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39 lines
1.0 KiB
39 lines
1.0 KiB
.. _module-pw_varint:
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---------
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pw_varint
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---------
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The ``pw_varint`` module provides functions for encoding and decoding variable
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length integers, or varints. For smaller values, varints require less memory
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than a fixed-size encoding. For example, a 32-bit (4-byte) integer requires 1--5
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bytes when varint-encoded.
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`Protocol Buffers <https://developers.google.com/protocol-buffers/docs/encoding#varints>`_
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use a variable-length encoding for integers.
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Compatibility
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=============
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* C
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* C++11 (with :doc:`../pw_polyfill/docs`)
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API
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===
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.. cpp:function:: size_t EncodedSize(uint64_t integer)
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Returns the size of an integer when encoded as a varint. Works on both signed
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and unsigned integers.
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.. cpp:function:: size_t ZigZagEncodedSize(int64_t integer)
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Returns the size of a signed integer when ZigZag encoded as a varint.
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.. cpp:function:: uint64_t MaxValueInBytes(size_t bytes)
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Returns the maximum integer value that can be encoded as a varint into the
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specified number of bytes.
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Dependencies
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============
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* ``pw_span``
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