在node.js中WritableState.length和WritableState.writelen是什么意思？

我把

WritableState.length

和

WritableState.writelen

搞混了。因此，我编写以下代码来理解它们之间的区别

const fs = require('fs');
const filename = 'test.log';
const writeStream = fs.createWriteStream(filename, {flags: 'a+'});

for (let i = 0; i < 10; i++) {
    writeStream.write('a');
    const length = writeStream._writableState.length;
    const writelen = writeStream._writableState.writelen;
    console.log(
        `totalCharacterToWrite: ${i + 1}`,
        `writableState.length: ${length}`,
        `writableState.writelen: ${writelen}`
    );
}

setTimeout(() => {
    const length = writeStream._writableState.length;
    const writelen = writeStream._writableState.writelen;
    console.log(
        `writableState.length after writeStream closed: ${length}`,
        `writableState.writelen after writeStream closed: ${writelen}`
    );
}, 10);

根据结果，我推测

writeablestate。length

表示要写入的字符总数，而

writeablestate。writelen

表示每次写入操作要写入的字符总数

---

我的猜测正确吗？关于

WritableState.length

和

WritableState.writelen

的含义，还有其他细节吗？我以前从来没有对它们大惊小怪过，甚至没有看过它们。你有什么问题导致你不得不在内部挖掘？

totalCharacterToWrite: 1 writableState.length: 1 writableState.writelen: 1
totalCharacterToWrite: 2 writableState.length: 2 writableState.writelen: 1
totalCharacterToWrite: 3 writableState.length: 3 writableState.writelen: 1
totalCharacterToWrite: 4 writableState.length: 4 writableState.writelen: 1
totalCharacterToWrite: 5 writableState.length: 5 writableState.writelen: 1
totalCharacterToWrite: 6 writableState.length: 6 writableState.writelen: 1
totalCharacterToWrite: 7 writableState.length: 7 writableState.writelen: 1
totalCharacterToWrite: 8 writableState.length: 8 writableState.writelen: 1
totalCharacterToWrite: 9 writableState.length: 9 writableState.writelen: 1
totalCharacterToWrite: 10 writableState.length: 10 writableState.writelen: 1
writableState.length after writeStream closed: 0 writableState.writelen after writeStream closed: 0