From 97a621325b647dd53c6566453ca3a66435636cd8 Mon Sep 17 00:00:00 2001
From: Nullart <john@nullart.net>
Date: Tue, 19 Jun 2018 21:33:42 +0800
Subject: [PATCH] bug fix: book order limit for binance

---
 freqtrade/constants.py         |  2 +-
 freqtrade/exchange/__init__.py | 10 ++++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/freqtrade/constants.py b/freqtrade/constants.py
index 4031f9eed..4e15d471c 100644
--- a/freqtrade/constants.py
+++ b/freqtrade/constants.py
@@ -83,7 +83,7 @@ CONF_SCHEMA = {
             'properties': {
                 'use_book_order': {'type': 'boolean'},
                 'book_order_min': {'type': 'number', 'minimum': 1},
-                'book_order_max': {'type': 'number', 'minimum': 1}
+                'book_order_max': {'type': 'number', 'minimum': 1, 'maximum': 50}
             },
             'required': ['use_book_order']
         },
diff --git a/freqtrade/exchange/__init__.py b/freqtrade/exchange/__init__.py
index e25f4c8b9..be5c3940d 100644
--- a/freqtrade/exchange/__init__.py
+++ b/freqtrade/exchange/__init__.py
@@ -243,6 +243,16 @@ def get_balances() -> dict:
 @retrier
 def get_order_book(pair: str, limit: Optional[int] = 100) -> dict:
     try:
+        params = {}
+        # 20180619: bittrex doesnt support limits -.-
+        # 20180619: binance limit fix.. binance currently has valid range
+        if _API.name == 'Binance':
+            limit_range = [5, 10, 20, 50, 100, 500, 1000]
+            for limitx in limit_range:
+                if limit < limitx:
+                    limit = limitx
+                    break
+
         return _API.fetch_order_book(pair, limit)
     except ccxt.NotSupported as e:
         raise OperationalException(