eth-gas-proxy

commit 5c6b65dd50842e5a3aa26fbfbd28639e8d1e5fc7
parent e06ab63d8e7285d2428c00e2e0b71f1bd66c3b0c
Author: nolash <dev@holbrook.no>
Date:   Tue, 26 Jan 2021 11:38:13 +0100

Add web3 middleware

Diffstat:
M
gas_proxy/proxy.py
 | 
24
+++++++++++++++---------
M
gas_proxy/runnable/server.py
 | 
19
++++++++++++++++---
A
requirements.txt
 | 
2
++
A
scripts/test.py
 | 
25
+++++++++++++++++++++++++
A
tests/test_middleware.py
 | 
73
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

5 files changed, 131 insertions(+), 12 deletions(-)
diff --git a/gas_proxy/proxy.py b/gas_proxy/proxy.py
@@ -3,7 +3,6 @@ import logging
 
 import websocket
 
-logging.basicConfig(level=logging.DEBUG)
 logg = logging.getLogger()
 
 
@@ -12,30 +11,36 @@ class Oracle:
     def get(self):
         raise NotImplementedError
 
-class Web3WebsocketOracle(Oracle):
+class JSONRPCOracle(Oracle):
 
 
-    def __init__(self, connection_string, cache=None):
-        logg.debug('connecting to {}'.format(connection_string))
-        self.ws = websocket.create_connection(connection_string)
+    def __init__(self, socket, cache=None):
         self.query = {
             "jsonrpc": "2.0",
             "method": "eth_gasPrice",
             "params": [],
             "id": 0,
         }
+        self.id_seq = 0
+        self.socket = socket
         self.cache = cache
 
 
     def __del__(self):
-        self.ws.close()
+        self.socket.close()
 
 
-    def get(self):
+    def get(self, request_id=None):
         o = None
+        if request_id == None:
+            request_id = str(self.id_seq)
+            self.id_seq += 1
+   
+        self.query['id'] = request_id
+
         try:
-            self.ws.send(json.dumps(self.query))
-            result = self.ws.recv()
+            self.socket.send(json.dumps(self.query))
+            result = self.socket.recv()
             o = json.loads(result)
             result_hex = o['result'][2:]
             if len(result_hex) % 2 != 0:
@@ -43,6 +48,7 @@ class Web3WebsocketOracle(Oracle):
             result_bytes = bytes.fromhex(result_hex)
             result_num = int.from_bytes(result_bytes, 'big')
         except Exception as e:
+            logg.exception('backend error')
             if self.cache == None:
                 raise(e)
             result_num = self.cache.get()
diff --git a/gas_proxy/runnable/server.py b/gas_proxy/runnable/server.py
@@ -1,13 +1,16 @@
+import re
 import os
 import argparse
 import logging
 import socket
 import json
 
-from gas_proxy.proxy import Web3WebsocketOracle as Oracle
+import websocket
+
+from gas_proxy.proxy import JSONRPCOracle as Oracle
 from gas_proxy.cache.mem import MemCache
 
-logging.basicConfig(level=logging.DEBUG)
+logging.basicConfig(level=logging.WARNING)
 logg = logging.getLogger()
 
 
@@ -26,9 +29,19 @@ if args.vv:
 elif args.v:
     logging.getLogger().setLevel(logging.INFO)
 
+re_websocket = r'^wss?://(.+):(\d+)/?$'
+m = re.match(re_websocket, args.provider)
+if m == None:
+    raise ValueError('websocket providers only')
+
+logg.debug('using websocket host {} port {}'.format(m.group(1), m.group(2)))
+connection_string = args.provider
+
 if __name__ == '__main__':
     memcache = MemCache()
-    ws = Oracle(args.provider, cache=memcache)
+
+    ws = websocket.create_connection(connection_string)
+    ws = Oracle(ws, cache=memcache)
 
     s = socket.socket(family=socket.AF_INET, type=socket.SOCK_STREAM)
     s.bind((args.host, args.port))
diff --git a/requirements.txt b/requirements.txt
@@ -0,0 +1,2 @@
+web3==5.12.2
+websocket-client==0.57.0
diff --git a/scripts/test.py b/scripts/test.py
@@ -0,0 +1,25 @@
+import logging
+import time
+
+import web3
+import websocket
+
+from gas_proxy.web3 import GasMiddleware
+
+logging.basicConfig(level=logging.DEBUG)
+logg = logging.getLogger()
+
+re_websocket = r'wss?://'
+
+def socket_constructor():
+    return websocket.create_connection('ws://localhost:8545')
+
+GasMiddleware.socket_constructor = socket_constructor
+GasMiddleware.last_gas = "0x1000"
+
+w3 = web3.Web3(web3.Web3.WebsocketProvider('ws://localhost:8545'))
+w3.middleware_onion.add(GasMiddleware)
+
+while True:
+    print(w3.eth.gas_price())
+    time.sleep(1)
diff --git a/tests/test_middleware.py b/tests/test_middleware.py
@@ -0,0 +1,73 @@
+import json
+import logging
+
+import unittest
+
+from gas_proxy.web3 import GasMiddleware
+
+logging.basicConfig(level=logging.DEBUG)
+
+
+class Mocket:
+
+
+    def __init__(self):
+        self.last_id = None
+        self.response = None
+        self.active = True
+
+
+    def toggle(self):
+        self.active = not self.active
+
+
+    def send(self, d):
+        if not self.active:
+            raise ConnectionError('socket deactivated')
+        o = json.loads(d)
+        self.last_id = o['id']
+        r = {
+            "jsonrpc": "2.0",
+            "id": self.last_id,
+            "result": "0x1324",
+                }
+        self.response = json.dumps(r)
+
+    def recv(self, c=0):
+        return self.response
+
+
+class MiddlewareTest(unittest.TestCase):
+
+
+    def setUp(self):
+        self.socket = Mocket()
+
+        def socket_constructor():
+            return self.socket
+
+        GasMiddleware.socket_constructor = socket_constructor
+
+
+    def tearDown(self):
+        pass
+
+
+    def test_middleware(self):
+        GasMiddleware.last_gas = "0x2a"
+        middleware = GasMiddleware(None, None)
+
+        self.socket.toggle()
+        r = middleware.__call__("eth_gasPrice", [])
+        self.assertEqual(r['result'], "0x2a")
+
+        self.socket.toggle()
+        r = middleware.__call__("eth_gasPrice", [])
+        self.assertEqual(r['result'], "0x1324")
+
+        self.socket.toggle()
+        r = middleware.__call__("eth_gasPrice", [])
+        self.assertEqual(r['result'], "0x1324")
+
+if __name__ == '__main__':
+    unittest.main()