如何找出CreateBlockBlobFromStream方法的流长度

Question

我正在尝试使用azure-storage上传流,但该方法CreateBlockBlobFromStream需要流长度.我不知道在哪里长度.

我的代码

const Readable = require('stream').Readable;
const rs = Readable();

rs._read = () => {     
    //here I read a file, loop through the lines and then generate some xml
};

const blobSvc = azure.createBlobService(storageName, key);
blobSvc.createBlockBlobFromStream ('data','test.xml', rs, ???, (err, r, resp) => {});

Answer 1

而不是createBlockBlobFromStream尝试使用createWriteStreamToBlockBlob.

以下代码示例将字母az压入myblob.txt.

var azure = require('azure-storage');
const Readable = require('stream').Readable;
const rs = Readable();

var c = 97;
rs._read = () => {     
  rs.push(String.fromCharCode(c++));
  if (c > 'z'.charCodeAt(0)) rs.push(null);
};

var accountName = "youraccountname";
var accessKey = "youraccountkey";
var host = "https://yourhost.blob.core.windows.net";
var blobSvc = azure.createBlobService(accountName, accessKey, host);

rs.pipe(blobSvc.createWriteStreamToBlockBlob('mycontainer', 'myblob.txt'));

如果要读取具有可读流的文件,代码将如下所示:

var fs = require("fs");
// ...
var stream = fs.createReadStream('test.xml');
stream.pipe(blobSvc.createWriteStreamToBlockBlob('mycontainer', 'test.xml'));