[MINOR] halog: gain back performance before SKIP_CHAR fix
The SKIP_CHAR fix caused a measurable performance drop. Since we can
consider all chars below 0x20 as delimiters, we can avoid a cache lookup
which requires a char to pointer conversion.
diff --git a/contrib/halog/halog.c b/contrib/halog/halog.c
index 6478981..82f179a 100644
--- a/contrib/halog/halog.c
+++ b/contrib/halog/halog.c
@@ -36,13 +36,8 @@
#define MAXLINE 16384
#define QBITS 4
-const char sep[256] = {
- [0] = 1,
- [' '] = 1, ['\t'] = 1,
- ['\r'] = 1, ['\n'] = 1,
-};
-
-#define SKIP_CHAR(p,c) do { while (1) if (sep[(unsigned char)*p]) break; else if (*(p++) == c) break; } while (0)
+#define SEP(c) ((unsigned char)(c) <= ' ')
+#define SKIP_CHAR(p,c) do { while (1) { int __c = (unsigned char)*p++; if (__c == c) break; if (__c <= ' ') { p--; break; } } } while (0)
/* [0] = err/date, [1] = req, [2] = conn, [3] = resp, [4] = data */
static struct eb_root timers[5] = {
@@ -515,7 +510,7 @@
p = b;
err = 0;
f = 0;
- while (!sep[(unsigned char)*p]) {
+ while (!SEP(*p)) {
if (++f == 4)
break;
SKIP_CHAR(p, '/');
@@ -539,7 +534,7 @@
p = b;
err = 0;
f = 0;
- while (!sep[(unsigned char)*p]) {
+ while (!SEP(*p)) {
tps = str2ic(p);
if (tps < 0) {
tps = -1;
@@ -612,7 +607,7 @@
p = b;
err = 0;
f = 0;
- while (!sep[(unsigned char)*p]) {
+ while (!SEP(*p)) {
array[f] = str2ic(p);
if (array[f] < 0) {
array[f] = -1;
@@ -777,7 +772,7 @@
p = b;
err = 0;
f = 0;
- while (!sep[(unsigned char)*p]) {
+ while (!SEP(*p)) {
array[f] = str2ic(p);
if (array[f] < 0) {
array[f] = -1;
@@ -845,7 +840,7 @@
* parse the 5 timers to detect errors, it takes avg 55 ns per line.
*/
e = b; err = 0; f = 0;
- while (!sep[(unsigned char)*e]) {
+ while (!SEP(*e)) {
array[f] = str2ic(e);
if (array[f] < 0) {
array[f] = -1;