move max_checkpoint from network to constants

electrum/blockchain.py

@@ -28,6 +28,7 @@ from .bitcoin import Hash, hash_encode, int_to_hex, rev_hex
 from . import constants
 from .util import bfh, bh2u
 
+
 MAX_TARGET = 0x00000000FFFF0000000000000000000000000000000000000000000000000000
 
 
@@ -315,7 +316,7 @@ class Blockchain(util.PrintError):
 
     def get_hash(self, height):
         def is_height_checkpoint():
-            within_cp_range = height < len(self.checkpoints) * 2016
+            within_cp_range = height <= constants.net.max_checkpoint()
             at_chunk_boundary = (height+1) % 2016 == 0
             return within_cp_range and at_chunk_boundary
 

electrum/constants.py

@@ -37,7 +37,14 @@ def read_json(filename, default):
     return r
 
 
-class BitcoinMainnet:
+class AbstractNet:
+
+    @classmethod
+    def max_checkpoint(cls) -> int:
+        return max(0, len(cls.CHECKPOINTS) * 2016 - 1)
+
+
+class BitcoinMainnet(AbstractNet):
 
     TESTNET = False
     WIF_PREFIX = 0x80
@@ -66,7 +73,7 @@ class BitcoinMainnet:
     BIP44_COIN_TYPE = 0
 
 
-class BitcoinTestnet:
+class BitcoinTestnet(AbstractNet):
 
     TESTNET = True
     WIF_PREFIX = 0xef

electrum/interface.py

@@ -41,6 +41,7 @@ from . import pem
 from .version import ELECTRUM_VERSION, PROTOCOL_VERSION
 from . import blockchain
 from .blockchain import deserialize_header
+from . import constants
 
 
 class NotificationSession(ClientSession):
@@ -267,7 +268,7 @@ class Interface(PrintError):
         asyncio.get_event_loop().create_task(self.group.cancel_remaining())
 
     async def run_fetch_blocks(self, sub_reply, replies):
-        if self.tip < self.network.max_checkpoint():
+        if self.tip < constants.net.max_checkpoint():
             raise GracefulDisconnect('server tip below max checkpoint')
 
         async with self.network.bhi_lock:
@@ -298,7 +299,7 @@ class Interface(PrintError):
                 could_connect, num_headers = await self.request_chunk(height, next_height)
                 self.tip = max(height + num_headers, self.tip)
                 if not could_connect:
-                    if height <= self.network.max_checkpoint():
+                    if height <= constants.net.max_checkpoint():
                         raise Exception('server chain conflicts with checkpoints or genesis')
                     last, height = await self.step(height)
                     self.tip = max(height, self.tip)
@@ -328,8 +329,8 @@ class Interface(PrintError):
             bad_header = header
             height -= 1
             checkp = False
-            if height <= self.network.max_checkpoint():
-                height = self.network.max_checkpoint() + 1
+            if height <= constants.net.max_checkpoint():
+                height = constants.net.max_checkpoint() + 1
                 checkp = True
 
             header = await self.get_block_header(height, 'backward')
@@ -343,8 +344,8 @@ class Interface(PrintError):
                 delta = self.tip - height
                 next_height = self.tip - 2 * delta
                 checkp = False
-                if next_height <= self.network.max_checkpoint():
-                    next_height = self.network.max_checkpoint() + 1
+                if next_height <= constants.net.max_checkpoint():
+                    next_height = constants.net.max_checkpoint() + 1
                     checkp = True
                 height = next_height
 

electrum/network.py

@@ -818,10 +818,6 @@ class Network(PrintError):
         with open(path, 'w', encoding='utf-8') as f:
             f.write(json.dumps(cp, indent=4))
 
-    @classmethod
-    def max_checkpoint(cls):
-        return max(0, len(constants.net.CHECKPOINTS) * 2016 - 1)
-
     def start(self, fx=None):
         self.fut = threading.Thread(target=self._run, args=(fx,))
         self.fut.start()

electrum/tests/test_network.py

@@ -2,7 +2,7 @@ import asyncio
 import tempfile
 import unittest
 
-from electrum.constants import set_regtest
+from electrum import constants
 from electrum.simple_config import SimpleConfig
 from electrum import blockchain
 from electrum.interface import Interface
@@ -11,9 +11,6 @@ class MockInterface(Interface):
     def __init__(self, config):
         self.config = config
         super().__init__(None, 'mock-server:50000:t', self.config.electrum_path(), None)
-        class FakeNetwork:
-            max_checkpoint = lambda: 0
-        self.network = FakeNetwork
         self.q = asyncio.Queue()
         self.blockchain = blockchain.Blockchain(self.config, 2002, None)
         self.tip = 12
@@ -26,6 +23,17 @@ class MockInterface(Interface):
         return item
 
 class TestNetwork(unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+        constants.set_regtest()
+
+    @classmethod
+    def tearDownClass(cls):
+        super().tearDownClass()
+        constants.set_mainnet()
+
     def setUp(self):
         self.config = SimpleConfig({'electrum_path': tempfile.mkdtemp(prefix="test_network")})
         self.interface = MockInterface(self.config)
@@ -107,5 +115,5 @@ class TestNetwork(unittest.TestCase):
         self.assertEqual(times, 2)
 
 if __name__=="__main__":
-    set_regtest()
+    constants.set_regtest()
     unittest.main()