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>
They are both slower than the new BLK_SHA1 implementation, so it is
pointless to keep them around.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a 64-bit value, hence having it first provides a better
alignment.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
.. and simplify the ctx->size logic.
We now count the size in bytes, which means that 'lenW' was always just
the low 6 bits of the total size, so we don't carry it around separately
any more. And we do the 'size in bits' shift at the end.
Suggested by Nicolas Pitre and linux@horizon.com.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Based on the mozilla SHA1 routine, but doing the input data accesses a
word at a time and with 'htonl()' instead of loading bytes and shifting.
It requires an architecture that is ok with unaligned 32-bit loads and a
fast htonl().
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
