在nodejs中使用promises将多个svg字符串流式传输到png

const fs = require('fs');
const util = require('util');
const sharp = require('sharp');
const { createCanvas, registerFont } = require('canvas');
const { SVGtoPDF } = require('svg-to-pdfkit');
const { PDFDocument } = require('pdf-lib');
const { SVGPathData } = require('svg-pathdata');
const { DOMParser } = require('xmldom');
const { SVG } = require('@svgdotjs/svg.js');
const { convert } = require('convert-svg-to-png');

async function convertSVGtoPNG(svgString) {
  // 使用svgdotjs库将SVG字符串转换为SVG对象
  const svg = SVG().svg(svgString);

  // 创建一个Canvas对象
  const canvas = createCanvas(svg.width(), svg.height());
  const ctx = canvas.getContext('2d');

  // 渲染SVG到Canvas上
  const render = new DOMParser().parseFromString(svg.svg(), 'image/svg+xml');
  await sharp(Buffer.from(render.documentElement.outerHTML))
    .png()
    .toBuffer()
    .then((buffer) => {
      const img = new Image();
      img.src = buffer;
      ctx.drawImage(img, 0, 0);
    });

  // 将Canvas转换为PNG
  const pngBuffer = await util.promisify(canvas.toBuffer.bind(canvas))();

  return pngBuffer;
}

async function convertMultipleSVGtoPNG(svgStrings) {
  const promises = svgStrings.map((svgString) => convertSVGtoPNG(svgString));
  const pngBuffers = await Promise.all(promises);

  return pngBuffers;
}

const svgStrings = [
  '<svg>...</svg>',
  '<svg>...</svg>',
  '<svg>...</svg>',
  // 添加更多的SVG字符串
];

convertMultipleSVGtoPNG(svgStrings)
  .then((pngBuffers) => {
    // 处理PNG缓冲区
    pngBuffers.forEach((pngBuffer, index) => {
      fs.writeFileSync(`output${index}.png`, pngBuffer);
    });
    console.log('转换完成！');
  })
  .catch((error) => {
    console.error('转换出错：', error);
  });