from util import user_dir, appdata_dir, print_error
from bitcoin import *
+try:
+ from ltc_scrypt import getPoWHash
+except ImportError:
+ print_msg("Warning: scrypt not available, using fallback")
+ from scrypt import scrypt_1024_1_1_80 as getPoWHash
class Blockchain(threading.Thread):
self.config = config
self.network = network
self.lock = threading.Lock()
- self.height = 0
self.local_height = 0
self.running = False
- self.headers_url = 'http://headers.electrum.org/blockchain_headers'
+ self.headers_url = 'http://novacoin.su/static/blockchain_headers'
self.set_local_height()
self.queue = Queue.Queue()
+ def height(self):
+ return self.local_height
+
+
def stop(self):
with self.lock: self.running = False
chain = self.get_chain( i, header )
# skip that server if the result is not consistent
- if not chain: continue
+ if not chain:
+ print_error('e')
+ continue
# verify the chain
if self.verify_chain( chain ):
print_error("height:", height, i.server)
for header in chain:
self.save_header(header)
- self.height = height
else:
print_error("error", i.server)
# todo: dismiss that server
continue
+
self.network.new_blockchain_height(height, i)
-
+ def calculate_target(self, bits):
+ # convert to bignum
+ MM = 256*256*256
+ a = bits%MM
+ if a < 0x8000:
+ a *= 256
+ return (a) * pow(2, 8 * (bits/MM - 3))
+
+
def verify_chain(self, chain):
first_header = chain[0]
height = header.get('block_height')
prev_hash = self.hash_header(prev_header)
- bits, target = self.get_target(height/2016)
- _hash = self.hash_header(header)
+ header_hash = self.hash_header(header)
+
try:
assert prev_hash == header.get('prev_block_hash')
- assert bits == header.get('bits')
- assert eval('0x'+_hash) < target
- except:
+ if header.get('nonce') != 0:
+ assert int('0x'+_hash,16) < self.calculate_target(header.get('bits'))
+ except Exception:
return False
prev_header = header
else:
prev_header = self.read_header(index*2016-1)
if prev_header is None: raise
- previous_hash = self.hash_header(prev_header)
-
- bits, target = self.get_target(index)
+ _hash = self.hash_header(prev_header)
for i in range(num):
height = index*2016 + i
raw_header = data[i*80:(i+1)*80]
header = self.header_from_string(raw_header)
- _hash = self.hash_header(header)
+ header_hash = self.hash_header(header)
+
assert previous_hash == header.get('prev_block_hash')
- assert bits == header.get('bits')
- assert eval('0x'+_hash) < target
+ if header.get('nonce') != 0:
+ assert int('0x'+header_hash,16) < calculate_target(header.get('bits'))
previous_header = header
- previous_hash = _hash
+ previous_hash = header_hash
self.save_chunk(index, data)
print_error("validated chunk %d"%height)
-
- def verify_header(self, header):
- # add header to the blockchain file
- # if there is a reorg, push it in a stack
-
- height = header.get('block_height')
-
- prev_header = self.read_header(height -1)
- if not prev_header:
- # return False to request previous header
- return False
-
- prev_hash = self.hash_header(prev_header)
- bits, target = self.get_target(height/2016)
- _hash = self.hash_header(header)
- try:
- assert prev_hash == header.get('prev_block_hash')
- assert bits == header.get('bits')
- assert eval('0x'+_hash) < target
- except:
- # this can be caused by a reorg.
- print_error("verify header failed"+ repr(header))
- verifier.undo_verifications()
-
- # return False to request previous header.
- return False
-
- self.save_header(header)
- print_error("verify header:", _hash, height)
- return True
def header_to_string(self, res):
def header_from_string(self, s):
- hex_to_int = lambda s: eval('0x' + s[::-1].encode('hex'))
+ hex_to_int = lambda s: int('0x' + s[::-1].encode('hex'), 16)
h = {}
h['version'] = hex_to_int(s[0:4])
h['prev_block_hash'] = hash_encode(s[4:36])
return h
def hash_header(self, header):
- return rev_hex(Hash(self.header_to_string(header).decode('hex')).encode('hex'))
+ return rev_hex(getPoWHash(self.header_to_string(header).decode('hex')).encode('hex'))
def path(self):
return os.path.join( self.config.path, 'blockchain_headers')
socket.setdefaulttimeout(30)
print_error("downloading ", self.headers_url )
urllib.urlretrieve(self.headers_url, filename)
- except:
+ print_error("done.")
+ except Exception:
print_error( "download failed. creating file", filename )
open(filename,'wb+').close()
h = os.path.getsize(name)/80 - 1
if self.local_height != h:
self.local_height = h
- self.height = self.local_height
def read_header(self, block_height):
h = self.header_from_string(h)
return h
-
- def get_target(self, index):
-
- max_target = 0x00000000FFFF0000000000000000000000000000000000000000000000000000
- if index == 0: return 0x1d00ffff, max_target
-
- first = self.read_header((index-1)*2016)
- last = self.read_header(index*2016-1)
-
- nActualTimespan = last.get('timestamp') - first.get('timestamp')
- nTargetTimespan = 14*24*60*60
- nActualTimespan = max(nActualTimespan, nTargetTimespan/4)
- nActualTimespan = min(nActualTimespan, nTargetTimespan*4)
-
- bits = last.get('bits')
- # convert to bignum
- MM = 256*256*256
- a = bits%MM
- if a < 0x8000:
- a *= 256
- target = (a) * pow(2, 8 * (bits/MM - 3))
-
- # new target
- new_target = min( max_target, (target * nActualTimespan)/nTargetTimespan )
-
- # convert it to bits
- c = ("%064X"%new_target)[2:]
- i = 31
- while c[0:2]=="00":
- c = c[2:]
- i -= 1
-
- c = eval('0x'+c[0:6])
- if c > 0x800000:
- c /= 256
- i += 1
-
- new_bits = c + MM * i
- return new_bits, new_target
-
-
def request_header(self, i, h, queue):
print_error("requesting header %d from %s"%(h, i.server))
i.send([ ('blockchain.block.get_header',[h])], lambda i,r: queue.put((i,r)))
def get_and_verify_chunks(self, i, header, height):
- requested_chunks = []
+
queue = Queue.Queue()
min_index = (self.local_height + 1)/2016
max_index = (height + 1)/2016
- for n in range(min_index, max_index + 1):
- print_error( "requesting chunk", n )
- i.send([ ('blockchain.block.get_chunk',[n])], lambda i,r:queue.put(r))
- requested_chunks.append(n)
- break
-
- while requested_chunks:
- try:
- r = queue.get(timeout=1)
- except Queue.Empty:
+ n = min_index
+ while n < max_index + 1:
+ print_error( "Requesting chunk:", n )
+ r = i.synchronous_get([ ('blockchain.block.get_chunk',[n])])[0]
+ if not r:
continue
- if not r: continue
-
- if r.get('error'):
- print_error('Verifier received an error:', r)
- continue
-
- # 3. handle response
- params = r['params']
- result = r['result']
-
- index = params[0]
try:
- self.verify_chunk(index, result)
- except:
- return False
- requested_chunks.remove(index)
+ self.verify_chunk(n, r)
+ n = n + 1
+ except Exception:
+ print_error('Verify chunk failed!')
+ n = n - 1
+ if n < 0:
+ return False
return True
-
-
-
-
-
-
git://git.novaco.in / electrum-nvc.git / blobdiff