From: Junio C Hamano <gitster@pobox.com>
To: "brian m. carlson" <sandals@crustytoothpaste.net>
Cc: <git@vger.kernel.org>, Jonathan Tan <jonathantanmy@google.com>
Subject: Re: [PATCH 27/44] builtin/show-index: provide options to determine hash algo
Date: Mon, 18 May 2020 09:20:22 -0700 [thread overview]
Message-ID: <xmqqimgt5i61.fsf@gitster.c.googlers.com> (raw)
In-Reply-To: <20200513005424.81369-28-sandals@crustytoothpaste.net> (brian m. carlson's message of "Wed, 13 May 2020 00:54:07 +0000")
"brian m. carlson" <sandals@crustytoothpaste.net> writes:
> It's possible to use a variety of index formats with show-index, and we
> need a way to indicate the hash algorithm which is in use for a
> particular index we'd like to show. Default to using the value for the
> repository we're in by calling setup_git_directory_gently, and allow
> overriding it by using a --hash argument.
I think you meant to say that "show-index" does not autodetect what
hash algorithm is used from its input, and the new argument is a way
for the user to help the command when the hash algorithm is
different from what is used in the current repository?
I ask because I found that your version can be read to say that
"show-index" can show the contents of a given pack index using any
hash algorithm we support, and the user can specify --hash=SHA-256
when running the command on a pack .idx that uses SHA-1 object names
to auto-convert it, and readers wouldn't be able to guess which was
meant with only the above five lines.
> Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
> ---
> builtin/show-index.c | 29 ++++++++++++++++++++++++-----
> git.c | 2 +-
> 2 files changed, 25 insertions(+), 6 deletions(-)
>
> diff --git a/builtin/show-index.c b/builtin/show-index.c
> index 0826f6a5a2..ebfa2e9abd 100644
> --- a/builtin/show-index.c
> +++ b/builtin/show-index.c
> @@ -1,9 +1,12 @@
> #include "builtin.h"
> #include "cache.h"
> #include "pack.h"
> +#include "parse-options.h"
>
> -static const char show_index_usage[] =
> -"git show-index";
> +static const char *const show_index_usage[] = {
> + "git show-index [--hash=HASH]",
> + NULL
> +};
Do we say --hash=SHA-1 etc. or --hash-algo=SHA-256 in other places?
Would the word "hash" alone clear enough that it does not refer to
a specific "hash" value but the name of an algorithm?
The generating side seems to use "index-pack --object-format=<algo>"
and the transport seems to use a capability "object-format=<algo>",
neither of which is directly visible to the end users, but I think
they follow "git init --object-format=<algo>", so we are consistent
there.
Perhaps we should follow suit here, too?
> int cmd_show_index(int argc, const char **argv, const char *prefix)
> {
> @@ -11,10 +14,26 @@ int cmd_show_index(int argc, const char **argv, const char *prefix)
> unsigned nr;
> unsigned int version;
> static unsigned int top_index[256];
> - const unsigned hashsz = the_hash_algo->rawsz;
> + unsigned hashsz;
> + const char *hash_name = NULL;
> + int hash_algo;
> + const struct option show_index_options[] = {
> + OPT_STRING(0, "hash", &hash_name, N_("hash"),
> + N_("specify the hash algorithm to use")),
init-db has an entry identical to this except for the second token
given to the macro is "object-format" instead of "hash". Both may
want to change what's inside N_() to "hash algorithm".
> + OPT_END()
> + };
> +
> + argc = parse_options(argc, argv, prefix, show_index_options, show_index_usage, 0);
> +
> + if (hash_name) {
> + hash_algo = hash_algo_by_name(hash_name);
> + if (hash_algo == GIT_HASH_UNKNOWN)
> + die(_("Unknown hash algorithm"));
> + repo_set_hash_algo(the_repository, hash_algo);
> + }
> +
> + hashsz = the_hash_algo->rawsz;
>
> - if (argc != 1)
> - usage(show_index_usage);
> if (fread(top_index, 2 * 4, 1, stdin) != 1)
> die("unable to read header");
> if (top_index[0] == htonl(PACK_IDX_SIGNATURE)) {
> diff --git a/git.c b/git.c
> index 2e4efb4ff0..e53e8159a2 100644
> --- a/git.c
> +++ b/git.c
> @@ -573,7 +573,7 @@ static struct cmd_struct commands[] = {
> { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
> { "show", cmd_show, RUN_SETUP },
> { "show-branch", cmd_show_branch, RUN_SETUP },
> - { "show-index", cmd_show_index },
> + { "show-index", cmd_show_index, RUN_SETUP_GENTLY },
Hmph, this is not necessary to support peeking an .idx file in
another repository that uses a different hash algorithm than ours
(we do need the --hash=<algo> override to tell that the algo is
different from what we read from our repository settings). Is this
absolutely necessary?
Ah, I am misreading the patch. We didn't even do setup but we now
optionally do, in order to see if we are in a repository and what
object format it uses to give the default value to --hash=<algo>
when the argument is not given. The need for RUN_SETUP_GENTLY
is understandable.
As we do not take any path argument on the command line, the other
side effect of setup_git_directory() that takes us up to the top
level of the working tree does not hurt us, either, so this is a
good change, I think.
Thanks.
> { "show-ref", cmd_show_ref, RUN_SETUP },
> { "sparse-checkout", cmd_sparse_checkout, RUN_SETUP | NEED_WORK_TREE },
> { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
next prev parent reply other threads:[~2020-05-18 16:20 UTC|newest]
Thread overview: 175+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-13 0:53 [PATCH 00/44] SHA-256 part 2/3: protocol functionality brian m. carlson
2020-05-13 0:53 ` [PATCH 01/44] t1050: match object ID paths in a hash-insensitive way brian m. carlson
2020-05-13 0:53 ` [PATCH 02/44] Documentation: document v1 protocol object-format capability brian m. carlson
2020-05-13 19:28 ` Martin Ågren
2020-05-14 1:12 ` Junio C Hamano
2020-05-15 23:22 ` brian m. carlson
2020-05-16 0:02 ` Junio C Hamano
2020-05-13 0:53 ` [PATCH 03/44] connect: have ref processing code take struct packet_reader brian m. carlson
2020-05-13 19:30 ` Martin Ågren
2020-05-13 0:53 ` [PATCH 04/44] wrapper: add function to compare strings with different NUL termination brian m. carlson
2020-05-13 19:32 ` Martin Ågren
2020-05-13 0:53 ` [PATCH 05/44] remote: advertise the object-format capability on the server side brian m. carlson
2020-05-13 0:53 ` [PATCH 06/44] connect: add function to parse multiple v1 capability values brian m. carlson
2020-05-13 0:53 ` [PATCH 07/44] connect: add function to fetch value of a v2 server capability brian m. carlson
2020-05-13 19:37 ` Martin Ågren
2020-05-13 0:53 ` [PATCH 08/44] pkt-line: add a member for hash algorithm brian m. carlson
2020-05-13 0:53 ` [PATCH 09/44] transport: add a hash algorithm member brian m. carlson
2020-05-13 0:53 ` [PATCH 10/44] connect: add function to detect supported v1 hash functions brian m. carlson
2020-05-13 19:39 ` Martin Ågren
2020-05-13 22:49 ` brian m. carlson
2020-05-13 0:53 ` [PATCH 11/44] send-pack: detect when the server doesn't support our hash brian m. carlson
2020-05-13 19:41 ` Martin Ågren
2020-05-13 22:52 ` brian m. carlson
2020-05-13 0:53 ` [PATCH 12/44] connect: make parse_feature_value extern brian m. carlson
2020-05-13 19:48 ` Martin Ågren
2020-05-13 0:53 ` [PATCH 13/44] fetch-pack: detect when the server doesn't support our hash brian m. carlson
2020-05-13 0:53 ` [PATCH 14/44] connect: detect algorithm when fetching refs brian m. carlson
2020-05-16 10:40 ` Martin Ågren
2020-05-16 19:59 ` brian m. carlson
2020-05-13 0:53 ` [PATCH 15/44] builtin/receive-pack: detect when the server doesn't support our hash brian m. carlson
2020-05-16 10:41 ` Martin Ågren
2020-05-13 0:53 ` [PATCH 16/44] docs: update remote helper docs for object-format extensions brian m. carlson
2020-05-13 0:53 ` [PATCH 17/44] transport-helper: implement " brian m. carlson
2020-05-13 0:53 ` [PATCH 18/44] remote-curl: " brian m. carlson
2020-05-13 0:53 ` [PATCH 19/44] builtin/clone: initialize hash algorithm properly brian m. carlson
2020-05-16 10:48 ` Martin Ågren
2020-05-13 0:54 ` [PATCH 20/44] t5562: pass object-format in synthesized test data brian m. carlson
2020-05-16 10:55 ` Martin Ågren
2020-05-16 19:50 ` brian m. carlson
2020-05-13 0:54 ` [PATCH 21/44] t5704: send object-format capability with SHA-256 brian m. carlson
2020-05-16 11:02 ` Martin Ågren
2020-05-16 19:14 ` brian m. carlson
2020-05-13 0:54 ` [PATCH 22/44] fetch-pack: parse and advertise the object-format capability brian m. carlson
2020-05-16 11:03 ` Martin Ågren
2020-05-13 0:54 ` [PATCH 23/44] setup: set the_repository's hash algo when checking format brian m. carlson
2020-05-16 11:03 ` Martin Ågren
2020-05-16 19:29 ` brian m. carlson
2020-05-13 0:54 ` [PATCH 24/44] t3200: mark assertion with SHA1 prerequisite brian m. carlson
2020-05-16 11:04 ` Martin Ågren
2020-05-13 0:54 ` [PATCH 25/44] packfile: compute and use the index CRC offset brian m. carlson
2020-05-16 11:12 ` Martin Ågren
2020-05-13 0:54 ` [PATCH 26/44] t5302: modernize test formatting brian m. carlson
2020-05-13 0:54 ` [PATCH 27/44] builtin/show-index: provide options to determine hash algo brian m. carlson
2020-05-18 16:20 ` Junio C Hamano [this message]
2020-05-19 0:31 ` brian m. carlson
2020-05-13 0:54 ` [PATCH 28/44] t1302: expect repo format version 1 for SHA-256 brian m. carlson
2020-05-13 0:54 ` [PATCH 29/44] Documentation/technical: document object-format for protocol v2 brian m. carlson
2020-05-13 0:54 ` [PATCH 30/44] connect: pass full packet reader when parsing v2 refs brian m. carlson
2020-05-16 11:13 ` Martin Ågren
2020-05-13 0:54 ` [PATCH 31/44] connect: parse v2 refs with correct hash algorithm brian m. carlson
2020-05-16 11:14 ` Martin Ågren
2020-05-17 22:37 ` brian m. carlson
2020-05-13 0:54 ` [PATCH 32/44] serve: advertise object-format capability for protocol v2 brian m. carlson
2020-05-16 11:15 ` Martin Ågren
2020-05-13 0:54 ` [PATCH 33/44] t5500: make hash independent brian m. carlson
2020-05-13 0:54 ` [PATCH 34/44] builtin/ls-remote: initialize repository based on fetch brian m. carlson
2020-05-16 11:16 ` Martin Ågren
2020-05-16 20:28 ` brian m. carlson
2020-05-13 0:54 ` [PATCH 35/44] remote-curl: detect algorithm for dumb HTTP by size brian m. carlson
2020-05-16 11:17 ` Martin Ågren
2020-05-13 0:54 ` [PATCH 36/44] builtin/index-pack: add option to specify hash algorithm brian m. carlson
2020-05-16 11:18 ` Martin Ågren
2020-05-16 20:47 ` brian m. carlson
2020-05-17 18:16 ` Martin Ågren
2020-05-17 20:52 ` brian m. carlson
2020-05-13 0:54 ` [PATCH 37/44] t1050: pass algorithm to index-pack when outside repo brian m. carlson
2020-05-13 0:54 ` [PATCH 38/44] remote-curl: avoid truncating refs with ls-remote brian m. carlson
2020-05-13 0:54 ` [PATCH 39/44] t/helper: initialize the repository for test-sha1-array brian m. carlson
2020-05-13 0:54 ` [PATCH 40/44] t5702: offer an object-format capability in the test brian m. carlson
2020-05-13 0:54 ` [PATCH 41/44] t5703: use object-format serve option brian m. carlson
2020-05-13 0:54 ` [PATCH 42/44] t5300: pass --object-format to git index-pack brian m. carlson
2020-05-13 0:54 ` [PATCH 43/44] bundle: detect hash algorithm when reading refs brian m. carlson
2020-05-13 0:54 ` [PATCH 44/44] remote-testgit: adapt for object-format brian m. carlson
2020-05-25 19:58 ` [PATCH v2 00/44] SHA-256 part 2/3: protocol functionality brian m. carlson
2020-05-25 19:58 ` [PATCH v2 01/44] t1050: match object ID paths in a hash-insensitive way brian m. carlson
2020-05-25 19:58 ` [PATCH v2 02/44] Documentation: document v1 protocol object-format capability brian m. carlson
2020-05-25 19:58 ` [PATCH v2 03/44] connect: have ref processing code take struct packet_reader brian m. carlson
2020-05-25 19:58 ` [PATCH v2 04/44] wrapper: add function to compare strings with different NUL termination brian m. carlson
2020-05-25 19:58 ` [PATCH v2 05/44] remote: advertise the object-format capability on the server side brian m. carlson
2020-05-25 19:58 ` [PATCH v2 06/44] connect: add function to parse multiple v1 capability values brian m. carlson
2020-05-25 19:58 ` [PATCH v2 07/44] connect: add function to fetch value of a v2 server capability brian m. carlson
2020-05-25 19:58 ` [PATCH v2 08/44] pkt-line: add a member for hash algorithm brian m. carlson
2020-05-25 19:58 ` [PATCH v2 09/44] transport: add a hash algorithm member brian m. carlson
2020-05-25 19:58 ` [PATCH v2 10/44] connect: add function to detect supported v1 hash functions brian m. carlson
2020-05-25 19:58 ` [PATCH v2 11/44] send-pack: detect when the server doesn't support our hash brian m. carlson
2020-05-25 19:58 ` [PATCH v2 12/44] connect: make parse_feature_value extern brian m. carlson
2020-05-25 19:58 ` [PATCH v2 13/44] fetch-pack: detect when the server doesn't support our hash brian m. carlson
2020-05-25 19:59 ` [PATCH v2 14/44] connect: detect algorithm when fetching refs brian m. carlson
2020-05-25 19:59 ` [PATCH v2 15/44] builtin/receive-pack: detect when the server doesn't support our hash brian m. carlson
2020-05-25 19:59 ` [PATCH v2 16/44] docs: update remote helper docs for object-format extensions brian m. carlson
2020-05-25 19:59 ` [PATCH v2 17/44] transport-helper: implement " brian m. carlson
2020-05-25 19:59 ` [PATCH v2 18/44] remote-curl: " brian m. carlson
2020-05-25 19:59 ` [PATCH v2 19/44] builtin/clone: initialize hash algorithm properly brian m. carlson
2020-05-25 19:59 ` [PATCH v2 20/44] t5562: pass object-format in synthesized test data brian m. carlson
2020-05-25 19:59 ` [PATCH v2 21/44] fetch-pack: parse and advertise the object-format capability brian m. carlson
2020-05-25 19:59 ` [PATCH v2 22/44] setup: set the_repository's hash algo when checking format brian m. carlson
2020-05-25 19:59 ` [PATCH v2 23/44] t3200: mark assertion with SHA1 prerequisite brian m. carlson
2020-05-25 19:59 ` [PATCH v2 24/44] packfile: compute and use the index CRC offset brian m. carlson
2020-05-25 19:59 ` [PATCH v2 25/44] t5302: modernize test formatting brian m. carlson
2020-05-25 19:59 ` [PATCH v2 26/44] builtin/show-index: provide options to determine hash algo brian m. carlson
2020-05-25 19:59 ` [PATCH v2 27/44] t1302: expect repo format version 1 for SHA-256 brian m. carlson
2020-05-25 19:59 ` [PATCH v2 28/44] Documentation/technical: document object-format for protocol v2 brian m. carlson
2020-05-25 19:59 ` [PATCH v2 29/44] connect: pass full packet reader when parsing v2 refs brian m. carlson
2020-05-25 19:59 ` [PATCH v2 30/44] connect: parse v2 refs with correct hash algorithm brian m. carlson
2020-05-25 19:59 ` [PATCH v2 31/44] serve: advertise object-format capability for protocol v2 brian m. carlson
2020-05-25 19:59 ` [PATCH v2 32/44] t5500: make hash independent brian m. carlson
2020-05-25 19:59 ` [PATCH v2 33/44] builtin/ls-remote: initialize repository based on fetch brian m. carlson
2020-05-25 19:59 ` [PATCH v2 34/44] remote-curl: detect algorithm for dumb HTTP by size brian m. carlson
2020-05-25 19:59 ` [PATCH v2 35/44] builtin/index-pack: add option to specify hash algorithm brian m. carlson
2020-05-25 19:59 ` [PATCH v2 36/44] t1050: pass algorithm to index-pack when outside repo brian m. carlson
2020-05-25 19:59 ` [PATCH v2 37/44] remote-curl: avoid truncating refs with ls-remote brian m. carlson
2020-05-25 19:59 ` [PATCH v2 38/44] t/helper: initialize the repository for test-sha1-array brian m. carlson
2020-05-25 19:59 ` [PATCH v2 39/44] t5702: offer an object-format capability in the test brian m. carlson
2020-05-25 19:59 ` [PATCH v2 40/44] t5703: use object-format serve option brian m. carlson
2020-05-25 19:59 ` [PATCH v2 41/44] t5704: send object-format capability with SHA-256 brian m. carlson
2020-05-25 19:59 ` [PATCH v2 42/44] t5300: pass --object-format to git index-pack brian m. carlson
2020-05-25 19:59 ` [PATCH v2 43/44] bundle: detect hash algorithm when reading refs brian m. carlson
2020-05-25 19:59 ` [PATCH v2 44/44] remote-testgit: adapt for object-format brian m. carlson
2020-06-19 17:55 ` [PATCH v3 00/44] SHA-256 part 2/3: protocol functionality brian m. carlson
2020-06-19 17:55 ` [PATCH v3 01/44] t1050: match object ID paths in a hash-insensitive way brian m. carlson
2020-06-19 17:55 ` [PATCH v3 02/44] Documentation: document v1 protocol object-format capability brian m. carlson
2020-06-19 17:55 ` [PATCH v3 03/44] connect: have ref processing code take struct packet_reader brian m. carlson
2020-06-19 17:55 ` [PATCH v3 04/44] wrapper: add function to compare strings with different NUL termination brian m. carlson
2020-06-19 17:55 ` [PATCH v3 05/44] remote: advertise the object-format capability on the server side brian m. carlson
2020-06-19 17:55 ` [PATCH v3 06/44] connect: add function to parse multiple v1 capability values brian m. carlson
2020-06-19 17:55 ` [PATCH v3 07/44] connect: add function to fetch value of a v2 server capability brian m. carlson
2020-06-19 17:55 ` [PATCH v3 08/44] pkt-line: add a member for hash algorithm brian m. carlson
2020-06-19 17:55 ` [PATCH v3 09/44] transport: add a hash algorithm member brian m. carlson
2020-06-19 17:55 ` [PATCH v3 10/44] connect: add function to detect supported v1 hash functions brian m. carlson
2020-06-19 17:55 ` [PATCH v3 11/44] send-pack: detect when the server doesn't support our hash brian m. carlson
2020-06-19 17:55 ` [PATCH v3 12/44] connect: make parse_feature_value extern brian m. carlson
2020-06-19 17:55 ` [PATCH v3 13/44] fetch-pack: detect when the server doesn't support our hash brian m. carlson
2020-06-19 17:55 ` [PATCH v3 14/44] connect: detect algorithm when fetching refs brian m. carlson
2020-06-19 17:55 ` [PATCH v3 15/44] builtin/receive-pack: detect when the server doesn't support our hash brian m. carlson
2020-06-19 17:55 ` [PATCH v3 16/44] docs: update remote helper docs for object-format extensions brian m. carlson
2020-06-19 17:55 ` [PATCH v3 17/44] transport-helper: implement " brian m. carlson
2020-06-19 17:55 ` [PATCH v3 18/44] remote-curl: " brian m. carlson
2020-06-19 17:55 ` [PATCH v3 19/44] builtin/clone: initialize hash algorithm properly brian m. carlson
2020-06-19 17:55 ` [PATCH v3 20/44] t5562: pass object-format in synthesized test data brian m. carlson
2020-06-19 17:55 ` [PATCH v3 21/44] fetch-pack: parse and advertise the object-format capability brian m. carlson
2020-06-19 17:55 ` [PATCH v3 22/44] setup: set the_repository's hash algo when checking format brian m. carlson
2020-06-19 17:55 ` [PATCH v3 23/44] t3200: mark assertion with SHA1 prerequisite brian m. carlson
2020-06-19 17:55 ` [PATCH v3 24/44] packfile: compute and use the index CRC offset brian m. carlson
2020-06-19 17:55 ` [PATCH v3 25/44] t5302: modernize test formatting brian m. carlson
2020-06-19 17:55 ` [PATCH v3 26/44] builtin/show-index: provide options to determine hash algo brian m. carlson
2020-06-19 17:55 ` [PATCH v3 27/44] t1302: expect repo format version 1 for SHA-256 brian m. carlson
2020-06-19 17:55 ` [PATCH v3 28/44] Documentation/technical: document object-format for protocol v2 brian m. carlson
2020-06-19 17:55 ` [PATCH v3 29/44] connect: pass full packet reader when parsing v2 refs brian m. carlson
2020-06-19 17:55 ` [PATCH v3 30/44] connect: parse v2 refs with correct hash algorithm brian m. carlson
2020-06-19 17:55 ` [PATCH v3 31/44] serve: advertise object-format capability for protocol v2 brian m. carlson
2020-06-19 17:55 ` [PATCH v3 32/44] t5500: make hash independent brian m. carlson
2020-06-19 17:55 ` [PATCH v3 33/44] builtin/ls-remote: initialize repository based on fetch brian m. carlson
2020-06-19 17:55 ` [PATCH v3 34/44] remote-curl: detect algorithm for dumb HTTP by size brian m. carlson
2020-06-19 17:55 ` [PATCH v3 35/44] builtin/index-pack: add option to specify hash algorithm brian m. carlson
2020-06-19 17:55 ` [PATCH v3 36/44] t1050: pass algorithm to index-pack when outside repo brian m. carlson
2020-06-19 17:55 ` [PATCH v3 37/44] remote-curl: avoid truncating refs with ls-remote brian m. carlson
2020-06-19 17:55 ` [PATCH v3 38/44] t/helper: initialize the repository for test-sha1-array brian m. carlson
2020-06-19 17:55 ` [PATCH v3 39/44] t5702: offer an object-format capability in the test brian m. carlson
2020-06-19 17:55 ` [PATCH v3 40/44] t5703: use object-format serve option brian m. carlson
2020-06-19 17:55 ` [PATCH v3 41/44] t5704: send object-format capability with SHA-256 brian m. carlson
2020-06-19 17:55 ` [PATCH v3 42/44] t5300: pass --object-format to git index-pack brian m. carlson
2020-06-19 17:56 ` [PATCH v3 43/44] bundle: detect hash algorithm when reading refs brian m. carlson
2020-06-19 17:56 ` [PATCH v3 44/44] remote-testgit: adapt for object-format brian m. carlson
2020-06-19 21:09 ` [PATCH v3 00/44] SHA-256 part 2/3: protocol functionality Junio C Hamano
2020-06-20 1:33 ` brian m. carlson
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