from bitcoin import *
-class BlockchainVerifier(threading.Thread):
- """ Simple Payment Verification """
+class Blockchain(threading.Thread):
- def __init__(self, interface, config):
+ def __init__(self, config, network):
threading.Thread.__init__(self)
self.daemon = True
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.interface = interface
- interface.register_channel('verifier')
self.set_local_height()
+ self.queue = Queue.Queue()
-
-
- def start_interfaces(self):
- import interface
- servers = interface.DEFAULT_SERVERS
- servers = interface.filter_protocol(servers,'s')
- print_error("using %d servers"% len(servers))
- self.interfaces = map ( lambda server: interface.Interface({'server':server} ), servers )
-
- for i in self.interfaces:
- i.start()
- # subscribe to block headers
- i.register_channel('verifier')
- i.register_channel('get_header')
- i.send([ ('blockchain.headers.subscribe',[])], 'verifier')
- # note: each interface should send its results directly to a queue, instead of channels
- # pass the queue to the interface, so that several can share the same queue
-
-
- def get_new_response(self):
- # listen to interfaces, forward to verifier using the queue
- while self.is_running():
- for i in self.interfaces:
- try:
- r = i.get_response('verifier',timeout=0)
- except Queue.Empty:
- continue
-
- result = r.get('result')
- if result:
- return (i,result)
-
- time.sleep(1)
-
-
+
+ def height(self):
+ return self.local_height
def stop(self):
with self.lock: self.running = False
- #self.interface.poke('verifier')
+
def is_running(self):
with self.lock: return self.running
- def request_header(self, i, h):
- print_error("requesting header %d from %s"%(h, i.server))
- i.send([ ('blockchain.block.get_header',[h])], 'get_header')
+ def run(self):
+ self.init_headers_file()
+ self.set_local_height()
+ print_error( "blocks:", self.local_height )
+
+ with self.lock:
+ self.running = True
+
+ while self.is_running():
- def retrieve_header(self, i):
- while True:
try:
- r = i.get_response('get_header',timeout=1)
+ result = self.queue.get()
except Queue.Empty:
- print_error('timeout')
continue
- if r.get('error'):
- print_error('Verifier received an error:', r)
- continue
+ if not result: continue
- # 3. handle response
- method = r['method']
- params = r['params']
- result = r['result']
+ i, header = result
+ if not header: continue
+
+ height = header.get('block_height')
- if method == 'blockchain.block.get_header':
- return result
-
+ if height <= self.local_height:
+ continue
- def get_chain(self, interface, final_header):
+ if height > self.local_height + 50:
+ if not self.get_and_verify_chunks(i, header, height):
+ continue
- header = final_header
- chain = [ final_header ]
- requested_header = False
-
- while self.is_running():
+ if height > self.local_height:
+ # get missing parts from interface (until it connects to my chain)
+ chain = self.get_chain( i, header )
- if requested_header:
- header = self.retrieve_header(interface)
- if not header: return
- chain = [ header ] + chain
- requested_header = False
+ # skip that server if the result is not consistent
+ 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)
+ else:
+ print_error("error", i.server)
+ # todo: dismiss that server
+ continue
- height = header.get('block_height')
- previous_header = self.read_header(height -1)
- if not previous_header:
- self.request_header(interface, height - 1)
- requested_header = True
- continue
- # verify that it connects to my chain
- prev_hash = self.hash_header(previous_header)
- if prev_hash != header.get('prev_block_hash'):
- print_error("reorg")
- self.request_header(interface, height - 1)
- requested_header = True
- continue
+ self.network.new_blockchain_height(height, i)
+
- else:
- # the chain is complete
- return chain
def verify_chain(self, chain):
height = header.get('block_height')
prev_hash = self.hash_header(prev_header)
- bits, target = self.get_target(height/2016)
+ bits, target = self.get_target(height/2016, chain)
_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:
+ assert int('0x'+_hash,16) < target
+ except Exception:
return False
prev_header = header
return True
- def get_chunks(self, i, header, height):
- requested_chunks = []
- 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])], 'get_header')
- requested_chunks.append(n)
- break
-
- while requested_chunks:
- try:
- r = i.get_response('get_header',timeout=1)
- except Queue.Empty:
- continue
- if not r: continue
-
- if r.get('error'):
- print_error('Verifier received an error:', r)
- continue
-
- # 3. handle response
- method = r['method']
- params = r['params']
- result = r['result']
-
- if method == 'blockchain.block.get_chunk':
- index = params[0]
- self.verify_chunk(index, result)
- requested_chunks.remove(index)
-
def verify_chunk(self, index, hexdata):
data = hexdata.decode('hex')
_hash = self.hash_header(header)
assert previous_hash == header.get('prev_block_hash')
assert bits == header.get('bits')
- assert eval('0x'+_hash) < target
+ assert int('0x'+_hash,16) < target
previous_header = header
previous_hash = _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):
s = int_to_hex(res.get('version'),4) \
+ rev_hex(res.get('prev_block_hash')) \
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])
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):
return h
- def get_target(self, index):
+ def get_target(self, index, chain=None):
+ if chain is None:
+ chain = [] # Do not use mutables as default values!
max_target = 0x00000000FFFF0000000000000000000000000000000000000000000000000000
if index == 0: return 0x1d00ffff, max_target
first = self.read_header((index-1)*2016)
last = self.read_header(index*2016-1)
-
+ if last is None:
+ for h in chain:
+ if h.get('block_height') == index*2016-1:
+ last = h
+
nActualTimespan = last.get('timestamp') - first.get('timestamp')
nTargetTimespan = 14*24*60*60
nActualTimespan = max(nActualTimespan, nTargetTimespan/4)
c = c[2:]
i -= 1
- c = eval('0x'+c[0:6])
- if c > 0x800000:
+ c = int('0x'+c[0:6],16)
+ if c >= 0x800000:
c /= 256
i += 1
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 retrieve_header(self, i, queue):
+ while True:
+ try:
+ ir = queue.get(timeout=1)
+ except Queue.Empty:
+ print_error('timeout')
+ continue
- def run(self):
- self.start_interfaces()
-
- self.init_headers_file()
- self.set_local_height()
- print_error( "blocks:", self.local_height )
-
- with self.lock:
- self.running = True
-
- while self.is_running():
+ if not ir:
+ continue
- i, header = self.get_new_response()
-
- height = header.get('block_height')
+ i, r = ir
- if height > self.local_height + 50:
- self.get_chunks(i, header, height)
+ if r.get('error'):
+ print_error('Verifier received an error:', r)
+ continue
+ # 3. handle response
+ method = r['method']
+ params = r['params']
+ result = r['result']
- if height > self.local_height:
+ if method == 'blockchain.block.get_header':
+ return result
+
- # get missing parts from interface (until it connects to my chain)
- chain = self.get_chain( i, header )
- # skip that server if the result is not consistent
- if not chain: 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
+ def get_chain(self, interface, final_header):
-
+ header = final_header
+ chain = [ final_header ]
+ requested_header = False
+ queue = Queue.Queue()
+ while self.is_running():
+ if requested_header:
+ header = self.retrieve_header(interface, queue)
+ if not header: return
+ chain = [ header ] + chain
+ requested_header = False
-if __name__ == "__main__":
- import interface, simple_config
-
- config = simple_config.SimpleConfig({'verbose':True})
+ height = header.get('block_height')
+ previous_header = self.read_header(height -1)
+ if not previous_header:
+ self.request_header(interface, height - 1, queue)
+ requested_header = True
+ continue
- i0 = interface.Interface()
- i0.start()
+ # verify that it connects to my chain
+ prev_hash = self.hash_header(previous_header)
+ if prev_hash != header.get('prev_block_hash'):
+ print_error("reorg")
+ self.request_header(interface, height - 1, queue)
+ requested_header = True
+ continue
- bv = BlockchainVerifier(i0, config)
- bv.start()
+ else:
+ # the chain is complete
+ return chain
- # listen to interfaces, forward to verifier using the queue
- while 1:
- time.sleep(1)
+ def get_and_verify_chunks(self, i, header, height):
+ queue = Queue.Queue()
+ min_index = (self.local_height + 1)/2016
+ max_index = (height + 1)/2016
+ 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
+ try:
+ 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