git/refs/iterator.c, branch v2.40.2

git-compat-util.h: use "UNUSED", not "UNUSED(var)"

2022-09-01T17:49:48Z

As reported in [1] the "UNUSED(var)" macro introduced in 2174b8c75de (Merge branch 'jk/unused-annotation' into next, 2022-08-24) breaks coccinelle's parsing of our sources in files where it occurs. Let's instead partially go with the approach suggested in [2] of making this not take an argument. As noted in [1] "coccinelle" will ignore such tokens in argument lists that it doesn't know about, and it's less of a surprise to syntax highlighters. This undoes the "help us notice when a parameter marked as unused is actually use" part of 9b240347543 (git-compat-util: add UNUSED macro, 2022-08-19), a subsequent commit will further tweak the macro to implement a replacement for that functionality. 1. https://lore.kernel.org/git/220825.86ilmg4mil.gmgdl@evledraar.gmail.com/ 2. https://lore.kernel.org/git/220819.868rnk54ju.gmgdl@evledraar.gmail.com/ Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano

refs: mark unused virtual method parameters

2022-08-19T19:18:55Z

The refs code uses various polymorphic types (e.g., loose vs packed ref_stores, abstracted iterators). Not every virtual function or callback needs all of its parameters. Let's mark the unused ones to quiet -Wunused-parameter. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

refs: use designated initializers for "struct ref_iterator_vtable"

2022-03-17T17:36:11Z

Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano

use CALLOC_ARRAY

2021-03-14T00:00:09Z

Add and apply a semantic patch for converting code that open-codes CALLOC_ARRAY to use it instead. It shortens the code and infers the element size automatically. Signed-off-by: René Scharfe Signed-off-by: Junio C Hamano

refs.c: migrate internal ref iteration to pass thru repository argument

2018-08-21T17:22:50Z

In 60ce76d3581 (refs: add repository argument to for_each_replace_ref, 2018-04-11) and 0d296c57aec (refs: allow for_each_replace_ref to handle arbitrary repositories, 2018-04-11), for_each_replace_ref learned how to iterate over refs by a given arbitrary repository. New attempts in the object store conversion have shown that it is useful to have the repository handle available that the refs iteration is currently iterating over. To achieve this goal we will need to add a repository argument to each_ref_fn in refs.h. However as many callers rely on the signature such a patch would be too large. So convert the internals of the ref subsystem first to pass through a repository argument without exposing the change to the user. Assume the_repository for the passed through repository, although it is not used anywhere yet. Signed-off-by: Stefan Beller Signed-off-by: Derrick Stolee Signed-off-by: Junio C Hamano

Replace all die("BUG: ...") calls by BUG() ones

2018-05-06T10:06:13Z

In d8193743e08 (usage.c: add BUG() function, 2017-05-12), a new macro was introduced to use for reporting bugs instead of die(). It was then subsequently used to convert one single caller in 588a538ae55 (setup_git_env: convert die("BUG") to BUG(), 2017-05-12). The cover letter of the patch series containing this patch (cf 20170513032414.mfrwabt4hovujde2@sigill.intra.peff.net) is not terribly clear why only one call site was converted, or what the plan is for other, similar calls to die() to report bugs. Let's just convert all remaining ones in one fell swoop. This trick was performed by this invocation: sed -i 's/die("BUG: /BUG("/g' $(git grep -l 'die("BUG' \*.c) Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano

prefix_ref_iterator: break when we leave the prefix

2017-09-14T06:19:07Z

If the underlying iterator is ordered, then `prefix_ref_iterator` can stop as soon as it sees a refname that comes after the prefix. This will rarely make a big difference now, because `ref_cache_iterator` only iterates over the directory containing the prefix (and usually the prefix will span a whole directory anyway). But if *hint, hint* a future reference backend doesn't itself know where to stop the iteration, then this optimization will be a big win. Note that there is no guarantee that the underlying iterator doesn't include output preceding the prefix, so we have to skip over any unwanted references before we get to the ones that we want. Signed-off-by: Jeff King Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

ref_iterator: keep track of whether the iterator output is ordered

2017-09-14T06:19:07Z

References are iterated over in order by refname, but reflogs are not. Some consumers of reference iteration care about the difference. Teach each `ref_iterator` to keep track of whether its output is ordered. `overlay_ref_iterator` is one of the picky consumers. Add a sanity check in `overlay_ref_iterator_begin()` to verify that its inputs are ordered. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

prefix_ref_iterator: don't trim too much

2017-05-23T05:29:52Z

The `trim` parameter can be set independently of `prefix`. So if some caller were to set `trim` to be greater than `strlen(prefix)`, we could end up pointing the `refname` field of the iterator past the NUL of the actual reference name string. That can't happen currently, because `trim` is always set either to zero or to `strlen(prefix)`. But even the latter could lead to confusion, if a refname is exactly equal to the prefix, because then we would set the outgoing `refname` to the empty string. And we're about to decouple the `prefix` and `trim` arguments even more, so let's be cautious here. Report a bug if ever asked to trim a reference whose name is not longer than `trim`. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

do_for_each_ref(): reimplement using reference iteration

2016-06-20T18:38:20Z

Use the reference iterator interface to implement do_for_each_ref(). Delete a bunch of code supporting the old for_each_ref() implementation. And now that do_for_each_ref() is generic code (it is no longer tied to the files backend), move it to refs.c. The implementation is via a new function, do_for_each_ref_iterator(), which takes a reference iterator as argument and calls a callback function for each of the references in the iterator. This change requires the current_ref performance hack for peel_ref() to be implemented via ref_iterator_peel() rather than peel_entry() because we don't have a ref_entry handy (it is hidden under three layers: file_ref_iterator, merge_ref_iterator, and cache_ref_iterator). So: * do_for_each_ref_iterator() records the active iterator in current_ref_iter while it is running. * peel_ref() checks whether current_ref_iter is pointing at the requested reference. If so, it asks the iterator to peel the reference (which it can do efficiently via its "peel" virtual function). For extra safety, we do the optimization only if the refname *addresses* are the same, not only if the refname *strings* are the same, to forestall possible mixups between refnames that come from different ref_iterators. Please note that this optimization of peel_ref() is only available when iterating via do_for_each_ref_iterator() (including all of the for_each_ref() functions, which call it indirectly). It would be complicated to implement a similar optimization when iterating directly using a reference iterator, because multiple reference iterators can be in use at the same time, with interleaved calls to ref_iterator_advance(). (In fact we do exactly that in merge_ref_iterator.) But that is not necessary. peel_ref() is only called while iterating over references. Callers who iterate using the for_each_ref() functions benefit from the optimization described above. Callers who iterate using reference iterators directly have access to the ref_iterator, so they can call ref_iterator_peel() themselves to get an analogous optimization in a more straightforward manner. If we rewrite all callers to use the reference iteration API, then we can remove the current_ref_iter hack permanently. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano