1 files changed, 39 insertions, 0 deletions
diff --git a/drivers/md/dm-vdo/int-map.h b/drivers/md/dm-vdo/int-map.h
new file mode 100644
index 0000000000..1858ad7998
--- /dev/null
+++ b/drivers/md/dm-vdo/int-map.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#ifndef VDO_INT_MAP_H
+#define VDO_INT_MAP_H
+
+#include <linux/compiler.h>
+#include <linux/types.h>
+
+/**
+ * DOC: int_map
+ *
+ * An int_map associates pointers (void *) with integer keys (u64). NULL pointer values are
+ * not supported.
+ *
+ * The map is implemented as hash table, which should provide constant-time insert, query, and
+ * remove operations, although the insert may occasionally grow the table, which is linear in the
+ * number of entries in the map. The table will grow as needed to hold new entries, but will not
+ * shrink as entries are removed.
+ */
+
+struct int_map;
+
+int __must_check vdo_int_map_create(size_t initial_capacity, struct int_map **map_ptr);
+
+void vdo_int_map_free(struct int_map *map);
+
+size_t vdo_int_map_size(const struct int_map *map);
+
+void *vdo_int_map_get(struct int_map *map, u64 key);
+
+int __must_check vdo_int_map_put(struct int_map *map, u64 key, void *new_value,
+				 bool update, void **old_value_ptr);
+
+void *vdo_int_map_remove(struct int_map *map, u64 key);
+
+#endif /* VDO_INT_MAP_H */