class DBDB(object):
def __init__(self, f):
self._storage = Storage(f)
self._tree = BinaryTree(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 __getitem__(self, key):
self._assert_not_closed()
return self._tree.get(key)
def __setitem__(self, key, value):
self._assert_not_closed()
return self._tree.set(key, value)
def __delitem__(self, key):
self._assert_not_closed()
return self._tree.pop(key)
def __contains__(self, key):
try:
self[key]
except KeyError:
return False
else:
return True
def __len__(self):
return len(self._tree)
class DBDB(object):
def __init__(self, f):
self._storage = Storage(f)
self._tree = BinaryTree(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 __getitem__(self, key):
self._assert_not_closed()
return self._tree.get(key)
def __setitem__(self, key, value):
self._assert_not_closed()
return self._tree.set(key, value)
def __delitem__(self, key):
self._assert_not_closed()
return self._tree.pop(key)
def __contains__(self, key):
try:
self[key]
except KeyError:
return False
else:
return True
def __len__(self):
return len(self._tree)
def setup(self):
self.f = tempfile.NamedTemporaryFile()
self.p = Storage(self.f)
class TestStorage(object):
def setup(self):
self.f = tempfile.NamedTemporaryFile()
self.p = Storage(self.f)
def _get_superblock_and_data(self, value):
superblock = value[:Storage.SUPERBLOCK_SIZE]
data = value[Storage.SUPERBLOCK_SIZE:]
return superblock, data
def _get_f_contents(self):
self.f.flush()
with open(self.f.name, 'rb') as f:
return f.read()
def test_init_ensures_superblock(self):
EMPTY_SUPERBLOCK = (b'\x00' * Storage.SUPERBLOCK_SIZE)
self.f.seek(0, os.SEEK_END)
value = self._get_f_contents()
eq_(value, EMPTY_SUPERBLOCK)
def test_write(self):
self.p.write(b'ABCDE')
value = self._get_f_contents()
superblock, data = self._get_superblock_and_data(value)
eq_(data, b'\x00\x00\x00\x00\x00\x00\x00\x05ABCDE')
def test_read(self):
self.f.seek(Storage.SUPERBLOCK_SIZE)
self.f.write(b'\x00\x00\x00\x00\x00\x00\x00\x0801234567')
value = self.p.read(Storage.SUPERBLOCK_SIZE)
eq_(value, b'01234567')
def test_commit_root_address(self):
self.p.commit_root_address(257)
root_bytes = self._get_f_contents()[:8]
eq_(root_bytes, b'\x00\x00\x00\x00\x00\x00\x01\x01')
def test_get_root_address(self):
self.f.seek(0)
self.f.write(b'\x00\x00\x00\x00\x00\x00\x02\x02')
root_address = self.p.get_root_address()
eq_(root_address, 514)
def test_workflow(self):
a1 = self.p.write(b'one')
a2 = self.p.write(b'two')
self.p.commit_root_address(a2)
a3 = self.p.write(b'three')
eq_(self.p.get_root_address(), a2)
a4 = self.p.write(b'four')
self.p.commit_root_address(a4)
eq_(self.p.read(a1), b'one')
eq_(self.p.read(a2), b'two')
eq_(self.p.read(a3), b'three')
eq_(self.p.read(a4), b'four')
eq_(self.p.get_root_address(), a4)
def __init__(self, f):
self._storage = Storage(f)
self._tree = BinaryTree(self._storage)
def __init__(self, f):
self._storage = Storage(f)
self._tree = BinaryTree(self._storage)
def setup(self):
self.f = tempfile.NamedTemporaryFile()
self.p = Storage(self.f)
class TestStorage(object):
def setup(self):
self.f = tempfile.NamedTemporaryFile()
self.p = Storage(self.f)
def _get_superblock_and_data(self, value):
superblock = value[: Storage.SUPERBLOCK_SIZE]
data = value[Storage.SUPERBLOCK_SIZE :]
return superblock, data
def _get_f_contents(self):
self.f.flush()
with open(self.f.name, "rb") as f:
return f.read()
def test_init_ensures_superblock(self):
EMPTY_SUPERBLOCK = b"\x00" * Storage.SUPERBLOCK_SIZE
self.f.seek(0, os.SEEK_END)
value = self._get_f_contents()
eq_(value, EMPTY_SUPERBLOCK)
def test_write(self):
self.p.write(b"ABCDE")
value = self._get_f_contents()
superblock, data = self._get_superblock_and_data(value)
eq_(data, b"\x00\x00\x00\x00\x00\x00\x00\x05ABCDE")
def test_read(self):
self.f.seek(Storage.SUPERBLOCK_SIZE)
self.f.write(b"\x00\x00\x00\x00\x00\x00\x00\x0801234567")
value = self.p.read(Storage.SUPERBLOCK_SIZE)
eq_(value, b"01234567")
def test_commit_root_address(self):
self.p.commit_root_address(257)
root_bytes = self._get_f_contents()[:8]
eq_(root_bytes, b"\x00\x00\x00\x00\x00\x00\x01\x01")
def test_get_root_address(self):
self.f.seek(0)
self.f.write(b"\x00\x00\x00\x00\x00\x00\x02\x02")
root_address = self.p.get_root_address()
eq_(root_address, 514)
def test_workflow(self):
a1 = self.p.write(b"one")
a2 = self.p.write(b"two")
self.p.commit_root_address(a2)
a3 = self.p.write(b"three")
eq_(self.p.get_root_address(), a2)
a4 = self.p.write(b"four")
self.p.commit_root_address(a4)
eq_(self.p.read(a1), b"one")
eq_(self.p.read(a2), b"two")
eq_(self.p.read(a3), b"three")
eq_(self.p.read(a4), b"four")
eq_(self.p.get_root_address(), a4)
