2017-12-21 7 views
2

를 사용하여 파일에 저장합니다 : 지금까지 나는 다음과 같은 조각 파일을 쓸 수Nodejs는 base64로 디코딩하고 난 다음 코드 줄 사용하여 base64로 인코딩 된 이미지를 디코딩 내 Node.js를 응용 프로그램 이상 스트림

const fileDataDecoded = Buffer.from(base64EncodedfileData,'base64'); 

을 코드의 :

const fs = require('fs'); 
.... 
const fileDataDecoded = Buffer.from(base64EncodedfileData,'base64'); 
fs.writeFile("/tmp/test.png", fileDataDecoded, function(err) { 
    //Handle Error 
}); 

지금 내가 무엇을 달성하고자하는 버퍼를 통해 디코딩 된 파일이 실행되는 응용 프로그램에 더 나은 효율성을 acheive하기 위해 스트림을 통해 파일에 기록받을 것입니다.

다른 말로하면, 효율적인 방법으로 큰 파일을 작성하기 위해 데이터가 base64 디코딩되는 것과 동시에 filedata가 작성되기를 원합니다. Base64로 디코딩 된 데이터를 스트리밍하기 위해 버퍼를 통해 가능하지 않은 경우 base64 데이터를 디코딩하는 방법을 알고 싶습니다.

답변

1

읽을 수있는 스트림을 만들고 이미지 버퍼를 누를 수 있습니다. 그런 다음이 파일을 이처럼 쓰기 가능한 스트림에 파이프합니다.

var base64 = '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'; 

var fs = require('fs') 
var Readable = require('stream').Readable 

const imgBuffer = Buffer.from(base64, 'base64') 

var s = new Readable() 

s.push(imgBuffer) 
s.push(null) 

s.pipe(fs.createWriteStream("test.png")); 
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