def test_bigarray_resize():
data = zeros(8*PS, dtype=uint32)
f = BigFile_Data(data, PS)
fh = f.fileh_open()
# set first part & ensure it is set correctly
A = BigArray((10,3), uint32, fh)
A[:,:] = arange(10*3, dtype=uint32).reshape((10,3))
a = A[:]
assert array_equal(a.ravel(), arange(10*3, dtype=uint32))
# grow array
A.resize((11,3))
# a as already mapped, should stay the same
assert array_equal(a.ravel(), arange(10*3, dtype=uint32))
# mapping it once again maps it whole with new size
b = A[:]
assert isinstance(b, ndarray)
assert b.shape == (11,3)
assert b.dtype == dtype(uint32)
# head data is the same as a
assert array_equal(a, b[:10,:])
# tail is zeros
assert array_equal(b[10,:], zeros(3, dtype=uint32))
# old mapping stays valid and changes propageate to/from it
assert a[0,0] == 0
assert b[0,0] == 0
a[0,0] = 1
assert b[0,0] == 1
b[0,0] = 2
assert a[0,0] == 2
a[0,0] = 0
assert b[0,0] == 0
assert a[ -1,-1] == 10*3-1
assert b[10-1,-1] == 10*3-1
a[ -1,-1] = 1
assert b[10-1,-1] == 1
b[10-1,-1] = 2
assert a[ -1,-1] == 2
a[ -1,-1] = 10*3-1
assert b[10-1,-1] == 10*3-1
# we cannot access old mapping beyond it's end
assert raises(IndexError, 'a[10,:]')
# we can change tail
b[10,:] = arange(10*3, (10+1)*3)
# map it whole again and ensure we have correct data
c = A[:]
assert array_equal(c.ravel(), arange(11*3, dtype=uint32))
