From 2777208da3c95085222fc44ce1eab1746588a7f9 Mon Sep 17 00:00:00 2001
From: Inso <insomniak.fr@gmail.com>
Date: Wed, 30 Sep 2015 19:38:44 +0200
Subject: [PATCH] Detect blockchain rollback
---
src/cutecoin/core/net/network.py | 32 +++++++++++++++++++++++---------
src/cutecoin/core/net/node.py | 27 ++++++++++++++++++++++-----
2 files changed, 45 insertions(+), 14 deletions(-)
diff --git a/src/cutecoin/core/net/network.py b/src/cutecoin/core/net/network.py
index f9d7dc6e..4146da8d 100644
--- a/src/cutecoin/core/net/network.py
+++ b/src/cutecoin/core/net/network.py
@@ -12,7 +12,7 @@ import asyncio
from ucoinpy.documents.peer import Peer
from ucoinpy.documents.block import Block
-from ucoinpy.api import bma
+from ...tools.decorators import asyncify
from PyQt5.QtCore import pyqtSignal, pyqtSlot, QObject, QTimer
from collections import Counter
@@ -25,6 +25,7 @@ class Network(QObject):
"""
nodes_changed = pyqtSignal()
new_block_mined = pyqtSignal(int)
+ blockchain_rollback = pyqtSignal(int)
def __init__(self, currency, nodes):
"""
@@ -40,7 +41,7 @@ class Network(QObject):
self.add_node(n)
self.currency = currency
self._must_crawl = False
- self._block_found = self.latest_block_hash
+ self._refresh_block_found()
self._timer = QTimer()
@classmethod
@@ -189,6 +190,10 @@ class Network(QObject):
else:
return Block.Empty_Hash
+ def _refresh_block_found(self):
+ self._block_found = {'hash': self.latest_block_hash,
+ 'number': self.latest_block_number}
+
def check_nodes_sync(self):
"""
Check nodes sync with the following rules :
@@ -334,10 +339,19 @@ class Network(QObject):
self.nodes.remove(node)
self.nodes_changed.emit()
-
- logging.debug("{0} -> {1}".format(self._block_found[:10], self.latest_block_hash[:10]))
- if self._block_found != self.latest_block_hash and node.state == Node.ONLINE:
- logging.debug("Latest block changed : {0}".format(self.latest_block_number))
- self._block_found = self.latest_block_hash
- # Do not emit block change for empty block
- self.new_block_mined.emit(self.latest_block_number)
+ if node.state == Node.ONLINE:
+ logging.debug("{0} -> {1}".format(self._block_found['hash'][:10], self.latest_block_hash[:10]))
+ if self._block_found['hash'] != self.latest_block_hash:
+ logging.debug("Latest block changed : {0}".format(self.latest_block_number))
+ # If new latest block is lower than the previously found one
+ # or if the previously found block is different locally
+ # than in the main chain, we declare a rollback
+ if self._block_found['number'] and \
+ self.latest_block_number <= self._block_found['number'] \
+ or node.main_chain_previous_block and \
+ node.main_chain_previous_block['hash'] != self._block_found['hash']:
+ self._refresh_block_found()
+ self.blockchain_rollback.emit(self.latest_block_number)
+ else:
+ self._refresh_block_found()
+ self.new_block_mined.emit(self.latest_block_number)
diff --git a/src/cutecoin/core/net/node.py b/src/cutecoin/core/net/node.py
index c1b001ed..a64b6fa8 100644
--- a/src/cutecoin/core/net/node.py
+++ b/src/cutecoin/core/net/node.py
@@ -5,7 +5,6 @@ Created on 21 févr. 2015
"""
from ucoinpy.documents.peer import Peer, Endpoint, BMAEndpoint
-from ucoinpy.documents.block import Block
from ...tools.exceptions import InvalidNodeCurrency
from ...tools.decorators import asyncify
from ucoinpy.api import bma as bma
@@ -49,6 +48,7 @@ class Node(QObject):
self._uid = uid
self._pubkey = pubkey
self._block = block
+ self.main_chain_previous_block = None
self._state = state
self._neighbours = []
self._currency = currency
@@ -295,12 +295,29 @@ class Node(QObject):
self.state = Node.ONLINE
if not self.block or block_hash != self.block['hash']:
- self.set_block(block_data)
- logging.debug("Changed block {0} -> {1}".format(self.block['number'],
- block_data['number']))
- self.changed.emit()
+ try:
+ #TODO: Check previous block
+ self.main_chain_previous_block = yield from bma.blockchain.Block(conn_handler,
+ self.block['number']).get()
+ except ValueError as e:
+ if '404' in str(e):
+ self.main_chain_previous_block = None
+ logging.debug("Error in block reply")
+ self.changed.emit()
+ except ClientError:
+ logging.debug("Client error : {0}".format(self.pubkey))
+ self.state = Node.OFFLINE
+ except asyncio.TimeoutError:
+ logging.debug("Timeout error : {0}".format(self.pubkey))
+ self.state = Node.OFFLINE
+ finally:
+ self.set_block(block_data)
+ logging.debug("Changed block {0} -> {1}".format(self.block['number'],
+ block_data['number']))
+ self.changed.emit()
except ValueError as e:
if '404' in str(e):
+ self.main_chain_previous_block = None
self.set_block(None)
logging.debug("Error in block reply")
self.changed.emit()
--
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