Enhance Keyboard interrupt handling for dl-trades (stores data it already downloaded).

freqtrade/exchange/exchange.py

@@ -5,6 +5,7 @@ Cryptocurrency Exchanges support
 import asyncio
 import inspect
 import logging
+import signal
 from copy import deepcopy
 from datetime import datetime, timedelta, timezone
 from math import floor
@@ -2253,6 +2254,7 @@ class Exchange:
             from_id = t[-1][1]
             trades.extend(t[:-1])
         while True:
+            try:
                 t = await self._async_fetch_trades(pair,
                                                    params={self._trades_pagination_arg: from_id})
                 if t:
@@ -2268,6 +2270,9 @@ class Exchange:
                     from_id = t[-1][1]
                 else:
                     break
+            except asyncio.CancelledError:
+                logger.debug("Async operation Interrupted, breaking trades DL loop.")
+                break
 
         return (pair, trades)
 
@@ -2286,6 +2291,7 @@ class Exchange:
         # DEFAULT_TRADES_COLUMNS: 0 -> timestamp
         # DEFAULT_TRADES_COLUMNS: 1 -> id
         while True:
+            try:
                 t = await self._async_fetch_trades(pair, since=since)
                 if t:
                     since = t[-1][0]
@@ -2297,6 +2303,9 @@ class Exchange:
                         break
                 else:
                     break
+            except asyncio.CancelledError:
+                logger.debug("Async operation Interrupted, breaking trades DL loop.")
+                break
 
         return (pair, trades)
 
@@ -2344,9 +2353,12 @@ class Exchange:
             raise OperationalException("This exchange does not support downloading Trades.")
 
         with self._loop_lock:
-            return self.loop.run_until_complete(
-                self._async_get_trade_history(pair=pair, since=since,
-                                              until=until, from_id=from_id))
+            task = asyncio.ensure_future(self._async_get_trade_history(
+                pair=pair, since=since, until=until, from_id=from_id))
+
+            for sig in [signal.SIGINT, signal.SIGTERM]:
+                self.loop.add_signal_handler(sig, task.cancel)
+            return self.loop.run_until_complete(task)
 
     @retrier
     def _get_funding_fees_from_exchange(self, pair: str, since: Union[datetime, int]) -> float: