node.js - 逐行读取gzip流

Question

我有一个压缩的 gzip 文件，我想逐行阅读。

var fs = require('fs')
var zlib = require('zlib')
var gunzip = zlib.createGunzip()
var inp = fs.createReadStream('test.gz')
var n = 0

var lineProcessing = function (err, data) {
    if (!err) {
        n += 1
        console.log ("line: " + n)
        console.log (data.toString())
    }
}

inp
  .on('data', function (chunk) {
      zlib.gunzip (chunk, lineProcessing)
  })
  .on('end', function () {
    console.log ('ende');
  });

我想我需要为 zlib.createGunzip 设置一个 block 大小，我只在下一个 \n 之前读取它。但是如何动态确定呢？

Answer 1

readline 可能更容易使用为此:

const fs       = require('fs');
const zlib     = require('zlib');
const readline = require('readline');

let lineReader = readline.createInterface({
  input: fs.createReadStream('test.gz').pipe(zlib.createGunzip())
});

let n = 0;
lineReader.on('line', (line) => {
  n += 1
  console.log("line: " + n);
  console.log(line);
});