Re: [Qemu-devel] [PATCH V26 07/32] QemuOpts: add qemu_opt_get_*_del functions for replace work

[Leandro Dorileo <l@dorileo.org>]

On Tue, Apr 29, 2014 at 05:08:16PM +0800, Chunyan Liu wrote:
> Add qemu_opt_get_del, qemu_opt_get_bool_del, qemu_opt_get_number_del and
> qemu_opt_get_size_del to replace the same handling of QEMUOptionParameter
> (get and delete).
> 
> Several drivers are coded to parse a known subset of options, then
> remove them from the list before handing all remaining options to a
> second driver for further option processing.  get_*_del makes it easier
> to retrieve a known option (or its default) and remove it from the list
> all in one action.
> 
> Share common helper function:
> 
> For qemu_opt_get_bool/size/number, they and their get_*_del counterpart
> could share most of the code except whether or not deleting the opt from
> option list, so generate common helper functions.
> 
> For qemu_opt_get and qemu_opt_get_del, keep code duplication, since
> 1. qemu_opt_get_del returns malloc'd memory while qemu_opt_get returns
> in-place memory
> 2. qemu_opt_get_del returns (char *), qemu_opt_get returns (const char *),
> and could not change to (char *), since in one case, it will return
> desc->def_value_str, which is (const char *).
> 
> Reviewed-by: Eric Blake <eblake@redhat.com>
> Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
> Signed-off-by: Chunyan Liu <cyliu@suse.com>

Reviewed-by: Leandro Dorileo <l@dorileo.org>

> ---
>  include/qemu/option.h |   6 +++
>  util/qemu-option.c    | 116 ++++++++++++++++++++++++++++++++++++++++++++------
>  2 files changed, 109 insertions(+), 13 deletions(-)
> 
> diff --git a/include/qemu/option.h b/include/qemu/option.h
> index c3b0a91..6653e43 100644
> --- a/include/qemu/option.h
> +++ b/include/qemu/option.h
> @@ -111,6 +111,7 @@ struct QemuOptsList {
>  };
>  
>  const char *qemu_opt_get(QemuOpts *opts, const char *name);
> +char *qemu_opt_get_del(QemuOpts *opts, const char *name);
>  /**
>   * qemu_opt_has_help_opt:
>   * @opts: options to search for a help request
> @@ -126,6 +127,11 @@ bool qemu_opt_has_help_opt(QemuOpts *opts);
>  bool qemu_opt_get_bool(QemuOpts *opts, const char *name, bool defval);
>  uint64_t qemu_opt_get_number(QemuOpts *opts, const char *name, uint64_t defval);
>  uint64_t qemu_opt_get_size(QemuOpts *opts, const char *name, uint64_t defval);
> +bool qemu_opt_get_bool_del(QemuOpts *opts, const char *name, bool defval);
> +uint64_t qemu_opt_get_number_del(QemuOpts *opts, const char *name,
> +                                 uint64_t defval);
> +uint64_t qemu_opt_get_size_del(QemuOpts *opts, const char *name,
> +                               uint64_t defval);
>  int qemu_opt_unset(QemuOpts *opts, const char *name);
>  int qemu_opt_set(QemuOpts *opts, const char *name, const char *value);
>  void qemu_opt_set_err(QemuOpts *opts, const char *name, const char *value,
> diff --git a/util/qemu-option.c b/util/qemu-option.c
> index 4d2d4d1..32e1d50 100644
> --- a/util/qemu-option.c
> +++ b/util/qemu-option.c
> @@ -575,6 +575,19 @@ static void qemu_opt_del(QemuOpt *opt)
>      g_free(opt);
>  }
>  
> +/* qemu_opt_set allows many settings for the same option.
> + * This function deletes all settings for an option.
> + */
> +static void qemu_opt_del_all(QemuOpts *opts, const char *name)
> +{
> +    QemuOpt *opt, *next_opt;
> +
> +    QTAILQ_FOREACH_SAFE(opt, &opts->head, next, next_opt) {
> +        if (!strcmp(opt->name, name))
> +            qemu_opt_del(opt);
> +    }
> +}
> +
>  const char *qemu_opt_get(QemuOpts *opts, const char *name)
>  {
>      QemuOpt *opt = qemu_opt_find(opts, name);
> @@ -588,6 +601,34 @@ const char *qemu_opt_get(QemuOpts *opts, const char *name)
>      return opt ? opt->str : NULL;
>  }
>  
> +/* Get a known option (or its default) and remove it from the list
> + * all in one action. Return a malloced string of the option value.
> + * Result must be freed by caller with g_free().
> + */
> +char *qemu_opt_get_del(QemuOpts *opts, const char *name)
> +{
> +    QemuOpt *opt;
> +    const QemuOptDesc *desc;
> +    char *str = NULL;
> +
> +    if (opts == NULL) {
> +        return NULL;
> +    }
> +
> +    opt = qemu_opt_find(opts, name);
> +    if (!opt) {
> +        desc = find_desc_by_name(opts->list->desc, name);
> +        if (desc && desc->def_value_str) {
> +            str = g_strdup(desc->def_value_str);
> +        }
> +        return str;
> +    }
> +    str = opt->str;
> +    opt->str = NULL;
> +    qemu_opt_del_all(opts, name);
> +    return str;
> +}
> +
>  bool qemu_opt_has_help_opt(QemuOpts *opts)
>  {
>      QemuOpt *opt;
> @@ -600,50 +641,99 @@ bool qemu_opt_has_help_opt(QemuOpts *opts)
>      return false;
>  }
>  
> -bool qemu_opt_get_bool(QemuOpts *opts, const char *name, bool defval)
> +static bool qemu_opt_get_bool_helper(QemuOpts *opts, const char *name,
> +                                     bool defval, bool del)
>  {
>      QemuOpt *opt = qemu_opt_find(opts, name);
> +    bool ret = defval;
>  
>      if (opt == NULL) {
>          const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
>          if (desc && desc->def_value_str) {
> -            parse_option_bool(name, desc->def_value_str, &defval, &error_abort);
> +            parse_option_bool(name, desc->def_value_str, &ret, &error_abort);
>          }
> -        return defval;
> +        return ret;
>      }
>      assert(opt->desc && opt->desc->type == QEMU_OPT_BOOL);
> -    return opt->value.boolean;
> +    ret = opt->value.boolean;
> +    if (del) {
> +        qemu_opt_del_all(opts, name);
> +    }
> +    return ret;
>  }
>  
> -uint64_t qemu_opt_get_number(QemuOpts *opts, const char *name, uint64_t defval)
> +bool qemu_opt_get_bool(QemuOpts *opts, const char *name, bool defval)
> +{
> +    return qemu_opt_get_bool_helper(opts, name, defval, false);
> +}
> +
> +bool qemu_opt_get_bool_del(QemuOpts *opts, const char *name, bool defval)
> +{
> +    return qemu_opt_get_bool_helper(opts, name, defval, true);
> +}
> +
> +static uint64_t qemu_opt_get_number_helper(QemuOpts *opts, const char *name,
> +                                           uint64_t defval, bool del)
>  {
>      QemuOpt *opt = qemu_opt_find(opts, name);
> +    uint64_t ret = defval;
>  
>      if (opt == NULL) {
>          const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
>          if (desc && desc->def_value_str) {
> -            parse_option_number(name, desc->def_value_str, &defval,
> -                                &error_abort);
> +            parse_option_number(name, desc->def_value_str, &ret, &error_abort);
>          }
> -        return defval;
> +        return ret;
>      }
>      assert(opt->desc && opt->desc->type == QEMU_OPT_NUMBER);
> -    return opt->value.uint;
> +    ret = opt->value.uint;
> +    if (del) {
> +        qemu_opt_del_all(opts, name);
> +    }
> +    return ret;
>  }
>  
> -uint64_t qemu_opt_get_size(QemuOpts *opts, const char *name, uint64_t defval)
> +uint64_t qemu_opt_get_number(QemuOpts *opts, const char *name, uint64_t defval)
> +{
> +    return qemu_opt_get_number_helper(opts, name, defval, false);
> +}
> +
> +uint64_t qemu_opt_get_number_del(QemuOpts *opts, const char *name,
> +                                 uint64_t defval)
> +{
> +    return qemu_opt_get_number_helper(opts, name, defval, true);
> +}
> +
> +static uint64_t qemu_opt_get_size_helper(QemuOpts *opts, const char *name,
> +                                         uint64_t defval, bool del)
>  {
>      QemuOpt *opt = qemu_opt_find(opts, name);
> +    uint64_t ret = defval;
>  
>      if (opt == NULL) {
>          const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
>          if (desc && desc->def_value_str) {
> -            parse_option_size(name, desc->def_value_str, &defval, &error_abort);
> +            parse_option_size(name, desc->def_value_str, &ret, &error_abort);
>          }
> -        return defval;
> +        return ret;
>      }
>      assert(opt->desc && opt->desc->type == QEMU_OPT_SIZE);
> -    return opt->value.uint;
> +    ret = opt->value.uint;
> +    if (del) {
> +        qemu_opt_del_all(opts, name);
> +    }
> +    return ret;
> +}
> +
> +uint64_t qemu_opt_get_size(QemuOpts *opts, const char *name, uint64_t defval)
> +{
> +    return qemu_opt_get_size_helper(opts, name, defval, false);
> +}
> +
> +uint64_t qemu_opt_get_size_del(QemuOpts *opts, const char *name,
> +                               uint64_t defval)
> +{
> +    return qemu_opt_get_size_helper(opts, name, defval, true);
>  }
>  
>  static void qemu_opt_parse(QemuOpt *opt, Error **errp)
> -- 
> 1.8.4.5
> 
> 

-- 
Leandro Dorileo