+
+/* Writes the 'size' bytes in 'buf' to 'string' as hex bytes arranged 16 per
+ * line. Numeric offsets are also included, starting at 'ofs' for the first
+ * byte in 'buf'. If 'ascii' is true then the corresponding ASCII characters
+ * are also rendered alongside. */
+void
+ds_put_hex_dump(struct ds *ds, const void *buf_, size_t size,
+ uintptr_t ofs, bool ascii)
+{
+ const uint8_t *buf = buf_;
+ const size_t per_line = 16; /* Maximum bytes per line. */
+
+ while (size > 0)
+ {
+ size_t start, end, n;
+ size_t i;
+
+ /* Number of bytes on this line. */
+ start = ofs % per_line;
+ end = per_line;
+ if (end - start > size)
+ end = start + size;
+ n = end - start;
+
+ /* Print line. */
+ ds_put_format(ds, "%08jx ", (uintmax_t) ROUND_DOWN(ofs, per_line));
+ for (i = 0; i < start; i++)
+ ds_put_format(ds, " ");
+ for (; i < end; i++)
+ ds_put_format(ds, "%02hhx%c",
+ buf[i - start], i == per_line / 2 - 1? '-' : ' ');
+ if (ascii)
+ {
+ for (; i < per_line; i++)
+ ds_put_format(ds, " ");
+ ds_put_format(ds, "|");
+ for (i = 0; i < start; i++)
+ ds_put_format(ds, " ");
+ for (; i < end; i++) {
+ int c = buf[i - start];
+ ds_put_char(ds, c >= 32 && c < 127 ? c : '.');
+ }
+ for (; i < per_line; i++)
+ ds_put_format(ds, " ");
+ ds_put_format(ds, "|");
+ }
+ ds_put_format(ds, "\n");
+
+ ofs += n;
+ buf += n;
+ size -= n;
+ }
+}