Esempio n. 1
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def test_callback():
    R = []

    def the_callback(blockchain, ops):
        R.extend(ops)

    parent_for_0 = b'\0' * 32
    # same as test_fork, above

    BC = BlockChain(parent_for_0)
    BC.add_change_callback(the_callback)

    ITEMS = dict((i, FakeBlock(i)) for i in range(7))
    ITEMS[0] = FakeBlock(0, parent_for_0)

    ITEMS.update(dict((i, FakeBlock(i)) for i in range(301, 306)))
    ITEMS[301] = FakeBlock(301, 3)

    # send them all except 302
    BC.add_headers((ITEMS[i] for i in ITEMS.keys() if i != 302))

    # now send 302
    BC.add_headers([ITEMS[302]])

    expected = [("add", ITEMS[i], i) for i in range(7)]
    expected += [("remove", ITEMS[i], i) for i in range(6, 3, -1)]
    expected += [("add", ITEMS[i], i + 4 - 301) for i in range(301, 306)]

    assert R == expected
Esempio n. 2
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def test_callback():
    R = []

    def the_callback(blockchain, ops):
        R.extend(ops)

    parent_for_0 = b'\0' * 32
    # same as test_fork, above

    BC = BlockChain(parent_for_0)
    BC.add_change_callback(the_callback)

    ITEMS = dict((i, FakeBlock(i)) for i in range(7))
    ITEMS[0] = FakeBlock(0, parent_for_0)

    ITEMS.update(dict((i, FakeBlock(i)) for i in range(301, 306)))
    ITEMS[301] = FakeBlock(301, 3)

    # send them all except 302
    BC.add_headers((ITEMS[i] for i in ITEMS.keys() if i != 302))

    # now send 302
    BC.add_headers([ITEMS[302]])

    expected = [("add", ITEMS[i], i) for i in range(7)]
    expected += [("remove", ITEMS[i], i) for i in range(6, 3, -1)]
    expected += [("add", ITEMS[i], i+4-301) for i in range(301, 306)]

    assert R == expected
Esempio n. 3
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def test_fork():
    parent_for_0 = b'\0' * 32
    # 0 <= 1 <= ... <= 5 <= 6
    # 3 <= 301 <= 302 <= 303 <= 304 <= 305

    # parent_for_0 = "motherless"
    BC = BlockChain(parent_for_0)
    ITEMS = dict((i, FakeBlock(i)) for i in range(7))
    ITEMS[0] = FakeBlock(0, parent_for_0)

    ITEMS.update(dict((i, FakeBlock(i)) for i in range(301, 306)))
    ITEMS[301] = FakeBlock(301, 3)

    assert longest_block_chain(BC) == []
    assert BC.locked_length() == 0
    assert BC.length() == 0
    assert set(BC.chain_finder.missing_parents()) == set()

    # send them all except 302
    ops = BC.add_headers((ITEMS[i] for i in ITEMS.keys() if i != 302))
    assert ops == [("add", ITEMS[i], i) for i in range(7)]
    assert set(BC.chain_finder.missing_parents()) == set([parent_for_0, 302])

    # now send 302
    ops = BC.add_headers([ITEMS[302]])

    # we should see a change
    expected = [("remove", ITEMS[i], i) for i in range(6, 3, -1)]
    expected += [("add", ITEMS[i], i + 4 - 301) for i in range(301, 306)]
    assert ops == expected
    assert set(BC.chain_finder.missing_parents()) == set([parent_for_0])
Esempio n. 4
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def test_fork():
    parent_for_0 = b'\0' * 32
    # 0 <= 1 <= ... <= 5 <= 6
    # 3 <= 301 <= 302 <= 303 <= 304 <= 305

    # parent_for_0 = "motherless"
    BC = BlockChain(parent_for_0)
    ITEMS = dict((i, FakeBlock(i)) for i in range(7))
    ITEMS[0] = FakeBlock(0, parent_for_0)

    ITEMS.update(dict((i, FakeBlock(i)) for i in range(301, 306)))
    ITEMS[301] = FakeBlock(301, 3)

    assert longest_block_chain(BC) == []
    assert BC.locked_length() == 0
    assert BC.length() == 0
    assert set(BC.chain_finder.missing_parents()) == set()

    # send them all except 302
    ops = BC.add_headers((ITEMS[i] for i in ITEMS.keys() if i != 302))
    assert ops == [("add", ITEMS[i], i) for i in range(7)]
    assert set(BC.chain_finder.missing_parents()) == set([parent_for_0, 302])

    # now send 302
    ops = BC.add_headers([ITEMS[302]])

    # we should see a change
    expected = [("remove", ITEMS[i], i) for i in range(6, 3, -1)]
    expected += [("add", ITEMS[i], i+4-301) for i in range(301, 306)]
    assert ops == expected
    assert set(BC.chain_finder.missing_parents()) == set([parent_for_0])
Esempio n. 5
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def test_chain_locking():
    SIZE = 2000
    COUNT = 200
    ITEMS = [FakeBlock(i, i - 1) for i in range(SIZE * COUNT)]
    ITEMS[0] = FakeBlock(0, parent_for_0)
    BC = BlockChain(parent_for_0)
    assert longest_block_chain(BC) == []
    assert BC.locked_length() == 0
    assert BC.length() == 0
    assert set(BC.chain_finder.missing_parents()) == set()

    for i in range(COUNT):
        start, end = i * SIZE, (i + 1) * SIZE
        lock_start = max(0, start - 10)
        expected_parent = lock_start - 1 if lock_start else parent_for_0
        assert BC.length() == start
        assert BC.locked_length() == lock_start
        ops = BC.add_headers(ITEMS[start:end])
        assert ops == [("add", ITEMS[i], i) for i in range(start, end)]
        assert longest_locked_block_chain(BC) == list(range(lock_start, end))
        assert set(BC.chain_finder.missing_parents()) == {expected_parent}
        assert BC.parent_hash == expected_parent
        assert BC.locked_length() == lock_start
        assert BC.length() == end
        for i in range(start, end):
            v = BC.tuple_for_index(i)
            assert v[0] == i
            assert v[1] == parent_for_0 if i == 0 else i
        assert BC.index_for_hash(-1) is None
        assert BC.locked_length() == max(0, lock_start)
        BC.lock_to_index(end - 10)
        assert BC.locked_length() == end - 10
Esempio n. 6
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def test_chain_locking():
    SIZE = 2000
    COUNT = 200
    ITEMS = [FakeBlock(i, i-1) for i in range(SIZE*COUNT)]
    ITEMS[0] = FakeBlock(0, parent_for_0)
    BC = BlockChain(parent_for_0)
    assert longest_block_chain(BC) == []
    assert BC.locked_length() == 0
    assert BC.length() == 0
    assert set(BC.chain_finder.missing_parents()) == set()

    for i in range(COUNT):
        start, end = i*SIZE, (i+1)*SIZE
        lock_start = max(0, start-10)
        expected_parent = lock_start-1 if lock_start else parent_for_0
        assert BC.length() == start
        assert BC.locked_length() == lock_start
        ops = BC.add_headers(ITEMS[start:end])
        assert ops == [("add", ITEMS[i], i) for i in range(start, end)]
        assert longest_locked_block_chain(BC) == list(range(lock_start, end))
        assert set(BC.chain_finder.missing_parents()) == {expected_parent}
        assert BC.parent_hash == expected_parent
        assert BC.locked_length() == lock_start
        assert BC.length() == end
        for i in range(start, end):
            v = BC.tuple_for_index(i)
            assert v[0] == i
            assert v[1] == parent_for_0 if i == 0 else i
        assert BC.index_for_hash(-1) is None
        assert BC.locked_length() == max(0, lock_start)
        BC.lock_to_index(end-10)
        assert BC.locked_length() == end-10
Esempio n. 7
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def items_for_client(initial_blocks=[]):
    block_store = {}
    block_chain = BlockChain()
    blockfetcher = Blockfetcher()
    inv_collector = InvCollector()
    block_handler = BlockHandler(inv_collector, block_chain, block_store)
    fast_forward_add_peer = fast_forwarder_add_peer_f(block_chain)

    for block in initial_blocks:
        inv_collector.advertise_item(InvItem(ITEM_TYPE_BLOCK, block.hash()))
        block_store[block.hash()] = block
    block_chain.add_headers(initial_blocks)

    inv_q = inv_collector.new_inv_item_queue()
    ap = make_add_peer(fast_forward_add_peer, blockfetcher, block_handler, inv_collector, block_chain, block_store)
    ap.block_getter_task = asyncio.Task(block_getter(inv_q, inv_collector, block_handler, block_chain, block_store))
    return block_handler, block_chain, block_store, ap
Esempio n. 8
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def locked_blocks_iterator(blockfile,
                           start_info=(0, 0),
                           cached_headers=50,
                           batch_size=50):
    """
    This method loads blocks from disk, skipping any orphan blocks.
    """
    f = blockfile
    current_state = []

    def change_state(bc, ops):
        for op, bh, work in ops:
            if op == 'add':
                current_state.append(bh)
                pass
            else:
                current_state.pop()

    bc = BlockChain()
    bc.add_change_callback(change_state)
    bhs = []
    index = 0
    info_offset = start_info
    while 1:
        v = blockfile.next_offset(info_offset)
        if v is None:
            break
        block_offset, info_offset = v
        f.jump_to(block_offset)
        bh = Block.parse_as_header(f)
        bh.info = block_offset

        bhs.append(bh)
        if len(bhs) > batch_size:
            bc.add_headers(bhs)
            bhs = []
            if len(current_state) > cached_headers:
                for bh in current_state[:cached_headers]:
                    bh.index = index
                    yield bh
                    index += 1
                    bc.lock_to_index(index)
                current_state = current_state[cached_headers:]
Esempio n. 9
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def locked_blocks_iterator(start_info=(0, 0),
                           cached_headers=50,
                           batch_size=50,
                           base_dir=None,
                           headers_only=False):
    """
    This method loads blocks from disk, skipping any orphan blocks.
    """
    block_class = BlockHeader if headers_only else Block
    f = Blockfiles(base_dir, start_info)
    for initial_location in block_info_iterator(start_info, base_dir):
        f.jump_to(initial_location)
        initial_header = BlockHeader.parse(f)
        break
    current_state = []

    def change_state(bc, ops):
        for op, bh, work in ops:
            if op == 'add':
                current_state.append(bh)
                pass
            else:
                current_state.pop()

    bc = BlockChain()
    bc.add_change_callback(change_state)
    bhs = []
    index = 0
    for info in block_info_iterator(start_info, base_dir):
        bh = blockheader_for_offset_info(info, base_dir)
        bh.info = info
        bhs.append(bh)
        if len(bhs) > batch_size:
            bc.add_headers(bhs)
            bhs = []
            if len(current_state) > cached_headers:
                for bh in current_state[:cached_headers]:
                    f.jump_to(bh.info)
                    block = block_class.parse(f)
                    yield block
                    index += 1
                    bc.lock_to_index(index)
                current_state = current_state[cached_headers:]
Esempio n. 10
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def items_for_client(initial_blocks=[]):
    block_store = {}
    block_chain = BlockChain()
    blockfetcher = Blockfetcher()
    inv_collector = InvCollector()
    block_handler = BlockHandler(inv_collector, block_chain, block_store)
    fast_forward_add_peer = fast_forwarder_add_peer_f(block_chain)

    for block in initial_blocks:
        inv_collector.advertise_item(InvItem(ITEM_TYPE_BLOCK, block.hash()))
        block_store[block.hash()] = block
    block_chain.add_headers(initial_blocks)

    inv_q = inv_collector.new_inv_item_queue()
    ap = make_add_peer(fast_forward_add_peer, blockfetcher, block_handler,
                       inv_collector, block_chain, block_store)
    ap.block_getter_task = asyncio.Task(
        block_getter(inv_q, inv_collector, block_handler, block_chain,
                     block_store))
    return block_handler, block_chain, block_store, ap
Esempio n. 11
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def locked_blocks_iterator(start_info=(0, 0), cached_headers=50, batch_size=50, base_dir=None,
                           headers_only=False):
    """
    This method loads blocks from disk, skipping any orphan blocks.
    """
    parse_method = Block.parse_as_header if headers_only else Block.parse
    f = Blockfiles(base_dir, start_info)
    for initial_location in block_info_iterator(start_info, base_dir):
        f.jump_to(initial_location)
        parse_method(f)
        break
    current_state = []

    def change_state(bc, ops):
        for op, bh, work in ops:
            if op == 'add':
                current_state.append(bh)
                pass
            else:
                current_state.pop()
    bc = BlockChain()
    bc.add_change_callback(change_state)
    bhs = []
    index = 0
    for info in block_info_iterator(start_info, base_dir):
        bh = blockheader_for_offset_info(info, base_dir)
        bh.info = info
        bhs.append(bh)
        if len(bhs) > batch_size:
            bc.add_headers(bhs)
            bhs = []
            if len(current_state) > cached_headers:
                for bh in current_state[:cached_headers]:
                    f.jump_to(bh.info)
                    block = parse_method(f)
                    yield block
                    index += 1
                    bc.lock_to_index(index)
                current_state = current_state[cached_headers:]
Esempio n. 12
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def test_simple_getheader():
    BLOCKS = make_blocks(20)
    blockchain1 = BlockChain()
    blockchain1.add_headers(BLOCKS)

    block_store = dict((b.hash(), b) for b in BLOCKS)

    peer1, peer2 = create_handshaked_peers()

    block_store = {}
    block_chain = BlockChain()
    inv_collector = InvCollector()
    block_handler = BlockHandler(inv_collector, block_chain, block_store)

    for block in BLOCKS:
        inv_collector.advertise_item(InvItem(ITEM_TYPE_BLOCK, block.hash()))
        block_store[block.hash()] = block
    block_chain.add_headers(BLOCKS)

    inv_collector.add_peer(peer1)
    block_handler.add_peer(peer1)

    @asyncio.coroutine
    def run_peer2():
        r = []
        headers = yield from standards.get_headers_hashes(
            peer2, until_block_hash=b'\0' * 32)
        r.append(headers)
        return r

    f2 = asyncio.Task(run_peer2())

    asyncio.get_event_loop().run_until_complete(asyncio.wait([f2]))

    r = f2.result()
    assert len(r) == 1
    assert [b.hash() for b in r[0]] == [b.hash() for b in BLOCKS]
Esempio n. 13
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def test_simple_getheader():
    BLOCKS = make_blocks(20)
    blockchain1 = BlockChain()
    blockchain1.add_headers(BLOCKS)

    block_store = dict((b.hash(), b) for b in BLOCKS)

    peer1, peer2 = create_handshaked_peers()

    block_store = {}
    block_chain = BlockChain()
    inv_collector = InvCollector()
    block_handler = BlockHandler(inv_collector, block_chain, block_store)

    for block in BLOCKS:
        inv_collector.advertise_item(InvItem(ITEM_TYPE_BLOCK, block.hash()))
        block_store[block.hash()] = block
    block_chain.add_headers(BLOCKS)

    inv_collector.add_peer(peer1)
    block_handler.add_peer(peer1)

    @asyncio.coroutine
    def run_peer2():
        r = []
        headers = yield from standards.get_headers_hashes(peer2, until_block_hash=b"\0" * 32)
        r.append(headers)
        return r

    f2 = asyncio.Task(run_peer2())

    asyncio.get_event_loop().run_until_complete(asyncio.wait([f2]))

    r = f2.result()
    assert len(r) == 1
    assert [b.hash() for b in r[0]] == [b.hash() for b in BLOCKS]
Esempio n. 14
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def test_large():
    SIZE = 3000
    ITEMS = [FakeBlock(i) for i in range(SIZE)]
    ITEMS[0] = FakeBlock(0, parent_for_0)
    BC = BlockChain(parent_for_0)
    assert longest_block_chain(BC) == []
    assert BC.locked_length() == 0
    assert BC.length() == 0
    assert set(BC.chain_finder.missing_parents()) == set()

    ops = BC.add_headers(ITEMS)
    assert ops == [("add", ITEMS[i], i) for i in range(SIZE)]
    assert longest_block_chain(BC) == list(range(SIZE))
    assert set(BC.chain_finder.missing_parents()) == {parent_for_0}
    assert BC.parent_hash == parent_for_0
    assert BC.locked_length() == 0
    assert BC.length() == SIZE
    for i in range(SIZE):
        v = BC.tuple_for_index(i)
        assert v[0] == i
        assert v[1] == parent_for_0 if i == 0 else i
    assert BC.index_for_hash(-1) is None
Esempio n. 15
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def test_large():
    SIZE = 3000
    ITEMS = [FakeBlock(i) for i in range(SIZE)]
    ITEMS[0] = FakeBlock(0, parent_for_0)
    BC = BlockChain(parent_for_0)
    assert longest_block_chain(BC) == []
    assert BC.locked_length() == 0
    assert BC.length() == 0
    assert set(BC.chain_finder.missing_parents()) == set()

    ops = BC.add_headers(ITEMS)
    assert ops == [("add", ITEMS[i], i) for i in range(SIZE)]
    assert longest_block_chain(BC) == list(range(SIZE))
    assert set(BC.chain_finder.missing_parents()) == {parent_for_0}
    assert BC.parent_hash == parent_for_0
    assert BC.locked_length() == 0
    assert BC.length() == SIZE
    for i in range(SIZE):
        v = BC.tuple_for_index(i)
        assert v[0] == i
        assert v[1] == parent_for_0 if i == 0 else i
    assert BC.index_for_hash(-1) is None
Esempio n. 16
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def test_basic():
    BC = BlockChain(parent_for_0)
    ITEMS = [FakeBlock(i) for i in range(100)]
    ITEMS[0] = FakeBlock(0, parent_for_0)

    assert longest_block_chain(BC) == []
    assert BC.length() == 0
    assert BC.locked_length() == 0
    assert set(BC.chain_finder.missing_parents()) == set()
    assert BC.parent_hash == parent_for_0
    assert BC.index_for_hash(0) is None
    assert BC.index_for_hash(-1) is None

    ops = BC.add_headers(ITEMS[:5])
    assert ops == [("add", ITEMS[i], i) for i in range(5)]
    assert BC.parent_hash == parent_for_0
    assert longest_block_chain(BC) == list(range(5))
    assert BC.length() == 5
    assert BC.locked_length() == 0
    assert set(BC.chain_finder.missing_parents()) == {parent_for_0}
    for i in range(5):
        v = BC.tuple_for_index(i)
        assert v[0] == i
        assert v[1] == parent_for_0 if i == 0 else i
    assert BC.index_for_hash(-1) is None

    ops = BC.add_headers(ITEMS[:7])
    assert ops == [("add", ITEMS[i], i) for i in range(5, 7)]
    assert BC.parent_hash == parent_for_0
    assert longest_block_chain(BC) == list(range(7))
    assert BC.length() == 7
    assert BC.locked_length() == 0
    assert set(BC.chain_finder.missing_parents()) == {parent_for_0}
    for i in range(7):
        v = BC.tuple_for_index(i)
        assert v[0] == i
        assert v[1] == parent_for_0 if i == 0 else i
    assert BC.index_for_hash(-1) is None

    ops = BC.add_headers(ITEMS[10:14])
    assert ops == []
    assert BC.parent_hash == parent_for_0
    assert longest_block_chain(BC) == [0, 1, 2, 3, 4, 5, 6]
    assert BC.locked_length() == 0
    assert BC.locked_length() == 0
    assert BC.length() == 7
    assert set(BC.chain_finder.missing_parents()) == {parent_for_0, 9}
    for i in range(7):
        v = BC.tuple_for_index(i)
        assert v[0] == i
        assert v[1] == parent_for_0 if i == 0 else i
    assert BC.index_for_hash(-1) is None

    ops = BC.add_headers(ITEMS[7:10])
    assert ops == [("add", ITEMS[i], i) for i in range(7, 14)]
    assert longest_block_chain(BC) == list(range(14))
    assert set(BC.chain_finder.missing_parents()) == {parent_for_0}
    assert BC.parent_hash == parent_for_0
    assert BC.locked_length() == 0
    assert BC.length() == 14
    for i in range(14):
        v = BC.tuple_for_index(i)
        assert v[0] == i
        assert v[1] == parent_for_0 if i == 0 else i
    assert BC.index_for_hash(-1) is None

    ops = BC.add_headers(ITEMS[90:])
    assert ops == []
    assert longest_block_chain(BC) == list(range(14))
    assert set(BC.chain_finder.missing_parents()) == {parent_for_0, 89}
    assert BC.parent_hash == parent_for_0
    assert BC.locked_length() == 0
    assert BC.length() == 14
    for i in range(14):
        v = BC.tuple_for_index(i)
        assert v[0] == i
        assert v[1] == parent_for_0 if i == 0 else i
    assert BC.index_for_hash(-1) is None

    ops = BC.add_headers(ITEMS[14:90])
    assert ops == [("add", ITEMS[i], i) for i in range(14, 100)]
    assert longest_block_chain(BC) == list(range(100))
    assert set(BC.chain_finder.missing_parents()) == {parent_for_0}
    assert BC.parent_hash == parent_for_0
    assert BC.locked_length() == 0
    assert BC.length() == 100
    for i in range(100):
        v = BC.tuple_for_index(i)
        assert v[0] == i
        assert v[1] == parent_for_0 if i == 0 else i
    assert BC.index_for_hash(-1) is None
Esempio n. 17
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def test_basic():
    BC = BlockChain(parent_for_0)
    ITEMS = [FakeBlock(i) for i in range(100)]
    ITEMS[0] = FakeBlock(0, parent_for_0)

    assert longest_block_chain(BC) == []
    assert BC.length() == 0
    assert BC.locked_length() == 0
    assert set(BC.chain_finder.missing_parents()) == set()
    assert BC.parent_hash == parent_for_0
    assert BC.index_for_hash(0) is None
    assert BC.index_for_hash(-1) is None

    ops = BC.add_headers(ITEMS[:5])
    assert ops == [("add", ITEMS[i], i) for i in range(5)]
    assert BC.parent_hash == parent_for_0
    assert longest_block_chain(BC) == list(range(5))
    assert BC.length() == 5
    assert BC.locked_length() == 0
    assert set(BC.chain_finder.missing_parents()) == {parent_for_0}
    for i in range(5):
        v = BC.tuple_for_index(i)
        assert v[0] == i
        assert v[1] == parent_for_0 if i == 0 else i
    assert BC.index_for_hash(-1) is None

    ops = BC.add_headers(ITEMS[:7])
    assert ops == [("add", ITEMS[i], i) for i in range(5, 7)]
    assert BC.parent_hash == parent_for_0
    assert longest_block_chain(BC) == list(range(7))
    assert BC.length() == 7
    assert BC.locked_length() == 0
    assert set(BC.chain_finder.missing_parents()) == {parent_for_0}
    for i in range(7):
        v = BC.tuple_for_index(i)
        assert v[0] == i
        assert v[1] == parent_for_0 if i == 0 else i
    assert BC.index_for_hash(-1) is None

    ops = BC.add_headers(ITEMS[10:14])
    assert ops == []
    assert BC.parent_hash == parent_for_0
    assert longest_block_chain(BC) == [0, 1, 2, 3, 4, 5, 6]
    assert BC.locked_length() == 0
    assert BC.locked_length() == 0
    assert BC.length() == 7
    assert set(BC.chain_finder.missing_parents()) == {parent_for_0, 9}
    for i in range(7):
        v = BC.tuple_for_index(i)
        assert v[0] == i
        assert v[1] == parent_for_0 if i == 0 else i
    assert BC.index_for_hash(-1) is None

    ops = BC.add_headers(ITEMS[7:10])
    assert ops == [("add", ITEMS[i], i) for i in range(7, 14)]
    assert longest_block_chain(BC) == list(range(14))
    assert set(BC.chain_finder.missing_parents()) == {parent_for_0}
    assert BC.parent_hash == parent_for_0
    assert BC.locked_length() == 0
    assert BC.length() == 14
    for i in range(14):
        v = BC.tuple_for_index(i)
        assert v[0] == i
        assert v[1] == parent_for_0 if i == 0 else i
    assert BC.index_for_hash(-1) is None

    ops = BC.add_headers(ITEMS[90:])
    assert ops == []
    assert longest_block_chain(BC) == list(range(14))
    assert set(BC.chain_finder.missing_parents()) == {parent_for_0, 89}
    assert BC.parent_hash == parent_for_0
    assert BC.locked_length() == 0
    assert BC.length() == 14
    for i in range(14):
        v = BC.tuple_for_index(i)
        assert v[0] == i
        assert v[1] == parent_for_0 if i == 0 else i
    assert BC.index_for_hash(-1) is None

    ops = BC.add_headers(ITEMS[14:90])
    assert ops == [("add", ITEMS[i], i) for i in range(14, 100)]
    assert longest_block_chain(BC) == list(range(100))
    assert set(BC.chain_finder.missing_parents()) == {parent_for_0}
    assert BC.parent_hash == parent_for_0
    assert BC.locked_length() == 0
    assert BC.length() == 100
    for i in range(100):
        v = BC.tuple_for_index(i)
        assert v[0] == i
        assert v[1] == parent_for_0 if i == 0 else i
    assert BC.index_for_hash(-1) is None