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Re: [PATCH 2/2] hex: drop sha1_to_hex()

From
Jeff King <peff@peff.net>
Date
Nov 12, 2019, 10:57 UTC
Message-ID
<20191112105759.GA9714@sigill.intra.peff.net>
In-Reply-To
<xmqqa791hgu1.fsf@gitster-ct.c.googlers.com>
On Tue, Nov 12, 2019 at 01:13:58PM +0900, Junio C Hamano wrote:
Show 8 quoted lines
> >> We can't use oid_to_hex() because we don't have a 'struct object_id'
> >> in the first place, as sha1dc only ever deals with 20 unsigned chars.
> >
> > Ah, you're right. I admit I am still getting up to speed on all of the
> > new hash-agnostic versions of the various functions.
> 
> Thanks.  I've amended this one and the range diff since the pushout
> yesterday looks like this.
Thanks. This first hunk is what I would have done:
Show 13 quoted lines
> 1:  8a030f1796 ! 1:  02d21d4117 hex: drop sha1_to_hex()
>     @@ Commit message
>          hex: drop sha1_to_hex()
>      
>          There's only a single caller left of sha1_to_hex(), since everybody now
>     -    uses oid_to_hex() instead. This case is in the sha1dc wrapper, where we
>     +    uses hash_to_hex() instead. This case is in the sha1dc wrapper, where we
>          print a hex sha1 when we find a collision. This one will always be sha1,
>     -    regardless of the current hash algorithm, so we can't use oid_to_hex()
>     +    regardless of the current hash algorithm, so we can't use hash_to_hex()
>          here. In practice we'd probably not be running sha1 at all if it isn't
>          the current algorithm, but it's possible we might still occasionally
>          need to compute a sha1 in a post-sha256 world.
This second one is OK, but not entirely necessary:
Show 9 quoted lines
>     @@ cache.h: int hex_to_bytes(unsigned char *binary, const char *hex, size_t len);
>        * buffers, making it safe to make multiple calls for a single statement, like:
>        *
>      - *   printf("%s -> %s", sha1_to_hex(one), sha1_to_hex(two));
>     -+ *   printf("%s -> %s", oid_to_hex(one), oid_to_hex(two));
>     ++ *   printf("%s -> %s", hash_to_hex(one), hash_to_hex(two));
>        */
>       char *hash_to_hex_algop_r(char *buffer, const unsigned char *hash, const struct git_hash_algo *);
>       char *oid_to_hex_r(char *out, const struct object_id *oid);

This one-liner leaves the types of "one" and "two" unspecified. :) So it's not wrong to use hash_to_hex(), but maybe it's better to be pushing people towards oid_to_hex() as their first choice? It probably doesn't matter too much either way.

-Peff
Previous: Junio C HamanoNext: SZEDER Gábor
Message 8 of 17 in “getting rid of sha1_to_hex()”
  1. 0/2 getting rid of sha1_to_hex()Jeff King, Nov 11, 2019
  2. 1/2 hex: drop sha1_to_hex_r()Jeff King, Nov 11, 2019
  3. Johannes SchindelinNov 11, 2019
  4. 2/2 hex: drop sha1_to_hex()Jeff King, Nov 11, 2019
  5. SZEDER GáborNov 11, 2019
  6. Jeff KingNov 11, 2019
  7. Junio C HamanoNov 12, 2019
  8. Jeff KingNov 12, 2019
  9. SZEDER GáborNov 12, 2019
  10. Jeff KingNov 12, 2019
  11. Junio C HamanoNov 12, 2019
  12. Jeff KingNov 12, 2019
  13. Junio C HamanoNov 13, 2019
  14. Jeff KingNov 13, 2019
  15. Junio C HamanoNov 11, 2019
  16. Jeff KingNov 11, 2019
  17. brian m. carlsonNov 11, 2019

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