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electrum
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remove blockchain fork detection threshold

2.9.x
ThomasV 8 years ago
parent
82c2c22a6e
commit
bf7deaa1fb
2 changed files with 72 additions and 54 deletions
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  1. 94
      lib/blockchain.py
  2. 32
      lib/network.py

94
lib/blockchain.py
View File

@ -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'):
@ -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):
@ -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):
@ -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

32
lib/network.py
View File

@ -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():
@ -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)

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