cii: Add ring interface

cii/CMakeLists.txt

@@ -14,6 +14,7 @@ set(SOURCE_FILES
     src/hash.c
     src/list.c
     src/mem.c
+    src/ring.c
     src/seq.c
     src/set.c
     src/table.c
@@ -28,6 +29,7 @@ set(HEADER_FILES
     include/cii/hash.h
     include/cii/list.h
     include/cii/mem.h
+    include/cii/ring.h
     include/cii/seq.h
     include/cii/set.h
     include/cii/table.h

cii/include/cii/ring.h

@@ -0,0 +1,103 @@
+// Copyright (c) 2023 Xu Shaohua <[email protected]>. All rights reserved.
+// Use of this source is governed by GNU General Public License
+// that can be found in the LICENSE file.
+
+#ifndef CII_RING_H_
+#define CII_RING_H_
+
+#include <stddef.h>
+
+typedef struct ring_s ring_t;
+
+/**
+ * Creates and returns an empty ring.
+ *
+ * @return
+ */
+extern ring_t* ring_new(void);
+
+/**
+ * Creates and returns a ring whose values are initialized to its non-null pointer
+ * arguments.
+ *
+ * @param x
+ * @return
+ */
+extern ring_t* ring_ring(void* x, ...);
+
+/**
+ * Deallocates and clear a ring.
+ * @param ring
+ */
+extern void ring_free(ring_t** ring);
+
+/**
+ * Returns the number of values in a ring.
+ *
+ * @param ring
+ * @return
+ */
+extern size_t ring_length(ring_t* ring);
+
+/**
+ * Get the value at |index| in a ring.
+ *
+ * It is a checked runtime error if index is out of range.
+ *
+ * @param ring
+ * @param index
+ * @return
+ */
+extern void* ring_get(ring_t* ring, size_t index);
+
+/**
+ * Put a new value at |index| and returns old value.
+ *
+ * @param ring
+ * @param index
+ * @param value
+ * @return
+ */
+extern void* ring_put(ring_t* ring, size_t index, void* value);
+
+/**
+ * Add |value| at anywhere in a ring and returns |value|.
+ *
+ * @param ring
+ * @param pos
+ * @param value
+ * @return
+ */
+extern void* ring_add(ring_t* ring, int pos, void* value);
+
+/**
+ * Add a value to lower end of ring.
+ *
+ * @param ring
+ * @param value
+ * @return
+ */
+extern void* ring_add_low(ring_t* ring, void* value);
+
+/**
+ * Add a value to higher end of ring.
+ * @param ring
+ * @param value
+ * @return
+ */
+extern void* ring_add_high(ring_t* ring, void* value);
+
+/**
+ * Remove value at |index| and returns that value.
+ *
+ * @param ring
+ * @param index
+ * @return
+ */
+extern void* ring_remove(ring_t* ring, size_t index);
+
+extern void* ring_remove_low(ring_t* ring);
+
+extern void* ring_remove_high(ring_t* ring);
+
+#endif  // CII_RING_H_

cii/src/ring.c

@@ -0,0 +1,5 @@
+// Copyright (c) 2023 Xu Shaohua <[email protected]>. All rights reserved.
+// Use of this source is governed by GNU General Public License
+// that can be found in the LICENSE file.
+
+#include "cii/ring.h"