在旧的1.7存储客户端中有一个CloudBlob.CopyFromBlob(otherBlob)方法,但它似乎不存在于2.0版本中。复制blob的建议最佳做法是什么?我确实看到了ICloudBlob.BeginStartCopyFromBlob方法。如果这是合适的方法,我该如何使用它?
Gaurav Mantri在2.0版本上编写了一系列有关Azure存储的文章。我从他的Storage Client Library 2.0 – Migrating Blob Storage Code博客文章中获取了这个代码摘录,用于Blob Copy
CloudStorageAccount storageAccount = new CloudStorageAccount(new StorageCredentials(accountName, accountKey), true);
CloudBlobClient cloudBlobClient = storageAccount.CreateCloudBlobClient();
CloudBlobContainer sourceContainer = cloudBlobClient.GetContainerReference(containerName);
CloudBlobContainer targetContainer = cloudBlobClient.GetContainerReference(targetContainerName);
string blobName = "<Blob Name e.g. myblob.txt>";
CloudBlockBlob sourceBlob = sourceContainer.GetBlockBlobReference(blobName);
CloudBlockBlob targetBlob = targetContainer.GetBlockBlobReference(blobName);
targetBlob.StartCopyFromBlob(sourceBlob);
使用Storage 6.3(比原始问题更新的库)和异步方法使用StartCopyAsync(MSDN)
CloudStorageAccount storageAccount = CloudStorageAccount.Parse("Your Connection");
CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();
CloudBlobContainer container = blobClient.GetContainerReference("YourContainer");
CloudBlockBlob source = container.GetBlockBlobReference("Your Blob");
CloudBlockBlob target = container.GetBlockBlobReference("Your New Blob"");
await target.StartCopyAsync(source);
FYI截至SDK
的最新版本(7.x),由于BeginStartCopyBlob
功能不再存在,因此不再有效。
你可以这样做:
// this tunnels the data via your program,
// so it reuploads the blob instead of copying it on service side
using (var stream = await sourceBlob.OpenReadAsync())
{
await destinationBlob.UploadFromStreamAsync(stream);
}
如@(Alexey Shcherbak)所述,这是一种更好的方法:
await targetCloudBlob.StartCopyAsync(sourceCloudBlob.Uri);
while (targetCloudBlob.CopyState.Status == CopyStatus.Pending)
{
await Task.Delay(500);
// Need to fetch or "CopyState" will never update
await targetCloudBlob.FetchAttributesAsync();
}
if (targetCloudBlob.CopyState.Status != CopyStatus.Success)
{
throw new Exception("Copy failed: " + targetCloudBlob.CopyState.Status);
}
Naveen已经解释了使用StartCopyFromBlob
(同步方法)的正确语法。您提到的方法(BeginStartCopyFromBlob
)是异步替代方法,您可以将其与Task
结合使用,例如:
var blobClient = account.CreateCloudBlobClient();
// Upload picture.
var picturesContainer = blobClient.GetContainerReference("pictures");
picturesContainer.CreateIfNotExists();
var myPictureBlob = picturesContainer.GetBlockBlobReference("me.png");
using (var fs = new FileStream(@"C:\Users\Public\Pictures\Sample Pictures\Chrysanthemum.jpg", FileMode.Open))
myPictureBlob.UploadFromStream(fs);
// Backup picture.
var backupContainer = blobClient.GetContainerReference("backup");
backupContainer.CreateIfNotExists();
var backupBlob = picturesContainer.GetBlockBlobReference("me.png");
var task = Task.Factory.FromAsync<string>(backupBlob.BeginStartCopyFromBlob(myPictureBlob, null, null), backupBlob.EndStartCopyFromBlob);
task.ContinueWith((t) =>
{
if (!t.IsFaulted)
{
while (true)
{
Console.WriteLine("Copy state for {0}: {1}", backupBlob.Uri, backupBlob.CopyState.Status);
Thread.Sleep(500);
}
}
else
{
Console.WriteLine("Error: " + t.Exception);
}
});
启动Azure存储8,在存储帐户之间移动Blob我使用类似于下面的代码,希望它可以帮助某人:
//copy blobs - from
CloudStorageAccount sourceStorageAccount = new CloudStorageAccount(new StorageCredentials(storageFromName, storageFromKey), true);
CloudBlobClient sourceCloudBlobClient = sourceStorageAccount.CreateCloudBlobClient();
CloudBlobContainer sourceContainer = sourceCloudBlobClient.GetContainerReference(containerFromName);
//copy blobs - to
CloudStorageAccount targetStorageAccount = new CloudStorageAccount(new StorageCredentials(storageToName, storageToKey), true);
CloudBlobClient targetCloudBlobClient = targetStorageAccount.CreateCloudBlobClient();
CloudBlobContainer targetContainer = targetCloudBlobClient.GetContainerReference(containerToName);
//create target container if didn't exists
try{
await targetContainer.CreateIfNotExistsAsync();
}
catch(Exception e){
log.Error(e.Message);
}
CloudBlockBlob sourceBlob = sourceContainer.GetBlockBlobReference(blobName);
CloudBlockBlob targetBlob = targetContainer.GetBlockBlobReference(blobName);
try{
//initialize copying
await targetBlob.StartCopyAsync(sourceBlob.Uri);
}
catch(Exception ex){
log.Error(ex.Message);
//return error, in my case HTTP
return req.CreateResponse(HttpStatusCode.BadRequest, "Error, source BLOB probably has private access only: " +ex.Message);
}
//fetch current attributes
targetBlob.FetchAttributes();
//waiting for completion
while (targetBlob.CopyState.Status == CopyStatus.Pending){
log.Info("Status: " + targetBlob.CopyState.Status);
Thread.Sleep(500);
targetBlob.FetchAttributes();
}
//check status
if (targetBlob.CopyState.Status != CopyStatus.Success){
//return error, in my case HTTP
return req.CreateResponse(HttpStatusCode.BadRequest, "Copy failed with status: " + targetBlob.CopyState.Status);
}
//finally remove source in case Copy Status was Success
sourceBlob.Delete();
//and return success (in my case HTTP)
return req.CreateResponse(HttpStatusCode.OK, "Done.");
对我来说,WindowsAzure.Storage 8.0.1,James Hancock的解决方案做了服务器端副本,但客户端副本状态卡在Pending
上(永远循环)。解决方案是在FetchAttributes()
之后在targetCloudBlob
上调用Thread.sleep(500)
。
// Aaron Sherman's code
targetCloudBlob.StartCopy(sourceCloudBlob.Uri);
while (targetCloudBlob.CopyState.Status == CopyStatus.Pending)
{
Thread.Sleep(500);
targetCloudBlob.FetchAttributes();
}
// James Hancock's remaining code
这是我简短的简单回答。
public void Copy(CloudBlockBlob srcBlob, CloudBlobContainer destContainer)
{
CloudBlockBlob destBlob;
if (srcBlob == null)
{
throw new Exception("Source blob cannot be null.");
}
if (!destContainer.Exists())
{
throw new Exception("Destination container does not exist.");
}
//Copy source blob to destination container
string name = srcBlob.Uri.Segments.Last();
destBlob = destContainer.GetBlockBlobReference(name);
destBlob.StartCopyAsync(srcBlob);
}