Add command line arguments to poll script

api.py

@@ -4,35 +4,41 @@ import os
 import atexit
 import time
 import grequests
+from argparse import ArgumentParser
 from Queue import PriorityQueue
 
-interval = 3        # poll exchange tickers every 3 seconds
+interval = 2        # poll exchange tickers every 2 seconds
 cap_interval = 60   # poll check market cap every minute
 
 exchanges = {
     'https://btc-e.com/api/3/ticker/btc_usd':
-        ('btce', ('btc_usd', 'last'), 'USD', interval),
+        ['btce', ('btc_usd', 'last'), 'USD', interval],
     'https://api.gdax.com/products/BTC-USD/ticker':
-        ('coinbase', ('price',), 'USD', interval),
+        ['coinbase', ('price',), 'USD', interval],
     'https://www.bitstamp.net/api/v2/ticker/btcusd/':
-        ('bitstamp', ('last',), 'USD', interval),
+        ['bitstamp', ('last',), 'USD', interval],
     'https://api.bitfinex.com/v1/pubticker/btcusd':
-        ('bitfinex', ('last_price',), 'USD', interval),
+        ['bitfinex', ('last_price',), 'USD', interval],
     'https://data.btcchina.com/data/ticker?market=btccny':
-        ('btcchina', ('ticker', 'last'), 'CNY', interval),
+        ['btcchina', ('ticker', 'last'), 'CNY', interval],
     'http://api.huobi.com/staticmarket/ticker_btc_json.js':
-        ('huobi', ('ticker', 'last'), 'CNY', interval),
+        ['huobi', ('ticker', 'last'), 'CNY', interval],
     'https://www.okcoin.com/api/v1/ticker.do?symbol=btc_usd':
-        ('okcoin', ('ticker', 'last'), 'CNY', interval),
+        ['okcoin', ('ticker', 'last'), 'CNY', interval],
     'https://api.kraken.com/0/public/Ticker?pair=XXBTZEUR':
-        ('kraken', ('result', 'XXBTZEUR', 'c', 0), 'EUR', interval),
+        ['kraken', ('result', 'XXBTZEUR', 'c', 0), 'EUR', interval],
     'https://api.coinmarketcap.com/v1/ticker/bitcoin/':
-        ('coinmarketcap', (0, 'market_cap_usd'), 'USD', cap_interval),
+        ['coinmarketcap', (0, 'market_cap_usd'), 'USD', cap_interval],
 }
 
 queue = PriorityQueue(len(exchanges))
 
 def generate_requests():
+    assert queue.empty()
+
+    for url in exchanges.iterkeys():
+        queue.put((0, url))
+
     while True:
         scheduled, url = queue.get()
         wait = scheduled - time.time()
@@ -43,12 +49,39 @@ def generate_requests():
         yield grequests.get(url, timeout=5)
 
 if __name__ == '__main__':
-    for url in exchanges.iterkeys():
-        queue.put((0, url))
+    # parse command line options
+    parser = ArgumentParser(description='Poll bitcoin API services.')
+    parser.add_argument('-d', '--dir', metavar='PATH', type=str,
+                        default='/dev/shm/tothemoon',
+                        help='directory to save poll results in '
+                        '(default dev/shm/tothemoon)')
+    parser.add_argument('-i', '--interval', metavar='SECONDS', type=float,
+                        default=interval,
+                        help='poll interval per exchange in seconds '
+                        '(default %f)' % interval)
+    parser.add_argument('-l', '--list', action='store_true', default=False,
+                        help='list exchange info')
+    args = parser.parse_args()
+
+    root = args.dir
+
+    for ex in exchanges.itervalues():
+        if ex[0] != 'coinmarketcap':
+            ex[3] = args.interval
+
+    if args.list:
+        for url, (exid, indices, currency, interval) in exchanges.iteritems():
+            print exid
+            print '  url:     ', url
+            print '  currency:', currency
+            print '  lookup:   response[%s]' % ']['.join(repr(i) for i in indices)
+            print '  interval:', interval, 'seconds'
+            print '  path:     %s/%s' % (root, exid)
+        sys.exit(0)
 
-    root = sys.argv[1] if len(sys.argv) == 2 else '/dev/shm/tothemoon'
     create_root = not os.path.isdir(root)
 
+    # clean up created files on exit
     def remove_files():
         for ex in exchanges.itervalues():
             path = root + '/' + ex[0]
@@ -60,6 +93,7 @@ if __name__ == '__main__':
 
     atexit.register(remove_files)
 
+    # create root directory if necessary
     if create_root:
         try:
             os.mkdir(root)
@@ -68,6 +102,8 @@ if __name__ == '__main__':
             print >>sys.stderr, e.strerror
             sys.exit(1)
 
+    # keep updating URLs from priority queue, adding them back to the queue
+    # scheduled after their current interval
     try:
         for res in grequests.imap(generate_requests()):
             exid, indices, currency, interval = exchanges[res.request.url]