tMerge pull request #1268 from kyuupichan/blockchain_nothread - electrum - Electrum Bitcoin wallet
 (HTM) git clone https://git.parazyd.org/electrum
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       ---
 (DIR) commit f307b18546c2fddb7f0ae8c817fe0a65890a9133
 (DIR) parent 56f8fc62f9964743b13d045438804f26735a3eb5
 (HTM) Author: ThomasV <electrumdev@gmail.com>
       Date:   Wed, 24 Jun 2015 09:00:52 +0200
       
       Merge pull request #1268 from kyuupichan/blockchain_nothread
       
       Make the blockchain class not a thread
       Diffstat:
         M lib/blockchain.py                   |     168 ++++++++-----------------------
         M lib/network.py                      |     110 +++++++++++++++++++++++++++----
       
       2 files changed, 139 insertions(+), 139 deletions(-)
       ---
 (DIR) diff --git a/lib/blockchain.py b/lib/blockchain.py
       t@@ -17,71 +17,32 @@
        # along with this program. If not, see <http://www.gnu.org/licenses/>.
        
        
       -import threading, time, Queue, os, sys, shutil
       -from util import user_dir, print_error
       +import os
        import util
        from bitcoin import *
        
        
       -class Blockchain(util.DaemonThread):
       -
       +class Blockchain():
       +    '''Manages blockchain headers and their verification'''
            def __init__(self, config, network):
       -        util.DaemonThread.__init__(self)
                self.config = config
                self.network = network
       -        self.lock = threading.Lock()
                self.headers_url = 'http://headers.electrum.org/blockchain_headers'
       -        self.queue = Queue.Queue()
                self.local_height = 0
                self.set_local_height()
        
       +    def print_error(self, *msg):
       +        util.print_error("[blockchain]", *msg)
       +
            def height(self):
                return self.local_height
        
       -    def run(self):
       +    def init(self):
                self.init_headers_file()
                self.set_local_height()
                self.print_error("%d blocks" % self.local_height)
        
       -        while self.is_running():
       -            try:
       -                result = self.queue.get(timeout=0.1)
       -            except Queue.Empty:
       -                continue
       -            if not result:
       -                continue
       -            i, header = result
       -            if not header:
       -                continue
       -            height = header.get('block_height')
       -            if height <= self.local_height:
       -                continue
       -            if height > self.local_height + 50:
       -                if not self.get_and_verify_chunks(i, header, height):
       -                    continue
       -            if height > self.local_height:
       -                # 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:
       -                    self.print_error('e')
       -                    continue
       -                # verify the chain
       -                if self.verify_chain( chain ):
       -                    self.print_error("height:", height, i.server)
       -                    for header in chain:
       -                        self.save_header(header)
       -                else:
       -                    self.print_error("error", i.server)
       -                    # todo: dismiss that server
       -                    continue
       -            self.network.new_blockchain_height(height, i)
       -
       -        self.print_error("stopped")
       -
       -
            def verify_chain(self, chain):
       -
                first_header = chain[0]
                prev_header = self.read_header(first_header.get('block_height') -1)
        
       t@@ -132,7 +93,7 @@ class Blockchain(util.DaemonThread):
                    previous_hash = _hash
        
                self.save_chunk(index, data)
       -        self.print_error("validated chunk %d"%height)
       +        self.print_error("validated chunk %d to height %d" % (index, height))
        
        
        
       t@@ -259,81 +220,38 @@ class Blockchain(util.DaemonThread):
                new_bits = c + MM * i
                return new_bits, new_target
        
       -
       -    def request_header(self, i, h, queue):
       -        self.print_error("requesting header %d from %s"%(h, i.server))
       -        i.send_request({'method':'blockchain.block.get_header', 'params':[h]}, queue)
       -
       -    def retrieve_request(self, queue):
       -        t = time.time()
       -        while self.is_running():
       -            try:
       -                ir = queue.get(timeout=0.1)
       -            except Queue.Empty:
       -                if time.time() - t > 10:
       -                    return
       -                else:
       -                    continue
       -            i, r = ir
       -            result = r['result']
       -            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():
       -
       -            if requested_header:
       -                header = self.retrieve_request(queue)
       -                if not header:
       -                    self.print_error('chain request timed out, giving up')
       -                    return
       -                chain = [ header ] + chain
       -                requested_header = False
       -
       -            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'):
       -                self.print_error("reorg")
       -                self.request_header(interface, height - 1, queue)
       -                requested_header = True
       -                continue
       -
       -            else:
       -                # the chain is complete
       -                return chain
       -
       -
       -    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:
       -            self.print_error( "Requesting chunk:", n )
       -            i.send_request({'method':'blockchain.block.get_chunk', 'params':[n]}, queue)
       -            r = self.retrieve_request(queue)
       -            if not r:
       -                return False
       -            try:
       -                self.verify_chunk(n, r)
       -                n = n + 1
       -            except Exception:
       -                self.print_error('Verify chunk failed!')
       -                n = n - 1
       -                if n < 0:
       -                    return False
       -
       -        return True
       +    def connect_header(self, chain, header):
       +        '''Builds a header chain until it connects.  Returns True if it has
       +        successfully connected, False if verification failed, otherwise the
       +        height of the next header needed.'''
       +        chain.append(header)  # Ordered by decreasing height
       +        previous_height = header['block_height'] - 1
       +        previous_header = self.read_header(previous_height)
       +
       +        # Missing header, request it
       +        if not previous_header:
       +            return previous_height
       +
       +        # Does it connect to my chain?
       +        prev_hash = self.hash_header(previous_header)
       +        if prev_hash != header.get('prev_block_hash'):
       +            self.print_error("reorg")
       +            return previous_height
       +
       +        # The chain is complete.  Reverse to order by increasing height
       +        chain.reverse()
       +        if self.verify_chain(chain):
       +            self.print_error("connected at height:", previous_height)
       +            for header in chain:
       +                self.save_header(header)
       +            return True
       +
       +        return False
       +
       +    def connect_chunk(self, idx, chunk):
       +        try:
       +            self.verify_chunk(idx, chunk)
       +            return idx + 1
       +        except Exception:
       +            self.print_error('verify_chunk failed')
       +            return idx - 1
 (DIR) diff --git a/lib/network.py b/lib/network.py
       t@@ -13,6 +13,7 @@ import util
        from bitcoin import *
        import interface
        from blockchain import Blockchain
       +from collections import deque
        
        DEFAULT_PORTS = {'t':'50001', 's':'50002', 'h':'8081', 'g':'8082'}
        
       t@@ -141,6 +142,8 @@ class Network(util.DaemonThread):
                self.queue = Queue.Queue()
                self.requests_queue = pipe.send_queue
                self.response_queue = pipe.get_queue
       +        # A deque of interface header requests, processed left-to-right
       +        self.bc_requests = deque()
                # Server for addresses and transactions
                self.default_server = self.config.get('server')
                # Sanitize default server
       t@@ -295,11 +298,6 @@ class Network(util.DaemonThread):
                for i in range(self.num_server - 1):
                    self.start_random_interface()
        
       -    def start(self):
       -        self.running = True
       -        self.blockchain.start()
       -        util.DaemonThread.start(self)
       -
            def set_proxy(self, proxy):
                self.proxy = proxy
                if proxy:
       t@@ -412,7 +410,6 @@ class Network(util.DaemonThread):
                # Our set of interfaces changed
                self.notify('interfaces')
        
       -
            def process_response(self, i, response):
                # the id comes from the daemon or the network proxy
                _id = response.get('id')
       t@@ -435,6 +432,10 @@ class Network(util.DaemonThread):
                    addr = response.get('params')[0]
                    self.addr_responses[addr] = result
                    self.response_queue.put(response)
       +        elif method == 'blockchain.block.get_chunk':
       +            self.on_get_chunk(i, response)
       +        elif method == 'blockchain.block.get_header':
       +            self.on_get_header(i, response)
                else:
                    self.response_queue.put(response)
        
       t@@ -508,10 +509,91 @@ class Network(util.DaemonThread):
                        else:
                            self.switch_to_interface(self.default_server)
        
       +    def request_chunk(self, interface, data, idx):
       +        interface.print_error("requesting chunk %d" % idx)
       +        interface.send_request({'method':'blockchain.block.get_chunk', 'params':[idx]})
       +        data['chunk_idx'] = idx
       +        data['req_time'] = time.time()
       +
       +    def on_get_chunk(self, interface, response):
       +        '''Handle receiving a chunk of block headers'''
       +        if self.bc_requests:
       +            req_if, data = self.bc_requests[0]
       +            req_idx = data.get('chunk_idx')
       +            # Ignore unsolicited chunks
       +            if req_if == interface and req_idx == response['params'][0]:
       +                idx = self.blockchain.connect_chunk(req_idx, response['result'])
       +                # If not finished, get the next chunk
       +                if idx < 0 or self.get_local_height() >= data['if_height']:
       +                    self.bc_requests.popleft()
       +                else:
       +                    self.request_chunk(interface, data, idx)
       +
       +    def request_header(self, interface, data, height):
       +        interface.print_error("requesting header %d" % height)
       +        interface.send_request({'method':'blockchain.block.get_header', 'params':[height]})
       +        data['header_height'] = height
       +        data['req_time'] = time.time()
       +        if not 'chain' in data:
       +            data['chain'] = []
       +
       +    def on_get_header(self, interface, response):
       +        '''Handle receiving a single block header'''
       +        if self.bc_requests:
       +            req_if, data = self.bc_requests[0]
       +            req_height = data.get('header_height', -1)
       +            # Ignore unsolicited headers
       +            if req_if == interface and req_height == response['params'][0]:
       +                next_height = self.blockchain.connect_header(data['chain'], response['result'])
       +                # If not finished, get the next header
       +                if next_height in [True, False]:
       +                    self.bc_requests.popleft()
       +                    if not next_height:
       +                        interface.print_error("header didn't connect, dismissing interface")
       +                        interface.stop()
       +                else:
       +                    self.request_header(interface, data, next_height)
       +
       +    def bc_request_headers(self, interface, data):
       +        '''Send a request for the next header, or a chunk of them, if necessary'''
       +        local_height, if_height = self.get_local_height(), data['if_height']
       +        if if_height <= local_height:
       +            return False
       +        elif if_height > local_height + 50:
       +            self.request_chunk(interface, data, (local_height + 1) / 2016)
       +        else:
       +            self.request_header(interface, data, if_height)
       +        return True
       +
       +    def handle_bc_requests(self):
       +        '''Work through each interface that has notified us of a new header.
       +        Send it requests if it is ahead of our blockchain object'''
       +        while self.bc_requests:
       +            interface, data = self.bc_requests.popleft()
       +            # If the connection was lost move on
       +            if not interface.is_connected():
       +                continue
       +
       +            req_time = data.get('req_time')
       +            if not req_time:
       +                # No requests sent yet.  This interface has a new height.
       +                # Request headers if it is ahead of our blockchain
       +                if not self.bc_request_headers(interface, data):
       +                    continue
       +            elif time.time() - req_time > 10:
       +                interface.print_error("blockchain request timed out")
       +                interface.stop()
       +                continue
       +            # Put updated request state back at head of deque
       +            self.bc_requests.appendleft((interface, data))
       +            break
       +
            def run(self):
       +        self.blockchain.init()
                while self.is_running():
                    self.check_interfaces()
                    self.handle_requests()
       +            self.handle_bc_requests()
                    try:
                        i, response = self.queue.get(timeout=0.1)
                    except Queue.Empty:
       t@@ -526,19 +608,19 @@ class Network(util.DaemonThread):
                self.stop_network()
                self.print_error("stopped")
        
       -
            def on_header(self, i, r):
       -        result = r.get('result')
       -        if not result:
       +        header = r.get('result')
       +        if not header:
                    return
       -        height = result.get('block_height')
       +        height = header.get('block_height')
                if not height:
                    return
                self.heights[i.server] = height
       -        self.merkle_roots[i.server] = result.get('merkle_root')
       -        self.utxo_roots[i.server] = result.get('utxo_root')
       -        # notify blockchain about the new height
       -        self.blockchain.queue.put((i,result))
       +        self.merkle_roots[i.server] = header.get('merkle_root')
       +        self.utxo_roots[i.server] = header.get('utxo_root')
       +
       +        # Queue this interface's height for asynchronous catch-up
       +        self.bc_requests.append((i, {'if_height': height}))
        
                if i == self.interface:
                    self.switch_lagging_interface()