2 files changed, 83 insertions, 0 deletions

diff --git a/toxcore/util.c b/toxcore/util.c
index 5a72c4a4..d6db946d 100644
--- a/toxcore/util.c
+++ b/toxcore/util.c
@@ -185,3 +185,76 @@ 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;
+}
+void rb_clear(RingBuffer *b)
+{
+    while (!rb_empty(b)) {
+        void *p;
+        rb_read(b, &p);
+        free(p);
+    }
+}
+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_free(RingBuffer *b)
+{
+    if (b) {
+        rb_clear(b);
+        free(b->data);
+        free(b);
+    }
+}
\ No newline at end of file
diff --git a/toxcore/util.h b/toxcore/util.h
index fab26e29..6c3d3b38 100644
--- a/toxcore/util.h
+++ b/toxcore/util.h
@@ -30,6 +30,7 @@
 #include <pthread.h>
 
 #define MIN(a,b) (((a)<(b))?(a):(b))
+#define PAIR(TYPE1__, TYPE2__) struct { TYPE1__ first; TYPE2__ second; }
 
 void unix_time_update();
 uint64_t unix_time();
@@ -56,4 +57,13 @@ int load_state(load_state_callback_func load_state_callback, void *outer,
 /* Returns -1 if failed or 0 if success */
 int create_recursive_mutex(pthread_mutex_t *mutex);
 
+/* Ring buffer */
+typedef struct RingBuffer RingBuffer;
+bool rb_full(const RingBuffer *b);
+bool rb_empty(const RingBuffer *b);
+void* rb_write(RingBuffer* b, void* p);
+bool rb_read(RingBuffer* b, void** p);
+void rb_clear(RingBuffer *b);
+RingBuffer *rb_new(int size);
+void rb_free(RingBuffer *b);
 #endif /* __UTIL_H__ */