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()
+ self.servers_height = {}
+ self.is_lagging = False
-
-
- 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 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']
-
- if method == 'blockchain.block.get_header':
- return result
-
+ i, header = result
+ if not header: continue
+
+ height = header.get('block_height')
+ self.servers_height[i.server] = height
- def get_chain(self, interface, final_header):
+ if height > self.local_height + 50:
+ self.get_chunks(i, header, height)
+ self.network.trigger_callback('updated')
- 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: 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
- 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
+ h = self.servers_height.get(self.network.interface.server)
+ if h is not None and h < height - 1:
+ print_error( "Server is lagging", height, h)
+ if self.config.get('auto_cycle'):
+ self.network.set_server(i.server)
+ else:
+ self.network.is_lagging = True
+ else:
+ self.network.is_lagging = False
+
+ self.network.trigger_callback('updated')
- # 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
- else:
- # the chain is complete
- return chain
def verify_chain(self, chain):
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')
return True
-
-
def header_to_string(self, res):
s = int_to_hex(res.get('version'),4) \
+ rev_hex(res.get('prev_block_hash')) \
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 )
+ if not ir:
+ continue
- with self.lock:
- self.running = True
+ i, r = ir
+
+ 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_header':
+ return result
+
+
+
+ def get_chain(self, interface, final_header):
+
+ header = final_header
+ chain = [ final_header ]
+ requested_header = False
+ queue = Queue.Queue()
while self.is_running():
- i, header = self.get_new_response()
-
- height = header.get('block_height')
+ if requested_header:
+ header = self.retrieve_header(interface, queue)
+ if not header: return
+ chain = [ header ] + chain
+ requested_header = False
- if height > self.local_height + 50:
- self.get_chunks(i, header, height)
+ 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
+ # 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
- if height > self.local_height:
+ else:
+ # the chain is complete
+ return chain
- # 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_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:
+ 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']
-if __name__ == "__main__":
- import interface, simple_config
-
- config = simple_config.SimpleConfig({'verbose':True})
+ index = params[0]
+ self.verify_chunk(index, result)
+ requested_chunks.remove(index)
- i0 = interface.Interface()
- i0.start()
- bv = BlockchainVerifier(i0, config)
- bv.start()
- # listen to interfaces, forward to verifier using the queue
- while 1:
- time.sleep(1)