javascript - Nodejs频繁写文件

Question

我有一个监听器来监听内容的变化，一旦内容修改，它就会发出处理函数:

$('#editor').on('onchange', () => changeHandler('...','...'));

function changeHandler(filePath, content){
    var ws = fs.createWriteStream(filePath, 'utf8');
    ws.write(content);
}

我的问题是'onchange'发生得太频繁，所以'write file'处理得太频繁，期间可能会丢失数据。有人可以给点建议吗？

更新现在我已经根据下面的答案更改了代码:

this.buffer = null; //used to cache

// once content changed, maybe too often
changeHandler() {        
    if (this.editor.curOp && this.editor.curOp.command.name) {
        var id = $('.nav-items li.active .lk-hosts').attr('data-hosts-id');
        var content = this.editor.getValue();
        // cache data, not immediately write to file
        this.buffer = {id: id, content: content};
    }        
}

setInterval(()=> {
        // means there's data in cache
        if (this.buffer !== null) {
            let id = this.buffer.id;
            let content = this.buffer.content;
            // reset cache to null
            this.buffer = null;
            // write file
            this.writeContent(id, content, (err)=> {
            })
        }
    }, 800);

谢谢大家的回答!

Answer 1

为什么不简单地构建一个缓冲区来收集写入的文本，然后仅在写入达到一定数量时才写入文件:

$('#editor').on('onchange', () => changeHandler('...','...'));

var writeBuffer = ''; // can also make this an array
var writeBufferSize = 0;
var filePath = 'path_to_file';
var ws = fs.createWriteStream(filePath, 'utf8');

function changeHandler(content){
    if (writeBufferSize == SOME_THRESHOLD) {
        ws.write(writeBuffer);
        writeBuffer = '';
        writeBufferSize = 0;
    } else {
        writeBuffer += content + '\n';
        writeBufferSize++;
    }
}

如果您选择的写入缓冲区阈值太大，您可能希望将写入委托(delegate)给某个工作线程以并行完成，在这种情况下，您可以创建另一个临时写入缓冲区来填充原始写入缓冲区写好，然后将两者交换。