make sdust working with kalloc

sdust.h

@@ -0,0 +1,23 @@
+#ifndef SDUST_H
+#define SDUST_H
+
+struct sdust_buf_s;
+typedef struct sdust_buf_s sdust_buf_t;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// the simple interface
+uint64_t *sdust(const uint8_t *seq, int l_seq, int T, int W, int *n);
+
+// the following interface dramatically reduce heap allocations when sdust is frequently called.
+sdust_buf_t *sdust_buf_init(void);
+void sdust_buf_destroy(sdust_buf_t *buf);
+const uint64_t *sdust_core(const uint8_t *seq, int l_seq, int T, int W, int *n, sdust_buf_t *buf);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif