electrum/client/interface.py

#!/usr/bin/env python
#
# Electrum - lightweight Bitcoin client
# Copyright (C) 2011 thomasv@gitorious
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.


import random, socket, ast

        
import thread, traceback, sys, time

DEFAULT_TIMEOUT=5

class Interface:
    def __init__(self):
        self.default_servers = ['ecdsa.org','electrum.novit.ro']  # list of default servers
        self.host = random.choice( self.default_servers )         # random choice when the wallet is created
        self.servers = self.default_servers                       # actual list from IRC
        self.rtime = 0
        self.blocks = 0 
        self.message = ''
        self.set_port(50000)
        self.is_connected = False
        self.was_updated = True # fixme: use a semaphore
        self.was_polled = False # True after the first poll

    def set_port(self, port_number):
        self.port = port_number
        if self.use_http():
            self.handler = self.http_json_handler
        else:
            self.handler = self.native_handler

    def use_http(self): 
        return self.port in [80,81,8080,8081]

    def native_handler(self, method, params = ''):
        import time
        cmds = {'session.new':'new_session',
                'peers':'peers',
                'session.poll':'poll',
                'session.update':'update_session',
                'blockchain.transaction.broadcast':'tx',
                'blockchain.address.get_history':'h'
                }
        cmd = cmds[method]
        if type(params) != type(''): params = repr( params )
        t1 = time.time()
        request = repr ( (cmd, params) ) + "#"
        s = socket.socket( socket.AF_INET, socket.SOCK_STREAM)
        s.settimeout(DEFAULT_TIMEOUT)
        s.connect(( self.host if cmd!='peers' else self.peers_server, self.port) )
        s.send( request )
        out = ''
        while 1:
            msg = s.recv(1024)
            if msg: out += msg
            else: break
        s.close()
        self.rtime = time.time() - t1
        self.is_connected = True
        if cmd in[ 'peers','h']:
            out = ast.literal_eval( out )
        return out

    def http_json_handler(self, method, params = []):
        import urllib2, json, time
        if type(params) != type([]): params = [ params ]
        t1 = time.time()
        data = { 'method':method, 'id':'jsonrpc', 'params':params }
        data_json = json.dumps(data)
        host = 'http://%s:%d'%( self.host if cmd!='peers' else self.peers_server, self.port )
        req = urllib2.Request(host, data_json, {'content-type': 'application/json'})
        response_stream = urllib2.urlopen(req)
        response = json.loads( response_stream.read() )
        out = response.get('result')
        if not out:
            print response
        self.rtime = time.time() - t1
        self.is_connected = True
        return out

    def send_tx(self, data):
        out = self.handler('blockchain.transaction.broadcast', data )
        return out

    def retrieve_history(self, address):
        out = self.handler('blockchain.address.get_history', address )
        return out

    def poll(self):
        out = self.handler('session.poll', self.session_id )
        blocks, changed_addr = ast.literal_eval( out )
        if blocks == -1: raise BaseException("session not found")
        self.blocks = int(blocks)
        if changed_addr: self.was_updated = True
        self.was_polled = True
        return changed_addr

    def new_session(self, addresses, version):
        self.was_polled = False
        out = self.handler('session.new', [ version, addresses ] )
        self.session_id, self.message = ast.literal_eval( out )

    def update_session(self, addresses):
        out = self.handler('session.update', [ self.session_id, addresses ] )
        return out
    
    def update_servers_thread(self):
        # if my server is not reachable, I should get the list from one of the default servers
        # requesting servers could be an independent process
        while True:
            for server in self.default_servers:
                try:
                    self.peers_server = server
                    out = self.handler('peers')
                    self.servers = map( lambda x:x[1], out )
                    # print "Received server list from %s" % self.peers_server, out
                    break
                except socket.timeout:
                    continue
                except socket.error:
                    continue

            time.sleep(5*60)

    def poll_interval(self):
        return 15 if self.use_http() else 5

    def update_wallet(self, wallet):
        is_new = False
        changed_addresses = self.poll()
        for addr, blk_hash in changed_addresses.items():
            if wallet.status.get(addr) != blk_hash:
                print "updating history for", addr
                wallet.history[addr] = self.retrieve_history(addr)
                wallet.status[addr] = blk_hash
                is_new = True

        if is_new:
            wallet.synchronize()
            wallet.update_tx_history()
            wallet.save()
            return True
        else:
            return False

    def update_wallet_thread(self, wallet):
        while True:
            try:
                self.is_connected = False
                self.new_session(wallet.all_addresses(), wallet.electrum_version)
            except socket.error:
                print "Not connected"
                time.sleep(self.poll_interval())
                continue
            except:
                traceback.print_exc(file=sys.stdout)
                time.sleep(self.poll_interval())
                continue

            while True:
                try:
                    if self.update_wallet(wallet):
                        self.update_session( wallet.all_addresses() )

                    time.sleep(self.poll_interval())
                except BaseException:
                    traceback.print_exc(file=sys.stdout)
                    print "starting new session"
                    break
                except socket.gaierror:
                    self.is_connected = False
                    break
                except socket.error:
                    print "socket.error"
                    self.is_connected = False
                    break
                except:
                    self.is_connected = False
                    print "error"
                    traceback.print_exc(file=sys.stdout)
                    break
                

    def start(self, wallet):
        thread.start_new_thread(self.update_wallet_thread, (wallet,))

    def get_servers(self):
        thread.start_new_thread(self.update_servers_thread, ())