Added gas price data feed from gas-oracle.zoltu.io

nucypher/utilities/datafeeds.py

@@ -132,3 +132,25 @@ class UpvestGasPriceDatafeed(EthereumGasPriceDatafeed):
         self._probe_feed()
         self.gas_prices = {self.get_canonical_speed(k): int(Web3.toWei(v, 'gwei'))
                            for k, v in self._raw_data['estimates'].items()}
+
+
+class ZoltuGasPriceDatafeed(EthereumGasPriceDatafeed):
+    """Gas price datafeed from gas-oracle.zoltu.io"""
+
+    name = "gas-oracle.zoltu.io datafeed"
+    api_url = "https://gas-oracle.zoltu.io"
+    _speed_names = {
+        SLOW: 'percentile_40',
+        MEDIUM: 'percentile_75',
+        FAST: 'percentile_95',
+        FASTEST: 'percentile_98'
+    }
+    _default_speed = 'fast'
+
+    def _parse_gas_prices(self):
+        self._probe_feed()
+        self.gas_prices = dict()
+        for canonical_speed_name, zoltu_speed in self._speed_names.items():
+            gwei_price = self._raw_data[zoltu_speed].split(" ")[0]
+            wei_price = int(Web3.toWei(gwei_price, 'gwei'))
+            self.gas_prices[canonical_speed_name] = wei_price

tests/unit/test_datafeeds.py

@@ -23,10 +23,12 @@ from requests.exceptions import ConnectionError
 from web3 import Web3
 
 from nucypher.utilities.datafeeds import (
-    EtherchainGasPriceDatafeed,
     Datafeed,
+    EtherchainGasPriceDatafeed,
+    EthereumGasPriceDatafeed,
     UpvestGasPriceDatafeed,
-    EthereumGasPriceDatafeed)
+    ZoltuGasPriceDatafeed
+)
 from nucypher.utilities.gas_strategies import construct_datafeed_fallback_strategy
 
 etherchain_json = {
@@ -47,6 +49,39 @@ upvest_json = {
     }
 }
 
+zoltu_json = {
+    "number_of_blocks": 200,
+    "latest_block_number": 11294588,
+    "percentile_1": "1 nanoeth",
+    "percentile_2": "1 nanoeth",
+    "percentile_3": "3.452271231 nanoeth",
+    "percentile_4": "10 nanoeth",
+    "percentile_5": "10 nanoeth",
+    "percentile_10": "18.15 nanoeth",
+    "percentile_15": "25 nanoeth",
+    "percentile_20": "28 nanoeth",
+    "percentile_25": "30 nanoeth",
+    "percentile_30": "32 nanoeth",
+    "percentile_35": "37 nanoeth",
+    "percentile_40": "41 nanoeth",
+    "percentile_45": "44 nanoeth",
+    "percentile_50": "47.000001459 nanoeth",
+    "percentile_55": "50 nanoeth",
+    "percentile_60": "52.5 nanoeth",
+    "percentile_65": "55.20000175 nanoeth",
+    "percentile_70": "56.1 nanoeth",
+    "percentile_75": "58 nanoeth",
+    "percentile_80": "60.20000175 nanoeth",
+    "percentile_85": "63 nanoeth",
+    "percentile_90": "64 nanoeth",
+    "percentile_95": "67 nanoeth",
+    "percentile_96": "67.32 nanoeth",
+    "percentile_97": "68 nanoeth",
+    "percentile_98": "70 nanoeth",
+    "percentile_99": "71 nanoeth",
+    "percentile_100": "74 nanoeth"
+}
+
 
 def test_probe_datafeed(mocker):
 
@@ -156,6 +191,28 @@ def test_upvest():
             assert gas_strategy("web3", "tx") == Web3.toWei(105.2745, 'gwei')
 
 
+def test_zoltu():
+    feed = ZoltuGasPriceDatafeed()
+
+    assert set(feed._speed_names.values()).issubset(zoltu_json.keys())
+    # assert feed._default_speed in zoltu_json.keys()
+
+    with patch.object(feed, '_probe_feed'):
+        feed._raw_data = zoltu_json
+        assert feed.get_gas_price('slow') == Web3.toWei(41, 'gwei')
+        assert feed.get_gas_price('medium') == Web3.toWei(58, 'gwei')
+        assert feed.get_gas_price('fast') == Web3.toWei(67, 'gwei')
+        assert feed.get_gas_price('fastest') == Web3.toWei(70, 'gwei')
+        assert feed.get_gas_price() == feed.get_gas_price('fast')  # Default
+        parsed_gas_prices = feed.gas_prices
+
+    with patch('nucypher.utilities.datafeeds.ZoltuGasPriceDatafeed._parse_gas_prices', autospec=True):
+        ZoltuGasPriceDatafeed.gas_prices = dict()
+        with patch.dict(ZoltuGasPriceDatafeed.gas_prices, values=parsed_gas_prices):
+            gas_strategy = feed.construct_gas_strategy()
+            assert gas_strategy("web3", "tx") == Web3.toWei(67, 'gwei')
+
+
 def test_datafeed_fallback_gas_price_strategy():
 
     mocked_gas_price = 0xFABADA