tremove blockchain fork detection threshold - electrum - Electrum Bitcoin wallet
(HTM) git clone https://git.parazyd.org/electrum
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---
(DIR) commit bf7deaa1fb2ac3b608305db3e30b32ff7c7d05ce
(DIR) parent 82c2c22a6e4b9307dcb45fd7b40ab2fbc48a7b0f
(HTM) Author: ThomasV <thomasv@electrum.org>
Date: Thu, 13 Jul 2017 16:23:41 +0200
remove blockchain fork detection threshold
Diffstat:
M lib/blockchain.py | 94 ++++++++++++++++++++-----------
M lib/network.py | 32 ++++++++++++-------------------
2 files changed, 72 insertions(+), 54 deletions(-)
---
(DIR) diff --git a/lib/blockchain.py b/lib/blockchain.py
t@@ -62,26 +62,30 @@ def hash_header(header):
class Blockchain(util.PrintError):
+
'''Manages blockchain headers and their verification'''
- def __init__(self, config, checkpoint):
+
+ def __init__(self, config, filename, fork_point):
self.config = config
- self.checkpoint = checkpoint
- self.filename = 'blockchain_headers' if checkpoint == 0 else 'blockchain_fork_%d'%checkpoint
- self.set_local_height()
+ self.filename = filename
self.catch_up = None # interface catching up
+ if fork_point is None:
+ self.is_saved = True
+ self.checkpoint = int(filename[16:]) if filename.startswith('blockchain_fork_') else 0
+ else:
+ self.is_saved = False
+ self.checkpoint = fork_point
+ self.headers = []
+ self.set_local_height()
def height(self):
- return self.local_height
+ return self.local_height + len(self.headers)
def verify_header(self, header, prev_header, bits, target):
prev_hash = hash_header(prev_header)
_hash = hash_header(header)
if prev_hash != header.get('prev_block_hash'):
raise BaseException("prev hash mismatch: %s vs %s" % (prev_hash, header.get('prev_block_hash')))
- #if not self.pass_checkpoint(header):
- # raise BaseException('failed checkpoint')
- #if self.checkpoint_height == header.get('block_height'):
- # self.print_error("validated checkpoint", self.checkpoint_height)
if bitcoin.TESTNET:
return
if bits != header.get('bits'):
t@@ -115,24 +119,50 @@ class Blockchain(util.PrintError):
return os.path.join(d, self.filename)
def save_chunk(self, index, chunk):
+ if not self.is_saved:
+ self.fork_and_save()
filename = self.path()
- f = open(filename, 'rb+')
- f.seek(index * 2016 * 80)
- f.truncate()
- h = f.write(chunk)
- f.close()
+ with open(filename, 'rb+') as f:
+ f.seek(index * 2016 * 80)
+ f.truncate()
+ h = f.write(chunk)
self.set_local_height()
+ def fork_and_save(self):
+ import shutil
+ self.print_error("save fork")
+ height = self.checkpoint
+ filename = "blockchain_fork_%d"%height
+ new_path = os.path.join(util.get_headers_dir(self.config), filename)
+ shutil.copy(self.path(), new_path)
+ with open(new_path, 'rb+') as f:
+ f.seek((height) * 80)
+ f.truncate()
+ self.filename = filename
+ self.is_saved = True
+ for h in self.headers:
+ self.write_header(h)
+ self.headers = []
+
def save_header(self, header):
+ height = header.get('block_height')
+ if not self.is_saved:
+ assert height == self.checkpoint + len(self.headers) + 1
+ self.headers.append(header)
+ if len(self.headers) > 10:
+ self.fork_and_save()
+ return
+ self.write_header(header)
+
+ def write_header(self, header):
+ height = header.get('block_height')
data = serialize_header(header).decode('hex')
assert len(data) == 80
- height = header.get('block_height')
filename = self.path()
- f = open(filename, 'rb+')
- f.seek(height * 80)
- f.truncate()
- h = f.write(data)
- f.close()
+ with open(filename, 'rb+') as f:
+ f.seek(height * 80)
+ f.truncate()
+ h = f.write(data)
self.set_local_height()
def set_local_height(self):
t@@ -143,15 +173,22 @@ class Blockchain(util.PrintError):
if self.local_height != h:
self.local_height = h
- def read_header(self, block_height):
+ def read_header(self, height):
+ if not self.is_saved and height >= self.checkpoint:
+ i = height - self.checkpoint
+ if i >= len(self.headers):
+ return None
+ header = self.headers[i]
+ assert header.get('block_height') == height
+ return header
name = self.path()
if os.path.exists(name):
f = open(name, 'rb')
- f.seek(block_height * 80)
+ f.seek(height * 80)
h = f.read(80)
f.close()
if len(h) == 80:
- h = deserialize_header(h, block_height)
+ h = deserialize_header(h, height)
return h
def get_hash(self, height):
t@@ -173,17 +210,6 @@ class Blockchain(util.PrintError):
f.truncate()
f.close()
- def fork(self, height):
- import shutil
- filename = "blockchain_fork_%d"%height
- new_path = os.path.join(util.get_headers_dir(self.config), filename)
- shutil.copy(self.path(), new_path)
- with open(new_path, 'rb+') as f:
- f.seek((height) * 80)
- f.truncate()
- f.close()
- return filename
-
def get_target(self, index, chain=None):
if bitcoin.TESTNET:
return 0, 0
(DIR) diff --git a/lib/network.py b/lib/network.py
t@@ -205,13 +205,12 @@ class Network(util.DaemonThread):
config = {} # Do not use mutables as default values!
util.DaemonThread.__init__(self)
self.config = SimpleConfig(config) if type(config) == type({}) else config
- self.num_server = 8 if not self.config.get('oneserver') else 0
- self.blockchains = { 0:Blockchain(self.config, 0) }
+ self.num_server = 18 if not self.config.get('oneserver') else 0
+ self.blockchains = { 0:Blockchain(self.config, 'blockchain_headers', None) }
for x in os.listdir(self.config.path):
if x.startswith('blockchain_fork_'):
- n = int(x[16:])
- b = Blockchain(self.config, n)
- self.blockchains[n] = b
+ b = Blockchain(self.config, x, None)
+ self.blockchains[b.checkpoint] = b
self.print_error("blockchains", self.blockchains.keys())
self.blockchain_index = config.get('blockchain_index', 0)
if self.blockchain_index not in self.blockchains.keys():
t@@ -864,23 +863,16 @@ class Network(util.DaemonThread):
if interface.bad != interface.good + 1:
next_height = (interface.bad + interface.good) // 2
else:
- interface.print_error("found connection at %d"% interface.good)
delta1 = interface.blockchain.height() - interface.good
delta2 = interface.tip - interface.good
- threshold = self.config.get('fork_threshold', 5)
- if delta1 > threshold and delta2 > threshold:
- interface.print_error("chain split detected: %d (%d %d)"% (interface.good, delta1, delta2))
- interface.blockchain.fork(interface.bad)
- interface.blockchain = Blockchain(self.config, interface.bad)
- self.blockchains[interface.bad] = interface.blockchain
- if interface.blockchain.catch_up is None:
- interface.blockchain.catch_up = interface.server
- interface.print_error("catching up")
- interface.mode = 'catch_up'
- next_height = interface.good
- else:
- # todo: if current catch_up is too slow, queue others
- next_height = None
+ interface.print_error("chain split detected at %d"%interface.good, delta1, delta2)
+ interface.blockchain = Blockchain(self.config, False, interface.bad)
+ interface.blockchain.catch_up = interface.server
+ self.blockchains[interface.bad] = interface.blockchain
+ interface.print_error("catching up")
+ interface.mode = 'catch_up'
+ next_height = interface.good
+
elif interface.mode == 'catch_up':
if can_connect:
interface.blockchain.save_header(header)