Merge commit 'upstream/0.3'
[pysam.git] / tabix / kstring.c
diff --git a/tabix/kstring.c b/tabix/kstring.c
new file mode 100644 (file)
index 0000000..e0203fa
--- /dev/null
@@ -0,0 +1,165 @@
+#include <stdarg.h>
+#include <stdio.h>
+#include <ctype.h>
+#include <string.h>
+#include <stdint.h>
+#include "kstring.h"
+
+int ksprintf(kstring_t *s, const char *fmt, ...)
+{
+       va_list ap;
+       int l;
+       va_start(ap, fmt);
+       l = vsnprintf(s->s + s->l, s->m - s->l, fmt, ap); // This line does not work with glibc 2.0. See `man snprintf'.
+       va_end(ap);
+       if (l + 1 > s->m - s->l) {
+               s->m = s->l + l + 2;
+               kroundup32(s->m);
+               s->s = (char*)realloc(s->s, s->m);
+               va_start(ap, fmt);
+               l = vsnprintf(s->s + s->l, s->m - s->l, fmt, ap);
+       }
+       va_end(ap);
+       s->l += l;
+       return l;
+}
+
+// s MUST BE a null terminated string; l = strlen(s)
+int ksplit_core(char *s, int delimiter, int *_max, int **_offsets)
+{
+       int i, n, max, last_char, last_start, *offsets, l;
+       n = 0; max = *_max; offsets = *_offsets;
+       l = strlen(s);
+       
+#define __ksplit_aux do {                                                                                              \
+               if (_offsets) {                                                                                                 \
+                       s[i] = 0;                                                                                                       \
+                       if (n == max) {                                                                                         \
+                               max = max? max<<1 : 2;                                                                  \
+                               offsets = (int*)realloc(offsets, sizeof(int) * max);    \
+                       }                                                                                                                       \
+                       offsets[n++] = last_start;                                                                      \
+               } else ++n;                                                                                                             \
+       } while (0)
+
+       for (i = 0, last_char = last_start = 0; i <= l; ++i) {
+               if (delimiter == 0) {
+                       if (isspace(s[i]) || s[i] == 0) {
+                               if (isgraph(last_char)) __ksplit_aux; // the end of a field
+                       } else {
+                               if (isspace(last_char) || last_char == 0) last_start = i;
+                       }
+               } else {
+                       if (s[i] == delimiter || s[i] == 0) {
+                               if (last_char != 0 && last_char != delimiter) __ksplit_aux; // the end of a field
+                       } else {
+                               if (last_char == delimiter || last_char == 0) last_start = i;
+                       }
+               }
+               last_char = s[i];
+       }
+       *_max = max; *_offsets = offsets;
+       return n;
+}
+
+/**********************
+ * Boyer-Moore search *
+ **********************/
+
+// reference: http://www-igm.univ-mlv.fr/~lecroq/string/node14.html
+int *ksBM_prep(const uint8_t *pat, int m)
+{
+       int i, *suff, *prep, *bmGs, *bmBc;
+       prep = calloc(m + 256, 1);
+       bmGs = prep; bmBc = prep + m;
+       { // preBmBc()
+               for (i = 0; i < 256; ++i) bmBc[i] = m;
+               for (i = 0; i < m - 1; ++i) bmBc[pat[i]] = m - i - 1;
+       }
+       suff = calloc(m, sizeof(int));
+       { // suffixes()
+               int f = 0, g;
+               suff[m - 1] = m;
+               g = m - 1;
+               for (i = m - 2; i >= 0; --i) {
+                       if (i > g && suff[i + m - 1 - f] < i - g)
+                               suff[i] = suff[i + m - 1 - f];
+                       else {
+                               if (i < g) g = i;
+                               f = i;
+                               while (g >= 0 && pat[g] == pat[g + m - 1 - f]) --g;
+                               suff[i] = f - g;
+                       }
+               }
+       }
+       { // preBmGs()
+               int j = 0;
+               for (i = 0; i < m; ++i) bmGs[i] = m;
+               for (i = m - 1; i >= 0; --i)
+                       if (suff[i] == i + 1)
+                               for (; j < m - 1 - i; ++j)
+                                       if (bmGs[j] == m)
+                                               bmGs[j] = m - 1 - i;
+               for (i = 0; i <= m - 2; ++i)
+                       bmGs[m - 1 - suff[i]] = m - 1 - i;
+       }
+       free(suff);
+       return prep;
+}
+
+int *ksBM_search(const uint8_t *str, int n, const uint8_t *pat, int m, int *_prep, int *n_matches)
+{
+       int i, j, *prep, *bmGs, *bmBc;
+       int *matches = 0, mm = 0, nm = 0;
+       prep = _prep? _prep : ksBM_prep(pat, m);
+       bmGs = prep; bmBc = prep + m;
+       j = 0;
+       while (j <= n - m) {
+               for (i = m - 1; i >= 0 && pat[i] == str[i+j]; --i);
+               if (i < 0) {
+                       if (nm == mm) {
+                               mm = mm? mm<<1 : 1;
+                               matches = realloc(matches, mm * sizeof(int));
+                       }
+                       matches[nm++] = j;
+                       j += bmGs[0];
+               } else {
+                       int max = bmBc[str[i+j]] - m + 1 + i;
+                       if (max < bmGs[i]) max = bmGs[i];
+                       j += max;
+               }
+       }
+       *n_matches = nm;
+       if (_prep == 0) free(prep);
+       return matches;
+}
+
+#ifdef KSTRING_MAIN
+#include <stdio.h>
+int main()
+{
+       kstring_t *s;
+       int *fields, n, i;
+       s = (kstring_t*)calloc(1, sizeof(kstring_t));
+       // test ksprintf()
+       ksprintf(s, " abcdefg:    %d ", 100);
+       printf("'%s'\n", s->s);
+       // test ksplit()
+       fields = ksplit(s, 0, &n);
+       for (i = 0; i < n; ++i)
+               printf("field[%d] = '%s'\n", i, s->s + fields[i]);
+       free(s);
+
+       {
+               static char *str = "abcdefgcdg";
+               static char *pat = "cd";
+               int n, *matches;
+               matches = ksBM_search(str, strlen(str), pat, strlen(pat), 0, &n);
+               printf("%d: \n", n);
+               for (i = 0; i < n; ++i)
+                       printf("- %d\n", matches[i]);
+               free(matches);
+       }
+       return 0;
+}
+#endif