mongoose/src/fmt.c
2024-09-24 18:01:07 -03:00

224 lines
7.4 KiB
C

#include "fmt.h"
#include "printf.h"
#include "util.h"
static bool is_digit(int c) {
return c >= '0' && c <= '9';
}
static int addexp(char *buf, int e, int sign) {
int n = 0;
buf[n++] = 'e';
buf[n++] = (char) sign;
if (e > 400) return 0;
if (e < 10) buf[n++] = '0';
if (e >= 100) buf[n++] = (char) (e / 100 + '0'), e -= 100 * (e / 100);
if (e >= 10) buf[n++] = (char) (e / 10 + '0'), e -= 10 * (e / 10);
buf[n++] = (char) (e + '0');
return n;
}
static int xisinf(double x) {
union {
double f;
uint64_t u;
} ieee754 = {x};
return ((unsigned) (ieee754.u >> 32) & 0x7fffffff) == 0x7ff00000 &&
((unsigned) ieee754.u == 0);
}
static int xisnan(double x) {
union {
double f;
uint64_t u;
} ieee754 = {x};
return ((unsigned) (ieee754.u >> 32) & 0x7fffffff) +
((unsigned) ieee754.u != 0) >
0x7ff00000;
}
static size_t mg_dtoa(char *dst, size_t dstlen, double d, int width, bool tz) {
char buf[40];
int i, s = 0, n = 0, e = 0;
double t, mul, saved;
if (d == 0.0) return mg_snprintf(dst, dstlen, "%s", "0");
if (xisinf(d)) return mg_snprintf(dst, dstlen, "%s", d > 0 ? "inf" : "-inf");
if (xisnan(d)) return mg_snprintf(dst, dstlen, "%s", "nan");
if (d < 0.0) d = -d, buf[s++] = '-';
// Round
saved = d;
mul = 1.0;
while (d >= 10.0 && d / mul >= 10.0) mul *= 10.0;
while (d <= 1.0 && d / mul <= 1.0) mul /= 10.0;
for (i = 0, t = mul * 5; i < width; i++) t /= 10.0;
d += t;
// Calculate exponent, and 'mul' for scientific representation
mul = 1.0;
while (d >= 10.0 && d / mul >= 10.0) mul *= 10.0, e++;
while (d < 1.0 && d / mul < 1.0) mul /= 10.0, e--;
// printf(" --> %g %d %g %g\n", saved, e, t, mul);
if (e >= width && width > 1) {
n = (int) mg_dtoa(buf, sizeof(buf), saved / mul, width, tz);
// printf(" --> %.*g %d [%.*s]\n", 10, d / t, e, n, buf);
n += addexp(buf + s + n, e, '+');
return mg_snprintf(dst, dstlen, "%.*s", n, buf);
} else if (e <= -width && width > 1) {
n = (int) mg_dtoa(buf, sizeof(buf), saved / mul, width, tz);
// printf(" --> %.*g %d [%.*s]\n", 10, d / mul, e, n, buf);
n += addexp(buf + s + n, -e, '-');
return mg_snprintf(dst, dstlen, "%.*s", n, buf);
} else {
for (i = 0, t = mul; t >= 1.0 && s + n < (int) sizeof(buf); i++) {
int ch = (int) (d / t);
if (n > 0 || ch > 0) buf[s + n++] = (char) (ch + '0');
d -= ch * t;
t /= 10.0;
}
// printf(" --> [%g] -> %g %g (%d) [%.*s]\n", saved, d, t, n, s + n, buf);
if (n == 0) buf[s++] = '0';
while (t >= 1.0 && n + s < (int) sizeof(buf)) buf[n++] = '0', t /= 10.0;
if (s + n < (int) sizeof(buf)) buf[n + s++] = '.';
// printf(" 1--> [%g] -> [%.*s]\n", saved, s + n, buf);
for (i = 0, t = 0.1; s + n < (int) sizeof(buf) && n < width; i++) {
int ch = (int) (d / t);
buf[s + n++] = (char) (ch + '0');
d -= ch * t;
t /= 10.0;
}
}
while (tz && n > 0 && buf[s + n - 1] == '0') n--; // Trim trailing zeroes
if (n > 0 && buf[s + n - 1] == '.') n--; // Trim trailing dot
n += s;
if (n >= (int) sizeof(buf)) n = (int) sizeof(buf) - 1;
buf[n] = '\0';
return mg_snprintf(dst, dstlen, "%s", buf);
}
static size_t mg_lld(char *buf, int64_t val, bool is_signed, bool is_hex) {
const char *letters = "0123456789abcdef";
uint64_t v = (uint64_t) val;
size_t s = 0, n, i;
if (is_signed && val < 0) buf[s++] = '-', v = (uint64_t) (-val);
// This loop prints a number in reverse order. I guess this is because we
// write numbers from right to left: least significant digit comes last.
// Maybe because we use Arabic numbers, and Arabs write RTL?
if (is_hex) {
for (n = 0; v; v >>= 4) buf[s + n++] = letters[v & 15];
} else {
for (n = 0; v; v /= 10) buf[s + n++] = letters[v % 10];
}
// Reverse a string
for (i = 0; i < n / 2; i++) {
char t = buf[s + i];
buf[s + i] = buf[s + n - i - 1], buf[s + n - i - 1] = t;
}
if (val == 0) buf[n++] = '0'; // Handle special case
return n + s;
}
static size_t scpy(void (*out)(char, void *), void *ptr, char *buf,
size_t len) {
size_t i = 0;
while (i < len && buf[i] != '\0') out(buf[i++], ptr);
return i;
}
size_t mg_xprintf(void (*out)(char, void *), void *ptr, const char *fmt, ...) {
size_t len = 0;
va_list ap;
va_start(ap, fmt);
len = mg_vxprintf(out, ptr, fmt, &ap);
va_end(ap);
return len;
}
size_t mg_vxprintf(void (*out)(char, void *), void *param, const char *fmt,
va_list *ap) {
size_t i = 0, n = 0;
while (fmt[i] != '\0') {
if (fmt[i] == '%') {
size_t j, k, x = 0, is_long = 0, w = 0 /* width */, pr = ~0U /* prec */;
char pad = ' ', minus = 0, c = fmt[++i];
if (c == '#') x++, c = fmt[++i];
if (c == '-') minus++, c = fmt[++i];
if (c == '0') pad = '0', c = fmt[++i];
while (is_digit(c)) w *= 10, w += (size_t) (c - '0'), c = fmt[++i];
if (c == '.') {
c = fmt[++i];
if (c == '*') {
pr = (size_t) va_arg(*ap, int);
c = fmt[++i];
} else {
pr = 0;
while (is_digit(c)) pr *= 10, pr += (size_t) (c - '0'), c = fmt[++i];
}
}
while (c == 'h') c = fmt[++i]; // Treat h and hh as int
if (c == 'l') {
is_long++, c = fmt[++i];
if (c == 'l') is_long++, c = fmt[++i];
}
if (c == 'p') x = 1, is_long = 1;
if (c == 'd' || c == 'u' || c == 'x' || c == 'X' || c == 'p' ||
c == 'g' || c == 'f') {
bool s = (c == 'd'), h = (c == 'x' || c == 'X' || c == 'p');
char tmp[40];
size_t xl = x ? 2 : 0;
if (c == 'g' || c == 'f') {
double v = va_arg(*ap, double);
if (pr == ~0U) pr = 6;
k = mg_dtoa(tmp, sizeof(tmp), v, (int) pr, c == 'g');
} else if (is_long == 2) {
int64_t v = va_arg(*ap, int64_t);
k = mg_lld(tmp, v, s, h);
} else if (is_long == 1) {
long v = va_arg(*ap, long);
k = mg_lld(tmp, s ? (int64_t) v : (int64_t) (unsigned long) v, s, h);
} else {
int v = va_arg(*ap, int);
k = mg_lld(tmp, s ? (int64_t) v : (int64_t) (unsigned) v, s, h);
}
for (j = 0; j < xl && w > 0; j++) w--;
for (j = 0; pad == ' ' && !minus && k < w && j + k < w; j++)
n += scpy(out, param, &pad, 1);
n += scpy(out, param, (char *) "0x", xl);
for (j = 0; pad == '0' && k < w && j + k < w; j++)
n += scpy(out, param, &pad, 1);
n += scpy(out, param, tmp, k);
for (j = 0; pad == ' ' && minus && k < w && j + k < w; j++)
n += scpy(out, param, &pad, 1);
} else if (c == 'm' || c == 'M') {
mg_pm_t f = va_arg(*ap, mg_pm_t);
if (c == 'm') out('"', param);
n += f(out, param, ap);
if (c == 'm') n += 2, out('"', param);
} else if (c == 'c') {
int ch = va_arg(*ap, int);
out((char) ch, param);
n++;
} else if (c == 's') {
char *p = va_arg(*ap, char *);
if (pr == ~0U) pr = p == NULL ? 0 : strlen(p);
for (j = 0; !minus && pr < w && j + pr < w; j++)
n += scpy(out, param, &pad, 1);
n += scpy(out, param, p, pr);
for (j = 0; minus && pr < w && j + pr < w; j++)
n += scpy(out, param, &pad, 1);
} else if (c == '%') {
out('%', param);
n++;
} else {
out('%', param);
out(c, param);
n += 2;
}
i++;
} else {
out(fmt[i], param), n++, i++;
}
}
return n;
}