Python mmap.ACCESS_COPY Examples

The following are 4 code examples of mmap.ACCESS_COPY(). You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may also want to check out all available functions/classes of the module mmap , or try the search function .
Example #1
Source File: DataModel.py    From dcc with Apache License 2.0 5 votes vote down vote up 
def __init__(self, filename):
        self._filename = filename

        self._f = open(filename, "rb")

        # memory-map the file, size 0 means whole file
        self._mapped = mmap.mmap(self._f.fileno(), 0, access=mmap.ACCESS_COPY)

        super(FileDataModel, self).__init__(self._mapped)
Example #2
Source File: DataModel.py    From qiew with GNU General Public License v2.0 5 votes vote down vote up 
def __init__(self, filename):
        self._filename = filename

        self._f = open(filename, "rb")

        # memory-map the file, size 0 means whole file
        self._mapped = mmap.mmap(self._f.fileno(), 0, access=mmap.ACCESS_COPY)

        super(FileDataModel, self).__init__(self._mapped)
Example #3
Source File: DataModel.py    From MARA_Framework with GNU Lesser General Public License v3.0 5 votes vote down vote up 
def __init__(self, filename):
        self._filename = filename

        self._f = open(filename, "rb")

        # memory-map the file, size 0 means whole file
        self._mapped = mmap.mmap(self._f.fileno(), 0, access=mmap.ACCESS_COPY)

        super(FileDataModel, self).__init__(self._mapped)
Example #4
Source File: test_core.py    From Carnets with BSD 3-Clause "New" or "Revised" License 5 votes vote down vote up 
def test_mmap_allocate_error(self):
        """
        Regression test for https://github.com/astropy/astropy/issues/1380

        Temporarily patches mmap.mmap to raise an OSError if mode is ACCESS_COPY.
        """

        mmap_original = mmap.mmap

        # We patch mmap here to raise an error if access=mmap.ACCESS_COPY, which
        # emulates an issue that an OSError is raised if the available address
        # space is less than the size of the file even if memory mapping is used.

        def mmap_patched(*args, **kwargs):
            if kwargs.get('access') == mmap.ACCESS_COPY:
                exc = OSError()
                exc.errno = errno.ENOMEM
                raise exc
            else:
                return mmap_original(*args, **kwargs)

        with fits.open(self.data('test0.fits'), memmap=True) as hdulist:
            with patch.object(mmap, 'mmap', side_effect=mmap_patched) as p:
                with pytest.warns(AstropyUserWarning, match=r"Could not memory "
                                  r"map array with mode='readonly'"):
                    data = hdulist[1].data
                p.reset_mock()
            assert not data.flags.writeable