Rengasbufferina

Rengasbufferina, commonly called a ring buffer or circular buffer in English, is a fixed-size data structure that behaves as a circular queue. It uses a single contiguous block of memory and supports efficient, constant-time insertion and removal with wrap-around when the end of the buffer is reached.

Implementation typically stores elements in an array of a predetermined capacity, along with a read index (head) and a write index (tail). The buffer is considered empty when head equals tail (often with an additional empty/full flag or a count). It is considered full when advancing the tail would collide with the head. Enqueue writes at the tail position and advances the tail modulo the capacity; Dequeue reads from the head and advances the head similarly. Some implementations use a capacity of N and reserve one slot to distinguish full from empty, others maintain a size counter.

Rengasbufferina is widely used in real-time and embedded systems, audio processing, and producer-consumer patterns because it provides predictable latency and avoids dynamic memory allocation. Variants exist for single-producer single-consumer, multi-producer, and multi-consumer scenarios, often requiring synchronization or lock-free techniques to guard against data races.

Advantages include constant-time operations, locality of reference, and no fragmentation. Limitations include fixed capacity that can lead to overflow if not managed, possible data loss or overwriting depending on policy, and the need for careful synchronization in concurrent environments. Design choices include how full/empty states are detected and whether to overwrite old data on overflow.