def test_non_ndarray_inputs():
# Regression check for gh-5604
class MyArray(object):
def __init__(self, data):
self.data = data
@property
def __array_interface__(self):
return self.data.__array_interface__
class MyArray2(object):
def __init__(self, data):
self.data = data
def __array__(self):
return self.data
for cls in [MyArray, MyArray2]:
x = np.arange(5)
assert_(np.may_share_memory(cls(x[::2]), x[1::2]))
assert_(not np.shares_memory(cls(x[::2]), x[1::2]))
assert_(np.shares_memory(cls(x[1::3]), x[::2]))
assert_(np.may_share_memory(cls(x[1::3]), x[::2]))
def check_may_share_memory_easy_fuzz(get_max_work, same_steps, min_count):
# Check that overlap problems with common strides are solved with
# little work.
x = np.zeros([17,34,71,97], dtype=np.int16)
feasible = 0
infeasible = 0
pair_iter = iter_random_view_pairs(x, same_steps)
while min(feasible, infeasible) < min_count:
a, b = next(pair_iter)
bounds_overlap = np.may_share_memory(a, b)
may_share_answer = np.may_share_memory(a, b)
easy_answer = np.may_share_memory(a, b, max_work=get_max_work(a, b))
exact_answer = np.may_share_memory(a, b, max_work=MAY_SHARE_EXACT)
if easy_answer != exact_answer:
# assert_equal is slow...
assert_equal(easy_answer, exact_answer)
if may_share_answer != bounds_overlap:
assert_equal(may_share_answer, bounds_overlap)
if bounds_overlap:
if exact_answer:
feasible += 1
else:
infeasible += 1
def test_may_share_memory_manual():
# Manual test cases for may_share_memory
# Base arrays
xs0 = [
np.zeros([13, 21, 23, 22], dtype=np.int8),
np.zeros([13, 21, 23*2, 22], dtype=np.int8)[:,:,::2,:]
]
# Generate all negative stride combinations
xs = []
for x in xs0:
for ss in itertools.product(*(([slice(None), slice(None, None, -1)],)*4)):
xp = x[ss]
xs.append(xp)
for x in xs:
# The default is a simple extent check
assert_(np.may_share_memory(x[:,0,:], x[:,1,:]))
assert_(np.may_share_memory(x[:,0,:], x[:,1,:], max_work=None))
# Exact checks
check_may_share_memory_exact(x[:,0,:], x[:,1,:])
check_may_share_memory_exact(x[:,::7], x[:,3::3])
try:
xp = x.ravel()
if xp.flags.owndata:
continue
xp = xp.view(np.int16)
except ValueError:
continue
# 0-size arrays cannot overlap
check_may_share_memory_exact(x.ravel()[6:6],
xp.reshape(13, 21, 23, 11)[:,::7])
# Test itemsize is dealt with
check_may_share_memory_exact(x[:,::7],
xp.reshape(13, 21, 23, 11))
check_may_share_memory_exact(x[:,::7],
xp.reshape(13, 21, 23, 11)[:,3::3])
check_may_share_memory_exact(x.ravel()[6:7],
xp.reshape(13, 21, 23, 11)[:,::7])
# Check unit size
x = np.zeros([1], dtype=np.int8)
check_may_share_memory_exact(x, x)
check_may_share_memory_exact(x, x.copy())
def _compare_index_result(self, arr, index, mimic_get, no_copy):
"""Compare mimicked result to indexing result.
"""
arr = arr.copy()
indexed_arr = arr[index]
assert_array_equal(indexed_arr, mimic_get)
# Check if we got a view, unless its a 0-sized or 0-d array.
# (then its not a view, and that does not matter)
if indexed_arr.size != 0 and indexed_arr.ndim != 0:
assert_(np.may_share_memory(indexed_arr, arr) == no_copy)
# Check reference count of the original array
if HAS_REFCOUNT:
if no_copy:
# refcount increases by one:
assert_equal(sys.getrefcount(arr), 3)
else:
assert_equal(sys.getrefcount(arr), 2)
# Test non-broadcast setitem:
b = arr.copy()
b[index] = mimic_get + 1000
if b.size == 0:
return # nothing to compare here...
if no_copy and indexed_arr.ndim != 0:
# change indexed_arr in-place to manipulate original:
indexed_arr += 1000
assert_array_equal(arr, b)
return
# Use the fact that the array is originally an arange:
arr.flat[indexed_arr.ravel()] += 1000
assert_array_equal(arr, b)
def test_basic(self):
d = np.ones((50, 60))
d2 = np.ones((30, 60, 6))
assert_(np.may_share_memory(d, d))
assert_(np.may_share_memory(d, d[::-1]))
assert_(np.may_share_memory(d, d[::2]))
assert_(np.may_share_memory(d, d[1:, ::-1]))
assert_(not np.may_share_memory(d[::-1], d2))
assert_(not np.may_share_memory(d[::2], d2))
assert_(not np.may_share_memory(d[1:, ::-1], d2))
assert_(np.may_share_memory(d2[1:, ::-1], d2))
def __array_finalize__(self, obj):
if hasattr(obj, '_mmap') and np.may_share_memory(self, obj):
self._mmap = obj._mmap
self.filename = obj.filename
self.offset = obj.offset
self.mode = obj.mode
else:
self._mmap = None
self.filename = None
self.offset = None
self.mode = None
def check_may_share_memory_exact(a, b):
got = np.may_share_memory(a, b, max_work=MAY_SHARE_EXACT)
assert_equal(np.may_share_memory(a, b),
np.may_share_memory(a, b, max_work=MAY_SHARE_BOUNDS))
a.fill(0)
b.fill(0)
a.fill(1)
exact = b.any()
err_msg = ""
if got != exact:
err_msg = " " + "\n ".join([
"base_a - base_b = %r" % (a.__array_interface__['data'][0] - b.__array_interface__['data'][0],),
"shape_a = %r" % (a.shape,),
"shape_b = %r" % (b.shape,),
"strides_a = %r" % (a.strides,),
"strides_b = %r" % (b.strides,),
"size_a = %r" % (a.size,),
"size_b = %r" % (b.size,)
])
assert_equal(got, exact, err_msg=err_msg)
def test_matrix_memory_sharing(self):
assert_(np.may_share_memory(self.m, self.m.ravel()))
assert_(not np.may_share_memory(self.m, self.m.flatten()))
def test_array_memory_sharing(self):
assert_(np.may_share_memory(self.a, self.a.ravel()))
assert_(not np.may_share_memory(self.a, self.a.flatten()))
