mirror of
https://gitlab.gnome.org/GNOME/glib.git
synced 2024-09-20 01:06:15 +02:00
ee247c0a2d
GArray supports a "zero_terminated" flag, but GPtrArray doesn't. This is odd, because especially for a pointer array it makes sense to have a %NULL sentinel. This would be for example useful to track or construct a strv array with a GPtrArray. As workaround for this missing feature you could use a GArray instead (ugly) or to explicitly add the %NULL element. However the latter increases the "len" of the array, which can be problematic if you want to still use the GPtrArray for other purposes. Add API for marking a GPtrArray as %NULL terminated. In that case, the API will ensure that there is always a valid %NULL sentinel after the array. Note that the API does not enforce that a %NULL terminated API actually has any data allocated. That means, even with a %NULL terminated array, pdata can still be %NULL (only if len is zero). Add g_ptr_array_new_null_terminated() constructor. The null-terminated flag cannot be cleared. Once the GPtrArray is flagged to be %NULL terminated, it sticks. The purpose is that once a user checks whether a GPtrArray instance is safe to be treated as a %NULL terminated array, the decision does not need to be re-evaluated. Also add a g_ptr_array_is_null_terminated(). That is useful because it allows you to check whether a GPtrArray created by somebody else is safe to use as a %NULL terminated array. Since there is no API to make an array not %NULL terminated anymore, this is not error prone. The new flag is tracked as a guint8 in GRealPtrArray. On common 64 bit architectures this does not increase the size of the struct as it fits in an existing hole. Note that this is not a bitfield because it's probably more efficient to access the entire guint8. However, there is still a 3 bytes hole (on common 32 and 64 architectures), so if we need to add more flags in the future, we still have space for 24 bits, despite the new flag not being a bitfield. The biggest downside of the patch is the runtime overhead that most operations now need to check whether %NULL termination is requested. Includes some tweaks and additional tests by Philip Withnall. https://gitlab.gnome.org/GNOME/glib/-/issues/353 |
||
|---|---|---|
| .. | ||
| reference | ||
| CODEOWNERS | ||
| debugging.txt | ||
| macros.txt | ||
| meson-version.md | ||
| rationales.md | ||
| supported-platforms.md | ||
| toolchain-requirements.md | ||