From: Jeff King <firstname.lastname@example.org> To: Taylor Blau <email@example.com> Cc: firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com Subject: Re: [PATCH v3 4/4] upload-pack.c: introduce 'uploadpackfilter.tree.maxDepth' Date: Fri, 31 Jul 2020 17:36:04 -0400 [thread overview] Message-ID: <20200731213604.GA1457058@coredump.intra.peff.net> (raw) In-Reply-To: <20200731212905.GE3409@syl.lan> On Fri, Jul 31, 2020 at 05:29:05PM -0400, Taylor Blau wrote: > > > @@ -1029,6 +1040,11 @@ static void die_if_using_banned_filter(struct upload_pack_data *data) > > > > > > strbuf_addf(&buf, "git upload-pack: filter '%s' not supported", > > > list_object_filter_config_name(banned->choice)); > > > + if (banned->choice == LOFC_TREE_DEPTH && > > > + data->tree_filter_max_depth != ULONG_MAX) > > > + strbuf_addf(&buf, _(" (maximum depth: %lu, but got: %lu)"), > > > + data->tree_filter_max_depth, > > > + banned->tree_exclude_depth); > > > > Hmm. So I see now why you wanted to go with the strbuf in the earlier > > patch. This does still feel awkward, though. You check "is it allowed" > > in an earlier function, we get "nope, it's not allowed", and now we have > > to reimplement the check here. That seems like a maintenance burden. > > I'm not sure that I follow. Is the earlier function that you're > referring to 'banned_filter'? If so, the only use of that function is > within 'die_if_using_banned_filter'. 'banned_filter' exists only insofar > as to answer the question "return me the first banned filter, if one > exists, or NULL otherwise". > > Then, dying here is as simple as (1) lookup the banned filter, and (2) > check if it's NULL or not. > > If you're referring to 'allows_filter_choice', I guess I see what you're > getting it, but to be honest I'm not sure if I'm buying it. Yeah, it's allows_filter_choice() that knows "if it's a tree we must check the depth". And now die_if_using_banned_filter() needs to know that, too. The policy is implemented twice. I do appreciate that the way you've written it means that if somebody forgets to update die_if_using_banned_filter() to match the logic in allows_filter_choice(), we'd at least still die, just with a less good error message. But it seems better still not to require the two to match in the first place. > If we were > to combine 'allows_filter_choice', 'banned_filter', and > 'die_if_using_banned_filter' into one function that traversed the filter > tree and 'die()'d as soon as it got to a banned one, that function would > have to know how to: > > 1. Recurse through the tree when it hits a LOFC_COMBINE node. > > 2. At each node, translate the filter->choice into the appropriate key > name, look it up, and then figure out how to interpret its allowed > status (including falling back to the default if unspecified). > > 3. And, it would have to figure out how to format the message at each > step. > > (3) I think is made easier, since we know what message to format based > on whether or not we're in the 'opts->choice == LOFC_TREE_DEPTH' arm or > not. But, there are two more things that we now have to cram into that > same function. You can still split those things into functions; see the patch I posted. > Maybe I'm being too strict an adherent to having simpler functions, but > I'm failing to see how to combine these in a way that's cleaner than > what's written here. To me this is less about "clean" and more about "don't ever duplicate policy code". I don't mind duplicating boilerplate, but introducing a place where somebody touching function X must remember to also touch Y (and gets no compiler support to remind them) is a bad thing. I guess you can call that "clean", but I'd take longer or more functions as a tradeoff to avoid that. My suggested patch does introduce more side effects. I think that's OK because there really is only a single caller here. But if you wanted it cleaner, then I think having allows_filter_choice() fill out an error strbuf would eliminate my concern without drastically altering the flow of your code. -Peff
next prev parent reply other threads:[~2020-07-31 21:36 UTC|newest] Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-07-23 1:48 [PATCH v2 0/4] upload-pack: custom allowed object filters Taylor Blau 2020-07-23 1:48 ` [PATCH v2 1/4] list_objects_filter_options: introduce 'list_object_filter_config_name' Taylor Blau 2020-07-23 1:49 ` [PATCH v2 2/4] upload-pack.c: allow banning certain object filter(s) Taylor Blau 2020-07-23 1:49 ` [PATCH v2 3/4] upload-pack.c: pass 'struct list_objects_filter_options *' Taylor Blau 2020-07-23 1:49 ` [PATCH v2 4/4] upload-pack.c: introduce 'uploadpackfilter.tree.maxDepth' Taylor Blau 2020-07-23 20:43 ` [PATCH v2 0/4] upload-pack: custom allowed object filters SZEDER Gábor 2020-07-24 16:51 ` Taylor Blau 2020-07-24 19:51 ` Jeff King 2020-07-27 14:25 ` Taylor Blau 2020-07-27 19:34 ` SZEDER Gábor 2020-07-27 19:36 ` Taylor Blau 2020-07-27 19:42 ` Jeff King 2020-07-27 19:59 ` SZEDER Gábor 2020-07-27 20:03 ` Taylor Blau 2020-07-31 20:26 ` [PATCH v3 " Taylor Blau 2020-07-31 20:26 ` [PATCH v3 1/4] list_objects_filter_options: introduce 'list_object_filter_config_name' Taylor Blau 2020-07-31 20:26 ` [PATCH v3 2/4] upload-pack.c: allow banning certain object filter(s) Taylor Blau 2020-07-31 20:54 ` Jeff King 2020-07-31 21:20 ` Taylor Blau 2020-07-31 20:26 ` [PATCH v3 3/4] upload-pack.c: pass 'struct list_objects_filter_options *' Taylor Blau 2020-07-31 20:26 ` [PATCH v3 4/4] upload-pack.c: introduce 'uploadpackfilter.tree.maxDepth' Taylor Blau 2020-07-31 21:01 ` Jeff King 2020-07-31 21:22 ` Jeff King 2020-07-31 21:30 ` Taylor Blau 2020-07-31 21:29 ` Taylor Blau 2020-07-31 21:36 ` Jeff King [this message] 2020-07-31 21:43 ` Jeff King 2020-08-03 18:00 ` [PATCH v4 0/3] upload-pack: custom allowed object filters Taylor Blau 2020-08-03 18:00 ` [PATCH v4 2/3] upload-pack.c: allow banning certain object filter(s) Taylor Blau 2020-08-03 18:00 ` [PATCH v4 1/3] list_objects_filter_options: introduce 'list_object_filter_config_name' Taylor Blau 2020-08-03 18:00 ` [PATCH v4 3/3] upload-pack.c: introduce 'uploadpackfilter.tree.maxDepth' Taylor Blau 2020-08-04 0:37 ` [PATCH v4 0/3] upload-pack: custom allowed object filters Jeff King
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style List information: http://vger.kernel.org/majordomo-info.html * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20200731213604.GA1457058@coredump.intra.peff.net \ --firstname.lastname@example.org \ --email@example.com \ --firstname.lastname@example.org \ --email@example.com \ --firstname.lastname@example.org \ --email@example.com \ --subject='Re: [PATCH v3 4/4] upload-pack.c: introduce '\''uploadpackfilter.tree.maxDepth'\''' \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
Code repositories for project(s) associated with this inbox: https://80x24.org/mirrors/git.git This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).