tsubscribe to / verify headers - electrum - Electrum Bitcoin wallet
HTML git clone https://git.parazyd.org/electrum
DIR Log
DIR Files
DIR Refs
DIR Submodules
---
DIR commit f91dde55dd8bf710feadcef7d0c806218efa43c3
DIR parent b3b31fdc07517ea5af36b1eb37d595d5e0d2237f
HTML Author: thomasv <thomasv@gitorious>
Date: Thu, 25 Oct 2012 15:40:30 +0200
subscribe to / verify headers
Diffstat:
M lib/interface.py | 4 ++++
M lib/verifier.py | 111 +++++++++++++++++++++++--------
2 files changed, 89 insertions(+), 26 deletions(-)
---
DIR diff --git a/lib/interface.py b/lib/interface.py
t@@ -97,6 +97,10 @@ class Interface(threading.Thread):
result = params[0]
params = []
+ elif method == 'blockchain.headers.subscribe':
+ result = params[0]
+ params = []
+
elif method == 'blockchain.address.subscribe':
addr = params[0]
result = params[1]
DIR diff --git a/lib/verifier.py b/lib/verifier.py
t@@ -38,8 +38,14 @@ class WalletVerifier(threading.Thread):
self.targets = config.get('targets',{}) # compute targets
self.lock = threading.Lock()
- #self.config.set_key('verified_tx', [], True)
- #for i in range(70): self.get_target(i)
+ self.pending_headers = [] # headers that have not been verified
+
+ self.height = 0
+ self.local_height = 0
+ self.set_local_numblocks()
+
+ #prev_header = self.read_header(0)
+ #print prev_header
#sys.exit()
t@@ -47,10 +53,14 @@ class WalletVerifier(threading.Thread):
def run(self):
requested_merkle = []
requested_chunks = []
+ requested_headers = []
+
+ # subscribe to block headers
+ self.interface.send([ ('blockchain.headers.subscribe',[])], 'verifier')
while True:
# request missing chunks
- max_index = self.wallet.blocks/2016
+ max_index = (self.height+1)/2016
if not requested_chunks:
for i in range(0, max_index + 1):
# test if we can read the first header of the chunk
t@@ -60,8 +70,14 @@ class WalletVerifier(threading.Thread):
requested_chunks.append(i)
break
- # todo: request missing blocks too
-
+ # request missing headers
+ if not requested_chunks and self.local_height:
+ for i in range(self.local_height + 1, self.height + 1):
+ if i not in requested_headers:
+ print "requesting header", i
+ self.interface.send([ ('blockchain.block.get_header',[i])], 'verifier')
+ requested_headers.append(i)
+
# request missing tx merkle
txlist = self.wallet.get_tx_hashes()
for tx in txlist:
t@@ -92,8 +108,21 @@ class WalletVerifier(threading.Thread):
self.verify_chunk(index, result)
requested_chunks.remove(index)
+ elif method == 'blockchain.headers.subscribe':
+ self.height = result.get('block_height')
+ self.pending_headers.append(result)
+
elif method == 'blockchain.block.get_header':
- self.verify_header(result)
+ height = result.get('block_height')
+ requested_headers.remove(height)
+ self.pending_headers.append(result)
+
+ # process pending headers
+ # todo: sort them first
+ for header in self.pending_headers:
+ self.verify_header(header)
+ self.pending_headers = []
+
def request_merkle(self, tx_hash):
t@@ -114,8 +143,8 @@ class WalletVerifier(threading.Thread):
def verify_chunk(self, index, hexdata):
data = hexdata.decode('hex')
height = index*2016
- numblocks = len(data)/80
- print "validate_chunk", index, numblocks
+ num = len(data)/80
+ print "validate_chunk", index, num
if index == 0:
previous_hash = ("0"*64)
t@@ -126,7 +155,7 @@ class WalletVerifier(threading.Thread):
bits, target = self.get_target(index)
- for i in range(numblocks):
+ for i in range(num):
height = index*2016 + i
raw_header = data[i*80:(i+1)*80]
header = self.header_from_string(raw_header)
t@@ -141,24 +170,38 @@ class WalletVerifier(threading.Thread):
self.save_chunk(index, data)
- def validate_header(self, header):
- """ if there is a previous or a next block in the list, check the hash"""
+ 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')
- with self.lock:
- self.headers[height] = header # detect conflicts
- prev_header = next_header = None
- if height-1 in self.headers:
- prev_header = self.headers[height-1]
- if height+1 in self.headers:
- next_header = self.headers[height+1]
-
- if prev_header:
- prev_hash = self.hash_header(prev_header)
+
+ prev_header = self.read_header(height -1)
+ if not prev_header:
+ raise "no previous header", height
+ return
+
+ #prev_hash = prev_header.get('block_height')
+ 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
+ ok = True
+ except:
+ print "verify header failed", header
+ raise
+ # this could be caused by a reorg. request the previous header
+ ok = False
+ #request previous one
+
+ if ok:
self.save_header(header)
- if next_header:
- _hash = self.hash_header(header)
- assert _hash == next_header.get('prev_block_hash')
+ print "verify header: ok", height
+
+
def header_to_string(self, res):
t@@ -194,14 +237,12 @@ class WalletVerifier(threading.Thread):
h = Hash( h + hash_decode(item[1:]) ) if is_left else Hash( hash_decode(item[1:]) + h )
return hash_encode(h)
-
def path(self):
wdir = user_dir()
if not os.path.exists( wdir ):
wdir = os.path.dirname(self.config.path)
return os.path.join( wdir, 'blockchain_headers')
-
def save_chunk(self, index, chunk):
filename = self.path()
if os.path.exists(filename):
t@@ -212,6 +253,24 @@ class WalletVerifier(threading.Thread):
f.seek(index*2016*80)
h = f.write(chunk)
f.close()
+ self.set_local_numblocks()
+
+ def save_header(self, header):
+ data = self.header_to_string(header).decode('hex')
+ assert len(data) == 80
+ height = header.get('block_height')
+ filename = self.path()
+ f = open(filename,'rw+')
+ f.seek(height*80)
+ h = f.write(data)
+ f.close()
+ self.set_local_numblocks()
+
+ def set_local_numblocks(self):
+ name = self.path()
+ if os.path.exists(name):
+ self.local_height = os.path.getsize(name)/80 - 1
+ # print "local height", self.local_height, os.path.getsize(name)/80.
def read_header(self, block_height):