Reference implementation
In the software development process, a reference implementation (or, less frequently, sample implementation or model implementation) is a program that implements all requirements from a corresponding specification. The reference implementation often accompanies a technical standard, and demonstrates what should be considered the "correct" behavior of any other implementation of it.
Characteristics and examples
[edit ]Reference implementations of algorithms, for instance cryptographic algorithms, are often the result or the input of standardization processes. In this function they are often dedicated to the public domain with their source code as public domain software. Examples are the first CERN's httpd,[1] Serpent cipher, base64 variants,[2] and SHA-3.[3] The Openwall Project maintains a list of several algorithms with their reference source code in the public domain.[4]
A reference implementation may or may not be production quality. For example, the Fraunhofer reference implementation of the MP3 standard usually does not compare favorably to other common implementations, such as LAME, in listening tests that determine sound quality.[5] In contrast, CPython, the reference implementation of the Python programming language,[6] is also the implementation most widely used in production.
Testing
[edit ]Testing the implementation-vs-specification relationship further enhances the production's inter-process efficiencies:
A reference implementation is, in general, an implementation of a specification to be used as a definitive interpretation for that specification. During the development of the ... conformance test suite, at least one relatively trusted implementation of each interface is necessary to (1) discover errors or ambiguities in the specification, and (2) validate the correct functioning of the test suite.[7]
Characteristics of a Reference Implementation:
- Developed concurrently with the specification and test suite;
- Verifies that specification is implementable;
- Enables the test suite to be tested;
- Serves as a Gold Standard against which other implementations can be measured;
- Helps to clarify the intent of the specification in situations where conformance tests are inadequate[8]
References
[edit ]- ^ Smith, Tim; Flückiger, François. "Licensing the Web: For everyone". CERN . Archived from the original on 2021年12月10日. Retrieved 2014年08月17日.
- ^ Devolve, Chris (2005年11月20日). "libb64: Base64 Encoding/Decoding Routines". SourceForge . Archived from the original on 2010年07月30日. Retrieved 2016年02月06日.
- ^ Bertoni, Guido; Daemen, Joan; Peeters, Michaël; Van Assche, Gilles (2013年02月27日). "KeccakReferenceAndOptimized-3.2.zip" (ZIP). keccak.noekeon.org. /KeccakReferenceAndOptimized/Sources/mainReference.c. Archived from the original (ZIP) on 2013年09月30日. Retrieved 2016年02月06日.
The Keccak sponge function, designed by: Bertoni, Guido; Daemen, Joan; Peeters, Michaël; Van Assche, Gilles. For more information, feedback or questions, please refer to our website: keccak.noekeon.org/ / Implementation by the designers, hereby denoted as "the implementer". / To the extent possible under law, the implementer has waived all copyright and related or neighboring rights to the source code in this file. creativecommons.org/publicdomain/zero/1.0/
- ^ solar (2009年11月05日). "Source code snippets and frameworks placed in the public domain". Openwall Community Wiki . Archived from the original on 2019年01月26日. Retrieved 2017年11月16日.
- ^ Daulton, Steve (2019年06月11日). "Media Info doesn't match Format Options selected for Exported MP3's - #6 by steve - Windows". Audacity Forum. Archived from the original on 2023年12月02日. Retrieved 2024年09月05日.
- ^ Snow, Eric (2012年04月26日). "PEP 421 – Adding sys.implementation". peps.python.org . Python Software Foundation (which owns "python.org"). Motivation. Archived from the original on 2022年04月11日. Retrieved 2017年01月06日.
For a number of years now, the distinction between Python-the-language and CPython (the reference implementation) has been growing. Most of this change is due to the emergence of Jython, IronPython, and PyPy as viable alternate implementations of Python.
- ^ Dalci, Eric; Fong, Elizabeth; Goldfine, Alan (2003年03月26日). "Requirements for GSC-IS Reference Implementations" (PDF). National Institute of Standards and Technology, Information Technology Laboratory . Archived from the original (PDF) on 2006年09月28日. Retrieved 2006年07月22日.
- ^ Curran, Patrick (2003年12月10日). "Conformance Testing: An Industry Perspective" (PDF). National Institute of Standards and Technology . Sun Microsystems. Archived from the original (PDF) on 2003年12月19日. Retrieved 2006年07月22日.