[1/2] qemu-option: Introduce default mechanism

This adds qemu_opts_set_defaults, an interface provide default values
for a QemuOpts set. Default options are parsed from a string and then
prepended to the list of existing options, or they serve as the sole
QemuOpts set.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 qemu-option.c |   58 +++++++++++++++++++++++++++++++++++++++++++++++++-------
 qemu-option.h |    2 +
 2 files changed, 52 insertions(+), 8 deletions(-)

On 01/27/2012 12:54 PM, Jan Kiszka wrote:
> This adds qemu_opts_set_defaults, an interface provide default values
> for a QemuOpts set. Default options are parsed from a string and then
> prepended to the list of existing options, or they serve as the sole
> QemuOpts set.
>
> Signed-off-by: Jan Kiszka<jan.kiszka@siemens.com>

Applied.  Thanks.

Regards,

Anthony Liguori

> ---
>   qemu-option.c |   58 +++++++++++++++++++++++++++++++++++++++++++++++++-------
>   qemu-option.h |    2 +
>   2 files changed, 52 insertions(+), 8 deletions(-)
>
> diff --git a/qemu-option.c b/qemu-option.c
> index a303f87..4626ccf 100644
> --- a/qemu-option.c
> +++ b/qemu-option.c
> @@ -603,7 +603,8 @@ static void qemu_opt_del(QemuOpt *opt)
>       g_free(opt);
>   }
>
> -int qemu_opt_set(QemuOpts *opts, const char *name, const char *value)
> +static int opt_set(QemuOpts *opts, const char *name, const char *value,
> +                   bool prepend)
>   {
>       QemuOpt *opt;
>       const QemuOptDesc *desc = opts->list->desc;
> @@ -626,7 +627,11 @@ int qemu_opt_set(QemuOpts *opts, const char *name, const char *value)
>       opt = g_malloc0(sizeof(*opt));
>       opt->name = g_strdup(name);
>       opt->opts = opts;
> -    QTAILQ_INSERT_TAIL(&opts->head, opt, next);
> +    if (prepend) {
> +        QTAILQ_INSERT_HEAD(&opts->head, opt, next);
> +    } else {
> +        QTAILQ_INSERT_TAIL(&opts->head, opt, next);
> +    }
>       if (desc[i].name != NULL) {
>           opt->desc = desc+i;
>       }
> @@ -640,6 +645,11 @@ int qemu_opt_set(QemuOpts *opts, const char *name, const char *value)
>       return 0;
>   }
>
> +int qemu_opt_set(QemuOpts *opts, const char *name, const char *value)
> +{
> +    return opt_set(opts, name, value, false);
> +}
> +
>   int qemu_opt_set_bool(QemuOpts *opts, const char *name, bool val)
>   {
>       QemuOpt *opt;
> @@ -691,6 +701,9 @@ QemuOpts *qemu_opts_find(QemuOptsList *list, const char *id)
>
>       QTAILQ_FOREACH(opts,&list->head, next) {
>           if (!opts->id) {
> +            if (!id) {
> +                return opts;
> +            }
>               continue;
>           }
>           if (strcmp(opts->id, id) != 0) {
> @@ -806,7 +819,8 @@ int qemu_opts_print(QemuOpts *opts, void *dummy)
>       return 0;
>   }
>
> -int qemu_opts_do_parse(QemuOpts *opts, const char *params, const char *firstname)
> +static int opts_do_parse(QemuOpts *opts, const char *params,
> +                         const char *firstname, bool prepend)
>   {
>       char option[128], value[1024];
>       const char *p,*pe,*pc;
> @@ -841,7 +855,7 @@ int qemu_opts_do_parse(QemuOpts *opts, const char *params, const char *firstname
>           }
>           if (strcmp(option, "id") != 0) {
>               /* store and parse */
> -            if (qemu_opt_set(opts, option, value) == -1) {
> +            if (opt_set(opts, option, value, prepend) == -1) {
>                   return -1;
>               }
>           }
> @@ -852,8 +866,13 @@ int qemu_opts_do_parse(QemuOpts *opts, const char *params, const char *firstname
>       return 0;
>   }
>
> -QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params,
> -                          int permit_abbrev)
> +int qemu_opts_do_parse(QemuOpts *opts, const char *params, const char *firstname)
> +{
> +    return opts_do_parse(opts, params, firstname, false);
> +}
> +
> +static QemuOpts *opts_parse(QemuOptsList *list, const char *params,
> +                            int permit_abbrev, bool defaults)
>   {
>       const char *firstname;
>       char value[1024], *id = NULL;
> @@ -870,11 +889,19 @@ QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params,
>           get_opt_value(value, sizeof(value), p+4);
>           id = value;
>       }
> -    opts = qemu_opts_create(list, id, 1);
> +    if (defaults) {
> +        if (!id&&  !QTAILQ_EMPTY(&list->head)) {
> +            opts = qemu_opts_find(list, NULL);
> +        } else {
> +            opts = qemu_opts_create(list, id, 0);
> +        }
> +    } else {
> +        opts = qemu_opts_create(list, id, 1);
> +    }
>       if (opts == NULL)
>           return NULL;
>
> -    if (qemu_opts_do_parse(opts, params, firstname) != 0) {
> +    if (opts_do_parse(opts, params, firstname, defaults) != 0) {
>           qemu_opts_del(opts);
>           return NULL;
>       }
> @@ -882,6 +909,21 @@ QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params,
>       return opts;
>   }
>
> +QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params,
> +                          int permit_abbrev)
> +{
> +    return opts_parse(list, params, permit_abbrev, false);
> +}
> +
> +void qemu_opts_set_defaults(QemuOptsList *list, const char *params,
> +                            int permit_abbrev)
> +{
> +    QemuOpts *opts;
> +
> +    opts = opts_parse(list, params, permit_abbrev, true);
> +    assert(opts);
> +}
> +
>   static void qemu_opts_from_qdict_1(const char *key, QObject *obj, void *opaque)
>   {
>       char buf[32];
> diff --git a/qemu-option.h b/qemu-option.h
> index 07958e4..e6f61e6 100644
> --- a/qemu-option.h
> +++ b/qemu-option.h
> @@ -125,6 +125,8 @@ void qemu_opts_del(QemuOpts *opts);
>   int qemu_opts_validate(QemuOpts *opts, const QemuOptDesc *desc);
>   int qemu_opts_do_parse(QemuOpts *opts, const char *params, const char *firstname);
>   QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params, int permit_abbrev);
> +void qemu_opts_set_defaults(QemuOptsList *list, const char *params,
> +                            int permit_abbrev);
>   QemuOpts *qemu_opts_from_qdict(QemuOptsList *list, const QDict *qdict);
>   QDict *qemu_opts_to_qdict(QemuOpts *opts, QDict *qdict);
>