Messages in this thread | | | Date | Mon, 7 Aug 2023 19:42:09 -0700 | Subject | Re: [PATCH 1/2] hexdump: minimize the output width of the offset | From | Randy Dunlap <> |
| |
On 8/7/23 18:10, Leizhen (ThunderTown) wrote: > > > On 2023/8/8 6:37, Randy Dunlap wrote: >> Hi-- >> >> On 8/5/23 00:21, thunder.leizhen@huaweicloud.com wrote: >>> From: Zhen Lei <thunder.leizhen@huawei.com> >>> >>> The offset of case DUMP_PREFIX_OFFSET always starts from 0. Currently, >>> the output width is fixed to 8. But we usually dump only tens or hundreds >>> of bytes, occasionally thousands of bytes. Therefore, the output offset >>> value always has a number of leading zeros, which increases the number of >>> bytes printed and reduces readability. Let's minimize the output width of >>> the offset based on the number of significant bits of its maximum value. >>> >>> Before: >>> dump_size=36: >>> 00000000: c0 ba 8c 80 00 80 ff ff 6c 93 ee 2f ee bf ff ff >>> 00000010: 00 50 1e 98 ff 27 ff ff 01 00 00 00 00 00 00 00 >>> 00000020: 80 ca 2f 98 >>> >>> After: >>> dump_size=8: >>> 0: c0 ba 89 80 00 80 ff ff >>> >>> dump_size=36: >>> 00: c0 3a 91 80 00 80 ff ff 6c 93 ae 76 30 ce ff ff >>> 10: 00 60 cd 60 7d 4e ff ff 01 00 00 00 00 00 00 00 >>> 20: 40 9e 29 40 >>> >>> dump_size=300: >>> 000: c0 ba 8d 80 00 80 ff ff 6c 93 ce d4 78 a7 ff ff >>> 010: 00 00 16 18 0c 40 ff ff 01 00 00 00 00 00 00 00 >>> 020: 01 00 00 00 00 00 00 00 e8 bc 8d 80 00 80 ff ff >>> ... ... >>> 110: 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >>> 120: 00 08 12 01 0c 40 ff ff 00 00 01 00 >>> >>> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> >>> --- >>> lib/hexdump.c | 13 +++++++++++-- >>> 1 file changed, 11 insertions(+), 2 deletions(-) >>> >>> diff --git a/lib/hexdump.c b/lib/hexdump.c >>> index 06833d404398d74..86cb4cc3eec485a 100644 >>> --- a/lib/hexdump.c >>> +++ b/lib/hexdump.c >>> @@ -263,12 +263,21 @@ void print_hex_dump(const char *level, const char *prefix_str, int prefix_type, >>> const void *buf, size_t len, bool ascii) >>> { >>> const u8 *ptr = buf; >>> - int i, linelen, remaining = len; >>> + int i, linelen, width = 0, remaining = len; >>> unsigned char linebuf[32 * 3 + 2 + 32 + 1]; >>> >>> if (rowsize != 16 && rowsize != 32) >>> rowsize = 16; >>> >>> + if (prefix_type == DUMP_PREFIX_OFFSET) { >>> + unsigned long tmp = len - 1; /* offset start from 0, so minus 1 */ >>> + >>> + do { >>> + width++; >>> + tmp >>= 4; >>> + } while (tmp); >>> + } >>> + >> >> You could put all of that ^^^ in the case DUMP_PREFIX_OFFSET below. > > for (i = 0; i < len; i += rowsize) { > > "case DUMP_PREFIX_OFFSET" is in the loop, and moving the code above > to the case DUMP_PREFIX_OFFSET will be calculate multiple times. But > following your prompt, I thought again, I can control it with the > local variable width. I will post v2 right away.
Ah I see. My apologies.
>> Otherwise LGTM. >> >> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> >> Thanks. >> >>> for (i = 0; i < len; i += rowsize) { >>> linelen = min(remaining, rowsize); >>> remaining -= rowsize; >>> @@ -282,7 +291,7 @@ void print_hex_dump(const char *level, const char *prefix_str, int prefix_type, >>> level, prefix_str, ptr + i, linebuf); >>> break; >>> case DUMP_PREFIX_OFFSET: >>> - printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf); >>> + printk("%s%s%0*x: %s\n", level, prefix_str, width, i, linebuf); >>> break; >>> default: >>> printk("%s%s%s\n", level, prefix_str, linebuf); >> >
-- ~Randy
| |