Re: [Qemu-devel] [PATCH 1/2] qapi: add visitor for parsing int[KMGT] input string

["Andreas Färber" <afaerber@suse.de>]

Am 06.12.2012 22:12, schrieb Igor Mammedov:
> Caller of visit_type_unit_suffixed_int() will have to specify
> value of 'K' suffix via unit argument.
> For Kbytes it's 1024, for Khz it's 1000.
> 
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---
>  v2:
>   - convert type_freq to type_unit_suffixed_int.
>   - provide qapi_dealloc_type_unit_suffixed_int() impl.
> ---
>  qapi/qapi-dealloc-visitor.c |  7 +++++++
>  qapi/qapi-visit-core.c      | 13 +++++++++++++
>  qapi/qapi-visit-core.h      |  8 ++++++++
>  qapi/string-input-visitor.c | 22 ++++++++++++++++++++++
>  4 files changed, 50 insertions(+)
> 
> diff --git a/qapi/qapi-dealloc-visitor.c b/qapi/qapi-dealloc-visitor.c
> index 75214e7..57e662c 100644
> --- a/qapi/qapi-dealloc-visitor.c
> +++ b/qapi/qapi-dealloc-visitor.c
> @@ -143,6 +143,12 @@ static void qapi_dealloc_type_enum(Visitor *v, int *obj, const char *strings[],
>  {
>  }
>  
> +static void qapi_dealloc_type_unit_suffixed_int(Visitor *v, int64_t *obj,
> +                                                const char *name,
> +                                                const int unit, Error **errp)
> +{
> +}
> +
>  Visitor *qapi_dealloc_get_visitor(QapiDeallocVisitor *v)
>  {
>      return &v->visitor;
> @@ -170,6 +176,7 @@ QapiDeallocVisitor *qapi_dealloc_visitor_new(void)
>      v->visitor.type_str = qapi_dealloc_type_str;
>      v->visitor.type_number = qapi_dealloc_type_number;
>      v->visitor.type_size = qapi_dealloc_type_size;
> +    v->visitor.type_unit_suffixed_int = qapi_dealloc_type_unit_suffixed_int;
>  
>      QTAILQ_INIT(&v->stack);
>  
> diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
> index 7a82b63..dcbc1a9 100644
> --- a/qapi/qapi-visit-core.c
> +++ b/qapi/qapi-visit-core.c
> @@ -311,3 +311,16 @@ void input_type_enum(Visitor *v, int *obj, const char *strings[],
>      g_free(enum_str);
>      *obj = value;
>  }
> +
> +void visit_type_unit_suffixed_int(Visitor *v, int64_t *obj, const char *name,
> +                                  const int unit, Error **errp)
> +{
> +    if (!error_is_set(errp)) {

if (error_is_set(errp)) {

> +        return;
> +    }
> +    if (v->type_unit_suffixed_int) {
> +        v->type_unit_suffixed_int(v, obj, name, unit, errp);
> +    } else {
> +        visit_type_int64(v, obj, name, errp);
> +    }
> +}
> diff --git a/qapi/qapi-visit-core.h b/qapi/qapi-visit-core.h
> index 60aceda..04e690a 100644
> --- a/qapi/qapi-visit-core.h
> +++ b/qapi/qapi-visit-core.h
> @@ -62,6 +62,12 @@ struct Visitor
>      void (*type_int64)(Visitor *v, int64_t *obj, const char *name, Error **errp);
>      /* visit_type_size() falls back to (*type_uint64)() if type_size is unset */
>      void (*type_size)(Visitor *v, uint64_t *obj, const char *name, Error **errp);
> +    /*
> +     * visit_unit_suffixed_int() falls back to (*type_int64)()
> +     * if type_unit_suffixed_int is unset
> +    */

Indentation is one off.

> +    void (*type_unit_suffixed_int)(Visitor *v, int64_t *obj, const char *name,
> +                                   const int unit, Error **errp);

Are we expecting differently suffixed ints? Otherwise we could
optionally shorten to type_suffixed_int (but that probably still doesn't
fit within one comment line ;)).

>  };
>  
>  void visit_start_handle(Visitor *v, void **obj, const char *kind,
> @@ -91,5 +97,7 @@ void visit_type_size(Visitor *v, uint64_t *obj, const char *name, Error **errp);
>  void visit_type_bool(Visitor *v, bool *obj, const char *name, Error **errp);
>  void visit_type_str(Visitor *v, char **obj, const char *name, Error **errp);
>  void visit_type_number(Visitor *v, double *obj, const char *name, Error **errp);
> +void visit_type_unit_suffixed_int(Visitor *v, int64_t *obj, const char *name,
> +                                  const int unit, Error **errp);
>  
>  #endif
> diff --git a/qapi/string-input-visitor.c b/qapi/string-input-visitor.c
> index 497eb9a..d2bd154 100644
> --- a/qapi/string-input-visitor.c
> +++ b/qapi/string-input-visitor.c
> @@ -110,6 +110,27 @@ static void parse_start_optional(Visitor *v, bool *present,
>      *present = true;
>  }
>  
> +static void parse_type_unit_suffixed_int(Visitor *v, int64_t *obj,
> +                                         const char *name, const int unit,
> +                                         Error **errp)
> +{
> +    StringInputVisitor *siv = DO_UPCAST(StringInputVisitor, visitor, v);
> +    char *endp = (char *) siv->string;
> +    long long val = 0;
> +
> +    if (siv->string) {
> +        val = strtosz_suffix_unit(siv->string, &endp,
> +                             STRTOSZ_DEFSUFFIX_B, unit);
> +    }
> +    if (!siv->string || val == -1 || *endp) {
> +        error_set(errp, QERR_INVALID_PARAMETER_VALUE, name,
> +              "a value representable as a non-negative int64");

Weird indentation remaining, looks as if we could align with errp within
80 chars.

However, I wonder if "unit" is the (physically etc.) correct term here?
Isn't the "unit" Hz / byte / ... and 1000 more of a conversion factor or
something? At least that's the way I've seen unit used in the API of
another project, passing an enum of Hertz, gram, meter/second, etc.

Andreas

> +        return;
> +    }
> +
> +    *obj = val;
> +}
> +
>  Visitor *string_input_get_visitor(StringInputVisitor *v)
>  {
>      return &v->visitor;
> @@ -132,6 +153,7 @@ StringInputVisitor *string_input_visitor_new(const char *str)
>      v->visitor.type_str = parse_type_str;
>      v->visitor.type_number = parse_type_number;
>      v->visitor.start_optional = parse_start_optional;
> +    v->visitor.type_unit_suffixed_int = parse_type_unit_suffixed_int;
>  
>      v->string = str;
>      return v;
> 


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