1 files changed, 84 insertions, 0 deletions

diff --git a/toxcore/util.c b/toxcore/util.c
index c320cdc4..28d8721c 100644
--- a/toxcore/util.c
+++ b/toxcore/util.c
@@ -192,3 +192,87 @@ int create_recursive_mutex(pthread_mutex_t *mutex)
 
     return 0;
 }
+
+
+struct RingBuffer {
+    uint16_t size; /* Max size */
+    uint16_t start;
+    uint16_t end;
+    void   **data;
+};
+
+bool rb_full(const RingBuffer *b)
+{
+    return (b->end + 1) % b->size == b->start;
+}
+bool rb_empty(const RingBuffer *b)
+{
+    return b->end == b->start;
+}
+void *rb_write(RingBuffer *b, void *p)
+{
+    void *rc = NULL;
+
+    if ((b->end + 1) % b->size == b->start) /* full */
+        rc = b->data[b->start];
+
+    b->data[b->end] = p;
+    b->end = (b->end + 1) % b->size;
+
+    if (b->end == b->start)
+        b->start = (b->start + 1) % b->size;
+
+    return rc;
+}
+bool rb_read(RingBuffer *b, void **p)
+{
+    if (b->end == b->start) { /* Empty */
+        *p = NULL;
+        return false;
+    }
+
+    *p = b->data[b->start];
+    b->start = (b->start + 1) % b->size;
+    return true;
+}
+RingBuffer *rb_new(int size)
+{
+    RingBuffer *buf = calloc(sizeof(RingBuffer), 1);
+
+    if (!buf) return NULL;
+
+    buf->size = size + 1; /* include empty elem */
+
+    if (!(buf->data = calloc(buf->size, sizeof(void *)))) {
+        free(buf);
+        return NULL;
+    }
+
+    return buf;
+}
+void rb_kill(RingBuffer *b)
+{
+    if (b) {
+        free(b->data);
+        free(b);
+    }
+}
+uint16_t rb_size(const RingBuffer *b)
+{
+    if (rb_empty(b))
+        return 0;
+
+    return
+        b->end > b->start ?
+        b->end - b->start :
+        (b->size - b->start) + b->end;
+}
+uint16_t rb_data(const RingBuffer *b, void **dest)
+{
+    uint16_t i = 0;
+
+    for (; i < rb_size(b); i++)
+        dest[i] = b->data[(b->start + i) % b->size];
+
+    return i;
+}