Add DataBuffer class

gui_dev/src/utils/DataBuffer.js

@@ -0,0 +1,63 @@
+export class DataBuffer {
+  /**
+   * Creates an instance of DataBuffer
+   * @param {number} capacity - The capacity of the buffer
+   * @param {number} sampleRate - The sample rate of the data
+   * @param {number} numChannels - The number of channels in the data
+   */
+  constructor(capacity, numDataPoints) {
+    this.capacity = capacity;
+    this.numDataPoints = numDataPoints;
+
+    this.data = new Float32Array(capacity * numDataPoints);
+
+    this.writeHead = 0;
+    this.readHead = 0;
+  }
+
+  /**
+   * Store the header of the data, in form an array of strings
+   * @param {Array.<String>} header
+   */
+  setHeader(header) {
+    this.header = header;
+  }
+
+  /**
+   * Adds a datapoint to the buffer
+   * @param {Float32Array} data - The data to add
+   */
+  addTimePoint(data) {
+    for (let i = 0; i < data.length; i++) {
+      this.data[this.writeHead * this.numDataPoints + i] = data[i];
+    }
+
+    this.writeHead = (this.writeHead + 1) % this.capacity;
+
+    // Overwrite the oldest data point if the buffer is full (maybe prevent this?)
+    if (this.writeHead === this.readHead) {
+      this.readHead = (this.readHead + 1) % this.capacity;
+    }
+  }
+
+  /**
+   * Get the next data point from the buffer
+   * @returns {Float32Array} - The data points
+   */
+  getNextDataPoint() {
+    if (this.readHead === this.writeHead) {
+      return null;
+    }
+
+    // Create a view into the buffer for the current read position
+    const result = this.data.subarray(
+      this.readHead * this.numDataPoints,
+      (this.readHead + 1) * this.numDataPoints
+    );
+
+    // Advance the read head
+    this.readHead = (this.readHead + 1) % this.capacity;
+
+    return result;
+  }
+}