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import sys
import os
import mmap
import pytest
from pathlib import Path
from tempfile import NamedTemporaryFile, TemporaryFile
from numpy import (
memmap, sum, average, prod, ndarray, isscalar, add, subtract, multiply)
from numpy import arange, allclose, asarray
from numpy.testing import (
assert_, assert_equal, assert_array_equal, suppress_warnings, IS_PYPY,
break_cycles
)
class TestMemmap:
def setup_method(self):
self.tmpfp = NamedTemporaryFile(prefix='mmap')
self.shape = (3, 4)
self.dtype = 'float32'
self.data = arange(12, dtype=self.dtype)
self.data.resize(self.shape)
def teardown_method(self):
self.tmpfp.close()
self.data = None
if IS_PYPY:
break_cycles()
break_cycles()
def test_roundtrip(self):
# Write data to file
fp = memmap(self.tmpfp, dtype=self.dtype, mode='w+',
shape=self.shape)
fp[:] = self.data[:]
del fp # Test __del__ machinery, which handles cleanup
# Read data back from file
newfp = memmap(self.tmpfp, dtype=self.dtype, mode='r',
shape=self.shape)
assert_(allclose(self.data, newfp))
assert_array_equal(self.data, newfp)
assert_equal(newfp.flags.writeable, False)
def test_open_with_filename(self, tmp_path):
tmpname = tmp_path / 'mmap'
fp = memmap(tmpname, dtype=self.dtype, mode='w+',
shape=self.shape)
fp[:] = self.data[:]
del fp
def test_unnamed_file(self):
with TemporaryFile() as f:
fp = memmap(f, dtype=self.dtype, shape=self.shape)
del fp
def test_attributes(self):
offset = 1
mode = "w+"
fp = memmap(self.tmpfp, dtype=self.dtype, mode=mode,
shape=self.shape, offset=offset)
assert_equal(offset, fp.offset)
assert_equal(mode, fp.mode)
del fp
def test_filename(self, tmp_path):
tmpname = tmp_path / "mmap"
fp = memmap(tmpname, dtype=self.dtype, mode='w+',
shape=self.shape)
abspath = Path(os.path.abspath(tmpname))
fp[:] = self.data[:]
assert_equal(abspath, fp.filename)
b = fp[:1]
assert_equal(abspath, b.filename)
del b
del fp
def test_path(self, tmp_path):
tmpname = tmp_path / "mmap"
fp = memmap(Path(tmpname), dtype=self.dtype, mode='w+',
shape=self.shape)
# os.path.realpath does not resolve symlinks on Windows
# see: https://bugs.python.org/issue9949
# use Path.resolve, just as memmap class does internally
abspath = str(Path(tmpname).resolve())
fp[:] = self.data[:]
assert_equal(abspath, str(fp.filename.resolve()))
b = fp[:1]
assert_equal(abspath, str(b.filename.resolve()))
del b
del fp
def test_filename_fileobj(self):
fp = memmap(self.tmpfp, dtype=self.dtype, mode="w+",
shape=self.shape)
assert_equal(fp.filename, self.tmpfp.name)
@pytest.mark.skipif(sys.platform == 'gnu0',
reason="Known to fail on hurd")
def test_flush(self):
fp = memmap(self.tmpfp, dtype=self.dtype, mode='w+',
shape=self.shape)
fp[:] = self.data[:]
assert_equal(fp[0], self.data[0])
fp.flush()
def test_del(self):
# Make sure a view does not delete the underlying mmap
fp_base = memmap(self.tmpfp, dtype=self.dtype, mode='w+',
shape=self.shape)
fp_base[0] = 5
fp_view = fp_base[0:1]
assert_equal(fp_view[0], 5)
del fp_view
# Should still be able to access and assign values after
# deleting the view
assert_equal(fp_base[0], 5)
fp_base[0] = 6
assert_equal(fp_base[0], 6)
def test_arithmetic_drops_references(self):
fp = memmap(self.tmpfp, dtype=self.dtype, mode='w+',
shape=self.shape)
tmp = (fp + 10)
if isinstance(tmp, memmap):
assert_(tmp._mmap is not fp._mmap)
def test_indexing_drops_references(self):
fp = memmap(self.tmpfp, dtype=self.dtype, mode='w+',
shape=self.shape)
tmp = fp[(1, 2), (2, 3)]
if isinstance(tmp, memmap):
assert_(tmp._mmap is not fp._mmap)
def test_slicing_keeps_references(self):
fp = memmap(self.tmpfp, dtype=self.dtype, mode='w+',
shape=self.shape)
assert_(fp[:2, :2]._mmap is fp._mmap)
def test_view(self):
fp = memmap(self.tmpfp, dtype=self.dtype, shape=self.shape)
new1 = fp.view()
new2 = new1.view()
assert_(new1.base is fp)
assert_(new2.base is fp)
new_array = asarray(fp)
assert_(new_array.base is fp)
def test_ufunc_return_ndarray(self):
fp = memmap(self.tmpfp, dtype=self.dtype, shape=self.shape)
fp[:] = self.data
with suppress_warnings() as sup:
sup.filter(FutureWarning, "np.average currently does not preserve")
for unary_op in [sum, average, prod]:
result = unary_op(fp)
assert_(isscalar(result))
assert_(result.__class__ is self.data[0, 0].__class__)
assert_(unary_op(fp, axis=0).__class__ is ndarray)
assert_(unary_op(fp, axis=1).__class__ is ndarray)
for binary_op in [add, subtract, multiply]:
assert_(binary_op(fp, self.data).__class__ is ndarray)
assert_(binary_op(self.data, fp).__class__ is ndarray)
assert_(binary_op(fp, fp).__class__ is ndarray)
fp += 1
assert(fp.__class__ is memmap)
add(fp, 1, out=fp)
assert(fp.__class__ is memmap)
def test_getitem(self):
fp = memmap(self.tmpfp, dtype=self.dtype, shape=self.shape)
fp[:] = self.data
assert_(fp[1:, :-1].__class__ is memmap)
# Fancy indexing returns a copy that is not memmapped
assert_(fp[[0, 1]].__class__ is ndarray)
def test_memmap_subclass(self):
class MemmapSubClass(memmap):
pass
fp = MemmapSubClass(self.tmpfp, dtype=self.dtype, shape=self.shape)
fp[:] = self.data
# We keep previous behavior for subclasses of memmap, i.e. the
# ufunc and __getitem__ output is never turned into a ndarray
assert_(sum(fp, axis=0).__class__ is MemmapSubClass)
assert_(sum(fp).__class__ is MemmapSubClass)
assert_(fp[1:, :-1].__class__ is MemmapSubClass)
assert(fp[[0, 1]].__class__ is MemmapSubClass)
def test_mmap_offset_greater_than_allocation_granularity(self):
size = 5 * mmap.ALLOCATIONGRANULARITY
offset = mmap.ALLOCATIONGRANULARITY + 1
fp = memmap(self.tmpfp, shape=size, mode='w+', offset=offset)
assert_(fp.offset == offset)
def test_no_shape(self):
self.tmpfp.write(b'a'*16)
mm = memmap(self.tmpfp, dtype='float64')
assert_equal(mm.shape, (2,))
def test_empty_array(self):
# gh-12653
with pytest.raises(ValueError, match='empty file'):
memmap(self.tmpfp, shape=(0,4), mode='w+')
self.tmpfp.write(b'\0')
# ok now the file is not empty
memmap(self.tmpfp, shape=(0,4), mode='w+')
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