leizongmin / node-lei-stream Goto Github PK

autoNext: false 文件行数为 20000+

RangeError: Maximum call stack size exceeded
    at new TickObject (node.js:482:24)
    at process.nextTick (node.js:500:26)
    at ReadLineStream.next (C:\Git\programming-pearls\chapter1\node_modules\lei-stream\lib\readline.js:74:13)
    at ReadLineStream.<anonymous> (C:\Git\programming-pearls\chapter1\index.js:31:10)
    at emitOne (events.js:77:13)
    at ReadLineStream.emit (events.js:169:7)
    at ReadLineStream.next (C:\Git\programming-pearls\chapter1\node_modules\lei-stream\lib\readline.js:107:8)
    at ReadLineStream.<anonymous> (C:\Git\programming-pearls\chapter1\index.js:31:10)
    at emitOne (events.js:77:13)
    at ReadLineStream.emit (events.js:169:7)

暂时的解决方法:

// 读取到一行数据时触发data事件 
s.on('data', function (line) {
    console.log(line);
    process.nextTick(function () {
        s.next();
    });
});

export function readLine(stream: ReadStream, options?: ReadLineStreamOptions): ReadableStream;
这里ReadableStream 应该是ReadLineStream

你好 麻烦问下
我的需求是在一个大文件中以追加的方式写入数据，我在使用中加上了{flags:'r+'} 但是查看文件还是只有一条数据
在我的文件中 我加入了 {flags:'r+'}

var s = writeLineStream(fs.createWriteStream('./myfile.txt',{flags:'r+'}), {

    newline: '\n',

    encoding: function (data) {

      return JSON.stringify(data);

    },

    cacheLines: 0

  });

在模块文件writeline.js中 我也加入了{flags:'r+'}

if the file has lots of lines,such as 5000 lines
and run the script below,node8 will throw error:"RangeError: Maximum call stack size exceeded"

require('lei-stream').readLine('filename').go(function abc (data,next) {
	for(a of ['a']){
		console.log(data);
	}
	next();
});

🚨 You need to enable Continuous Integration on all branches of this repository. 🚨

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例如
一个gb18030编码格式的txt文件，在每一行读取的时候，我需要转码。需要用到Buffer对象。
但是on('data')获取到的数据时toString之后的。
具体是这一行，去掉toString后能成功。
https://github.com/leizongmin/node-lei-stream/blob/master/lib/readline.js#L110

不知道有没有更好的方法获得原Buffer对象

RT

function readAndAnalysize2(file) {
let lines=0;
// readLineStream第一个参数为ReadStream实例，也可以为文件名
const s = readLine(fs.createReadStream(file), {
// 换行符，默认\n
newline: '\n',
// 是否自动读取下一行，默认false
autoNext: false
});

// 读取到一行数据时触发data事件
s.on('data', (data) => {
    console.log(data);
    lines++;
    if (lines < 20) {
        s.next();
    } else {
        console.log("wait!");
    }
});

// 流结束时触发end事件
s.on('end', () => {
    console.log('end');
});

// 读取时出错
s.on('error', (err) => {
    console.error(err);
});

s.next();

}

上面这个例子，执行了20次之后，程序自动退出了。预期情况应该是程序在空闲中，等待其他逻辑的执行。
源码我没有找到哪里有process.exit()的调用。