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116 lines
4.4 KiB
116 lines
4.4 KiB
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This file is part of Magnum. |
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Copyright © 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, |
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2020, 2021, 2022 Vladimír Vondruš <mosra@centrum.cz> |
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Permission is hereby granted, free of charge, to any person obtaining a |
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copy of this software and associated documentation files (the "Software"), |
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to deal in the Software without restriction, including without limitation |
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the rights to use, copy, modify, merge, publish, distribute, sublicense, |
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and/or sell copies of the Software, and to permit persons to whom the |
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Software is furnished to do so, subject to the following conditions: |
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The above copyright notice and this permission notice shall be included |
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in all copies or substantial portions of the Software. |
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
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THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
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FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
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DEALINGS IN THE SOFTWARE. |
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.. |
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.. doctest setup |
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>>> from corrade import containers |
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.. py:class:: corrade.containers.ArrayView |
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Provides one-dimensional tightly packed view on a memory range. Convertible |
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both from and to Python objects supporting the Buffer Protocol, with one |
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dimension and stride of :py:`1`. See :ref:`StridedArrayView1D` and others |
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for more generic views. :ref:`ArrayView` is immutable, see |
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:ref:`MutableArrayView` for the mutable alternative. All slicing operations |
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are supported, specifying a non-trivial stride will return |
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:ref:`StridedArrayView1D` instead of :ref:`ArrayView`. Example usage: |
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.. code:: pycon |
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>>> a = b'hello' |
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>>> b = containers.ArrayView(a) |
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>>> b[2] |
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'l' |
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>>> bytes(b[1:4]) |
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b'ell' |
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`Memory ownership and reference counting`_ |
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========================================== |
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Unlike in C++, the view keeps a reference to the original memory owner |
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object in the :ref:`owner` field, meaning that calling :py:`del` on the |
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original object will *not* invalidate the view. Slicing a view creates a |
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new view referencing the same original object, without any dependency on |
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the previous view. That means a long chained slicing operation will not cause |
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increased memory usage. |
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.. code:: pycon |
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>>> b.owner is a |
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True |
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>>> b[1:4][:-1].owner is a |
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True |
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The :py:`owner` is :py:`None` if the view is empty. |
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`Comparison to Python's memoryview`_ |
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==================================== |
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The :ref:`ArrayView` class is equivalent to one-dimensional |
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:ref:`memoryview` with a stride of :py:`1`. For multiple dimensions and |
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non-trivial strides, :ref:`StridedArrayView1D` and friends provide a |
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superset of :ref:`memoryview` features. |
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.. py:class:: corrade.containers.MutableArrayView |
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Equivalent to :ref:`ArrayView`, but implementing :ref:`__setitem__()` as |
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well. |
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.. py:class:: corrade.containers.StridedArrayView1D |
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Provides one-dimensional read-only view on a memory range with custom |
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stride values. See :ref:`StridedArrayView2D`, :ref:`StridedArrayView3D`, |
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:ref:`MutableStridedArrayView1D` and others for multi-dimensional and |
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mutable equivalents. |
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`Comparison to Python's memoryview`_ |
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==================================== |
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The :ref:`StridedArrayView1D` and its multi-dimensional variants are |
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equivalent to any :ref:`memoryview`, but additionally supporting |
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multi-dimensional slicing as well (which raises :ref:`NotImplementedError` |
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in Py3.7 :ref:`memoryview`). |
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.. py:class:: corrade.containers.MutableStridedArrayView1D |
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Equivalent to :ref:`StridedArrayView1D`, but implementing |
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:ref:`__setitem__()` as well. |
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.. py:class:: corrade.containers.StridedArrayView2D |
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See :ref:`StridedArrayView1D` for more information. |
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.. py:class:: corrade.containers.MutableStridedArrayView2D |
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See :ref:`StridedArrayView1D` and :ref:`MutableStridedArrayView1D` for more |
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information. |
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.. py:class:: corrade.containers.StridedArrayView3D |
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See :ref:`StridedArrayView1D` for more information. |
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.. py:class:: corrade.containers.MutableStridedArrayView3D |
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See :ref:`StridedArrayView1D` and :ref:`MutableStridedArrayView1D` for more |
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information.
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