auto import from //depot/cupcake/@135843
diff --git a/tools/apriori/debug.c b/tools/apriori/debug.c
new file mode 100644
index 0000000..263e09f
--- /dev/null
+++ b/tools/apriori/debug.c
@@ -0,0 +1,38 @@
+#include <debug.h>
+#include <stdio.h>
+#include <ctype.h>
+
+#define NUM_COLS (32)
+
+int dump_hex_buffer(FILE *s, void *b, size_t len, size_t elsize) {
+ int num_nonprintable = 0;
+ int i, last;
+ char *pchr = (char *)b;
+ fputc('\n', s);
+ fprintf(s, "%p: ", b);
+ for (i = last = 0; i < len; i++) {
+ if (!elsize) {
+ if (i && !(i % 4)) fprintf(s, " ");
+ if (i && !(i % 8)) fprintf(s, " ");
+ } else {
+ if (i && !(i % elsize)) fprintf(s, " ");
+ }
+
+ if (i && !(i % NUM_COLS)) {
+ while (last < i) {
+ if (isprint(pchr[last]))
+ fputc(pchr[last], s);
+ else {
+ fputc('.', s);
+ num_nonprintable++;
+ }
+ last++;
+ }
+ fprintf(s, " (%d)\n%p: ", i, b);
+ }
+ fprintf(s, "%02x", (unsigned char)pchr[i]);
+ }
+ if (i && (i % NUM_COLS)) fputs("\n", s);
+ return num_nonprintable;
+}
+