[PATCH 07/40] util: Add helpers for auto-freeing GSList filled with strings

[Michal Privoznik]

On 2/6/21 9:32 AM, Peter Krempa wrote:
> glib's 'g_autoslist()' doesn't support lists of 'char *' strings. Add a
> type alias 'virGSListString' so that we can register an 'autoptr'
> function for it for simple usage of GSList with strings.
> 
> Signed-off-by: Peter Krempa <pkrempa at redhat.com>
> ---
>   src/libvirt_private.syms |  4 ++++
>   src/util/meson.build     |  1 +
>   src/util/virglibutil.c   | 27 +++++++++++++++++++++++++++
>   src/util/virglibutil.h   | 28 ++++++++++++++++++++++++++++
>   4 files changed, 60 insertions(+)
>   create mode 100644 src/util/virglibutil.c
>   create mode 100644 src/util/virglibutil.h
> 


> diff --git a/src/util/virglibutil.h b/src/util/virglibutil.h
> new file mode 100644
> index 0000000000..2bff69f22f
> --- /dev/null
> +++ b/src/util/virglibutil.h
> @@ -0,0 +1,28 @@
> +/*
> + * virglibutil.h: Utilities helping with glib usage
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library.  If not, see
> + * <http://www.gnu.org/licenses/>.
> + */
> +
> +#pragma once
> +
> +#include "internal.h"
> +
> +void
> +virGSListStringFree(GSList *l);
> +
> +typedef GSList virGSListString;

So, GSList is a singly linked list. This doubles memory usage because 
for every string we have to also store pointer to next. Is O(n^2) that 
bad so that we have to sacrifice memory complexity?

Michal