libgit2 has two distinct requirements that were previously solved by
`git_buf`. We require:
1. A general purpose string class that provides a number of utility APIs
for manipulating data (eg, concatenating, truncating, etc).
2. A structure that we can use to return strings to callers that they
can take ownership of.
By using a single class (`git_buf`) for both of these purposes, we have
confused the API to the point that refactorings are difficult and
reasoning about correctness is also difficult.
Move the utility class `git_buf` to be called `git_str`: this represents
its general purpose, as an internal string buffer class. The name also
is an homage to Junio Hamano ("gitstr").
The public API remains `git_buf`, and has a much smaller footprint. It
is generally only used as an "out" param with strict requirements that
follow the documentation. (Exceptions exist for some legacy APIs to
avoid breaking callers unnecessarily.)
Utility functions exist to convert a user-specified `git_buf` to a
`git_str` so that we can call internal functions, then converting it
back again.
Propagate failures caused by pool initialization errors.
Currently, the delete functions of maps do not provide a return value. Like this, it is impossible to tell whether the entry has really been deleted or not. Change the implementation to provide either a return value of zero if the entry has been successfully deleted or `GIT_ENOTFOUND` if the key could not be found. Convert callers to the `delete_at` functions to instead use this higher-level interface.
Currently, one would use the function `git_strmap_insert` to insert key/value pairs into a map. This function has historically been a macro, which is why its syntax is kind of weird: instead of returning an error code directly, it instead has to be passed a pointer to where the return value shall be stored. This does not match libgit2's common idiom of directly returning error codes. Introduce a new function `git_strmap_set`, which takes as parameters the map, key and value and directly returns an error code. Convert all callers of `git_strmap_insert` to make use of it.
The current way of looking up an entry from a map is tightly coupled with the map implementation, as one first has to look up the index of the key and then retrieve the associated value by using the index. As a caller, you usually do not care about any indices at all, though, so this is more complicated than really necessary. Furthermore, it invites for errors to happen if the correct error checking sequence is not being followed. Introduce a new high-level function `git_strmap_get` that takes a map and a key and returns a pointer to the associated value if such a key exists. Otherwise, a `NULL` pointer is returned. Adjust all callers that can trivially be converted.
Currently, the lifecycle functions for maps (allocation, deallocation, resize) are not named in a uniform way and do not have a uniform function signature. Rename the functions to fix that, and stick to libgit2's naming scheme of saying `git_foo_new`. This results in the following new interface for allocation: - `int git_<t>map_new(git_<t>map **out)` to allocate a new map, returning an error code if we ran out of memory - `void git_<t>map_free(git_<t>map *map)` to free a map - `void git_<t>map_clear(git<t>map *map)` to remove all entries from a map This commit also fixes all existing callers.
Move to the `git_error` name in the internal API for error-related functions.
Instead of using the `khiter_t`, `git_strmap_iter` and `khint_t` types, simply use `size_t` instead. This decouples code from the khash stuff and makes it possible to move the khash includes into the implementation files.
Some implementation files were missing the license headers. This commit adds them.