linearize-hashes.py

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#!/usr/bin/python
#
# linearize-hashes.py:  List blocks in a linear, no-fork version of the chain.
#
# Copyright (c) 2013-2014 The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
#

from __future__ import print_function
import json
import struct
import re
import base64
import httplib
import sys

settings = {}

class BitcoinRPC:
        def __init__(self, host, port, username, password):
                authpair = "%s:%s" % (username, password)
                self.authhdr = "Basic %s" % (base64.b64encode(authpair))
                self.conn = httplib.HTTPConnection(host, port, False, 30)

        def execute(self, obj):
                self.conn.request('POST', '/', json.dumps(obj),
                        { 'Authorization' : self.authhdr,
                          'Content-type' : 'application/json' })

                resp = self.conn.getresponse()
                if resp is None:
                        print("JSON-RPC: no response", file=sys.stderr)
                        return None

                body = resp.read()
                resp_obj = json.loads(body)
                return resp_obj

        @staticmethod
        def build_request(idx, method, params):
                obj = { 'version' : '1.1',
                        'method' : method,
                        'id' : idx }
                if params is None:
                        obj['params'] = []
                else:
                        obj['params'] = params
                return obj

        @staticmethod
        def response_is_error(resp_obj):
                return 'error' in resp_obj and resp_obj['error'] is not None

def get_block_hashes(settings, max_blocks_per_call=10000):
        rpc = BitcoinRPC(settings['host'], settings['port'],
                         settings['rpcuser'], settings['rpcpassword'])

        height = settings['min_height']
        while height < settings['max_height']+1:
                num_blocks = min(settings['max_height']+1-height, max_blocks_per_call)
                batch = []
                for x in range(num_blocks):
                        batch.append(rpc.build_request(x, 'getblockhash', [height + x]))

                reply = rpc.execute(batch)

                for x,resp_obj in enumerate(reply):
                        if rpc.response_is_error(resp_obj):
                                print('JSON-RPC: error at height', height+x, ': ', resp_obj['error'], file=sys.stderr)
                                exit(1)
                        assert(resp_obj['id'] == x) # assume replies are in-sequence
                        print(resp_obj['result'])

                height += num_blocks

if __name__ == '__main__':
        if len(sys.argv) != 2:
                print("Usage: linearize-hashes.py CONFIG-FILE")
                sys.exit(1)

        f = open(sys.argv[1])
        for line in f:
                # skip comment lines
                m = re.search('^\s*#', line)
                if m:
                        continue

                # parse key=value lines
                m = re.search('^(\w+)\s*=\s*(\S.*)$', line)
                if m is None:
                        continue
                settings[m.group(1)] = m.group(2)
        f.close()

        if 'host' not in settings:
                settings['host'] = '127.0.0.1'
        if 'port' not in settings:
                settings['port'] = 9998
        if 'min_height' not in settings:
                settings['min_height'] = 0
        if 'max_height' not in settings:
                settings['max_height'] = 313000
        if 'rpcuser' not in settings or 'rpcpassword' not in settings:
                print("Missing username and/or password in cfg file", file=stderr)
                sys.exit(1)

        settings['port'] = int(settings['port'])
        settings['min_height'] = int(settings['min_height'])
        settings['max_height'] = int(settings['max_height'])

        get_block_hashes(settings)