1 files changed, 46 insertions, 0 deletions
diff --git a/src/contrib/ucw/heap.h b/src/contrib/ucw/heap.h
new file mode 100644
index 0000000..f85bb82
--- /dev/null
+++ b/src/contrib/ucw/heap.h
@@ -0,0 +1,46 @@
+/*  Copyright (C) 2022 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+  
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+  
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+struct heap_val {
+	int pos;
+};
+
+typedef struct heap_val heap_val_t;
+
+struct heap {
+   int num;		/* Number of elements */
+   int max_size;	/* Size of allocated memory */
+   int (*cmp)(void *, void *);
+   heap_val_t **data;
+};		/* Array follows */
+
+#define INITIAL_HEAP_SIZE	512 /* initial heap size */
+#define HEAP_INCREASE_STEP	2 /* multiplier for each inflation, keep conservative */
+#define HEAP_DECREASE_THRESHOLD	2 /* threshold for deflation, keep conservative */
+#define HELEMENT(h,num) 	((h)->data + (num))
+#define HHEAD(h) 		HELEMENT((h), 1)
+#define EMPTY_HEAP(h) 		((h)->num == 0)
+
+int heap_init(struct heap *, int (*cmp)(void *, void *), int);
+void heap_deinit(struct heap *);
+
+void heap_delmin(struct heap *);
+int heap_insert(struct heap *, heap_val_t *);
+int heap_find(struct heap *, heap_val_t *);
+void heap_delete(struct heap *, int);
+void heap_replace(struct heap *, int, heap_val_t *);