Re: [Qemu-devel] [PATCH 3/9] block: Move json: parsing to bdrv_fill_options()

["Benoît Canet" <benoit.canet@irqsave.net>]

The Wednesday 11 Jun 2014 à 16:04:57 (+0200), Kevin Wolf wrote :
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  block.c | 88 +++++++++++++++++++++++++++++++++--------------------------------
>  1 file changed, 45 insertions(+), 43 deletions(-)
> 
> diff --git a/block.c b/block.c
> index effb3e6..b9c2b41 100644
> --- a/block.c
> +++ b/block.c
> @@ -1006,19 +1006,62 @@ free_and_fail:
>      return ret;
>  }
>  
> +static QDict *parse_json_filename(const char *filename, Error **errp)
> +{
> +    QObject *options_obj;
> +    QDict *options;
> +    int ret;
> +
> +    ret = strstart(filename, "json:", &filename);
> +    assert(ret);
> +
> +    options_obj = qobject_from_json(filename);
> +    if (!options_obj) {
> +        error_setg(errp, "Could not parse the JSON options");
> +        return NULL;
> +    }
> +
> +    if (qobject_type(options_obj) != QTYPE_QDICT) {
> +        qobject_decref(options_obj);
> +        error_setg(errp, "Invalid JSON object given");
> +        return NULL;
> +    }
> +
> +    options = qobject_to_qdict(options_obj);
> +    qdict_flatten(options);
> +
> +    return options;
> +}

I am under the impression that this code move could be avoided by using a function
prototype: the patch would be less cluttered.

> +
>  /*
>   * Fills in default options for opening images and converts the legacy
>   * filename/flags pair to option QDict entries.
>   */
> -static int bdrv_fill_options(QDict **options, const char *filename, int flags,
> +static int bdrv_fill_options(QDict **options, const char **pfilename, int flags,
>                               Error **errp)
>  {
> +    const char *filename = *pfilename;
>      const char *drvname;
>      bool protocol = flags & BDRV_O_PROTOCOL;
>      bool parse_filename = false;
>      Error *local_err = NULL;
>      BlockDriver *drv;
>  
> +    /* Parse json: pseudo-protocol */
> +    if (filename && g_str_has_prefix(filename, "json:")) {
> +        QDict *json_options = parse_json_filename(filename, &local_err);
> +        if (local_err) {
> +            error_propagate(errp, local_err);
> +            return -EINVAL;
> +        }
> +
> +        /* Options given in the filename have lower priority than options
> +         * specified directly */
> +        qdict_join(*options, json_options, false);
> +        QDECREF(json_options);
> +        *pfilename = filename = NULL;
> +    }
> +
>      if (!protocol) {
>          return 0;
>      }
> @@ -1339,33 +1382,6 @@ out:
>      g_free(tmp_filename);
>  }
>  
> -static QDict *parse_json_filename(const char *filename, Error **errp)
> -{
> -    QObject *options_obj;
> -    QDict *options;
> -    int ret;
> -
> -    ret = strstart(filename, "json:", &filename);
> -    assert(ret);
> -
> -    options_obj = qobject_from_json(filename);
> -    if (!options_obj) {
> -        error_setg(errp, "Could not parse the JSON options");
> -        return NULL;
> -    }
> -
> -    if (qobject_type(options_obj) != QTYPE_QDICT) {
> -        qobject_decref(options_obj);
> -        error_setg(errp, "Invalid JSON object given");
> -        return NULL;
> -    }
> -
> -    options = qobject_to_qdict(options_obj);
> -    qdict_flatten(options);
> -
> -    return options;
> -}
Second part of the uneeded move.
Maybe you could declare bdrv_fill_options below parse_json_filename in the first
patch to avoid the ulterior move.

> -
>  /*
>   * Opens a disk image (raw, qcow2, vmdk, ...)
>   *
> @@ -1429,21 +1445,7 @@ int bdrv_open(BlockDriverState **pbs, const char *filename,
>          options = qdict_new();
>      }
>  
> -    if (filename && g_str_has_prefix(filename, "json:")) {
> -        QDict *json_options = parse_json_filename(filename, &local_err);
> -        if (local_err) {
> -            ret = -EINVAL;
> -            goto fail;
> -        }
> -
> -        /* Options given in the filename have lower priority than options
> -         * specified directly */
> -        qdict_join(options, json_options, false);
> -        QDECREF(json_options);
> -        filename = NULL;
> -    }
> -
> -    ret = bdrv_fill_options(&options, filename, flags, &local_err);
> +    ret = bdrv_fill_options(&options, &filename, flags, &local_err);
>      if (local_err) {
>          error_propagate(errp, local_err);
>          return ret;
> -- 
> 1.8.3.1
> 
>