Example #1
0
 def generate_transaction(cls, tracker, share_data, block_target, desired_timestamp, desired_target, ref_merkle_link, net):
     previous_share = tracker.shares[share_data['previous_share_hash']] if share_data['previous_share_hash'] is not None else None
     
     height, last = tracker.get_height_and_last(share_data['previous_share_hash'])
     assert height >= net.REAL_CHAIN_LENGTH or last is None
     if height < net.TARGET_LOOKBEHIND:
         pre_target3 = net.MAX_TARGET
     else:
         attempts_per_second = get_pool_attempts_per_second(tracker, share_data['previous_share_hash'], net.TARGET_LOOKBEHIND, min_work=True, integer=True)
         pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1 if attempts_per_second else 2**256-1
         pre_target2 = math.clip(pre_target, (previous_share.max_target*9//10, previous_share.max_target*11//10))
         pre_target3 = math.clip(pre_target2, (0, net.MAX_TARGET))
     max_bits = bitcoin_data.FloatingInteger.from_target_upper_bound(pre_target3)
     bits = bitcoin_data.FloatingInteger.from_target_upper_bound(math.clip(desired_target, (pre_target3//10, pre_target3)))
     
     weights, total_weight, donation_weight = tracker.get_cumulative_weights(share_data['previous_share_hash'],
         min(height, net.REAL_CHAIN_LENGTH),
         65535*net.SPREAD*bitcoin_data.target_to_average_attempts(block_target),
     )
     assert total_weight == sum(weights.itervalues()) + donation_weight, (total_weight, sum(weights.itervalues()) + donation_weight)
     
     amounts = dict((script, share_data['subsidy']*(199*weight)//(200*total_weight)) for script, weight in weights.iteritems()) # 99.5% goes according to weights prior to this share
     this_script = bitcoin_data.pubkey_hash_to_script2(share_data['pubkey_hash'])
     amounts[this_script] = amounts.get(this_script, 0) + share_data['subsidy']//200 # 0.5% goes to block finder
     amounts[DONATION_SCRIPT] = amounts.get(DONATION_SCRIPT, 0) + share_data['subsidy'] - sum(amounts.itervalues()) # all that's left over is the donation weight and some extra satoshis due to rounding
     
     if sum(amounts.itervalues()) != share_data['subsidy'] or any(x < 0 for x in amounts.itervalues()):
         raise ValueError()
     
     dests = sorted(amounts.iterkeys(), key=lambda script: (script == DONATION_SCRIPT, amounts[script], script))[-4000:] # block length limit, unlikely to ever be hit
     
     share_info = dict(
         share_data=share_data,
         far_share_hash=None if last is None and height < 99 else tracker.get_nth_parent_hash(share_data['previous_share_hash'], 99),
         max_bits=max_bits,
         bits=bits,
         timestamp=math.clip(desired_timestamp, (
             (previous_share.timestamp + net.SHARE_PERIOD) - (net.SHARE_PERIOD - 1), # = previous_share.timestamp + 1
             (previous_share.timestamp + net.SHARE_PERIOD) + (net.SHARE_PERIOD - 1),
         )) if previous_share is not None else desired_timestamp,
     )
     
     return share_info, dict(
         version=1,
         tx_ins=[dict(
             previous_output=None,
             sequence=None,
             script=share_data['coinbase'].ljust(2, '\x00'),
         )],
         tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script] or script == DONATION_SCRIPT] + [dict(
             value=0,
             script='\x20' + cls.get_ref_hash(net, share_info, ref_merkle_link),
         )],
         lock_time=0,
     )
Example #2
0
 def generate_transaction(cls, tracker, share_data, block_target, desired_timestamp, desired_target, ref_merkle_link, desired_other_transaction_hashes_and_fees, net, known_txs=None, last_txout_nonce=0, base_subsidy=None):
     previous_share = tracker.items[share_data['previous_share_hash']] if share_data['previous_share_hash'] is not None else None
     
     height, last = tracker.get_height_and_last(share_data['previous_share_hash'])
     assert height >= net.REAL_CHAIN_LENGTH or last is None
     if height < net.TARGET_LOOKBEHIND:
         pre_target3 = net.MAX_TARGET
     else:
         attempts_per_second = get_pool_attempts_per_second(tracker, share_data['previous_share_hash'], net.TARGET_LOOKBEHIND, min_work=True, integer=True)
         pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1 if attempts_per_second else 2**256-1
         pre_target2 = math.clip(pre_target, (previous_share.max_target*9//10, previous_share.max_target*11//10))
         pre_target3 = math.clip(pre_target2, (net.MIN_TARGET, net.MAX_TARGET))
     max_bits = bitcoin_data.FloatingInteger.from_target_upper_bound(pre_target3)
     bits = bitcoin_data.FloatingInteger.from_target_upper_bound(math.clip(desired_target, (pre_target3//30, pre_target3)))
     
     new_transaction_hashes = []
     new_transaction_size = 0
     transaction_hash_refs = []
     other_transaction_hashes = []
     
     past_shares = list(tracker.get_chain(share_data['previous_share_hash'], min(height, 100)))
     tx_hash_to_this = {}
     for i, share in enumerate(past_shares):
         for j, tx_hash in enumerate(share.new_transaction_hashes):
             if tx_hash not in tx_hash_to_this:
                 tx_hash_to_this[tx_hash] = [1+i, j] # share_count, tx_count
     for tx_hash, fee in desired_other_transaction_hashes_and_fees:
         if tx_hash in tx_hash_to_this:
             this = tx_hash_to_this[tx_hash]
         else:
             if known_txs is not None:
                 this_size = bitcoin_data.tx_type.packed_size(known_txs[tx_hash])
                 if new_transaction_size + this_size > 50000: # only allow 50 kB of new txns/share
                     break
                 new_transaction_size += this_size
             new_transaction_hashes.append(tx_hash)
             this = [0, len(new_transaction_hashes)-1]
         transaction_hash_refs.extend(this)
         other_transaction_hashes.append(tx_hash)
     
     included_transactions = set(other_transaction_hashes)
     removed_fees = [fee for tx_hash, fee in desired_other_transaction_hashes_and_fees if tx_hash not in included_transactions]
     definite_fees = sum(0 if fee is None else fee for tx_hash, fee in desired_other_transaction_hashes_and_fees if tx_hash in included_transactions)
     if None not in removed_fees:
         share_data = dict(share_data, subsidy=share_data['subsidy'] - sum(removed_fees))
     else:
         assert base_subsidy is not None
         share_data = dict(share_data, subsidy=base_subsidy + definite_fees)
     
     weights, total_weight, donation_weight = tracker.get_cumulative_weights(previous_share.share_data['previous_share_hash'] if previous_share is not None else None,
         min(height, net.REAL_CHAIN_LENGTH-1),
         65535*net.SPREAD*bitcoin_data.target_to_average_attempts(block_target),
     )
     assert total_weight == sum(weights.itervalues()) + donation_weight, (total_weight, sum(weights.itervalues()) + donation_weight)
     
     amounts = dict((script, share_data['subsidy']*(199*weight)//(200*total_weight)) for script, weight in weights.iteritems()) # 99.5% goes according to weights prior to this share
     this_script = bitcoin_data.pubkey_hash_to_script2(share_data['pubkey_hash'])
     amounts[this_script] = amounts.get(this_script, 0) + share_data['subsidy']//200 # 0.5% goes to block finder
     amounts[DONATION_SCRIPT] = amounts.get(DONATION_SCRIPT, 0) + share_data['subsidy'] - sum(amounts.itervalues()) # all that's left over is the donation weight and some extra satoshis due to rounding
     
     if sum(amounts.itervalues()) != share_data['subsidy'] or any(x < 0 for x in amounts.itervalues()):
         raise ValueError()
     
     dests = sorted(amounts.iterkeys(), key=lambda script: (script == DONATION_SCRIPT, amounts[script], script))[-4000:] # block length limit, unlikely to ever be hit
     
     share_info = dict(
         share_data=share_data,
         far_share_hash=None if last is None and height < 99 else tracker.get_nth_parent_hash(share_data['previous_share_hash'], 99),
         max_bits=max_bits,
         bits=bits,
         timestamp=math.clip(desired_timestamp, (
             (previous_share.timestamp + net.SHARE_PERIOD) - (net.SHARE_PERIOD - 1), # = previous_share.timestamp + 1
             (previous_share.timestamp + net.SHARE_PERIOD) + (net.SHARE_PERIOD - 1),
         )) if previous_share is not None else desired_timestamp,
         new_transaction_hashes=new_transaction_hashes,
         transaction_hash_refs=transaction_hash_refs,
         absheight=((previous_share.absheight if previous_share is not None else 0) + 1) % 2**32,
         abswork=((previous_share.abswork if previous_share is not None else 0) + bitcoin_data.target_to_average_attempts(bits.target)) % 2**128,
     )
     
     gentx = dict(
         version=1,
         tx_ins=[dict(
             previous_output=None,
             sequence=None,
             script=share_data['coinbase'],
         )],
         tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script] or script == DONATION_SCRIPT] + [dict(
             value=0,
             script='\x6a\x28' + cls.get_ref_hash(net, share_info, ref_merkle_link) + pack.IntType(64).pack(last_txout_nonce),
         )],
         lock_time=0,
     )
     
     def get_share(header, last_txout_nonce=last_txout_nonce):
         min_header = dict(header); del min_header['merkle_root']
         share = cls(net, None, dict(
             min_header=min_header,
             share_info=share_info,
             ref_merkle_link=dict(branch=[], index=0),
             last_txout_nonce=last_txout_nonce,
             hash_link=prefix_to_hash_link(bitcoin_data.tx_type.pack(gentx)[:-32-8-4], cls.gentx_before_refhash),
             merkle_link=bitcoin_data.calculate_merkle_link([None] + other_transaction_hashes, 0),
         ))
         assert share.header == header # checks merkle_root
         return share
     
     return share_info, gentx, other_transaction_hashes, get_share
Example #3
0
def generate_transaction(tracker, share_data, block_target, desired_timestamp, net):
    previous_share_hash = share_data['previous_share_hash']
    new_script = share_data['new_script']
    subsidy = share_data['subsidy']
    donation = share_data['donation']
    assert 0 <= donation <= 65535
    
    if len(share_data['coinbase']) > 100:
        raise ValueError('coinbase too long!')
    
    previous_share = tracker.shares[previous_share_hash] if previous_share_hash is not None else None
    
    chain_length = getattr(net, 'REAL_CHAIN_LENGTH_FUNC', lambda _: net.REAL_CHAIN_LENGTH)(previous_share.timestamp if previous_share is not None else None)
    
    height, last = tracker.get_height_and_last(previous_share_hash)
    assert height >= chain_length or last is None
    if height < net.TARGET_LOOKBEHIND:
        bits = bitcoin_data.FloatingInteger.from_target_upper_bound(net.MAX_TARGET)
    else:
        attempts_per_second = get_pool_attempts_per_second(tracker, previous_share_hash, net.TARGET_LOOKBEHIND)
        pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1
        pre_target2 = math.clip(pre_target, (previous_share.target*9//10, previous_share.target*11//10))
        pre_target3 = math.clip(pre_target2, (0, net.MAX_TARGET))
        bits = bitcoin_data.FloatingInteger.from_target_upper_bound(pre_target3)
    
    attempts_to_block = bitcoin_data.target_to_average_attempts(block_target)
    max_att = net.SPREAD * attempts_to_block
    
    this_att = min(bitcoin_data.target_to_average_attempts(bits.target), max_att)
    other_weights, other_total_weight, other_donation_weight = tracker.get_cumulative_weights(previous_share_hash, min(height, chain_length), 65535*max(0, max_att - this_att))
    assert other_total_weight == sum(other_weights.itervalues()) + other_donation_weight, (other_total_weight, sum(other_weights.itervalues()) + other_donation_weight)
    weights, total_weight, donation_weight = math.add_dicts({new_script: this_att*(65535-donation)}, other_weights), this_att*65535 + other_total_weight, this_att*donation + other_donation_weight
    assert total_weight == sum(weights.itervalues()) + donation_weight, (total_weight, sum(weights.itervalues()) + donation_weight)
    
    SCRIPT = '4104ffd03de44a6e11b9917f3a29f9443283d9871c9d743ef30d5eddcd37094b64d1b3d8090496b53256786bf5c82932ec23c3b74d9f05a6f95a8b5529352656664bac'.decode('hex')
    
    # 1 satoshi is always donated so that a list of p2pool generated blocks can be easily found by looking at the donation address
    amounts = dict((script, (subsidy-1)*(199*weight)//(200*total_weight)) for (script, weight) in weights.iteritems())
    amounts[new_script] = amounts.get(new_script, 0) + (subsidy-1)//200
    amounts[SCRIPT] = amounts.get(SCRIPT, 0) + (subsidy-1)*(199*donation_weight)//(200*total_weight)
    amounts[SCRIPT] = amounts.get(SCRIPT, 0) + subsidy - sum(amounts.itervalues()) # collect any extra satoshis :P
    
    if sum(amounts.itervalues()) != subsidy:
        raise ValueError()
    if any(x < 0 for x in amounts.itervalues()):
        raise ValueError()
    
    dests = sorted(amounts.iterkeys(), key=lambda script: (amounts[script], script))
    dests = dests[-4000:] # block length limit, unlikely to ever be hit
    
    share_info = dict(
        share_data=share_data,
        bits=bits,
        timestamp=math.clip(desired_timestamp, (previous_share.timestamp - 60, previous_share.timestamp + 60)) if previous_share is not None else desired_timestamp,
    )
    
    return share_info, dict(
        version=1,
        tx_ins=[dict(
            previous_output=None,
            sequence=None,
            script=share_data['coinbase'].ljust(2, '\x00'),
        )],
        tx_outs=[dict(value=0, script='\x20' + pack.IntType(256).pack(bitcoin_data.hash256(share_info_type.pack(share_info))))] + [dict(value=amounts[script], script=script) for script in dests if amounts[script]],
        lock_time=0,
    )
Example #4
0
    def generate_transaction(cls, tracker, share_data, block_target, desired_timestamp, desired_target, ref_merkle_link, desired_other_transaction_hashes_and_fees, net, known_txs=None, last_txout_nonce=0, base_subsidy=None):

        previous_share = tracker.items[share_data['previous_share_hash']] if share_data['previous_share_hash'] is not None else None

        def get_coinbase_fee(share_data, outpointsnum):
            # calculate neccessary coinbase fee

            # coinbase usually seems like this:
            #
            # 01000000 - nVersion
            # 1a184351 - nTimestamp

            # 01 - Inputs num
            # 0000000000000000000000000000000000000000000000000000000000000000 - Input hash
            # ffffffff - Input index (-1)
            # 0a02732a062f503253482f - Scriptsig
            # ffffffff - nSequence

            # 15 - Outpoints num
            # (User outpoints, 44 bytes per each)
            # (Donation outpoint, 76 bytes)

            # P2Pool service outpoint (contains merkle link), 46 bytes
            #
            # 1027000000000000
            # 25
            # 2417cc2063b11fd5255c7e5605780de78163ffc698ed22856bff1a5d880c3c44e400000000

            # Giving users some time to upgrade
            coinbase_size = 50 + (1 + len(share_data['coinbase'])) + outpointsnum * 44 + 76 + 46

            # if coinbase size is greater than 1000 bytes, it should pay fee (0.01 per 1000 bytes)
            if coinbase_size > 1000:
                return int(ceil(coinbase_size / 1000.0) * minout)

            return 0

        if base_subsidy is None:
            base_subsidy = net.PARENT.SUBSIDY_FUNC(block_target)

        # current user payout script

        this_script = share_data['script']

        height, last = tracker.get_height_and_last(share_data['previous_share_hash'])

        assert height >= net.REAL_CHAIN_LENGTH or last is None
        if height < net.TARGET_LOOKBEHIND:
            pre_target3 = net.MAX_TARGET
        else:
            attempts_per_second = get_pool_attempts_per_second(tracker, share_data['previous_share_hash'], net.TARGET_LOOKBEHIND, min_work=True, integer=True)
            pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1 if attempts_per_second else 2**256-1
            pre_target2 = math.clip(pre_target, (previous_share.max_target*9//10, previous_share.max_target*11//10))
            pre_target3 = math.clip(pre_target2, (net.MIN_TARGET, net.MAX_TARGET))
        max_bits = bitcoin_data.FloatingInteger.from_target_upper_bound(pre_target3)
        bits = bitcoin_data.FloatingInteger.from_target_upper_bound(math.clip(desired_target, (pre_target3//10, pre_target3)))

        if p2pool.DEBUG:
            print
            print "Share Info Bits Target (DATA)"
            print bitcoin_data.target_to_difficulty(bits.target)
            print

        new_transaction_hashes = []
        new_transaction_size = 0
        transaction_hash_refs = []
        other_transaction_hashes = []

        past_shares = list(tracker.get_chain(share_data['previous_share_hash'], min(height, 100)))
        tx_hash_to_this = {}
        for i, share in enumerate(past_shares):
            for j, tx_hash in enumerate(share.new_transaction_hashes):
                if tx_hash not in tx_hash_to_this:
                    tx_hash_to_this[tx_hash] = [1+i, j] # share_count, tx_count
        for tx_hash, fee in desired_other_transaction_hashes_and_fees:
            if tx_hash in tx_hash_to_this:
                this = tx_hash_to_this[tx_hash]
            else:
                if known_txs is not None:
                    this_size = bitcoin_data.tx_type.packed_size(known_txs[tx_hash])
                    if new_transaction_size + this_size > 50000: # only allow 50 kB of new txns/share
                        break
                    new_transaction_size += this_size
                new_transaction_hashes.append(tx_hash)
                this = [0, len(new_transaction_hashes)-1]
            transaction_hash_refs.extend(this)
            other_transaction_hashes.append(tx_hash)

        included_transactions = set(other_transaction_hashes)

        share_data = dict(share_data, subsidy=base_subsidy)

        raw_weights, total_weight, donation_weight = tracker.get_cumulative_weights(share_data['previous_share_hash'],
            min(height, net.REAL_CHAIN_LENGTH),
            65535*net.SPREAD*bitcoin_data.target_to_average_attempts(block_target),
        )

        # calculate "raw" subsidy
        raw_subsidy = share_data['subsidy'] - 4 * minout - get_coinbase_fee(share_data, len(raw_weights) + 1)

        # calculate "raw" amounts
        raw_amounts = dict((script, raw_subsidy*weight//total_weight) for script, weight in raw_weights.iteritems())

        total_remowed_weight = 0
        weights = {}

        # iterate list and collect all weights, which produces less than 0.01 payout
        # it's neccessary due to NVC/PPC protocol-level limitations for coinbase outpoint size
        for x in raw_amounts.keys():
            if raw_amounts[x] < minout and x not in [this_script, DONATION_SCRIPT]:
                total_remowed_weight = total_remowed_weight + raw_weights[x]
            else:
                weights[x] = raw_weights[x]

        total_weight = total_weight - total_remowed_weight
        assert total_weight == sum(weights.itervalues()) + donation_weight, (total_weight, sum(weights.itervalues()) + donation_weight)


        # base subsidy value calculated as:
        # [subsidy - (0.01 for donation + 0.01 for current user + 0.01 for p2pool outpoint) - netfee]
        my_subsidy = share_data['subsidy'] - 3 * minout - get_coinbase_fee(share_data, len(weights) + 1)

        # subsidy goes according to weights prior to this share
        amounts = dict((script, my_subsidy*weight//total_weight) for script, weight in weights.iteritems())

        # all that's left over is the donation weight and some extra satoshis due to rounding
        amounts[DONATION_SCRIPT] = amounts.get(DONATION_SCRIPT, 0) + my_subsidy - sum(amounts.itervalues())

        if sum(amounts.itervalues()) != my_subsidy or any(x < 0 for x in amounts.itervalues()):
            raise ValueError()

        # add 0.01 coin to donation, to satisfy the protocol
        amounts[DONATION_SCRIPT] = amounts[DONATION_SCRIPT] + minout

        # add 0.01 to current user output, to satisfy the protocol
        amounts[this_script] = amounts.get(this_script, 0) + minout

        dests = sorted(amounts.iterkeys(), key=lambda script: (script == DONATION_SCRIPT, amounts[script], script))[-4000:] # block length limit, unlikely to ever be hi

        share_info = dict(
            share_data=share_data,
            far_share_hash=None if last is None and height < 99 else tracker.get_nth_parent_hash(share_data['previous_share_hash'], 99),
            max_bits=max_bits,
            bits=bits,
            timestamp=desired_timestamp,    # need better solution
#           timestamp=math.clip(desired_timestamp, (
#               (previous_share.timestamp + net.SHARE_PERIOD) - (net.SHARE_PERIOD - 1), # = previous_share.timestamp + 1
#               (previous_share.timestamp + net.SHARE_PERIOD) + (net.SHARE_PERIOD - 1),
#           )) if previous_share is not None else desired_timestamp,
            new_transaction_hashes=new_transaction_hashes,
            transaction_hash_refs=transaction_hash_refs,
        )

        if p2pool.DEBUG:
            print
            print "Desired timestamp (DATA)"
            print desired_timestamp
            print time.time()
            print
            print "Prev Share timestamp (DATA)"
            print previous_share.timestamp
            print time.time()
            print
            print "Share info timestamp (DATA)"
            print share_info['timestamp']
            print time.time()
            print

        gentx = dict(
            version=1,
            # coinbase timestamp must be older than share/block timestamp
            # maybe there are more elegant solution, but this hack works quite well for now
            timestamp=share_info['timestamp'],
            tx_ins=[dict(
                previous_output=None,
                sequence=None,
                script=share_data['coinbase'],
            )],
            tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script] or script == DONATION_SCRIPT] + [dict(
                # add 0.01 coin to service output, to satisfy the protocol
                value=minout,
                script='\x24' + cls.get_ref_hash(net, share_info, ref_merkle_link) + pack.IntType(32).pack(last_txout_nonce),
            )],
            lock_time=0,
        )

        def get_share(header, last_txout_nonce=last_txout_nonce):
            min_header = dict(header); del min_header['merkle_root']
            share = cls(net, None, dict(
                min_header=min_header,
                share_info=share_info,
                ref_merkle_link=dict(branch=[], index=0),
                last_txout_nonce=last_txout_nonce,
                hash_link=prefix_to_hash_link(bitcoin_data.tx_type.pack(gentx)[:-32-4-4], cls.gentx_before_refhash),
                merkle_link=bitcoin_data.calculate_merkle_link([None] + other_transaction_hashes, 0),
            ))
            assert share.header == header # checks merkle_root
            return share

        return share_info, gentx, other_transaction_hashes, get_share
Example #5
0
def _shift(x, shift, pad_item):
    left_pad = math2.clip(shift, (0, len(x)))
    right_pad = math2.clip(-shift, (0, len(x)))
    return [pad_item]*left_pad + x[right_pad:-left_pad if left_pad else None] + [pad_item]*right_pad
Example #6
0
File: data.py Project: gyver/p2pool
def generate_transaction(tracker, previous_share_hash, new_script, subsidy, nonce, block_target, net):
    height, last = tracker.get_height_and_last(previous_share_hash)
    if height < net.TARGET_LOOKBEHIND:
        target = bitcoin_data.FloatingIntegerType().truncate_to(2**256//2**20 - 1)
    else:
        attempts_per_second = get_pool_attempts_per_second(tracker, previous_share_hash, net)
        pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1
        previous_share = tracker.shares[previous_share_hash] if previous_share_hash is not None else None
        pre_target2 = math.clip(pre_target, (previous_share.target*9//10, previous_share.target*11//10))
        pre_target3 = math.clip(pre_target2, (0, net.MAX_TARGET))
        target = bitcoin_data.FloatingIntegerType().truncate_to(pre_target3)
    
    attempts_to_block = bitcoin_data.target_to_average_attempts(block_target)
    max_weight = net.SPREAD * attempts_to_block
    
    '''
    class fake_share(object):
        pass
    fake_share.new_script = new_script
    fake_share.target = target
    
    dest_weights = {}
    total_weight = 0
    for share in itertools.chain([fake_share], itertools.islice(tracker.get_chain_to_root(previous_share_hash), net.CHAIN_LENGTH)):
        weight = bitcoin_data.target_to_average_attempts(share.target)
        if weight > max_weight - total_weight:
            weight = max_weight - total_weight
        
        dest_weights[share.new_script] = dest_weights.get(share.new_script, 0) + weight
        total_weight += weight
        
        if total_weight == max_weight:
            break
    '''
    
    this_weight = min(bitcoin_data.target_to_average_attempts(target), max_weight)
    other_weights, other_weights_total = tracker.get_cumulative_weights(previous_share_hash, min(height, net.CHAIN_LENGTH), max(0, max_weight - this_weight))
    dest_weights, total_weight = math.add_dicts([{new_script: this_weight}, other_weights]), this_weight + other_weights_total
    total_weight = sum(dest_weights.itervalues())
    
    amounts = dict((script, subsidy*(396*weight)//(400*total_weight)) for (script, weight) in dest_weights.iteritems())
    amounts[new_script] = amounts.get(new_script, 0) + subsidy*2//400
    amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy*2//400
    amounts[net.SCRIPT] = amounts.get(net.SCRIPT, 0) + subsidy - sum(amounts.itervalues()) # collect any extra
    if sum(amounts.itervalues()) != subsidy:
        raise ValueError()
    if any(x < 0 for x in amounts.itervalues()):
        raise ValueError()
    
    pre_dests = sorted(amounts.iterkeys(), key=lambda script: (amounts[script], script))
    pre_dests = pre_dests[-4000:] # block length limit, unlikely to ever be hit
    
    dests = sorted(pre_dests, key=lambda script: (script == new_script, script))
    assert dests[-1] == new_script
    
    return dict(
        version=1,
        tx_ins=[dict(
            previous_output=None,
            sequence=None,
            script=coinbase_type.pack(dict(
                identifier=net.IDENTIFIER,
                share_data=dict(
                    previous_share_hash=previous_share_hash,
                    nonce=nonce,
                    target=target,
                ),
            )),
        )],
        tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script]],
        lock_time=0,
    )
Example #7
0
    def generate_transaction(cls, tracker, share_data, block_target, desired_timestamp, desired_target, ref_merkle_link, desired_other_transaction_hashes_and_fees, net, known_txs=None, last_txout_nonce=0, base_subsidy=None):
        previous_share = tracker.items[share_data['previous_share_hash']] if share_data['previous_share_hash'] is not None else None
        
        height, last = tracker.get_height_and_last(share_data['previous_share_hash'])
        assert height >= net.REAL_CHAIN_LENGTH or last is None
        if height < net.TARGET_LOOKBEHIND:
            pre_target3 = net.MAX_TARGET
        else:
            attempts_per_second = get_pool_attempts_per_second(tracker, share_data['previous_share_hash'], net.TARGET_LOOKBEHIND, min_work=True, integer=True)
            pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1 if attempts_per_second else 2**256-1
            pre_target2 = math.clip(pre_target, (previous_share.max_target*9//10, previous_share.max_target*11//10))
            pre_target3 = math.clip(pre_target2, (net.MIN_TARGET, net.MAX_TARGET))
        max_bits = bitcoin_data.FloatingInteger.from_target_upper_bound(pre_target3)
        bits = bitcoin_data.FloatingInteger.from_target_upper_bound(math.clip(desired_target, (pre_target3//30, pre_target3)))
        
        new_transaction_hashes = []
        new_transaction_size = 0
        transaction_hash_refs = []
        other_transaction_hashes = []
        
        past_shares = list(tracker.get_chain(share_data['previous_share_hash'], min(height, 100)))
        tx_hash_to_this = {}
        for i, share in enumerate(past_shares):
            for j, tx_hash in enumerate(share.new_transaction_hashes):
                if tx_hash not in tx_hash_to_this:
                    tx_hash_to_this[tx_hash] = [1+i, j] # share_count, tx_count
        for tx_hash, fee in desired_other_transaction_hashes_and_fees:
            if tx_hash in tx_hash_to_this:
                this = tx_hash_to_this[tx_hash]
            else:
                if known_txs is not None:
                    if known_txs[tx_hash]['timestamp'] > desired_timestamp - 30:
                        continue
                    this_size = bitcoin_data.tx_type.packed_size(known_txs[tx_hash])
                    if new_transaction_size + this_size > 50000: # only allow 50 kB of new txns/share
                        break
                    new_transaction_size += this_size
                new_transaction_hashes.append(tx_hash)
                this = [0, len(new_transaction_hashes)-1]
            transaction_hash_refs.extend(this)
            other_transaction_hashes.append(tx_hash)
        
        included_transactions = set(other_transaction_hashes)
        removed_fees = [fee for tx_hash, fee in desired_other_transaction_hashes_and_fees if tx_hash not in included_transactions]
        definite_fees = sum(0 if fee is None else fee for tx_hash, fee in desired_other_transaction_hashes_and_fees if tx_hash in included_transactions)
        if None not in removed_fees:
            share_data = dict(share_data, subsidy=share_data['subsidy'] - sum(removed_fees))
        else:
            assert base_subsidy is not None
            share_data = dict(share_data, subsidy=base_subsidy + definite_fees)
        
        weights, total_weight, donation_weight = tracker.get_cumulative_weights(previous_share.share_data['previous_share_hash'] if previous_share is not None else None,
            max(0, min(height, net.REAL_CHAIN_LENGTH) - 1),
            65535*net.SPREAD*bitcoin_data.target_to_average_attempts(block_target),
        )
        assert total_weight == sum(weights.itervalues()) + donation_weight, (total_weight, sum(weights.itervalues()) + donation_weight)
        
        worker_payout = share_data['subsidy']
        
        amounts = dict((script, worker_payout*(199*weight)//(200*total_weight)) for script, weight in weights.iteritems()) # 99.5% goes according to weights prior to this share
        this_script = bitcoin_data.pubkey_hash_to_script2(share_data['pubkey_hash'])
        amounts[this_script] = amounts.get(this_script, 0) + worker_payout//200 # 0.5% goes to block finder
        amounts[DONATION_SCRIPT] = amounts.get(DONATION_SCRIPT, 0) + worker_payout - sum(amounts.itervalues()) # all that's left over is the donation weight and some extra satoshis due to rounding
        
        if sum(amounts.itervalues()) != worker_payout or any(x < 0 for x in amounts.itervalues()):
            raise ValueError()
        
        dests = sorted(amounts.iterkeys(), key=lambda script: (script == DONATION_SCRIPT, amounts[script], script))[-4000:] # block length limit, unlikely to ever be hit
        
        worker_tx = [dict(value=amounts[script], script=script) for script in dests if amounts[script] or script == DONATION_SCRIPT]

        share_info = dict(
            share_data=share_data,
            far_share_hash=None if last is None and height < 99 else tracker.get_nth_parent_hash(share_data['previous_share_hash'], 99),
            max_bits=max_bits,
            bits=bits,
            timestamp=math.clip(desired_timestamp, (
                (previous_share.timestamp + net.SHARE_PERIOD) - (net.SHARE_PERIOD - 1), # = previous_share.timestamp + 1
                (previous_share.timestamp + net.SHARE_PERIOD) + (net.SHARE_PERIOD - 1),
            )) if previous_share is not None else desired_timestamp,
            new_transaction_hashes=new_transaction_hashes,
            transaction_hash_refs=transaction_hash_refs,
            absheight=((previous_share.absheight if previous_share is not None else 0) + 1) % 2**32,
            abswork=((previous_share.abswork if previous_share is not None else 0) + bitcoin_data.target_to_average_attempts(bits.target)) % 2**128,
        )
        
        gentx = dict(
            version=1,
            # coinbase timestamp must be older than share/block timestamp
            # maybe there are more elegant solution, but this hack works quite well for now
            timestamp=share_info['timestamp'],
            tx_ins=[dict(
                previous_output=None,
                sequence=None,
                script=share_data['coinbase'],
            )],
            tx_outs=worker_tx + [dict(
                value=0,
                script='\x6a\x28' + cls.get_ref_hash(net, share_info, ref_merkle_link) + pack.IntType(64).pack(last_txout_nonce),
            )],
            lock_time=0,
        )
        
        def get_share(header, last_txout_nonce=last_txout_nonce):
            min_header = dict(header); del min_header['merkle_root']
            share = cls(net, None, dict(
                min_header=min_header,
                share_info=share_info,
                ref_merkle_link=dict(branch=[], index=0),
                last_txout_nonce=last_txout_nonce,
                hash_link=prefix_to_hash_link(bitcoin_data.tx_type.pack(gentx)[:-32-8-4], cls.gentx_before_refhash),
                merkle_link=bitcoin_data.calculate_merkle_link([None] + other_transaction_hashes, 0),
            ))
            assert share.header == header # checks merkle_root
            return share
        
        return share_info, gentx, other_transaction_hashes, get_share
Example #8
0
    def generate_transaction(cls, tracker, share_data, block_target,
                             desired_timestamp, desired_target,
                             ref_merkle_link, other_transaction_hashes, net):
        previous_share = tracker.items[
            share_data['previous_share_hash']] if share_data[
                'previous_share_hash'] is not None else None

        height, last = tracker.get_height_and_last(
            share_data['previous_share_hash'])
        assert height >= net.REAL_CHAIN_LENGTH or last is None
        if height < net.TARGET_LOOKBEHIND:
            pre_target3 = net.MAX_TARGET
        else:
            attempts_per_second = get_pool_attempts_per_second(
                tracker,
                share_data['previous_share_hash'],
                net.TARGET_LOOKBEHIND,
                min_work=True,
                integer=True)
            pre_target = 2**256 // (
                net.SHARE_PERIOD *
                attempts_per_second) - 1 if attempts_per_second else 2**256 - 1
            pre_target2 = math.clip(pre_target,
                                    (previous_share.max_target * 9 // 10,
                                     previous_share.max_target * 11 // 10))
            pre_target3 = math.clip(pre_target2, (0, net.MAX_TARGET))
        max_bits = bitcoin_data.FloatingInteger.from_target_upper_bound(
            pre_target3)
        bits = bitcoin_data.FloatingInteger.from_target_upper_bound(
            math.clip(desired_target, (pre_target3 // 10, pre_target3)))

        weights, total_weight, donation_weight = tracker.get_cumulative_weights(
            share_data['previous_share_hash'],
            min(height, net.REAL_CHAIN_LENGTH),
            65535 * net.SPREAD *
            bitcoin_data.target_to_average_attempts(block_target),
        )
        assert total_weight == sum(weights.itervalues()) + donation_weight, (
            total_weight, sum(weights.itervalues()) + donation_weight)

        amounts = dict(
            (script,
             share_data['subsidy'] * (199 * weight) // (200 * total_weight))
            for script, weight in weights.iteritems(
            ))  # 99.5% goes according to weights prior to this share
        this_script = bitcoin_data.pubkey_hash_to_script2(
            share_data['pubkey_hash'])
        amounts[this_script] = amounts.get(
            this_script,
            0) + share_data['subsidy'] // 200  # 0.5% goes to block finder
        amounts[DONATION_SCRIPT] = amounts.get(
            DONATION_SCRIPT, 0
        ) + share_data['subsidy'] - sum(
            amounts.itervalues()
        )  # all that's left over is the donation weight and some extra satoshis due to rounding

        if sum(amounts.itervalues()) != share_data['subsidy'] or any(
                x < 0 for x in amounts.itervalues()):
            raise ValueError()

        dests = sorted(
            amounts.iterkeys(),
            key=lambda script:
            (script == DONATION_SCRIPT, amounts[script], script))[
                -4000:]  # block length limit, unlikely to ever be hit

        share_info = dict(
            share_data=share_data,
            far_share_hash=None if last is None and height < 99 else
            tracker.get_nth_parent_hash(share_data['previous_share_hash'], 99),
            max_bits=max_bits,
            bits=bits,
            timestamp=math.clip(
                desired_timestamp,
                (
                    (previous_share.timestamp + net.SHARE_PERIOD) -
                    (net.SHARE_PERIOD - 1),  # = previous_share.timestamp + 1
                    (previous_share.timestamp + net.SHARE_PERIOD) +
                    (net.SHARE_PERIOD - 1),
                )) if previous_share is not None else desired_timestamp,
        )

        gentx = dict(
            version=1,
            tx_ins=[
                dict(
                    previous_output=None,
                    sequence=None,
                    script=share_data['coinbase'].ljust(2, '\x00'),
                )
            ],
            tx_outs=[
                dict(value=amounts[script], script=script) for script in dests
                if amounts[script] or script == DONATION_SCRIPT
            ] + [
                dict(
                    value=0,
                    script='\x20' +
                    cls.get_ref_hash(net, share_info, ref_merkle_link),
                )
            ],
            lock_time=0,
        )

        def get_share(header, transactions):
            assert transactions[0] == gentx and [
                bitcoin_data.hash256(bitcoin_data.tx_type.pack(tx))
                for tx in transactions[1:]
            ] == other_transaction_hashes
            min_header = dict(header)
            del min_header['merkle_root']
            hash_link = prefix_to_hash_link(
                bitcoin_data.tx_type.pack(gentx)[:-32 - 4],
                cls.gentx_before_refhash)
            merkle_link = bitcoin_data.calculate_merkle_link(
                [None] + other_transaction_hashes, 0)
            pow_hash = net.PARENT.POW_FUNC(
                bitcoin_data.block_header_type.pack(header))
            return cls(net,
                       None,
                       dict(
                           min_header=min_header,
                           share_info=share_info,
                           hash_link=hash_link,
                           ref_merkle_link=dict(branch=[], index=0),
                       ),
                       merkle_link=merkle_link,
                       other_txs=transactions[1:]
                       if pow_hash <= header['bits'].target else None)

        return share_info, gentx, other_transaction_hashes, get_share
Example #9
0
 def generate_transaction(cls, tracker, share_data, block_target, desired_timestamp, desired_target, ref_merkle_link, desired_other_transaction_hashes, net, known_txs=None, last_txout_nonce=0):
     previous_share = tracker.items[share_data['previous_share_hash']] if share_data['previous_share_hash'] is not None else None
     
     height, last = tracker.get_height_and_last(share_data['previous_share_hash'])
     assert height >= net.REAL_CHAIN_LENGTH or last is None
     if height < net.TARGET_LOOKBEHIND:
         pre_target3 = net.MAX_TARGET
     else:
         attempts_per_second = get_pool_attempts_per_second(tracker, share_data['previous_share_hash'], net.TARGET_LOOKBEHIND, min_work=True, integer=True)
         pre_target = 2**256//(net.SHARE_PERIOD*attempts_per_second) - 1 if attempts_per_second else 2**256-1
         pre_target2 = math.clip(pre_target, (previous_share.max_target*9//10, previous_share.max_target*11//10))
         pre_target3 = math.clip(pre_target2, (net.MIN_TARGET, net.MAX_TARGET))
     max_bits = bitcoin_data.FloatingInteger.from_target_upper_bound(pre_target3)
     bits = bitcoin_data.FloatingInteger.from_target_upper_bound(math.clip(desired_target, (pre_target3//10, pre_target3)))
     
     weights, total_weight, donation_weight = tracker.get_cumulative_weights(share_data['previous_share_hash'],
         min(height, net.REAL_CHAIN_LENGTH),
         65535*net.SPREAD*bitcoin_data.target_to_average_attempts(block_target),
     )
     assert total_weight == sum(weights.itervalues()) + donation_weight, (total_weight, sum(weights.itervalues()) + donation_weight)
     
     amounts = dict((script, share_data['subsidy']*(199*weight)//(200*total_weight)) for script, weight in weights.iteritems()) # 99.5% goes according to weights prior to this share
     this_script = bitcoin_data.pubkey_hash_to_script2(share_data['pubkey_hash'])
     amounts[this_script] = amounts.get(this_script, 0) + share_data['subsidy']//200 # 0.5% goes to block finder
     amounts[DONATION_SCRIPT] = amounts.get(DONATION_SCRIPT, 0) + share_data['subsidy'] - sum(amounts.itervalues()) # all that's left over is the donation weight and some extra satoshis due to rounding
     
     if sum(amounts.itervalues()) != share_data['subsidy'] or any(x < 0 for x in amounts.itervalues()):
         raise ValueError()
     
     dests = sorted(amounts.iterkeys(), key=lambda script: (script == DONATION_SCRIPT, amounts[script], script))[-4000:] # block length limit, unlikely to ever be hit
     
     new_transaction_hashes = []
     new_transaction_size = 0
     transaction_hash_refs = []
     other_transaction_hashes = []
     
     for tx_hash in desired_other_transaction_hashes:
         for i, share in enumerate(tracker.get_chain(share_data['previous_share_hash'], min(height, 100))):
             if tx_hash in share.new_transaction_hashes:
                 this = dict(share_count=i+1, tx_count=share.new_transaction_hashes.index(tx_hash))
                 break
         else:
             if known_txs is not None:
                 this_size = bitcoin_data.tx_type.packed_size(known_txs[tx_hash])
                 if new_transaction_size + this_size > 50000: # only allow 50 kB of new txns/share
                     break
                 new_transaction_size += this_size
             new_transaction_hashes.append(tx_hash)
             this = dict(share_count=0, tx_count=len(new_transaction_hashes)-1)
         transaction_hash_refs.append(this)
         other_transaction_hashes.append(tx_hash)
     
     share_info = dict(
         share_data=share_data,
         far_share_hash=None if last is None and height < 99 else tracker.get_nth_parent_hash(share_data['previous_share_hash'], 99),
         max_bits=max_bits,
         bits=bits,
         timestamp=math.clip(desired_timestamp, (
             (previous_share.timestamp + net.SHARE_PERIOD) - (net.SHARE_PERIOD - 1), # = previous_share.timestamp + 1
             (previous_share.timestamp + net.SHARE_PERIOD) + (net.SHARE_PERIOD - 1),
         )) if previous_share is not None else desired_timestamp,
         new_transaction_hashes=new_transaction_hashes,
         transaction_hash_refs=transaction_hash_refs,
     )
     
     gentx = dict(
         version=1,
         tx_ins=[dict(
             previous_output=None,
             sequence=None,
             script=share_data['coinbase'],
         )],
         tx_outs=[dict(value=amounts[script], script=script) for script in dests if amounts[script] or script == DONATION_SCRIPT] + [dict(
             value=0,
             script='\x24' + cls.get_ref_hash(net, share_info, ref_merkle_link) + pack.IntType(32).pack(last_txout_nonce),
         )],
         lock_time=0,
     )
     
     def get_share(header, transactions):
         min_header=dict(header);del min_header['merkle_root']
         return cls(net, None, dict(
             min_header=min_header,
             share_info=share_info,
             ref_merkle_link=dict(branch=[], index=0),
             last_txout_nonce=last_txout_nonce,
             hash_link=prefix_to_hash_link(bitcoin_data.tx_type.pack(gentx)[:-32-4-4], cls.gentx_before_refhash),
             merkle_link=bitcoin_data.calculate_merkle_link([None] + other_transaction_hashes, 0),
         ))
     
     return share_info, gentx, other_transaction_hashes, get_share
Example #10
0
    def generate_transaction(cls,
                             tracker,
                             share_data,
                             block_target,
                             desired_timestamp,
                             desired_target,
                             ref_merkle_link,
                             desired_other_transaction_hashes_and_fees,
                             net,
                             known_txs=None,
                             last_txout_nonce=0,
                             base_subsidy=None,
                             segwit_data=None):
        previous_share = tracker.items[
            share_data['previous_share_hash']] if share_data[
                'previous_share_hash'] is not None else None

        height, last = tracker.get_height_and_last(
            share_data['previous_share_hash'])
        assert height >= net.REAL_CHAIN_LENGTH or last is None
        if height < net.TARGET_LOOKBEHIND:
            pre_target3 = net.MAX_TARGET
        else:
            attempts_per_second = get_pool_attempts_per_second(
                tracker,
                share_data['previous_share_hash'],
                net.TARGET_LOOKBEHIND,
                min_work=True,
                integer=True)
            pre_target = 2**256 // (
                net.SHARE_PERIOD *
                attempts_per_second) - 1 if attempts_per_second else 2**256 - 1
            pre_target2 = math.clip(pre_target,
                                    (previous_share.max_target * 9 // 10,
                                     previous_share.max_target * 11 // 10))
            pre_target3 = math.clip(pre_target2,
                                    (net.MIN_TARGET, net.MAX_TARGET))
        max_bits = bitcoin_data.FloatingInteger.from_target_upper_bound(
            pre_target3)
        bits = bitcoin_data.FloatingInteger.from_target_upper_bound(
            math.clip(desired_target, (pre_target3 // 30, pre_target3)))

        new_transaction_hashes = []
        new_transaction_size = 0
        transaction_hash_refs = []
        other_transaction_hashes = []

        past_shares = list(
            tracker.get_chain(share_data['previous_share_hash'],
                              min(height, 100)))
        tx_hash_to_this = {}
        for i, share in enumerate(past_shares):
            for j, tx_hash in enumerate(share.new_transaction_hashes):
                if tx_hash not in tx_hash_to_this:
                    tx_hash_to_this[tx_hash] = [1 + i,
                                                j]  # share_count, tx_count
        for tx_hash, fee in desired_other_transaction_hashes_and_fees:
            if tx_hash in tx_hash_to_this:
                this = tx_hash_to_this[tx_hash]
            else:
                if known_txs is not None:
                    this_size = bitcoin_data.tx_type.packed_size(
                        known_txs[tx_hash])
                    if new_transaction_size + this_size > cls.MAX_NEW_TXS_SIZE:  # limit the size of new txns/share
                        break
                    new_transaction_size += this_size
                new_transaction_hashes.append(tx_hash)
                this = [0, len(new_transaction_hashes) - 1]
            transaction_hash_refs.extend(this)
            other_transaction_hashes.append(tx_hash)

        included_transactions = set(other_transaction_hashes)
        removed_fees = [
            fee for tx_hash, fee in desired_other_transaction_hashes_and_fees
            if tx_hash not in included_transactions
        ]
        definite_fees = sum(
            0 if fee is None else fee
            for tx_hash, fee in desired_other_transaction_hashes_and_fees
            if tx_hash in included_transactions)
        if None not in removed_fees:
            share_data = dict(share_data,
                              subsidy=share_data['subsidy'] -
                              sum(removed_fees))
        else:
            assert base_subsidy is not None
            share_data = dict(share_data, subsidy=base_subsidy + definite_fees)

        weights, total_weight, donation_weight = tracker.get_cumulative_weights(
            previous_share.share_data['previous_share_hash']
            if previous_share is not None else None,
            max(0,
                min(height, net.REAL_CHAIN_LENGTH) - 1),
            65535 * net.SPREAD *
            bitcoin_data.target_to_average_attempts(block_target),
        )
        assert total_weight == sum(weights.itervalues()) + donation_weight, (
            total_weight, sum(weights.itervalues()) + donation_weight)

        amounts = dict(
            (script,
             share_data['subsidy'] * (199 * weight) // (200 * total_weight))
            for script, weight in weights.iteritems(
            ))  # 99.5% goes according to weights prior to this share
        this_script = bitcoin_data.pubkey_hash_to_script2(
            share_data['pubkey_hash'])
        amounts[this_script] = amounts.get(
            this_script,
            0) + share_data['subsidy'] // 200  # 0.5% goes to block finder
        amounts[DONATION_SCRIPT] = amounts.get(
            DONATION_SCRIPT, 0
        ) + share_data['subsidy'] - sum(
            amounts.itervalues()
        )  # all that's left over is the donation weight and some extra satoshis due to rounding

        if sum(amounts.itervalues()) != share_data['subsidy'] or any(
                x < 0 for x in amounts.itervalues()):
            raise ValueError()

        dests = sorted(
            amounts.iterkeys(),
            key=lambda script:
            (script == DONATION_SCRIPT, amounts[script], script))[
                -4000:]  # block length limit, unlikely to ever be hit

        segwit_activated = is_segwit_activated(cls.VERSION, net)
        if segwit_data is None and known_txs is None:
            segwit_activated = False
        if not (segwit_activated or known_txs is None) and any(
                bitcoin_data.is_segwit_tx(known_txs[h])
                for h in other_transaction_hashes):
            raise ValueError('segwit transaction included before activation')
        if segwit_activated and known_txs is not None:
            share_txs = [(known_txs[h], bitcoin_data.get_txid(known_txs[h]), h)
                         for h in other_transaction_hashes]
            segwit_data = dict(
                txid_merkle_link=bitcoin_data.calculate_merkle_link(
                    [None] + [tx[1] for tx in share_txs], 0),
                wtxid_merkle_root=bitcoin_data.merkle_hash([0] + [
                    bitcoin_data.get_wtxid(tx[0], tx[1], tx[2])
                    for tx in share_txs
                ]))
        if segwit_activated and segwit_data is not None:
            witness_reserved_value_str = '[P2Pool]' * 4
            witness_reserved_value = pack.IntType(256).unpack(
                witness_reserved_value_str)
            witness_commitment_hash = bitcoin_data.get_witness_commitment_hash(
                segwit_data['wtxid_merkle_root'], witness_reserved_value)

        share_info = dict(
            share_data=share_data,
            far_share_hash=None if last is None and height < 99 else
            tracker.get_nth_parent_hash(share_data['previous_share_hash'], 99),
            max_bits=max_bits,
            bits=bits,
            timestamp=math.clip(
                desired_timestamp,
                (
                    (previous_share.timestamp + net.SHARE_PERIOD) -
                    (net.SHARE_PERIOD - 1),  # = previous_share.timestamp + 1
                    (previous_share.timestamp + net.SHARE_PERIOD) +
                    (net.SHARE_PERIOD - 1),
                )) if previous_share is not None else desired_timestamp,
            new_transaction_hashes=new_transaction_hashes,
            transaction_hash_refs=transaction_hash_refs,
            absheight=((previous_share.absheight
                        if previous_share is not None else 0) + 1) % 2**32,
            abswork=(
                (previous_share.abswork if previous_share is not None else 0) +
                bitcoin_data.target_to_average_attempts(bits.target)) % 2**128,
        )
        if segwit_activated:
            share_info['segwit_data'] = segwit_data

        gentx = dict(
            version=1,
            tx_ins=[
                dict(
                    previous_output=None,
                    sequence=None,
                    script=share_data['coinbase'],
                )
            ],
            tx_outs=([
                dict(value=0,
                     script='\x6a\x24\xaa\x21\xa9\xed' +
                     pack.IntType(256).pack(witness_commitment_hash))
            ] if segwit_activated else []) + [
                dict(value=amounts[script], script=script) for script in dests
                if amounts[script] or script == DONATION_SCRIPT
            ] + [
                dict(value=0,
                     script='\x6a\x28' +
                     cls.get_ref_hash(net, share_info, ref_merkle_link) +
                     pack.IntType(64).pack(last_txout_nonce))
            ],
            lock_time=0,
        )
        if segwit_activated:
            gentx['marker'] = 0
            gentx['flag'] = 1
            gentx['witness'] = [[witness_reserved_value_str]]

        def get_share(header, last_txout_nonce=last_txout_nonce):
            min_header = dict(header)
            del min_header['merkle_root']
            share = cls(
                net, None,
                dict(
                    min_header=min_header,
                    share_info=share_info,
                    ref_merkle_link=dict(branch=[], index=0),
                    last_txout_nonce=last_txout_nonce,
                    hash_link=prefix_to_hash_link(
                        bitcoin_data.tx_id_type.pack(gentx)[:-32 - 8 - 4],
                        cls.gentx_before_refhash),
                    merkle_link=bitcoin_data.calculate_merkle_link(
                        [None] + other_transaction_hashes, 0),
                ))
            assert share.header == header  # checks merkle_root
            return share

        return share_info, gentx, other_transaction_hashes, get_share