sha1: allow limiting the size of the data passed to SHA1_Update()

Using the previous commit's inredirection mechanism for SHA1,
support a chunked implementation of SHA1_Update() that limits the
amount of data in the chunk passed to SHA1_Update().

This is enabled by using the Makefile variable SHA1_MAX_BLOCK_SIZE
to specify chunk size.  When using Apple's CommonCrypto library this
is set to 1GiB (the implementation cannot handle more 4GiB).

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

1 files changed, 2 insertions, 0 deletions

diff --git a/compat/sha1-chunked.h b/compat/sha1-chunked.h
new file mode 100644
index 0000000..7b2df28
--- /dev/null
+++ b/compat/sha1-chunked.h
@@ -0,0 +1,2 @@
+
+int git_SHA1_Update_Chunked(platform_SHA_CTX *c, const void *data, size_t len);