git/refs/ref-cache.c, branch v2.14.2

*.[ch] refactoring: make use of the FREE_AND_NULL() macro

2017-06-16T19:44:09Z

Replace occurrences of `free(ptr); ptr = NULL` which weren't caught by the coccinelle rule. These fall into two categories: - free/NULL assignments one after the other which coccinelle all put on one line, which is functionally equivalent code, but very ugly. - manually spotted occurrences where the NULL assignment isn't right after the free() call. Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano

cache_ref_iterator_begin(): avoid priming unneeded directories

2017-05-24T12:21:21Z

When iterating over references, reference priming is used to make sure that loose references are read into the ref-cache before packed references, to avoid races. It used to be that the prefix passed to reference iterators almost always ended in `/`, for example `refs/heads/`. In that case, the priming code would read all loose references under `find_containing_dir("refs/heads/")`, which is "refs/heads/". That's just what we want. But now that `ref-filter` knows how to pass refname prefixes to `for_each_fullref_in()`, the prefix might come from user input; for example, git for-each-ref refs/heads Since the argument doesn't include a trailing slash, the reference iteration code would prime all of the loose references under `find_containing_dir("refs/heads")`, which is "refs/". Thus we would unnecessarily read tags, remote-tracking references, etc., when the user is only interested in branches. It is a bit awkward to get around this problem. We can't just append a slash to the argument, because we don't know ab initio whether an argument like `refs/tags/release` corresponds to a single tag or to a directory containing tags. Moreover, until now a `prefix_ref_iterator` was used to make the final decision about which references fall within the prefix (the `cache_ref_iterator` only did a rough cut). This is also inefficient, because the `prefix_ref_iterator` can't know, for example, that while you are in a subdirectory that is completely within the prefix, you don't have to do the prefix check. So: * Move the responsibility for doing the prefix check directly to `cache_ref_iterator`. This means that `cache_ref_iterator_begin()` never has to wrap its return value in a `prefix_ref_iterator`. * Teach `cache_ref_iterator_begin()` (and `prime_ref_dir()`) to be stricter about what they iterate over and what directories they prime. * Teach `cache_ref_iterator` to keep track of whether the current `cache_ref_iterator_level` is fully within the prefix. If so, skip the prefix checks entirely. The main benefit of these optimizations is for loose references, since packed references are always read all at once. Note that after this change, `prefix_ref_iterator` is only ever used for its trimming feature and not for its "prefix" feature. But I'm not ripping out the latter yet, because it might be useful for another patch series that I'm working on. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

create_ref_entry(): remove `check_name` option

2017-05-23T05:29:56Z

Only one caller was using it, so move the check to that caller. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

refs/files-backend: convert many internals to struct object_id

2017-05-08T06:12:58Z

Convert many of the internals of the files backend to use struct object_id. Avoid converting public APIs (except one change to refs/ref-cache.c) to limit the scope of the changes. Convert one use of get_sha1_hex to parse_oid_hex, and rely on the fact that a strbuf will be NUL-terminated and that parse_oid_hex will fail on truncated input to avoid the need to check the length. This is a requirement to convert parse_object later on. Signed-off-by: brian m. carlson Signed-off-by: Junio C Hamano

do_for_each_entry_in_dir(): delete function

2017-04-17T04:32:46Z

Its only remaining caller was itself. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

cache_ref_iterator_begin(): make function smarter

2017-04-17T04:32:46Z

Change `cache_ref_iterator_begin()` to take two new arguments: * `prefix` -- to iterate only over references with the specified prefix. * `prime_dir` -- to "prime" (i.e., pre-load) the cache before starting the iteration. The new functionality makes it possible for `files_ref_iterator_begin()` to be made more ignorant of the internals of `ref_cache`, and `find_containing_dir()` and `prime_ref_dir()` to be made private. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

do_for_each_entry_in_dir(): eliminate `offset` argument

2017-04-17T04:32:46Z

It was never used. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

refs: handle "refs/bisect/" in `loose_fill_ref_dir()`

2017-04-17T04:32:46Z

That "refs/bisect/" has to be handled specially when filling the ref_cache for loose references is a peculiarity of the files backend, and the ref-cache code shouldn't need to know about it. So move this code to the callback function, `loose_fill_ref_dir()`. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

ref-cache: use a callback function to fill the cache

2017-04-17T04:32:46Z

It is a leveling violation for `ref_cache` to know about `files_ref_store` or that it should call `read_loose_refs()` to lazily fill cache directories. So instead, have its constructor take as an argument a callback function that it should use for lazy-filling, and change `files_ref_store` to supply a pointer to function `read_loose_refs` (renamed to `loose_fill_ref_dir`) when creating the ref cache for its loose refs. This means that we can generify the type of the back-pointer in `struct ref_cache` from `files_ref_store` to `ref_store`. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

refs: record the ref_store in ref_cache, not ref_dir

2017-04-17T04:32:46Z

Instead of keeping a pointer to the `ref_store` in every `ref_dir` entry, store it once in `struct ref_cache`, and change `struct ref_dir` to include a pointer to its containing `ref_cache` instead. This makes it easier to add to the information that is accessible from a `ref_dir` without increasing the size of every `ref_dir` instance. Note that previously, every `ref_dir` pointed at the containing `files_ref_store` regardless of whether it was a part of the loose or packed reference cache. Now we have to be sure to initialize the instances to point at the correct containing `ref_cache`. So change `create_dir_entry()` to take a `ref_cache` parameter, and change its callers to pass the correct `ref_cache` depending on the purpose of the new `dir_entry`. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano