sys
-from multiprocessing import Process
+import json
 
 ERR_SLEEP = 15
 MAX_NONCE = 1000000L
 
 settings = {}
-pp = pprint.PrettyPrinter(indent=4)
+
 
 class BitcoinRPC:
-	OBJID = 1
+    object_id = 1
 
     def __init__(self, host, port, username, password):
-		authpair = "%s:%s" % (username, password)
-		self.authhdr = "Basic %s" % (base64.b64encode(authpair))
-		self.conn = httplib.HTTPConnection(host, port, False, 30)
+        authpair = "{0}:{1}".format(username, password)
+        self.authhdr = "Basic {0}".format(base64.b64encode(authpair))
+        self.conn = httplib.HTTPConnection(host, port, strict=False, timeout=30)
+
     def rpc(self, method, params=None):
-		self.OBJID += 1
-		obj = { 'version' : '1.1',
+        self.object_id += 1
+        obj = {'version' : '1.1',
                'method' : method,
-			'id' : self.OBJID }
-		if params is None:
-			obj['params'] = []
-		else:
-			obj['params'] = params
+               'id' : self.object_id,
+               'params' : params or []}
+
         self.conn.request('POST', '/', json.dumps(obj),
             { 'Authorization' : self.authhdr,
               'Content-type' : 'application/json' })
 
         resp = self.conn.getresponse()
+
         if resp is None:
-			print "JSON-RPC: no response"
+            print("JSON-RPC: no response")
             return None
 
         body = resp.read()
         resp_obj = json.loads(body)
+
         if resp_obj is None:
-			print "JSON-RPC: cannot JSON-decode body"
+            print("JSON-RPC: cannot JSON-decode body")
             return None
+
         if 'error' in resp_obj and resp_obj['error'] != None:
             return resp_obj['error']
+
         if 'result' not in resp_obj:
-			print "JSON-RPC: no result in object"
+            print("JSON-RPC: no result in object")
             return None
 
         return resp_obj['result']
+
     def getblockcount(self):
         return self.rpc('getblockcount')
+
     def getwork(self, data=None):
         return self.rpc('getwork', data)
 
@@ -73,18 +77,24 @@ def bytereverse(x):
 
 def bufreverse(in_buf):
     out_words = []
+
     for i in range(0, len(in_buf), 4):
         word = struct.unpack('@I', in_buf[i:i+4])[0]
         out_words.append(struct.pack('@I', bytereverse(word)))
+
     return ''.join(out_words)
 
 def wordreverse(in_buf):
     out_words = []
+
     for i in range(0, len(in_buf), 4):
         out_words.append(in_buf[i:i+4])
+
     out_words.reverse()
+
     return ''.join(out_words)
 
+
 class Miner:
     def __init__(self, id):
         self.id = id
@@ -132,15 +142,16 @@ class Miner:
             hash = wordreverse(hash)
 
             hash_str = hash.encode('hex')
-			l = long(hash_str, 16)
+            long_hash = long(hash_str, 16)
 
             # proof-of-work test:  hash < target
-			if l < target:
-				print time.asctime(), "PROOF-OF-WORK found: %064x" % (l,)
+            if long_hash < target:
+                print(time.asctime(), "PROOF-OF-WORK found: "
+                                      "{0:064x}".format(long_hash))
                 return (nonce + 1, nonce_bin)
             else:
-				print time.asctime(), "PROOF-OF-WORK false positive %064x" % (l,)
-#				return (nonce + 1, nonce_bin)
+                print(time.asctime(), "PROOF-OF-WORK false"
+                                      "positive {0:064x}".format(long_hash))
 
         return (nonce + 1, None)
 
@@ -150,13 +161,16 @@ class Miner:
         solution = original_data[:152] + nonce + original_data[160:256]
         param_arr = [ solution ]
         result = rpc.getwork(param_arr)
-		print time.asctime(), "--> Upstream RPC result:", result
+
+        print(time.asctime(), "--> Upstream RPC result:", result)
 
     def iterate(self, rpc):
         work = rpc.getwork()
+
         if work is None:
             time.sleep(ERR_SLEEP)
             return
+
         if 'data' not in work or 'target' not in work:
             time.sleep(ERR_SLEEP)
             return
@@ -171,13 +185,13 @@ class Miner:
 
         self.max_nonce = long(
             (hashes_done * settings['scantime']) / time_diff)
+
         if self.max_nonce > 0xfffffffaL:
             self.max_nonce = 0xfffffffaL
 
         if settings['hashmeter']:
-			print "HashMeter(%d): %d hashes, %.2f Khash/sec" % (
-			      self.id, hashes_done,
-			      (hashes_done / 1000.0) / time_diff)
+            print("HashMeter({:d}): {:d} hashes, {:.2f} Khash/sec".format(
+                  self.id, hashes_done, (hashes_done / 1000.0) / time_diff))
 
         if nonce_bin is not None:
             self.submit_work(rpc, work['data'], nonce_bin)
@@ -185,22 +199,26 @@ class Miner:
     def loop(self):
         rpc = BitcoinRPC(settings['host'], settings['port'],
                  settings['rpcuser'], settings['rpcpass'])
-		if rpc is None:
-			return
+
+        if rpc is not None:
 
             while True:
                 self.iterate(rpc)
         
+        self.conn.close()
+
+
 def miner_thread(id):
     miner = Miner(id)
     miner.loop()
 
 if __name__ == '__main__':
     if len(sys.argv) != 2:
-		print "Usage: pyminer.py CONFIG-FILE"
+        print("Usage: pyminer.py CONFIG-FILE")
         sys.exit(1)
 
-	f = open(sys.argv[1])
+    with open(sys.argv[1]) as f:
+
         for line in f:
             # skip comment lines
             m = re.search('^\s*#', line)
@@ -211,21 +229,17 @@ if __name__ == '__main__':
             m = re.search('^(\w+)\s*=\s*(\S.*)$', line)
             if m is None:
                 continue
+
             settings[m.group(1)] = m.group(2)
-	f.close()
-
-	if 'host' not in settings:
-		settings['host'] = '127.0.0.1'
-	if 'port' not in settings:
-		settings['port'] = 8332
-	if 'threads' not in settings:
-		settings['threads'] = 1
-	if 'hashmeter' not in settings:
-		settings['hashmeter'] = 0
-	if 'scantime' not in settings:
-		settings['scantime'] = 30L
+
+    settings.setdefault('host', '127.0.0.1')
+    settings.setdefault('port', 8332)
+    settings.setdefault('threads', 1)
+    settings.setdefault('hashmeter', 0)
+    settings.setdefault('scantime', 30L)
+
     if 'rpcuser' not in settings or 'rpcpass' not in settings:
-		print "Missing username and/or password in cfg file"
+        print("Missing username and/or password in cfg file")
         sys.exit(1)
 
     settings['port'] = int(settings['port'])
@@ -233,20 +247,23 @@ if __name__ == '__main__':
     settings['hashmeter'] = int(settings['hashmeter'])
     settings['scantime'] = long(settings['scantime'])
 
-	thr_list = []
-	for thr_id in range(settings['threads']):
-		p = Process(target=miner_thread, args=(thr_id,))
+    thread_list = []
+
+    for thread_id in range(settings['threads']):
+        p = Process(target=miner_thread, args=(thread_id,))
         p.start()
-		thr_list.append(p)
+        thread_list.append(p)
         time.sleep(1) # stagger threads
 
-	print settings['threads'], "mining threads started"
+    print(settings['threads'], "mining threads started")
 
-	print time.asctime(), "Miner Starts - %s:%s" % (settings['host'], settings['port'])
+    print(time.asctime(), "Miner Starts - {0}:{1}".format(settings['host'],
+                                                          settings['port']))
     try:
-		for thr_proc in thr_list:
-			thr_proc.join()
+        for thread_process in thread_list:
+            thread_process.join()
     except KeyboardInterrupt:
         pass
-	print time.asctime(), "Miner Stops - %s:%s" % (settings['host'], settings['port'])
 
+    print(time.asctime(), "Miner Stops - {0}:{1}".format(settings['host'],
+                                                         settings['port']))