initial check-in

stretchy_buffer.h

@@ -0,0 +1,28 @@
+// stretchy buffer // init: NULL // free: sbfree() // push_back: sbpush() // size: sbcount() //
+#define stbcg_sbfree(a)         ((a) ? free(stb__sbraw(a)),0 : 0)
+#define stbcg_sbpush(a,v)       (stb__sbmaybegrow(a,1), (a)[stb__sbn(a)++] = (v))
+#define stbcg_sbcount(a)        ((a) ? stb__sbn(a) : 0)
+#define stbcg_sbadd(a,n)        (stb__sbmaybegrow(a,n), stb__sbn(a)+=(n), &(a)[stb__sbn(a)-(n)])
+#define stbcg_sblast(a)         ((a)[stb__sbn(a)-1])
+
+#include <stdlib.h>
+#define stb__sbraw(a) ((int *) (a) - 2)
+#define stb__sbm(a)   stb__sbraw(a)[0]
+#define stb__sbn(a)   stb__sbraw(a)[1]
+
+#define stb__sbneedgrow(a,n)  ((a)==0 || stb__sbn(a)+n >= stb__sbm(a))
+#define stb__sbmaybegrow(a,n) (stb__sbneedgrow(a,(n)) ? stb__sbgrow(a,n) : 0)
+#define stb__sbgrow(a,n)  stb__sbgrowf((void **) &(a), (n), sizeof(*(a)))
+
+static void stb__sbgrowf(void **arr, int increment, int itemsize)
+{
+   int d = *arr ? 2*stb__sbm(*arr) : 0, n2 = stbcg_sbcount(*arr) + increment;
+   int m = d > n2 ? d : n2;
+   void *p = realloc(*arr ? stb__sbraw(*arr) : 0, itemsize * m + sizeof(int)*2);
+   assert(p);
+   if (p) {
+      if (!*arr) ((int *) p)[1] = 0;
+      *arr = (void *) ((int *) p + 2);
+      stb__sbm(*arr) = m;
+   }
+}