walt-compiler/src/generator/generate-data.js

Alternative syntax for WebAssembly text format

// @flow
// import { stringEncoder } from '../utils/string';
import { u32 } from 'wasm-types';
import OutputStream from '../utils/output-stream';

export default function generateData(
  statics: any,
  DATA_SECTION_HEADER_SIZE: number
) {
  // Reserve N bytes for data size header
  let offsetAccumulator = DATA_SECTION_HEADER_SIZE;

  const map: { [string]: number } = {};

  const data = Object.entries(statics).reduce(
    (acc, [key, encoded]: [string, any]) => {
      acc.push({ offset: Number(offsetAccumulator), data: encoded });
      map[key] = offsetAccumulator;
      offsetAccumulator += encoded.size;
      return acc;
    },
    []
  );

  // reserved stream for the size header
  const lengthStream = new OutputStream();
  lengthStream.push(u32, offsetAccumulator, String(offsetAccumulator));

  return {
    data: [{ offset: 0, data: lengthStream }, ...data],
    map,
  };
}