git/reachable.c, branch v2.7.4

Merge branch 'jk/path-name-safety-2.5' into jk/path-name-safety-2.6

2016-03-16T17:42:02Z

* jk/path-name-safety-2.5: list-objects: pass full pathname to callbacks list-objects: drop name_path entirely list-objects: convert name_path to a strbuf show_object_with_name: simplify by using path_name() http-push: stop using name_path tree-diff: catch integer overflow in combine_diff_path allocation add helpers for detecting size_t overflow

Merge branch 'jk/path-name-safety-2.4' into jk/path-name-safety-2.5

2016-03-16T17:41:43Z

* jk/path-name-safety-2.4: list-objects: pass full pathname to callbacks list-objects: drop name_path entirely list-objects: convert name_path to a strbuf show_object_with_name: simplify by using path_name() http-push: stop using name_path tree-diff: catch integer overflow in combine_diff_path allocation add helpers for detecting size_t overflow

list-objects: pass full pathname to callbacks

2016-03-16T17:41:04Z

When we find a blob at "a/b/c", we currently pass this to our show_object_fn callbacks as two components: "a/b/" and "c". Callbacks which want the full value then call path_name(), which concatenates the two. But this is an inefficient interface; the path is a strbuf, and we could simply append "c" to it temporarily, then roll back the length, without creating a new copy. So we could improve this by teaching the callsites of path_name() this trick (and there are only 3). But we can also notice that no callback actually cares about the broken-down representation, and simply pass each callback the full path "a/b/c" as a string. The callback code becomes even simpler, then, as we do not have to worry about freeing an allocated buffer, nor rolling back our modification to the strbuf. This is theoretically less efficient, as some callbacks would not bother to format the final path component. But in practice this is not measurable. Since we use the same strbuf over and over, our work to grow it is amortized, and we really only pay to memcpy a few bytes. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

list-objects: drop name_path entirely

2016-03-16T17:41:03Z

In the previous commit, we left name_path as a thin wrapper around a strbuf. This patch drops it entirely. As a result, every show_object_fn callback needs to be adjusted. However, none of their code needs to be changed at all, because the only use was to pass it to path_name(), which now handles the bare strbuf. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

Merge branch 'js/gc-with-stale-symref' into maint

2015-10-20T22:22:42Z

"git gc" used to barf when a symbolic ref has gone dangling (e.g. the branch that used to be your upstream's default when you cloned from it is now gone, and you did "fetch --prune"). * js/gc-with-stale-symref: pack-objects: do not get distracted by broken symrefs gc: demonstrate failure with stale remote HEAD

pack-objects: do not get distracted by broken symrefs

2015-10-08T19:42:06Z

It is quite possible for, say, a remote HEAD to become broken, e.g. when the default branch was renamed. We should still be able to pack our objects when such a thing happens; simply ignore broken symrefs (because they cannot matter for the packing process anyway). This fixes https://github.com/git-for-windows/git/issues/423 Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano

add_one_ref(): rewrite to take an object_id argument

2015-05-25T19:19:34Z

Signed-off-by: Michael Haggerty Signed-off-by: brian m. carlson Signed-off-by: Junio C Hamano

each_ref_fn: change to take an object_id parameter

2015-05-25T19:19:27Z

Change typedef each_ref_fn to take a "const struct object_id *oid" parameter instead of "const unsigned char *sha1". To aid this transition, implement an adapter that can be used to wrap old-style functions matching the old typedef, which is now called "each_ref_sha1_fn"), and make such functions callable via the new interface. This requires the old function and its cb_data to be wrapped in a "struct each_ref_fn_sha1_adapter", and that object to be used as the cb_data for an adapter function, each_ref_fn_adapter(). This is an enormous diff, but most of it consists of simple, mechanical changes to the sites that call any of the "for_each_ref" family of functions. Subsequent to this change, the call sites can be rewritten one by one to use the new interface. Signed-off-by: Michael Haggerty Signed-off-by: brian m. carlson Signed-off-by: Junio C Hamano

reachable: only mark local objects as recent

2015-04-20T20:09:27Z

When pruning and repacking a repository that has an alternate object store configured, we may traverse a large number of objects in the alternate. This serves no purpose, and may be expensive to do. A longer explanation is below. Commits d3038d2 and abcb865 taught prune and pack-objects (respectively) to treat "recent" objects as tips for reachability, so that we keep whole chunks of history. They built on the object traversal in 660c889 (sha1_file: add for_each iterators for loose and packed objects, 2014-10-15), which covers both local and alternate objects. In both cases, covering alternate objects is unnecessary, as both commands can only drop objects from the local repository. In the case of prune, we traverse only the local object directory. And in the case of repacking, while we may or may not include local objects in our pack, we will never reach into the alternate with "repack -d". The "-l" option is only a question of whether we are migrating objects from the alternate into our repository, or leaving them untouched. It is possible that we may drop an object that is depended upon by another object in the alternate. For example, imagine two repositories, A and B, with A pointing to B as an alternate. Now imagine a commit that is in B which references a tree that is only in A. Traversing from recent objects in B might prevent A from dropping that tree. But this case isn't worth covering. Repo B should take responsibility for its own objects. It would never have had the commit in the first place if it did not also have the tree, and assuming it is using the same "keep recent chunks of history" scheme, then it would itself keep the tree, as well. So checking the alternate objects is not worth doing, and come with a significant performance impact. In both cases, we skip any recent objects that have already been marked SEEN (i.e., that we know are already reachable for prune, or included in the pack for a repack). So there is a slight waste of time in opening the alternate packs at all, only to notice that we have already considered each object. But much worse, the alternate repository may have a large number of objects that are not reachable from the local repository at all, and we end up adding them to the traversal. We can fix this by considering only local unseen objects. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

reachable: use revision machinery's --indexed-objects code

2014-10-19T22:07:07Z

This does the same thing as our custom code, so let's not repeat ourselves. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano