Re: [PATCH v2 3/7] migration: Refactor migrate_cap_add

[Markus Armbruster]

Eric Blake <eblake@redhat.com> writes:

> Instead of taking a list parameter and returning a new head at a
> distance, just return the new item for the caller to insert into a
> list via QAPI_LIST_PREPEND.
>
> Signed-off-by: Eric Blake <eblake@redhat.com>
> ---
>  migration/migration.c | 22 +++++++++-------------
>  1 file changed, 9 insertions(+), 13 deletions(-)
>
> diff --git a/migration/migration.c b/migration/migration.c
> index 3263aa55a9da..e8c414a7b8f0 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -1667,27 +1667,23 @@ void migrate_set_state(int *state, int old_state, int 
> new_state)
>      }
>  }
>
> -static MigrationCapabilityStatusList *migrate_cap_add(
> -    MigrationCapabilityStatusList *list,
> -    MigrationCapability index,
> -    bool state)
> +static MigrationCapabilityStatus *migrate_cap_add(MigrationCapability index,
> +                                                  bool state)
>  {
> -    MigrationCapabilityStatusList *cap;
> +    MigrationCapabilityStatus *cap;
>
> -    cap = g_new0(MigrationCapabilityStatusList, 1);
> -    cap->value = g_new0(MigrationCapabilityStatus, 1);
> -    cap->value->capability = index;
> -    cap->value->state = state;
> -    cap->next = list;
> +    cap = g_new0(MigrationCapabilityStatus, 1);
> +    cap->capability = index;
> +    cap->state = state;
>
>      return cap;
>  }
>
>  void migrate_set_block_enabled(bool value, Error **errp)
>  {
> -    MigrationCapabilityStatusList *cap;
> +    MigrationCapabilityStatusList *cap = NULL;
>
> -    cap = migrate_cap_add(NULL, MIGRATION_CAPABILITY_BLOCK, value);
> +    QAPI_LIST_PREPEND(cap, migrate_cap_add(MIGRATION_CAPABILITY_BLOCK, 
> value));

Line is too long for my taste.  Please consider

       MigrationCapabilityStatusList *caps = NULL;
       MigrationCapabilityStatus *cap;

       cap = migrate_cap_add(MIGRATION_CAPABILITY_BLOCK, value);
       QAPI_LIST_PREPEND(caps, cap);
       qmp_migrate_set_capabilities(caps, errp);
       qapi_free_MigrationCapabilityStatusList(caps);

>      qmp_migrate_set_capabilities(cap, errp);
>      qapi_free_MigrationCapabilityStatusList(cap);
>  }
> @@ -3874,7 +3870,7 @@ static bool migration_object_check(MigrationState *ms, 
> Error **errp)
>
>      for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
>          if (ms->enabled_capabilities[i]) {
> -            head = migrate_cap_add(head, i, true);
> +            QAPI_LIST_PREPEND(head, migrate_cap_add(i, true));
>          }
>      }

       ret = migrate_caps_check(cap_list, head, errp);

       /* It works with head == NULL */

Unrelated: this comment is not worth its keep.

       qapi_free_MigrationCapabilityStatusList(head);

       return ret;

Reviewed-by: Markus Armbruster <armbru@redhat.com>