README.md

hdr-histogram-wasm

This project exposes hdrhistogram APIs for use in the pewpew results viewer via WASM. It has superior performance to the native JavaScript version (HdrHistogramJS).

To build

First ensure you have wasm-pack and Rust installed. Then run wasm-pack build --release -t web --scope fs

Usage:

export class HDRHistogram {
/**
 * Free's the memory after creating a PewPew HDRHistogram object. MUST BE CALLED TO AVOID LEAKS
 */
  free(): void;

/**
 * Creates a PewPew HDRHistogram object from a stats file base64 string
 * @param {string} base64 encoded string from a stats result file
 * @param {string: optional} log_level What level to log at (default: error). Only set on first call. Subsequent log_level(s) are ignored
 */
  constructor(base64: string, log_level?: string);

/**
 * @returns {number}
 */
  getMean(): number;

/**
 * @returns {number}
 */
  getStdDeviation(): number;

/**
 * @returns {BigInt}
 */
  getTotalCount(): BigInt;

/**
 * @param {number} percentile
 * @returns {BigInt}
 */
  getValueAtPercentile(percentile: number): BigInt;

/**
 * @param {HDRHistogram} other
 */
  add(other: HDRHistogram): void;

/**
 * @returns {BigInt}
 */
  getMinNonZeroValue(): BigInt;

/**
 * @returns {BigInt}
 */
  getMaxValue(): BigInt;

/**
 * Clones the histogram. Clone must be free'd separately with copy.free();
 * @returns {HDRHistogram}
 */
  clone(): HDRHistogram;
}

Example:

let hdrHistogram;
try {
  hdrHistogram = new HDRHistogram(statsBase64String, "debug");
  console.log("Max Value: " + config.getMaxValue());
  console.log("Mean Value: " + config.getMean());
} finally {
  if (hdrHistogram) {
    hdrHistogram.free();
  }
}