fastify sitemap 生成站点地图 优化seo

[Triment]

sitemap是一个用于生成站点地图的库，官方提供了express 和生成文件的例子，而我用的网站是基于fastify构建的，需要对其进行修改
fastify代码

const app = fastify({ logger: !isProduction, trustProxy: true })
app.get('/sitemap.xml', SiteMap)

siteMap.ts

import { FastifyReply, FastifyRequest } from 'fastify'
import { createReadStream, createWriteStream, existsSync } from 'fs'
import { join, resolve } from 'path'
import { SitemapStream } from 'sitemap'
import { pipeline } from 'stream'
import { createGzip } from 'zlib'
let postCount = 0
export async function SiteMap(request: FastifyRequest, reply: FastifyReply) {
  reply.raw.setHeader('content-type', 'application/xml')
  reply.raw.setHeader('Content-Encoding', 'gzip')
  const count = await getPosts.count()//获取文章数量
  if (existsSync(resolve('./sitemap.xml')) && count === postCount) {//已生成并且文章数量没变就直接读取文件
    createReadStream(resolve('./sitemap.xml'), { encoding: 'utf8' }).pipe(reply.raw)
    return reply
  }
  postCount = count//更新文章数量
  try {
    const smStream = new SitemapStream({ hostname: 'www.xx.com' })
    const streamPipe = smStream.pipe(createGzip())
    const posts = getPosts()
    //create xml stream and pipe
    const xmlFile = createWriteStream(resolve('./sitemap.xml'))
    pipeline(smStream, xmlFile, (err) => {
      if (err) console.log(err)
    })
    //write data to smStream
    posts.map((post) => {
      smStream.write({
        url: join('/post', post.id),
        // changefreq: 'daily',
        lastmod: post.updateAt,
        priority: post.priority,
      })
    })
    //end smStream write and close write stream
    smStream.end()
    xmlFile.close((err) => {
      if (err) console.log(err)
    })
    streamPipe.pipe(reply.raw)
    return reply
  } catch (e) {
    console.error(e)
    reply.status(500).send()
  }
  return
}