+
+static int heap_cread_item (void *vp, char **dst, int *insertMode);
+
+int heap_cread_item2 (void *vp, char **dst, int *insertMode)
+{
+ struct heap_cread_info *p = (struct heap_cread_info *) vp;
+ int level = 0;
+
+ if (p->ret == 0) /* lookahead was 0?. Return that in read next round */
+ {
+ p->ret = -1;
+ return 0;
+ }
+ else if (p->ret == -1) /* Must read new item ? */
+ {
+ char *dst_1 = p->key_1;
+ p->ret = heap_cread_item(vp, &dst_1, &p->mode_1);
+ p->sz_1 = dst_1 - p->key_1;
+ }
+ else
+ { /* lookahead in 2 . Now in 1. */
+ p->sz_1 = p->sz_2;
+ p->mode_1 = p->mode_2;
+ memcpy (p->key_1, p->key_2, p->sz_2);
+ }
+ if (p->mode_1)
+ level = 1; /* insert */
+ else
+ level = -1; /* delete */
+ while(1)
+ {
+ char *dst_2 = p->key_2;
+ p->ret = heap_cread_item(vp, &dst_2, &p->mode_2);
+ if (!p->ret)
+ {
+ if (level)
+ break;
+ p->ret = -1;
+ return 0;
+ }
+ p->sz_2 = dst_2 - p->key_2;
+ if (p->sz_1 == p->sz_2 && memcmp(p->key_1, p->key_2, p->sz_1) == 0)
+ {
+ if (p->mode_2) /* adjust level according to deletes/inserts */
+ level++;
+ else
+ level--;
+ }
+ else
+ {
+ if (level)
+ break;
+ /* all the same. new round .. */
+ p->sz_1 = p->sz_2;
+ p->mode_1 = p->mode_2;
+ memcpy (p->key_1, p->key_2, p->sz_1);
+ if (p->mode_1)
+ level = 1; /* insert */
+ else
+ level = -1; /* delete */
+ }
+ }
+ /* outcome is insert (1) or delete (0) depending on final level */
+ if (level > 0)
+ *insertMode = 1;
+ else
+ *insertMode = 0;
+ memcpy (*dst, p->key_1, p->sz_1);
+#if PR_KEY
+ printf ("top: ");
+ pkey(*dst, *insertMode); fflush(stdout);
+#endif
+ (*dst) += p->sz_1;
+ return 1;
+}