Messages in this thread | | | Subject | Re: [RFCv3][PATCH 1/4] replace string_get_size() arrays | From | Joe Perches <> | Date | Sat, 01 Oct 2011 12:33:46 -0700 |
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On Fri, 2011-09-30 at 17:08 -0700, Dave Hansen wrote: > Instead of explicitly storing the entire string for each > possible units, just store the thing that varies: the > first character.
trivia
> diff -puN lib/string_helpers.c~string_get_size-pow2 lib/string_helpers.c > --- linux-2.6.git/lib/string_helpers.c~string_get_size-pow2 2011-09-30 16:50:31.628981352 -0700 > +++ linux-2.6.git-dave/lib/string_helpers.c 2011-09-30 17:04:02.211607364 -0700 > @@ -8,6 +8,23 @@ > #include <linux/module.h> > #include <linux/string_helpers.h> > > +static const char byte_units[] = "_KMGTPEZY";
u64 could be up to ~1.8**19 decimal zetta and yotta are not possible or necessary. u128 maybe someday, but then other changes would be necessary too.
> +static char *__units_str(enum string_size_units unit, char *buf, int index) > +{ > + int place = 0; > + > + /* index=0 is plain 'B' with no other unit */ > + if (index) { > + buf[place++] = byte_units[index];
index is unbounded (doesn't matter currently, it will for u128)
> @@ -23,26 +40,19 @@ > int string_get_size(u64 size, const enum string_size_units units, > char *buf, int len) [] > const unsigned int divisor[] = { > [STRING_UNITS_10] = 1000, > [STRING_UNITS_2] = 1024, > };
static const or it might be better to use unsigned int divisor = (string_size_units == STRING_UNITS_2) ? 1024 : 1000; as that would make the code clearer in a couple of uses of divisor[] later.
> @@ -61,7 +71,7 @@ int string_get_size(u64 size, const enum > } > > snprintf(buf, len, "%lld%s %s", (unsigned long long)size,
%llu
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