class TestRandomAccessMemory:
"""Test case for RAM."""
ram = None
def setup(self):
"""Init state."""
self.ram = RandomAccessMemory(WORD_SIZE, 512, endianess='big')
assert self.ram.word_size == WORD_SIZE
assert self.ram.memory_size == 512
assert len(self.ram) == 512
assert self.ram.is_protected is True
def test_check_address(self):
"""It a second part of information protection."""
for i in range(len(self.ram)):
self.ram.check_address(i)
for i in range(len(self.ram), 2 * len(self.ram)):
with raises(KeyError):
self.ram.check_address(i)
with raises(TypeError):
self.ram.check_address('R1')
def test_setitem(self):
"""Address should be checked."""
for i in range(len(self.ram)):
self.ram[i] = len(self.ram) + i
assert i in self.ram
for i in range(len(self.ram), 2 * len(self.ram)):
with raises(KeyError):
self.ram[i] = i
assert i not in self.ram
with raises(TypeError):
self.ram['R1'] = 10
assert 'R1' not in self.ram
with raises(ValueError):
self.ram[2] = 2 ** WORD_SIZE
def test_getitem(self):
"""Address should be checked."""
for i in range(2 * len(self.ram)):
with raises(KeyError):
self.ram.__getitem__(i)
with raises(TypeError):
self.ram.__getitem__('R1')
for i in range(len(self.ram) // 2):
self.ram[i] = i
assert self.ram[i] == i
def test_not_protected_getitem(self):
"""Test if programmer can shut in his leg."""
self.ram = RandomAccessMemory(WORD_SIZE, 512, 'big', is_protected=False)
for i in range(len(self.ram)):
assert self.ram[i] == 0
for i in range(len(self.ram), 2 * len(self.ram)):
with raises(KeyError):
self.ram.__getitem__(i)
def test_fetch(self):
"""Fetch is basic operation of transfer data."""
for i in range(5, 9):
self.ram[i] = i
assert self.ram.fetch(i, WORD_SIZE) == i
assert (self.ram.fetch(5, 4 * WORD_SIZE) ==
0x00000005000000060000000700000008)
assert (self.ram.fetch(5, 4 * WORD_SIZE) ==
big_endian_decode([5, 6, 7, 8], WORD_SIZE))
self.ram[5] = 0
assert (self.ram.fetch(5, 4 * WORD_SIZE) ==
big_endian_decode([0, 6, 7, 8], WORD_SIZE))
assert (self.ram.fetch(5, 4 * WORD_SIZE) ==
0x00000000000000060000000700000008)
with raises(KeyError):
self.ram.fetch(5, 4 * WORD_SIZE - 1)
with raises(KeyError):
self.ram.fetch(4, 4 * WORD_SIZE)
self.ram = RandomAccessMemory(WORD_SIZE, 512, endianess="little")
for i in range(5, 9):
self.ram[i] = i
assert self.ram.fetch(i, WORD_SIZE) == i
assert (self.ram.fetch(5, 4 * WORD_SIZE) ==
0x00000008000000070000000600000005)
assert (self.ram.fetch(5, 4 * WORD_SIZE) ==
little_endian_decode([5, 6, 7, 8], WORD_SIZE))
def test_put(self):
"""Test put operation."""
value_list = [0, 6, 7, 0]
value = big_endian_decode(value_list, WORD_SIZE)
self.ram.put(5, value, 4 * WORD_SIZE)
with raises(ValueError):
self.ram.put(5, 2 ** WORD_SIZE, WORD_SIZE)
self.ram.put(4, 4, WORD_SIZE)
for i in range(5, 9):
assert self.ram[i] == value_list[i - 5]
self.ram = RandomAccessMemory(WORD_SIZE, 512, endianess="little")
value = little_endian_decode(value_list, WORD_SIZE)
self.ram.put(5, value, 4 * WORD_SIZE)
for i in range(5, 9):
assert self.ram[i] == value_list[i - 5]
