gzip.ts

import * as fflate from "fflate";
import type { Codec, CodecConstructor } from "./types.js";

type ValidGZipLevelSetting = 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9;

interface GZipConfig {
  level?: number;
}

const GZip: CodecConstructor<GZipConfig> = class GZip implements Codec {
  public static codecId = "gzip";
  public level: ValidGZipLevelSetting;

  constructor(level = 1) {
    if (level < 0 || level > 9) {
      throw new Error("Invalid gzip compression level, it should be between 0 and 9");
    }
    this.level = level as ValidGZipLevelSetting;
  }

  static fromConfig({ level }: GZipConfig): GZip {
    return new GZip(level);
  }

  encode(data: Uint8Array): Uint8Array {
    return fflate.gzipSync(data, { level: this.level });
  }

  decode(data: Uint8Array): Uint8Array {
    return fflate.gunzipSync(data);
  }
};

export default GZip;