Re: [PATCH 2/7] tools lib: Add bitmap_snprintf function

Arnaldo Carvalho de Melo
2016-08-02T16:21:41Z

Em Mon, Aug 01, 2016 at 08:02:30PM +0200, Jiri Olsa escreveu:
> Add support to print bitmap list. Code mostly
> taken from kernel's bitmap_list_string.

Renaming it to bitmap_scnprintf() as it is a wrapper on top of
scnprintf() that has a different semanting for the return value than
snprintf().

- Arnaldo

> Link: http://lkml.kernel.org/n/tip-ictn3ke5ewrzwyn8webfeai9@git.kernel.org
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
> tools/include/linux/bitmap.h | 10 ++++++++++
> tools/lib/bitmap.c | 29 +++++++++++++++++++++++++++++
> 2 files changed, 39 insertions(+)
>
> diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h
> index 66ddd992e690..43a0d06beabb 100644
> --- a/tools/include/linux/bitmap.h
> +++ b/tools/include/linux/bitmap.h
> @@ -75,4 +75,14 @@ static inline unsigned long *bitmap_alloc(int nbits)
> return malloc(BITS_TO_LONGS(nbits) * sizeof(unsigned long));
> }
>
> +/**
> + * bitmap_snprintf - print bitmap list into buffer
> + * @bitmap: bitmap
> + * @nbits: size of bitmap
> + * @buf: buffer to store output
> + * @size: size of @buf
> + */
> +size_t bitmap_snprintf(unsigned long *bitmap, int nbits,
> + char *buf, size_t size);
> +
> #endif /* _PERF_BITOPS_H */
> diff --git a/tools/lib/bitmap.c b/tools/lib/bitmap.c
> index 0a1adc1111fd..184d97b276a1 100644
> --- a/tools/lib/bitmap.c
> +++ b/tools/lib/bitmap.c
> @@ -29,3 +29,32 @@ void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
> for (k = 0; k < nr; k++)
> dst[k] = bitmap1[k] | bitmap2[k];
> }
> +
> +size_t bitmap_snprintf(unsigned long *bitmap, int nbits,
> + char *buf, size_t size)
> +{
> + /* current bit is 'cur', most recently seen range is [rbot, rtop] */
> + int cur, rbot, rtop;
> + bool first = true;
> + size_t ret = 0;
> +
> + rbot = cur = find_first_bit(bitmap, nbits);
> + while (cur < nbits) {
> + rtop = cur;
> + cur = find_next_bit(bitmap, nbits, cur + 1);
> + if (cur < nbits && cur <= rtop + 1)
> + continue;
> +
> + if (!first)
> + ret += scnprintf(buf + ret, size - ret, ",");
> +
> + first = false;
> +
> + ret += scnprintf(buf + ret, size - ret, "%d", rbot);
> + if (rbot < rtop)
> + ret += scnprintf(buf + ret, size - ret, "-%d", rtop);
> +
> + rbot = cur;
> + }
> + return ret;
> +}
> --
> 2.4.11