git/block-sha1 at 7744a5d6921c457a05224cd7f5554e972df634b0 - git

Tree: 7744a5d692

Atousa Pahlevan Duprat 3bc72fde3f sha1: provide another level of indirection for the SHA-1 functions The git source uses git_SHA1_Update() and friends to call into the code that computes the hashes. Traditionally, we used to map these directly to underlying implementation of the SHA-1 hash (e.g. SHA1_Update() from OpenSSL or blk_SHA1_Update() from block-sha1/). This arrangement however makes it hard to tweak behaviour of the underlying implementation without fully replacing. If we want to introduce a tweaked_SHA1_Update() wrapper to implement the "Update" in a slightly different way, for example, the implementation of the wrapper still would want to call into the underlying implementation, but tweaked_SHA1_Update() cannot call git_SHA1_Update() to get to the underlying implementation (often but not always SHA1_Update()). Add another level of indirection that maps platform_SHA1_Update() and friends to their underlying implementations, and by default make git_SHA1_Update() and friends map to platform_SHA1_* functions. Doing it this way will later allow us to map git_SHA1_Update() to tweaked_SHA1_Update(), and the latter can use platform_SHA1_Update() in its implementation. Signed-off-by: Atousa Pahlevan Duprat <apahlevan@ieee.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	9 years ago
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sha1.c	…
sha1.h	sha1: provide another level of indirection for the SHA-1 functions	9 years ago

Atousa Pahlevan Duprat 3bc72fde3f sha1: provide another level of indirection for the SHA-1 functions

The git source uses git_SHA1_Update() and friends to call into the
code that computes the hashes.  Traditionally, we used to map these
directly to underlying implementation of the SHA-1 hash (e.g.
SHA1_Update() from OpenSSL or blk_SHA1_Update() from block-sha1/).

This arrangement however makes it hard to tweak behaviour of the
underlying implementation without fully replacing.  If we want to
introduce a tweaked_SHA1_Update() wrapper to implement the "Update"
in a slightly different way, for example, the implementation of the
wrapper still would want to call into the underlying implementation,
but tweaked_SHA1_Update() cannot call git_SHA1_Update() to get to
the underlying implementation (often but not always SHA1_Update()).

Add another level of indirection that maps platform_SHA1_Update()
and friends to their underlying implementations, and by default make
git_SHA1_Update() and friends map to platform_SHA1_* functions.

Doing it this way will later allow us to map git_SHA1_Update() to
tweaked_SHA1_Update(), and the latter can use platform_SHA1_Update()
in its implementation.

Signed-off-by: Atousa Pahlevan Duprat <apahlevan@ieee.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

9 years ago

sha1.c

…

sha1.h

sha1: provide another level of indirection for the SHA-1 functions

9 years ago