[PATCH v4 03/12] hexdump: do few calculations ahead

Andy Shevchenko
2014-09-04T14:27:42Z

Instead of doing calculations in each case of different groupsize let's do them
beforehand. While here, change the switch by if-else-if construction.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
lib/hexdump.c | 34 ++++++++++------------------------
1 file changed, 10 insertions(+), 24 deletions(-)

diff --git a/lib/hexdump.c b/lib/hexdump.c
index 4677070..b82418f 100644
--- a/lib/hexdump.c
+++ b/lib/hexdump.c
@@ -87,6 +87,7 @@ void hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
bool ascii)
{
const u8 *ptr = buf;
+ int ngroups;
u8 ch;
int j, lx = 0;
int ascii_column;
@@ -98,45 +99,33 @@ void hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
goto nil;
if (len > rowsize) /* limit to one line at a time */
len = rowsize;
+ if (!is_power_of_2(groupsize) || groupsize > 8)
+ groupsize = 1;
if ((len % groupsize) != 0) /* no mixed size output */
groupsize = 1;

- switch (groupsize) {
- case 8: {
+ ngroups = len / groupsize;
+ ascii_column = rowsize * 2 + rowsize / groupsize + 1;
+ if (groupsize == 8) {
const u64 *ptr8 = buf;
- int ngroups = len / groupsize;

for (j = 0; j < ngroups; j++)
lx += scnprintf(linebuf + lx, linebuflen - lx,
"%s%16.16llx", j ? " " : "",
(unsigned long long)*(ptr8 + j));
- ascii_column = rowsize * 2 + rowsize / 8 + 2;
- break;
- }
-
- case 4: {
+ } else if (groupsize == 4) {
const u32 *ptr4 = buf;
- int ngroups = len / groupsize;

for (j = 0; j < ngroups; j++)
lx += scnprintf(linebuf + lx, linebuflen - lx,
"%s%8.8x", j ? " " : "", *(ptr4 + j));
- ascii_column = rowsize * 2 + rowsize / 4 + 2;
- break;
- }
-
- case 2: {
+ } else if (groupsize == 2) {
const u16 *ptr2 = buf;
- int ngroups = len / groupsize;

for (j = 0; j < ngroups; j++)
lx += scnprintf(linebuf + lx, linebuflen - lx,
"%s%4.4x", j ? " " : "", *(ptr2 + j));
- ascii_column = rowsize * 2 + rowsize / 2 + 2;
- break;
- }
-
- default:
+ } else {
for (j = 0; (j < len) && (lx + 3) <= linebuflen; j++) {
ch = ptr[j];
linebuf[lx++] = hex_asc_hi(ch);
@@ -145,14 +134,11 @@ void hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
}
if (j)
lx--;
-
- ascii_column = 3 * rowsize + 2;
- break;
}
if (!ascii)
goto nil;

- while (lx < (linebuflen - 1) && lx < (ascii_column - 1))
+ while (lx < (linebuflen - 1) && lx < ascii_column)
linebuf[lx++] = ' ';
for (j = 0; (j < len) && (lx + 2) < linebuflen; j++) {
ch = ptr[j];
--
2.1.0