Now that our strmap is no longer modified but replaced, we can use the
same strmap for the snapshot's values and it will be freed when we don't
need it anymore.
When we delete an entry, we also want to refresh the configuration to
catch any changes that happened externally.
This allows us to simplify the logic, as we no longer need to delete
these variables internally. The whole state will be refreshed and the
deleted entries won't be there.
With the isolation of complex reads, we can now try to refresh the
on-disk file before reading a value from it.
This changes the semantics a bit, as before we could be sure that a
string we got from the configuration was valid until we wrote or
refreshed. This is no longer the case, as a read can also invalidate the
pointer.
Current code sets the active map to a new one and builds it whilst it's
active. This is a race condition with someone else trying to access the
same config.
Instead, let's build up our new map and swap the active and new one.
In order to have consistent views of the config files for remotes,
submodules et al. and a configuration that represents what is currently
stored on-disk, we need a way to provide a view of the configuration
that does not change.
The goal here is to provide the snapshotting part by creating a
read-only copy of the state of the configuration at a particular point
in time, which does not change when a repository's main config changes.
This adds a basic test of doing simultaneous diffs on multiple
threads and adds basic locking for the attr file cache because
that was the immediate problem that arose from these tests.
This adds `git_config__lookup_entry` which will look up a key in
a config and return either the entry or NULL if the key was not
present. Optionally, it can either suppress all errors or can
return them (although not finding the key is not an error for this
function). Unlike other accessors, this does not normalize the
config key string, so it must only be used when the key is known
to be in normalized form (i.e. all lower-case before the first dot
and after the last dot, with no invalid characters).
This also adds three high-level helper functions to look up config
values with no errors and a fallback value. The three functions
are for string, bool, and int values, and will resort to the
fallback value for any error that arises. They are:
* `git_config__get_string_force`
* `git_config__get_bool_force`
* `git_config__get_int_force`
None of them normalize the config `key` either, so they can only
be used for internal cases where the key is known to be in normal
format.
We used to move `data_start` forward, which is wrong as that needs to
point to the beginning of the buffer in order to perform size
calculations.
Introduce a `write_start` variable which indicates where we should start
writing from, which is what the `data_start` was being wrongly reused to
be.
At some moment git_config_delete_entry lost the ability to delete one entry of
a multivar configuration. The moment you had more than one fetch or push
ref spec for a remote you will not be able to save that remote anymore. The
changes in network::remote::remotes::save show that problem.
I needed to create a new git_config_delete_multivar because I was not able to
remove one or several entries of a multivar config with the current API.
Several tries modifying how git_config_set_multivar(..., NULL) behaved were
not successful.
git_config_delete_multivar is very similar to git_config_set_multivar, and
delegates into config_delete_multivar of config_file. This function search
for the cvar_t that will be deleted, storing them in a temporal array, and
rebuilding the linked list. After calling config_write to delete the entries,
the cvar_t stored in the temporal array are freed.
There is a little fix in config_write, it avoids an infinite loop when using
a regular expression (case for the multivars). This error was found by the
test network::remote::remotes::tagopt.
This makes the git_buf struct that was used internally into an
externally available structure and eliminates the git_buffer.
As part of that, some of the special cases that arose with the
externally used git_buffer were blended into the git_buf, such as
being careful about git_buf objects that may have a NULL ptr and
allowing for bufs with a valid ptr and size but zero asize as a
way of referring to externally owned data.
As the include depth increases, the chance of a realloc
increases. This means that whenever we run git_array_alloc() or call
config_parse(), we need to remember what our reader's index is so we
can look it up again.
We need to refresh the variables from the included files if they are
changed, so loop over all included files and re-parse the files if any
of them has changed.
In order to support config includes, we must differentiate between the
backend's main file and the file we are currently parsing.
This lays the groundwork for includes, keeping the current behaviours.
`git_config_set_string(config, "config.section", "")` fails when
escaping the value.
The buffer in `escape_value` is allocated without NULL-termination. And
in case of empty string 0 is passed for buffer size in `git_buf_grow`.
`git_buf_detach` returns NULL when the allocated size is 0 and that
leads to an error return in `GITERR_CHECK_ALLOC` called after
`escape_value`
The change in `config_file.c` was suggested by Russell Belfer <rb@github.com>
