Messages in this thread Patch in this message | | | Subject | Re: [PATCH 1/2] hexdump: minimize the output width of the offset | From | "Leizhen (ThunderTown)" <> | Date | Tue, 8 Aug 2023 09:10:05 +0800 |
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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.
> 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); >
-- Regards, Zhen Lei
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