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| author | Junio C Hamano <gitster@pobox.com> | 2011-11-17 16:26:54 -0800 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2011-11-30 14:27:59 -0800 |
| commit | 6c526148644475acbc047faaeb57d42fde1f667d (patch) | |
| tree | 1bf8400d2f5dff6ea15775b8b8af47af2e740617 /csum-file.h | |
| parent | 0e990530ae6d6c6805d31c666953541f762dd402 (diff) | |
| download | git-6c526148644475acbc047faaeb57d42fde1f667d.tar.gz | |
csum-file: introduce sha1file_checkpoint
It is useful to be able to rewind a check-summed file to a certain
previous state after writing data into it using sha1write() API. The
fast-import command does this after streaming a blob data to the packfile
being generated and then noticing that the same blob has already been
written, and it does this with a private code truncate_pack() that is
commented as "Yes, this is a layering violation".
Introduce two API functions, sha1file_checkpoint(), that allows the caller
to save a state of a sha1file, and then later revert it to the saved state.
Use it to reimplement truncate_pack().
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'csum-file.h')
| -rw-r--r-- | csum-file.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/csum-file.h b/csum-file.h index 6a7967c6bf..3b540bdc21 100644 --- a/csum-file.h +++ b/csum-file.h @@ -17,6 +17,15 @@ struct sha1file { unsigned char buffer[8192]; }; +/* Checkpoint */ +struct sha1file_checkpoint { + off_t offset; + git_SHA_CTX ctx; +}; + +extern void sha1file_checkpoint(struct sha1file *, struct sha1file_checkpoint *); +extern int sha1file_truncate(struct sha1file *, struct sha1file_checkpoint *); + /* sha1close flags */ #define CSUM_CLOSE 1 #define CSUM_FSYNC 2 |