+void
+svm_fifo_overwrite_head (svm_fifo_t * f, u8 * data, u32 len)
+{
+ u32 first_chunk;
+ first_chunk = f->nitems - f->head;
+ ASSERT (len <= f->nitems);
+ if (len <= first_chunk)
+ clib_memcpy (&f->data[f->head], data, len);
+ else
+ {
+ clib_memcpy (&f->data[f->head], data, first_chunk);
+ clib_memcpy (&f->data[0], data + first_chunk, len - first_chunk);
+ }
+}