Provide a macro that will allow us to run a function with posix-like
return values multiple times in a retry loop, with an optional cleanup
function called between invocations.
While we already provide functionality to look up a worktree from a
repository, we cannot do so the other way round. That is given a
repository, we want to look up its worktree if it actually exists.
Getting the worktree of a repository is useful when we want to get
certain meta information like the parent's location, getting the locked
status, etc.
The functions `git_commit_header_field` and
`git_commit_extract_signature` both receive buffers used to hand back
the results to the user. While these functions called `git_buf_sanitize`
on these buffers, this is not the right thing to do, as it will simply
initialize or zero-terminate passed buffers. As we want to overwrite
contents, we instead have to call `git_buf_clear` to completely reset
them.
Implement a new function that is able to determine if a branch is
checked out in any repository connected to the current
repository. In particular, this is required to check if for a
given repository and branch, there exists any working tree
connected to that repository that is referencing this branch.
Implement `git_repository_head_for_worktree` and
`git_repository_head_detached_for_worktree` for directly accessing a
worktree's HEAD without opening it as a `git_repository` first.
Implement the `git_worktree_prune` function. This function can be
used to delete working trees from a repository. According to the
flags passed to it, it can either delete the working tree's
gitdir only or both gitdir and the working directory.
Working trees support locking by creating a file `locked` inside
the tree's gitdir with an optional reason inside. Support this
feature by adding functions to get and set the locking status.
Add a new function that checks wether a given `struct
git_worktree` is valid. The validation includes checking if the
gitdir, parent directory and common directory are present.
Introduce a new `struct git_worktree`, which holds information
about a possible working tree connected to a repository.
Introduce functions to allow opening working trees for a
repository.
The commondir variable stores the path to the common directory.
The common directory is used to store objects and references
shared across multiple repositories. A current use case is the
newly introduced `git worktree` feature, which sets up a separate
working copy, where the backing git object store and references
are pointed to by the common directory.
Added `git_repository_submodule_cache_all` to initialze a cache of
submodules on the repository so that operations looking up N
submodules are O(N) and not O(N^2). Added a
`git_repository_submodule_cache_clear` function to remove the cache.
Also optimized the function that loads all submodules as it was itself
O(N^2) w.r.t the number of submodules, having to loop through the
`.gitmodules` file once per submodule. I changed it to process the
`.gitmodules` file once, into a map.
Signed-off-by: David Turner <dturner@twosigma.com>
The function to write trees allocates a new buffer for each tree.
This causes problems with performance when performing a lot
of actions involving writing trees, e.g. when doing many merges.
Fix the issue by instead handing in a shared buffer, which is then
re-used across the calls without having to re-allocate between
calls.
