Merge branch 'rework-directory-structure'

1 files changed, 156 insertions, 0 deletions

diff --git a/src/ringbuff.c b/src/ringbuff.c
new file mode 100644
index 0000000..1294b3b
--- /dev/null
+++ b/src/ringbuff.c
@@ -0,0 +1,156 @@
+#include <assert.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "util.h"
+
+/* --8<-- ring_type */
+typedef int T;
+
+struct ring_buffer {
+        size_t head, tail;
+        T      array[8]; /* fit for your needs... */
+};
+/* -->8-- */
+
+/* --8<-- ring_init */
+void
+ring_init(struct ring_buffer *rb)
+{
+        rb->head = rb->tail = 0;
+}
+/* -->8-- */
+
+/* --8<-- ring_push_front */
+bool
+ring_push_front(struct ring_buffer *rb, T data)
+{
+        const size_t prev = (rb->tail + NELEM(rb->array) - 1) % NELEM(rb->array);
+
+        if ( prev == rb->head ) {
+                return false;
+        }
+
+        rb->array[prev] = data;
+        rb->tail        = prev;
+
+        return true;
+}
+/* -->8-- */
+
+/* --8<-- ring_push_back */
+bool
+ring_push_back(struct ring_buffer *rb, T data)
+{
+        const size_t next = (rb->head + 1) % NELEM(rb->array);
+
+        if ( next == rb->tail ) {
+                return false;
+        }
+
+        rb->array[rb->head] = data;
+        rb->head            = next;
+
+        return true;
+}
+/* -->8-- */
+
+/* --8<-- ring_pop_front */
+bool
+ring_pop_front(struct ring_buffer *rb, T *data)
+{
+        if ( rb->head == rb->tail ) {
+                return false;
+        }
+
+        const size_t next = (rb->tail + 1) % NELEM(rb->array);
+
+        *data    = rb->array[rb->tail];
+        rb->tail = next;
+
+        return true;
+}
+/* -->8-- */
+
+/* --8<-- ring_pop_back */
+bool
+ring_pop_back(struct ring_buffer *rb, T *data)
+{
+        if ( rb->head == rb->tail ) {
+                return false;
+        }
+
+        const size_t prev = (rb->head + NELEM(rb->array) - 1) % NELEM(rb->array);
+
+        *data    = rb->array[prev];
+        rb->head = prev;
+
+        return true;
+}
+/* -->8-- */
+
+/* --8<-- ring_put */
+bool
+ring_put(struct ring_buffer *rb, T data)
+{
+        return ring_push_back(rb, data);
+}
+/* -->8-- */
+
+/* --8<-- ring_get */
+bool
+ring_get(struct ring_buffer *rb, T *data)
+{
+        return ring_pop_front(rb, data);
+}
+/* -->8-- */
+
+void
+debug_print(const char *msg, struct ring_buffer *rb)
+{
+        printf("%s: head: %zu, tail: %zu\n", msg, rb->head, rb->tail);
+}
+
+int
+main(void)
+{
+#if 0
+        struct ring_buffer rb;
+        ring_init(&rb);
+#else
+        struct ring_buffer rb = { .head = 0, .tail = 0 };
+#endif
+
+        assert(ring_push_back(&rb, 1) == true); // 1
+        assert(ring_push_back(&rb, 2) == true); // 1, 2
+        assert(ring_push_back(&rb, 3) == true); // 1, 2, 3
+        assert(ring_push_back(&rb, 4) == true); // 1, 2, 3, 4
+
+        debug_print("Stand", &rb);
+
+        assert(ring_push_front(&rb, 0) == true);  // 0, 1, 2, 3, 4
+        assert(ring_push_front(&rb, -1) == true); // -1, 0, 1, 2, 3, 4
+
+        debug_print("Stand", &rb);
+
+        T temp;
+        assert(ring_pop_back(&rb, &temp) == true);  // -1, 0, 1, 2, 3
+        assert(ring_pop_front(&rb, &temp) == true); // 0, 1, 2, 3
+
+        debug_print("Stand", &rb);
+
+        assert(ring_push_back(&rb, 4) == true);   // 0, 1, 2, 3, 4
+        assert(ring_push_back(&rb, 5) == true);   // 0, 1, 2, 3, 4, 5
+        assert(ring_push_back(&rb, 6) == true);   // 0, 1, 2, 3, 4, 5, 6
+        assert(ring_push_back(&rb, 7) == false);  // 0, 1, 2, 3, 4, 5, 6
+        assert(ring_push_front(&rb, 7) == false); // 0, 1, 2, 3, 4, 5, 6
+
+        while ( ring_pop_back(&rb, &temp) ) {
+                printf("temp: %d\n", temp);
+        }
+
+        debug_print("Stand", &rb);
+
+        return EXIT_SUCCESS;
+}