使用可读流实例而不是缓冲区重写函数，返回base64流

Question

我有一个使用库的函数，当返回的数据audio是缓冲区时，它可以正常工作：

PS：我不能将文件保存到系统-所以不能使用fs

(async function () { // Needed in my context
const stream = require('stream');
    try {
function gettingFile(params) {
    return new Promise((resolve, reject) => {
        library.getFile(params, function(error, data) {
            if (error) {
                reject(error);
            } else {
                var base64data = data.Audio.toString('base64');   <----- getFile returns data as Buffer, so far so good                        
                return resolve(base64data);           
            }
        });
    });
};
var retrievedBase64Data = await gettingFile(params);
callback(undefined, retrievedBase64Data);
    } catch (err) {                
        callback(err)              
    }
})()

但是，库最近发生了更改，data.audio现在返回一个可读流，因此我尝试了这个操作，但会崩溃：

(async function() {
    const stream = require('stream');
    try {
        function gettingFile(params) {
            return new Promise((resolve, reject) => {
                library.getFile(params, function(error, data) {
                    if (error) {
                        reject(error);
                    } else {
                        var fileStream = new stream.Writable();
                        data.Audio.pipe(fileStream);                    <-- getFile returns data as Readable Stream
                        var base64data = fileStream.toString('base64'); <-- I probably messed up.
                        return resolve(fileStream);
                    }
                });
            });
        };
        var retrievedBase64Data = await gettingFile(params);
        callback(undefined, retrievedBase64Data);
    } catch (err) {
        callback(err)
    }
})()

您知道如何使缓冲区切换到流吗？

Answer 1

      (async function() {
        const stream = require('stream');
        try {
            function gettingFile(params) {
                return new Promise((resolve, reject) => {
                    library.getFile(params, function(error, data) {
                        if (error) {
                            reject(error);
                        } else {
                          const writeStream = fs.createWriteStream('audioName') 
                          data.on('data',(chunk) => { 
                            console.log('data received');
                            writeStream.write(chunk); 
                          }); 
      
                          data.on('end', ()=>{
                              console.log('File saved!')
                              return resolve(writeStream)
                          });
                            
                          data.on('error', ()=>{
                              console.log(err.stack);
                          });
                        }
                    });
                });
            };
            var retrievedBase64Data = await gettingFile(params);
            callback(undefined, retrievedBase64Data);
        } catch (err) {
            callback(err)
        }
    })()