RingBuffer example

Author: tshemsedinov

JavaScript/3-ring.js

@@ -0,0 +1,36 @@
+'use strict';
+
+class RingBuffer {
+  constructor(size) {
+    this.size = size;
+    this.buffer = Buffer.alloc(size);
+    this.offset = 0;
+  }
+
+  write(data) {
+    const { size, offset } = this;
+    const { length } = data;
+    const available = size - offset;
+    const end = Math.min(offset + length, size + 1);
+    const rest = available - length;
+    let position = 0;
+    for (let i = offset; i < end; i++) {
+      this.buffer[i] = data.charCodeAt(position++);
+    }
+    this.offset += position;
+    if (this.offset > size) this.offset = 0;
+    if (rest < 0) this.write(data.slice(rest));
+  }
+}
+
+// Usage
+
+const ring = new RingBuffer(10);
+ring.write('1');
+console.log(ring.buffer.toString('utf8'));
+ring.write('23');
+console.log(ring.buffer.toString('utf8'));
+ring.write('4567890A');
+console.log(ring.buffer.toString('utf8'));
+ring.buffer.write('B');
+console.log(ring.buffer.toString('utf8'));