Node.js Stream readable.readableLength 属性
可读 Stream 中的readable.readableLength 属性,用于检查队列中准备好读取的字节数。
句法:
readable.readableLength
返回值:它返回队列中准备好读取的字节数。
下面的示例说明了 Node.js 中readable.readableLength 属性的使用:
示例 1:
// Node.js program to demonstrate the
// readable.readableLength Property
// Accessing stream module
const stream = require('stream');
// Creating a Readable stream
const readable = new stream.Readable("input.txt");
// Calling readable.readableLength
// Property
readable.readableLength;
输出:
0
示例 2:
// Node.js program to demonstrate the
// readable.readableLength property
// Include fs module
const fs = require("fs");
// Constructing readable stream
const readable = fs.createReadStream("input.txt");
// Instructions for reading data
readable.on('readable', () => {
let chunk;
// Using while loop and calling
// read method
while (null !== (chunk = readable.read())) {
// Displaying the chunk length
console.log(`read: ${chunk.length}`);
}
});
// Calling readableLength property
readable.readableLength;
输出:
0
read: 13
参考: https://nodejs.org/api/stream.html#stream_readable_readablelength。