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From: Junio C Hamano <gitster@pobox.com>
To: "brian m. carlson" <sandals@crustytoothpaste.net>
Cc: <git@vger.kernel.org>,  Patrick Steinhardt <ps@pks.im>
Subject: Re: [PATCH v2 1/9] docs: update pack index v3 format
Date: Fri, 03 Oct 2025 10:00:52 -0700	[thread overview]
Message-ID: <xmqq7bxbvs1n.fsf@gitster.g> (raw)
In-Reply-To: <20251002223855.1022847-2-sandals@crustytoothpaste.net> (brian m. carlson's message of "Thu, 2 Oct 2025 22:38:47 +0000")

"brian m. carlson" <sandals@crustytoothpaste.net> writes:

> diff --git a/Documentation/technical/hash-function-transition.adoc b/Documentation/technical/hash-function-transition.adoc
> index f047fd80ca..274dc993d4 100644
> --- a/Documentation/technical/hash-function-transition.adoc
> +++ b/Documentation/technical/hash-function-transition.adoc
> @@ -227,9 +227,9 @@ network byte order):
>      ** 4-byte length in bytes of shortened object names. This is the
>        shortest possible length needed to make names in the shortened
>        object name table unambiguous.
> -    ** 4-byte integer, recording where tables relating to this format
> +    ** 8-byte integer, recording where tables relating to this format
>        are stored in this index file, as an offset from the beginning.
> -  * 4-byte offset to the trailer from the beginning of this file.
> +  * 8-byte offset to the trailer from the beginning of this file.
>    * Zero or more additional key/value pairs (4-byte key, 4-byte
>      value). Only one key is supported: 'PSRC'. See the "Loose objects
>      and unreachable objects" section for supported values and how this
> @@ -276,10 +276,14 @@ network byte order):
>    up to and not including the table of CRC32 values.
>  - Zero or more NUL bytes.
>  - The trailer consists of the following:
> -  * A copy of the 20-byte SHA-256 checksum at the end of the
> +  * A copy of the full main hash checksum at the end of the
>      corresponding packfile.
> -  * 20-byte SHA-256 checksum of all of the above.
> +  * Full main hash checksum of all of the above.
> +
> +The "full main hash" is a full-length hash of the main (not compatibility)
> +algorithm in the repository.  Thus, if the main algorithm is SHA-256, this is
> +a 32-byte SHA-256 hash and for SHA-1, it's a 20-byte SHA-1 hash.

I see a nice improvement over v1 here.  Very good.

  reply	other threads:[~2025-10-03 17:00 UTC|newest]

Thread overview: 67+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-09-19  1:09 [PATCH 0/9] SHA-1/SHA-256 interoperability, part 1 brian m. carlson
2025-09-19  1:09 ` [PATCH 1/9] docs: update pack index v3 format brian m. carlson
2025-09-19 22:08   ` Junio C Hamano
2025-09-20 15:23     ` brian m. carlson
2025-09-20 17:01       ` Junio C Hamano
2025-09-24  7:55   ` Patrick Steinhardt
2025-09-25 21:39     ` brian m. carlson
2025-09-19  1:09 ` [PATCH 2/9] docs: update offset order for pack index v3 brian m. carlson
2025-09-19  1:09 ` [PATCH 3/9] docs: reflect actual double signature for tags brian m. carlson
2025-09-19 22:34   ` Junio C Hamano
2025-09-20 15:29     ` brian m. carlson
2025-09-20 17:04       ` Junio C Hamano
2025-09-24  7:55       ` Patrick Steinhardt
2025-09-25 21:46         ` brian m. carlson
2025-09-19  1:09 ` [PATCH 4/9] docs: improve ambiguous areas of pack format documentation brian m. carlson
2025-09-19 23:04   ` Junio C Hamano
2025-09-19  1:09 ` [PATCH 5/9] docs: add documentation for loose objects brian m. carlson
2025-09-19 19:10   ` Junio C Hamano
2025-09-19 19:13     ` Junio C Hamano
2025-09-19 19:15       ` brian m. carlson
2025-09-19 20:18       ` Junio C Hamano
2025-09-24  7:55       ` Patrick Steinhardt
2025-09-25 21:40         ` brian m. carlson
2025-09-19 23:16   ` Junio C Hamano
2025-09-24  7:55   ` Patrick Steinhardt
2025-09-30 16:39     ` brian m. carlson
2025-09-19  1:09 ` [PATCH 6/9] rev-parse: allow printing compatibility hash brian m. carlson
2025-09-19 23:24   ` Junio C Hamano
2025-09-24  7:55   ` Patrick Steinhardt
2025-09-25 21:48     ` brian m. carlson
2025-09-19  1:09 ` [PATCH 7/9] fsck: consider gpgsig headers expected in tags brian m. carlson
2025-09-19 23:31   ` Junio C Hamano
2025-09-22 21:38     ` brian m. carlson
2025-09-19  1:09 ` [PATCH 8/9] Allow specifying compatibility hash brian m. carlson
2025-09-24  7:56   ` Patrick Steinhardt
2025-09-30 16:44     ` brian m. carlson
2025-09-19  1:09 ` [PATCH 9/9] t: add a prerequisite for a " brian m. carlson
2025-09-24  7:56   ` Patrick Steinhardt
2025-10-02 22:38 ` [PATCH v2 0/9] SHA-1/SHA-256 interoperability, part 1 brian m. carlson
2025-10-02 22:38   ` [PATCH v2 1/9] docs: update pack index v3 format brian m. carlson
2025-10-03 17:00     ` Junio C Hamano [this message]
2025-10-02 22:38   ` [PATCH v2 2/9] docs: update offset order for pack index v3 brian m. carlson
2025-10-02 22:38   ` [PATCH v2 3/9] docs: reflect actual double signature for tags brian m. carlson
2025-10-02 22:38   ` [PATCH v2 4/9] docs: improve ambiguous areas of pack format documentation brian m. carlson
2025-10-03 17:07     ` Junio C Hamano
2025-10-03 21:06       ` brian m. carlson
2025-10-02 22:38   ` [PATCH v2 5/9] docs: add documentation for loose objects brian m. carlson
2025-10-03 17:05     ` Junio C Hamano
2025-10-02 22:38   ` [PATCH v2 6/9] rev-parse: allow printing compatibility hash brian m. carlson
2025-10-02 22:38   ` [PATCH v2 7/9] fsck: consider gpgsig headers expected in tags brian m. carlson
2025-10-02 22:38   ` [PATCH v2 8/9] t: allow specifying compatibility hash brian m. carlson
2025-10-03 17:14     ` Junio C Hamano
2025-10-03 20:45       ` brian m. carlson
2025-10-02 22:38   ` [PATCH v2 9/9] t1010: use BROKEN_OBJECTS prerequisite brian m. carlson
2025-10-09 21:56 ` [PATCH v3 0/9] SHA-1/SHA-256 interoperability, part 1 brian m. carlson
2025-10-09 21:56   ` [PATCH v3 1/9] docs: update pack index v3 format brian m. carlson
2025-10-09 21:56   ` [PATCH v3 2/9] docs: update offset order for pack index v3 brian m. carlson
2025-10-09 21:56   ` [PATCH v3 3/9] docs: reflect actual double signature for tags brian m. carlson
2025-10-09 21:56   ` [PATCH v3 4/9] docs: improve ambiguous areas of pack format documentation brian m. carlson
2025-10-09 21:56   ` [PATCH v3 5/9] docs: add documentation for loose objects brian m. carlson
2025-10-09 21:56   ` [PATCH v3 6/9] rev-parse: allow printing compatibility hash brian m. carlson
2025-10-09 21:56   ` [PATCH v3 7/9] fsck: consider gpgsig headers expected in tags brian m. carlson
2025-10-09 21:56   ` [PATCH v3 8/9] t: allow specifying compatibility hash brian m. carlson
2025-10-09 21:56   ` [PATCH v3 9/9] t1010: use BROKEN_OBJECTS prerequisite brian m. carlson
2025-10-13 15:24   ` [PATCH v3 0/9] SHA-1/SHA-256 interoperability, part 1 Junio C Hamano
2025-10-13 16:34     ` brian m. carlson
2025-10-14  5:53       ` Patrick Steinhardt

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