fix[binacne]Update binance per connection limit (#1087)

* fix[binacne]Update binance.py per connection limit

Now: A single connection can listen to a maximum of 1024 streams.

* fix typo

* fix address test

Author: lau-jay

cryptofeed/exchanges/binance.py

@@ -45,6 +45,7 @@ class Binance(Feed, BinanceRestMixin):
         ORDER_INFO: ORDER_INFO
     }
     request_limit = 20
+    per_connection_limit = 1024
 
     @classmethod
     def timestamp_normalize(cls, ts: float) -> float:
@@ -135,14 +136,14 @@ def _address(self) -> Union[str, Dict]:
                     pair = pair.lower()
                 subs.append(f"{pair}@{stream}")
 
-        if 0 < len(subs) < 200:
+        if 0 < len(subs) < self.per_connection_limit:
             return address + '/'.join(subs)
         else:
             def split_list(_list: list, n: int):
                 for i in range(0, len(_list), n):
                     yield _list[i:i + n]
 
-            return [address + '/'.join(chunk) for chunk in split_list(subs, 200)]
+            return [address + '/'.join(chunk) for chunk in split_list(subs, self.per_connection_limit)]
 
     def _reset(self):
         self._l2_book = {}

tests/unit/test_binance.py

@@ -22,7 +22,7 @@ def test_binance_address_generation():
         sub = random.sample(symbols, length)
         addr = Binance(symbols=sub, channels=channels)._address()
 
-        if length * len(channels) < 200:
+        if length * len(channels) < 1024:
             assert isinstance(addr, str)
             value = addr.split("=", 1)[1]
             value = value.split("/")