Re: [PATCH v2 1/3] util/cutils: Introduce freq_to_str() to display Hertz units

[Alistair Francis]

On Thu, Oct 1, 2020 at 9:57 AM Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
>
> Introduce freq_to_str() to convert frequency values in human
> friendly units using the SI units for Hertz.
>
> Suggested-by: Luc Michel <luc@lmichel.fr>
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  include/qemu/cutils.h | 12 ++++++++++++
>  util/cutils.c         | 14 ++++++++++++++
>  2 files changed, 26 insertions(+)
>
> diff --git a/include/qemu/cutils.h b/include/qemu/cutils.h
> index 3a86ec0321..4bbf4834ea 100644
> --- a/include/qemu/cutils.h
> +++ b/include/qemu/cutils.h
> @@ -158,6 +158,18 @@ int qemu_strtosz_metric(const char *nptr, const char 
> **end, uint64_t *result);
>
>  char *size_to_str(uint64_t val);
>
> +/**
> + * freq_to_str:
> + * @freq_hz: frequency to stringify
> + *
> + * Return human readable string for frequency @freq_hz.
> + * Use SI units like KHz, MHz, and so forth.
> + *
> + * The caller is responsible for releasing the value returned
> + * with g_free() after use.
> + */
> +char *freq_to_str(uint64_t freq_hz);
> +
>  /* used to print char* safely */
>  #define STR_OR_NULL(str) ((str) ? (str) : "null")
>
> diff --git a/util/cutils.c b/util/cutils.c
> index 8da34e04b0..be4e43a9ef 100644
> --- a/util/cutils.c
> +++ b/util/cutils.c
> @@ -885,6 +885,20 @@ char *size_to_str(uint64_t val)
>      return g_strdup_printf("%0.3g %sB", (double)val / div, suffixes[i]);
>  }
>
> +char *freq_to_str(uint64_t freq_hz)
> +{
> +    static const char *const suffixes[] = { "", "K", "M", "G", "T", "P", "E" 
> };
> +    double freq = freq_hz;
> +    size_t idx = 0;
> +
> +    while (freq >= 1000.0 && idx < ARRAY_SIZE(suffixes)) {
> +        freq /= 1000.0;
> +        idx++;
> +    }
> +
> +    return g_strdup_printf("%0.3g %sHz", freq, suffixes[idx]);
> +}
> +
>  int qemu_pstrcmp0(const char **str1, const char **str2)
>  {
>      return g_strcmp0(*str1, *str2);
> --
> 2.26.2
>
>