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Add benchmarking tool + improve integer formatting performance

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Typical priorities: make it fast before fixing all the bugs. *shrug*
This commit is contained in:
Yorhel 2025-01-28 14:49:29 +01:00
parent c16a9fa493
commit 9c8ce3f782
4 changed files with 259 additions and 13 deletions
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35
c/jsonfmt.c
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@ -5,7 +5,11 @@ static void fujson_fmt_str(fustr *out, const char *stri, size_t len, int utf8) {
const unsigned char *str = (const unsigned char *)stri;
unsigned char x = 0;
/* Validate entire string for conformance if this is flagged as a utf8 string, this lets us be lazy further on. */
/* Validate entire string for conformance if this is flagged as a utf8
* string, this lets us be lazy further on.
* Commenting this out doubles the performance for formatting unicode
* strings, I suspect there's room for optimizations in
* is_c9strict_utf8_string(). */
if (utf8 && !is_c9strict_utf8_string(str, len)) {
return; /* TODO: Throw error. */
}
@ -63,9 +67,22 @@ static void fujson_fmt_str(fustr *out, const char *stri, size_t len, int utf8) {
fustr_write(out, "\"", 1);
}
/* All digits between 0 and 100, a trick I borrowed from the Zig stdlib. */
static const char fujson_digits[] =
"00010203040506070809"
"10111213141516171819"
"20212223242526272829"
"30313233343536373839"
"40414243444546474849"
"50515253545556575859"
"60616263646566676869"
"70717273747576777879"
"80818283848586878889"
"90919293949596979899";
static void fujson_fmt_int(fustr *out, SV *val) {
char buf[32];
size_t idx = 32;
char *r = buf+31;
int neg = 0;
IV iv;
UV uv;
@ -83,13 +100,15 @@ static void fujson_fmt_int(fustr *out, SV *val) {
return;
}
while (uv > 0) {
/* TODO: can use a lookup table to optimize for 0 - 100; need benchmark */
buf[--idx] = '0' + (uv % 10);
uv /= 10;
while (uv >= 10) {
r -= 2;
memcpy(r, fujson_digits + ((uv % 100)<<1), 2);
uv /= 100;
}
if (neg) buf[--idx] = '-';
fustr_write(out, buf+idx, sizeof buf - idx);
if (uv > 0) *(--r) = '0' + (uv % 10);
if (neg) *(--r) = '-';
uv = 31 - (r - buf);
fustr_write(out, r, uv);
}
static void fujson_fmt_av(fustr *out, AV *av) {