On Tue, Jun 19, 2018 at 2:54 PM Derrick Stolee <stolee@xxxxxxxxx> wrote: > > On 6/12/2018 11:00 AM, Duy Nguyen wrote: > > On Thu, Jun 7, 2018 at 7:01 PM Derrick Stolee <stolee@xxxxxxxxx> wrote: > >> diff --git a/midx.c b/midx.c > >> index 616af66b13..3e55422a21 100644 > >> --- a/midx.c > >> +++ b/midx.c > >> @@ -1,9 +1,62 @@ > >> #include "git-compat-util.h" > >> #include "cache.h" > >> #include "dir.h" > >> +#include "csum-file.h" > >> +#include "lockfile.h" > >> #include "midx.h" > >> > >> +#define MIDX_SIGNATURE 0x4d494458 /* "MIDX" */ > >> +#define MIDX_VERSION 1 > >> +#define MIDX_HASH_VERSION 1 /* SHA-1 */ > > ... > >> +static size_t write_midx_header(struct hashfile *f, > >> + unsigned char num_chunks, > >> + uint32_t num_packs) > >> +{ > >> + char byte_values[4]; > >> + hashwrite_be32(f, MIDX_SIGNATURE); > >> + byte_values[0] = MIDX_VERSION; > >> + byte_values[1] = MIDX_HASH_VERSION; > > Quoting from "State of NewHash work, future directions, and discussion" [1] > > > > * If you need to serialize an algorithm identifier into your data > > format, use the format_id field of struct git_hash_algo. It's > > designed specifically for that purpose. > > > > [1] https://public-inbox.org/git/20180612024252.GA141166@xxxxxxxxxxxxxxxxxxxxxxxxx/T/#m5fdd09dcaf31266c45343fb6c0beaaa3e928bc60 > > Thanks! I'll also use the_hash_algo->rawsz to infer the length of the > hash function. BTW, since you're the author of commit-graph.c and may notice it has the same problem. Don't touch that code. Brian already has some WIP changes [1]. We just make sure new code does not add extra work for him. I expect he'll send all those patches out soon. [1] https://github.com/bk2204/git/commit/3f9031e06cfb21534eb7dfff7b54e7598ac1149f -- Duy