better implementation of ksprintf_fast()

diff --git a/kstring.c b/kstring.c
index e86c9ecae379f65e6d1d0f008fd65659efc13ed1..3262aef0b3bdc9317580463bafe97b237d2d7f53 100644 (file)
--- a/kstring.c
+++ b/kstring.c
@@ -3,6 +3,7 @@
 #include <ctype.h>
 #include <string.h>
 #include <stdint.h>
+#include <math.h>
 #include "kstring.h"
 
 int ksprintf(kstring_t *s, const char *fmt, ...)
@@ -170,6 +171,10 @@ char *kstrnstr(const char *str, const char *pat, int n, int **_prep)
  * fast sprintf *
  ****************/
 
+typedef struct {
+       int base, width, fill, left_aln, n_ell, n_Ell;
+} printf_conv_t;
+
 static inline void enlarge(kstring_t *s, int l)
 {
        if (s->l + l + 1 >= s->m) {
@@ -179,91 +184,123 @@ static inline void enlarge(kstring_t *s, int l)
        }
 }
 
-static int get_base(int c)
-{
-       if (c == 'o') return 8;
-       if (c == 'x') return 16;
-       return 10;
-}
-
 int ksprintf_fast(kstring_t *s, const char *fmt, ...)
 {
 
-#define write_integer(_ap, _s, _type, _base) do { \
+#define write_integer0(_c, _s, _type, _z, _conv) do { \
+               char buf[32]; \
+               int l = 0, k, w, f; \
+               _type x; \
+               if (_c != 0) { \
+                       for (x = _c < 0? -_c : _c; x > 0; x /= _z.base) buf[l++] = _conv[x%_z.base]; \
+                       if (_c < 0) buf[l++] = '-'; \
+               } else buf[l++] = '0'; \
+               f = l > _z.fill? l : _z.fill; \
+               w = f > _z.width? f : _z.width; \
+               enlarge(_s, w); \
+               if (w > f && !_z.left_aln) \
+                       for (k = f; k < w; ++k) _s->s[_s->l++] = ' '; \
+               if (f > l) \
+                       for (k = l; k < f; ++k) _s->s[_s->l++] = '0'; \
+               for (k = l - 1; k >= 0; --k) _s->s[_s->l++] = buf[k]; \
+               if (w > f && _z.left_aln) \
+                       for (k = f; k < w; ++k) _s->s[_s->l++] = ' '; \
+       } while (0)
+
+#define write_integer(_ap, _s, _type, _z, _conv) do { \
                _type c = va_arg(_ap, _type); \
-               if (c == 0) { \
-                       enlarge(_s, 1); \
-                       _s->s[_s->l++] = '0'; \
-                       _s->s[_s->l] = 0; \
-               } else { \
-                       char buf[32]; \
-                       int l, ll; \
-                       _type x; \
-                       for (l = 0, x = c < 0? -c : c; x > 0; x /= _base) buf[l++] = "0123456789abcdef"[x%_base]; \
-                       if (c < 0) buf[l++] = '-'; \
-                       enlarge(_s, l); \
-                       for (ll = l - 1; ll >= 0; --ll) _s->s[_s->l++] = buf[ll]; \
-                       _s->s[_s->l] = 0; \
-               } \
+               write_integer0(c, _s, _type, _z, _conv); \
        } while (0)
 
        va_list ap;
        const char *p = fmt, *q;
+       int state = 0;
+       printf_conv_t z, ztmp;
+       memset(&z, 0, sizeof(printf_conv_t)); z.fill = -1;
+       ztmp = z;
        va_start(ap, fmt);
        while (*p) {
-               if (*p == '%') {
-                       ++p;
+               if (state == 1) {
+                       int finished = 0;
                        if (*p == '%') {
                                enlarge(s, 1);
                                s->s[s->l++] = '%';
-                               s->s[s->l] = 0;
+                               finished = 1;
+                       } else if (*p >= '0' && *p <= '9') { // width
+                               char *r;
+                               z.width = strtol(p, &r, 10);
+                               p = r - 1;
+                       } else if (*p == '.') { // fill
+                               char *r;
+                               z.fill = strtol(p + 1, &r, 10);
+                               p = r - 1;
+                       } else if (*p == 'l') { // %l
+                               ++z.n_ell;
+                       } else if (*p == 'L') { // %L
+                               ++z.n_Ell;
+                       } else if (*p == '-') { // %-
+                               z.left_aln = 1;
                        } else if (*p == 's') { // %s
                                char *r = va_arg(ap, char*);
                                int l = strlen(r);
                                enlarge(s, l);
                                memcpy(s->s + s->l, r, l);
                                s->l += l;
-                               s->s[s->l] = 0;
+                               finished = 1;
                        } else if (*p == 'c') { // %c
                                enlarge(s, 1);
                                s->s[s->l++] = va_arg(ap, int);
-                               s->s[s->l] = 0;
+                               finished = 1;
                        } else if (*p == 'd' || *p == 'i') { // %d or %i
-                               write_integer(ap, s, int, 10);
-                       } else if (*p == 'u' || *p == 'o' || *p == 'x') { // %u, %o or %x
-                               int base = get_base(*p);
-                               write_integer(ap, s, unsigned, base);
-                       } else if (*p == 'l') {
-                               ++p;
-                               if (*p == 'l') {
-                                       ++p;
-                                       if (*p == 'd' || *p == 'i') { // %lld or %lli
-                                               write_integer(ap, s, long long, 10);
-                                       } else if (*p == 'u' || *p == 'o' || *p == 'x') {
-                                               int base = get_base(*p);
-                                               write_integer(ap, s, unsigned long long, base);
-                                       }
-                               } else if (*p == 'd' || *p == 'i') { // %ld or %li
-                                       write_integer(ap, s, long, 10);
-                               } else if (*p == 'u' || *p == 'o' || *p == 'x') {
-                                       int base = get_base(*p);
-                                       write_integer(ap, s, unsigned long, base);
+                               z.base = 10;
+                               if (z.n_ell == 0) write_integer(ap, s, int, z, "0123456789");
+                               else if (z.n_ell == 1) write_integer(ap, s, long, z, "0123456789");
+                               else write_integer(ap, s, long long, z, "0123456789");
+                               finished = 1;
+                       } else if (*p == 'u' || *p == 'o' || *p == 'x' || *p == 'X') { // %u, %o or %x
+                               const char *conv = (*p == 'X')? "0123456789ABCDEF" : "0123456789abcdef";
+                               if (*p == 'u') z.base = 10;
+                               else if (*p == 'o') z.base = 8;
+                               else if (*p == 'x' || *p == 'X') z.base = 16;
+                               if (z.n_ell == 0) write_integer(ap, s, unsigned, z, conv);
+                               else if (z.n_ell == 1) write_integer(ap, s, unsigned long, z, conv);
+                               else write_integer(ap, s, unsigned long long, z, conv);
+                               finished = 1;
+                       } else if (*p == 'f' || *p == 'e') {
+                               const char *t, *r = 0;
+                               double x = va_arg(ap, double);
+                               uint64_t *y = (uint64_t*)&x;
+                               int l;
+                               if ((*y >> 52 & 0x7ff) == 0x7ff) { // nan, inf or -inf
+                                       if (*y & 0x000fffffffffffffull) r = "nan";
+                                       else if (*y>>63) r = "-inf";
+                                       else r = "inf";
+                                       l = strlen(r);
+                                       enlarge(s, l);
+                                       for (t = r; *t; ++t) s->s[s->l++] = *t;
+                               } else if (*p == 'f') {
                                }
+                               finished = 1;
                        }
                        ++p;
+                       if (finished) state = 0;
                } else {
                        q = p;
                        while (*p && *p != '%') ++p;
-                       enlarge(s, p - q);
-                       memcpy(s->s + s->l, q, p - q);
-                       s->l += p - q;
-                       s->s[s->l] = 0;
+                       if (p > q) {
+                               enlarge(s, p - q);
+                               memcpy(s->s + s->l, q, p - q);
+                               s->l += p - q;
+                       }
+                       if (*p == '%') {
+                               state = 1;
+                               ++p;
+                               memset(&z, 0, sizeof(printf_conv_t)); z.fill = -1;
+                       }
                }
        }
        va_end(ap);
-
-#undef write_integer
-
+       s->s[s->l] = 0;
        return 0;
 }
 
@@ -282,7 +319,8 @@ int main()
        s = (kstring_t*)calloc(1, sizeof(kstring_t));
        { // test ksprintf_fast()
                long xx = -10;
-               ksprintf_fast(s, " pooiu %% %s %ld %c %x", "+++", xx, '*', 100); printf("'%s'\n", s->s); s->l = 0;
+               ksprintf_fast(s, " pooiu %% %s %ld %c%-5.4X %f", "+++", xx, '*', 110, 2.45); printf("'%s'\n", s->s); s->l = 0;
+               printf("%4.3x, %.1f\n", 100, 1e30);
        }
        // test ksprintf()
        ksprintf(s, " abcdefg:    %d ", 100);