def test_get_root_address():
f = tempfile.NamedTemporaryFile()
p = Storage(f)
f.seek(0)
f.write(b'\x00\x00\x00\x00\x00\x00\x02\x02')
root_address = p.get_root_address()
assert root_address == 514
class DBDB(object):
def __init__(self, f):
self._storage = Storage(f)
self._tree = RedBlackTree(self._storage)
def _assert_not_closed(self):
if self._storage.closed:
raise ValueError('Database closed.')
def close(self):
self._storage.close()
def commit(self):
self._assert_not_closed()
self._tree.commit()
def get(self, key):
self._assert_not_closed()
return self._tree.get(key)
def set(self, key, value):
self._assert_not_closed()
return self._tree.set(key, value)
def get_smaller_than(self, key):
self._assert_not_closed()
return self._tree.get_smaller_than(key)
def test_read():
f = tempfile.NamedTemporaryFile()
p = Storage(f)
f.seek(Storage.SUPERBLOCK_SIZE)
f.write(b'\x00\x00\x00\x00\x00\x00\x00\x0801234567')
value = p.read(Storage.SUPERBLOCK_SIZE)
assert value == b'01234567'
def test_write():
f = tempfile.NamedTemporaryFile()
p = Storage(f)
p.write(b'ABCDE')
value = _get_f_contents(f)
superblock, data = _get_superblock_and_data(value)
assert data == b'\x00\x00\x00\x00\x00\x00\x00\x05ABCDE'
def test_init_ensures_superblock():
f = tempfile.NamedTemporaryFile()
p = Storage(f)
EMPTY_SUPERBLOCK = (b'\x00' * Storage.SUPERBLOCK_SIZE)
f.seek(0, os.SEEK_END)
value = _get_f_contents(f)
assert value == EMPTY_SUPERBLOCK
def __init__(self, f):
self._storage = Storage(f)
self._tree = RedBlackTree(self._storage)
def test_workflow():
f = tempfile.NamedTemporaryFile()
p = Storage(f)
a1 = p.write(b'one')
a2 = p.write(b'two')
p.commit_root_address(a2)
a3 = p.write(b'three')
assert p.get_root_address() == a2
a4 = p.write(b'four')
p.commit_root_address(a4)
assert p.read(a1) == b'one'
assert p.read(a2) == b'two'
assert p.read(a3) == b'three'
assert p.read(a4) == b'four'
assert p.get_root_address() == a4
def test_commit_root_address():
f = tempfile.NamedTemporaryFile()
p = Storage(f)
p.commit_root_address(257)
root_bytes = _get_f_contents(f)[:8]
assert root_bytes == b'\x00\x00\x00\x00\x00\x00\x01\x01'