Node を使用してコンテンツ圧縮を実現する方法を実践しながら話しましょう

const zlib = require('zlib')
const fs = require('fs')
const stream = require('stream')
const testFile = 'tests/origin.log'
const targetFile = `${testFile}.gz`
const decodeFile = `${testFile}.un.gz`

# 执行
du -ah tests

# 结果如下
108K    tests/origin.log.gz
2.2M    tests/origin.log
2.2M    tests/origin.log.un.gz
4.6M    tests

// 压缩
const readStream = fs.createReadStream(testFile)
const writeStream = fs.createWriteStream(targetFile)
stream.pipeline(readStream, zlib.createGzip(), writeStream, err => {
    if (err) {
        console.error(err);
    }
})

// 解压
const readStream = fs.createReadStream(targetFile)
const writeStream = fs.createWriteStream(decodeFile)
stream.pipeline(readStream, zlib.createUnzip(), writeStream, err => {
    if (err) {
        console.error(err);
    }
})

const { promisify } = require('util')
const pipeline = promisify(stream.pipeline)

// 压缩
const readStream = fs.createReadStream(testFile)
const writeStream = fs.createWriteStream(targetFile)
pipeline(readStream, zlib.createGzip(), writeStream)
    .catch(err => {
        console.error(err);
    })

// 解压
const readStream = fs.createReadStream(targetFile)
const writeStream = fs.createWriteStream(decodeFile)
pipeline(readStream, zlib.createUnzip(), writeStream)
    .catch(err => {
        console.error(err);
    })

// 压缩
const buff = []
readStream.on('data', (chunk) => {
    buff.push(chunk)
})
readStream.on('end', () => {
    zlib.gzip(Buffer.concat(buff), targetFile, (err, resBuff) => {
        if(err){
            console.error(err);
            process.exit()
        }
        fs.writeFileSync(targetFile,resBuff)
    })
})

// 压缩
const buff = []
readStream.on('data', (chunk) => {
    buff.push(chunk)
})
readStream.on('end', () => {
    fs.writeFileSync(targetFile,zlib.gzipSync(Buffer.concat(buff)))
})

// 测试数据
const testData = fs.readFileSync(testFile, { encoding: 'utf-8' })

const transformStream = new stream.PassThrough()
transformStream.write(buffer)

// or
const transformStream = new stream.Duplex()
transformStream.push(Buffer.from(testData))
transformStream.push(null)

transformStream
    .pipe(zlib.createGzip())
    .pipe(fs.createWriteStream(targetFile))

const result = zlib.gzipSync(buffer)

fs.writeFileSync(targetFile, result)

const http = require('http')
const { PassThrough, pipeline } = require('stream')
const zlib = require('zlib')

// 测试数据
const testTxt = '测试数据123'.repeat(1000)

const app = http.createServer((req, res) => {
    const { url } = req
    // 读取支持的压缩算法
    const acceptEncoding = req.headers['accept-encoding'].match(/(br|deflate|gzip)/g)

    // 默认响应的数据类型
    res.setHeader('Content-Type', 'application/json; charset=utf-8')

    // 几个示例的路由
    const routes = [
        ['/gzip', () => {
            if (acceptEncoding.includes('gzip')) {
                res.setHeader('content-encoding', 'gzip')
                // 使用同步API直接压缩文本内容
                res.end(zlib.gzipSync(Buffer.from(testTxt)))
                return
            }
            res.end(testTxt)
        }],
        ['/deflate', () => {
            if (acceptEncoding.includes('deflate')) {
                res.setHeader('content-encoding', 'deflate')
                // 基于流的单次操作
                const originStream = new PassThrough()
                originStream.write(Buffer.from(testTxt))
                originStream.pipe(zlib.createDeflate()).pipe(res)
                originStream.end()
                return
            }
            res.end(testTxt)
        }],
        ['/br', () => {
            if (acceptEncoding.includes('br')) {
                res.setHeader('content-encoding', 'br')
                res.setHeader('Content-Type', 'text/html; charset=utf-8')
                // 基于流的多次写操作
                const originStream = new PassThrough()
                pipeline(originStream, zlib.createBrotliCompress(), res, (err) => {
                    if (err) {
                        console.error(err);
                    }
                })
                originStream.write(Buffer.from(&#39;<h1>BrotliCompress</h1>&#39;))
                originStream.write(Buffer.from(&#39;<h2>测试数据</h2>&#39;))
                originStream.write(Buffer.from(testTxt))
                originStream.end()
                return
            }
            res.end(testTxt)
        }]
    ]
    const route = routes.find(v => url.startsWith(v[0]))
    if (route) {
        route[1]()
        return
    }

    // 兜底
    res.setHeader(&#39;Content-Type&#39;, &#39;text/html; charset=utf-8&#39;)
    res.end(`<h1>404: ${url}</h1>
    <h2>已注册路由</h2>
    <ul>
        ${routes.map(r => `<li><a href="${r[0]}">${r[0]}</a></li>`).join(&#39;&#39;)}
    </ul>
    `)
    res.end()
})

app.listen(3000)