+void
+svm_fifo_overwrite_head (svm_fifo_t * f, u8 * data, u32 len)
+{
+ u32 first_chunk;
+ ASSERT (len <= f->nitems);
+ if (len < f->nitems - f->head)
+ clib_memcpy (&f->data[f->head], data, len);
+ else
+ {
+ first_chunk = len - (f->nitems - f->head);
+ clib_memcpy (&f->data[f->head], data, first_chunk);
+ clib_memcpy (f->data, data + first_chunk, len - first_chunk);
+ }
+}