使用在 Amazon S3 Glacier 中下载档案Amazon SDK for .NET - Simple Storage Service(Amazon S3)Glacier
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使用在 Amazon S3 Glacier 中下载档案Amazon SDK for .NET

无论是高级和低级 API由适用于 .NET 的亚马逊开发工具包提供了一种下载档案的方法。

使用Amazon SDK for .NET高级 API 下载档案

该高级 API 的 ArchiveTransferManager 类提供了您可以用来下载档案的 Download 方法。

重要

这些区域有:ArchiveTransferManager类会创建 Amazon Simple Notification Service (Amazon SNS) 主题和订阅该主题的 Amazon Simple Queue Service (Amazon SQS) 队列。然后,它启动了档案检索任务,并对队列进行轮询以便找到可用档案。如果存档可用,则开始下载。有关检索时间的详细信息,请参阅 档案检索选项

例如:使用Amazon SDK for .NET高级 API 下载档案

以下 C# 代码示例从文件库下载档案(examplevault)位于美国西部(俄勒冈)区域。

有关如何运行以下示例的分步说明,请参阅运行代码示例。您需要更新现有档案 ID 和已下载档案的本地文件保存路径旁显示的代码

using System; using Amazon.Glacier; using Amazon.Glacier.Transfer; using Amazon.Runtime; namespace glacier.amazon.com.docsamples { class ArchiveDownloadHighLevel { static string vaultName = "examplevault"; static string archiveId = "*** Provide archive ID ***"; static string downloadFilePath = "*** Provide the file name and path to where to store the download ***"; public static void Main(string[] args) { try { var manager = new ArchiveTransferManager(Amazon.RegionEndpoint.USWest2); var options = new DownloadOptions(); options.StreamTransferProgress += ArchiveDownloadHighLevel.progress; // Download an archive. Console.WriteLine("Intiating the archive retrieval job and then polling SQS queue for the archive to be available."); Console.WriteLine("Once the archive is available, downloading will begin."); manager.Download(vaultName, archiveId, downloadFilePath, options); Console.WriteLine("To continue, press Enter"); Console.ReadKey(); } catch (AmazonGlacierException e) { Console.WriteLine(e.Message); } catch (AmazonServiceException e) { Console.WriteLine(e.Message); } catch (Exception e) { Console.WriteLine(e.Message); } Console.WriteLine("To continue, press Enter"); Console.ReadKey(); } static int currentPercentage = -1; static void progress(object sender, StreamTransferProgressArgs args) { if (args.PercentDone != currentPercentage) { currentPercentage = args.PercentDone; Console.WriteLine("Downloaded {0}%", args.PercentDone); } } } }

使用Amazon SDK for .NET低级 API 下载档案

以下是使用的低级 API 下载 Amazon S3 Glacier (S3 Glacier) 档案的步骤。Amazon SDK for .NET.

  1. 创建 AmazonGlacierClient 类(客户端)的实例。

    你需要指定Amazon您要从中下载档案的区域。您使用此客户端执行的所有操作都会应用到此Amazon区域。

  2. 通过执行 archive-retrieval 方法启动 InitiateJob 任务。

    您可以通过创建一个实例提供作业信息,例如,您要下载的档案的档案 ID,以及您希望 S3 Glacier 向其发布作业完成消息的可选 Amazon SNS 主题。InitiateJobRequest类。S3 Glacier 会在响应中返回作业 ID。该响应位于一个 InitiateJobResponse 类的实例中。

    AmazonGlacierClient client; client = new AmazonGlacierClient(Amazon.RegionEndpoint.USWest2); InitiateJobRequest initJobRequest = new InitiateJobRequest() { VaultName = vaultName, JobParameters = new JobParameters() { Type = "archive-retrieval", ArchiveId = "*** Provide archive id ***", SNSTopic = "*** Provide Amazon SNS topic ARN ***", } }; InitiateJobResponse initJobResponse = client.InitiateJob(initJobRequest); string jobId = initJobResponse.JobId;

    您可以选择指定字节范围,以请求 S3 Glacier 只准备档案的一部分,如以下请求所示。该请求指定 S3 Glacier 只准备档案的 1 MB 到 2 MB 部分。

    AmazonGlacierClient client; client = new AmazonGlacierClient(Amazon.RegionEndpoint.USWest2); InitiateJobRequest initJobRequest = new InitiateJobRequest() { VaultName = vaultName, JobParameters = new JobParameters() { Type = "archive-retrieval", ArchiveId = "*** Provide archive id ***", SNSTopic = "*** Provide Amazon SNS topic ARN ***", } }; // Specify byte range. int ONE_MEG = 1048576; initJobRequest.JobParameters.RetrievalByteRange = string.Format("{0}-{1}", ONE_MEG, 2 * ONE_MEG -1); InitiateJobResponse initJobResponse = client.InitiateJob(initJobRequest); string jobId = initJobResponse.JobId;
  3. 等待任务完成。

    您必须等到任务输出已作好供您下载的准备。如果您在文件库中设置了标识 Amazon Simple Notification Service (Amazon SNS) 主题的通知配置,或者在启动作业时指定了 Amazon SNS 主题,则会在完成作业后向该主题发送消息。以下部分给出的代码示例使用适用于 S3 Glacier 的 Amazon SNS 来发布消息。

    你也可以通过调用调用 S3 GlacierDescribeJob方法确定作业完成状态。尽管如此,使用 Amazon SNS 主题进行通知才是推荐的方法。

  4. 通过执行 GetJobOutput 方法下载任务输出(档案数据)。

    您可以通过创建一个 GetJobOutputRequest 类的实例来提供请求信息,例如,任务 ID 和文件库名称。S3 Glacier 返回的输出位于GetJobOutputResponse对象。

    GetJobOutputRequest getJobOutputRequest = new GetJobOutputRequest() { JobId = jobId, VaultName = vaultName }; GetJobOutputResponse getJobOutputResponse = client.GetJobOutput(getJobOutputRequest); using (Stream webStream = getJobOutputResponse.Body) { using (Stream fileToSave = File.OpenWrite(fileName)) { CopyStream(webStream, fileToSave); } }

    前面的代码段会下载整个任务输出。您可以选择性地只取回输出的一部分,或者通过在您的 GetJobOutputRequest 中指定字节范围以较小的区块下载整个输出。

    GetJobOutputRequest getJobOutputRequest = new GetJobOutputRequest() { JobId = jobId, VaultName = vaultName }; getJobOutputRequest.SetRange(0, 1048575); // Download only the first 1 MB chunk of the output.

    为了回应你的GetJobOutput调用时,S3 Glacier 会在满足特定条件的情况下返回您下载的数据部分的校验和。有关更多信息,请参阅 下载数据时接收校验和

    要确认下载中没有错误,您随后可以在客户端计算校验和,并将它与在响应中发送的 S3 Glacier 校验和相比较。

    对于指定了可选范围的档案取回任务,您在获取任务描述时,它会包括您要取回的范围的校验和 (SHA256TreeHash)。您可以使用此值进一步确认您稍后下载的整个字节范围的准确性。例如,如果您启动任务以取回以树形哈希对齐的档案范围,然后以区块下载输出,使得您的每个 GetJobOutput 请求均返回一个校验和,则您可以在客户端计算您下载的每个部分的校验和,然后计算树形哈希。您可以将它与为响应您的描述作业请求而返回的校验和相比较,以确认您下载的整个字节范围与 S3 Glacier 中存储的字节范围相同。

    要了解可工作的示例,请参阅 示例 2:使用低级 API 检索档案Amazon SDK for .NET— 以块形式下载输出

示例 1:使用低级 API 检索档案Amazon SDK for .NET

以下 C# 代码示例会从指定的文件库下载档案。任务完成后,该示例会在单一 GetJobOutput 调用中下载整个输出。有关以区块下载输出的示例,请参阅“示例 2:使用低级 API 检索档案Amazon SDK for .NET— 以块形式下载输出”。

该示例执行以下任务:

  • 设置 Amazon Simple Notification Service (Amazon SNS) 主题

    完成作业后,S3 Glacier 会向此主题发送通知。

  • 设置 Amazon Simple Queue Service (Amazon SQS) 队列。

    该示例会向该队列附加策略,以使 Amazon SNS 主题能够发布消息。

  • 启动任务以下载指定的档案。

    在作业请求中,该示例会指定 Amazon SNS 主题,以便 S3 Glacier 可以在完成作业后发送消息。

  • 定期检查 Amazon SQS 队列是否有消息。

    如果有消息,则分析 JSON,并检查任务是否已成功完成。如果已成功完成,则下载档案。该代码示例使用 JSON.NET 库(请参阅 JSON.NET)来分析 JSON。

  • 通过删除它创建的 Amazon SNS 主题和 Amazon SQS 队列清除相关数据。

using System; using System.Collections.Generic; using System.IO; using System.Threading; using Amazon.Glacier; using Amazon.Glacier.Model; using Amazon.Runtime; using Amazon.SimpleNotificationService; using Amazon.SimpleNotificationService.Model; using Amazon.SQS; using Amazon.SQS.Model; using Newtonsoft.Json; namespace glacier.amazon.com.docsamples { class ArchiveDownloadLowLevelUsingSNSSQS { static string topicArn; static string queueUrl; static string queueArn; static string vaultName = "*** Provide vault name ***"; static string archiveID = "*** Provide archive ID ***"; static string fileName = "*** Provide the file name and path to where to store downloaded archive ***"; static AmazonSimpleNotificationServiceClient snsClient; static AmazonSQSClient sqsClient; const string SQS_POLICY = "{" + " \"Version\" : \"2012-10-17\"," + " \"Statement\" : [" + " {" + " \"Sid\" : \"sns-rule\"," + " \"Effect\" : \"Allow\"," + " \"Principal\" : {\"Service\" : \"sns.amazonaws.com\" }," + " \"Action\" : \"sqs:SendMessage\"," + " \"Resource\" : \"{QueueArn}\"," + " \"Condition\" : {" + " \"ArnLike\" : {" + " \"aws:SourceArn\" : \"{TopicArn}\"" + " }" + " }" + " }" + " ]" + "}"; public static void Main(string[] args) { AmazonGlacierClient client; try { using (client = new AmazonGlacierClient(Amazon.RegionEndpoint.USWest2)) { Console.WriteLine("Setup SNS topic and SQS queue."); SetupTopicAndQueue(); Console.WriteLine("To continue, press Enter"); Console.ReadKey(); Console.WriteLine("Retrieving..."); RetrieveArchive(client); } Console.WriteLine("Operations successful. To continue, press Enter"); Console.ReadKey(); } catch (AmazonGlacierException e) { Console.WriteLine(e.Message); } catch (AmazonServiceException e) { Console.WriteLine(e.Message); } catch (Exception e) { Console.WriteLine(e.Message); } finally { // Delete SNS topic and SQS queue. snsClient.DeleteTopic(new DeleteTopicRequest() { TopicArn = topicArn }); sqsClient.DeleteQueue(new DeleteQueueRequest() { QueueUrl = queueUrl }); } } static void SetupTopicAndQueue() { snsClient = new AmazonSimpleNotificationServiceClient(Amazon.RegionEndpoint.USWest2); sqsClient = new AmazonSQSClient(Amazon.RegionEndpoint.USWest2); long ticks = DateTime.Now.Ticks; topicArn = snsClient.CreateTopic(new CreateTopicRequest { Name = "GlacierDownload-" + ticks }).TopicArn; Console.Write("topicArn: "); Console.WriteLine(topicArn); CreateQueueRequest createQueueRequest = new CreateQueueRequest(); createQueueRequest.QueueName = "GlacierDownload-" + ticks; CreateQueueResponse createQueueResponse = sqsClient.CreateQueue(createQueueRequest); queueUrl = createQueueResponse.QueueUrl; Console.Write("QueueURL: "); Console.WriteLine(queueUrl); GetQueueAttributesRequest getQueueAttributesRequest = new GetQueueAttributesRequest(); getQueueAttributesRequest.AttributeNames = new List<string> { "QueueArn" }; getQueueAttributesRequest.QueueUrl = queueUrl; GetQueueAttributesResponse response = sqsClient.GetQueueAttributes(getQueueAttributesRequest); queueArn = response.QueueARN; Console.Write("QueueArn: "); Console.WriteLine(queueArn); // Setup the Amazon SNS topic to publish to the SQS queue. snsClient.Subscribe(new SubscribeRequest() { Protocol = "sqs", Endpoint = queueArn, TopicArn = topicArn }); // Add policy to the queue so SNS can send messages to the queue. var policy = SQS_POLICY.Replace("{TopicArn}", topicArn).Replace("{QueueArn}", queueArn); sqsClient.SetQueueAttributes(new SetQueueAttributesRequest() { QueueUrl = queueUrl, Attributes = new Dictionary<string, string> { { QueueAttributeName.Policy, policy } } }); } static void RetrieveArchive(AmazonGlacierClient client) { // Initiate job. InitiateJobRequest initJobRequest = new InitiateJobRequest() { VaultName = vaultName, JobParameters = new JobParameters() { Type = "archive-retrieval", ArchiveId = archiveID, Description = "This job is to download archive.", SNSTopic = topicArn, } }; InitiateJobResponse initJobResponse = client.InitiateJob(initJobRequest); string jobId = initJobResponse.JobId; // Check queue for a message and if job completed successfully, download archive. ProcessQueue(jobId, client); } private static void ProcessQueue(string jobId, AmazonGlacierClient client) { ReceiveMessageRequest receiveMessageRequest = new ReceiveMessageRequest() { QueueUrl = queueUrl, MaxNumberOfMessages = 1 }; bool jobDone = false; while (!jobDone) { Console.WriteLine("Poll SQS queue"); ReceiveMessageResponse receiveMessageResponse = sqsClient.ReceiveMessage(receiveMessageRequest); if (receiveMessageResponse.Messages.Count == 0) { Thread.Sleep(10000 * 60); continue; } Console.WriteLine("Got message"); Message message = receiveMessageResponse.Messages[0]; Dictionary<string, string> outerLayer = JsonConvert.DeserializeObject<Dictionary<string, string>>(message.Body); Dictionary<string, object> fields = JsonConvert.DeserializeObject<Dictionary<string, object>>(outerLayer["Message"]); string statusCode = fields["StatusCode"] as string; if (string.Equals(statusCode, GlacierUtils.JOB_STATUS_SUCCEEDED, StringComparison.InvariantCultureIgnoreCase)) { Console.WriteLine("Downloading job output"); DownloadOutput(jobId, client); // Save job output to the specified file location. } else if (string.Equals(statusCode, GlacierUtils.JOB_STATUS_FAILED, StringComparison.InvariantCultureIgnoreCase)) Console.WriteLine("Job failed... cannot download the archive."); jobDone = true; sqsClient.DeleteMessage(new DeleteMessageRequest() { QueueUrl = queueUrl, ReceiptHandle = message.ReceiptHandle }); } } private static void DownloadOutput(string jobId, AmazonGlacierClient client) { GetJobOutputRequest getJobOutputRequest = new GetJobOutputRequest() { JobId = jobId, VaultName = vaultName }; GetJobOutputResponse getJobOutputResponse = client.GetJobOutput(getJobOutputRequest); using (Stream webStream = getJobOutputResponse.Body) { using (Stream fileToSave = File.OpenWrite(fileName)) { CopyStream(webStream, fileToSave); } } } public static void CopyStream(Stream input, Stream output) { byte[] buffer = new byte[65536]; int length; while ((length = input.Read(buffer, 0, buffer.Length)) > 0) { output.Write(buffer, 0, length); } } } }

示例 2:使用低级 API 检索档案Amazon SDK for .NET— 以块形式下载输出

以下 C# 代码示例从 S3 Glacier 检索档案。该代码示例会通过在 GetJobOutputRequest 数据元中指定字节范围来以区块下载任务输出。

using System; using System.Collections.Generic; using System.IO; using System.Threading; using Amazon.Glacier; using Amazon.Glacier.Model; using Amazon.Glacier.Transfer; using Amazon.Runtime; using Amazon.SimpleNotificationService; using Amazon.SimpleNotificationService.Model; using Amazon.SQS; using Amazon.SQS.Model; using Newtonsoft.Json; using System.Collections.Specialized; namespace glacier.amazon.com.docsamples { class ArchiveDownloadLowLevelUsingSQLSNSOutputUsingRange { static string topicArn; static string queueUrl; static string queueArn; static string vaultName = "*** Provide vault name ***"; static string archiveId = "*** Provide archive ID ***"; static string fileName = "*** Provide the file name and path to where to store downloaded archive ***"; static AmazonSimpleNotificationServiceClient snsClient; static AmazonSQSClient sqsClient; const string SQS_POLICY = "{" + " \"Version\" : \"2012-10-17\"," + " \"Statement\" : [" + " {" + " \"Sid\" : \"sns-rule\"," + " \"Effect\" : \"Allow\"," + " \"Principal\" : {\"AWS\" : \"arn:aws:iam::123456789012:root\" }," + " \"Action\" : \"sqs:SendMessage\"," + " \"Resource\" : \"{QuernArn}\"," + " \"Condition\" : {" + " \"ArnLike\" : {" + " \"aws:SourceArn\" : \"{TopicArn}\"" + " }" + " }" + " }" + " ]" + "}"; public static void Main(string[] args) { AmazonGlacierClient client; try { using (client = new AmazonGlacierClient(Amazon.RegionEndpoint.USWest2)) { Console.WriteLine("Setup SNS topic and SQS queue."); SetupTopicAndQueue(); Console.WriteLine("To continue, press Enter"); Console.ReadKey(); Console.WriteLine("Download archive"); DownloadAnArchive(archiveId, client); } Console.WriteLine("Operations successful. To continue, press Enter"); Console.ReadKey(); } catch (AmazonGlacierException e) { Console.WriteLine(e.Message); } catch (AmazonServiceException e) { Console.WriteLine(e.Message); } catch (Exception e) { Console.WriteLine(e.Message); } finally { // Delete SNS topic and SQS queue. snsClient.DeleteTopic(new DeleteTopicRequest() { TopicArn = topicArn }); sqsClient.DeleteQueue(new DeleteQueueRequest() { QueueUrl = queueUrl }); } } static void SetupTopicAndQueue() { long ticks = DateTime.Now.Ticks; // Setup SNS topic. snsClient = new AmazonSimpleNotificationServiceClient(Amazon.RegionEndpoint.USWest2); sqsClient = new AmazonSQSClient(Amazon.RegionEndpoint.USWest2); topicArn = snsClient.CreateTopic(new CreateTopicRequest { Name = "GlacierDownload-" + ticks }).TopicArn; Console.Write("topicArn: "); Console.WriteLine(topicArn); CreateQueueRequest createQueueRequest = new CreateQueueRequest(); createQueueRequest.QueueName = "GlacierDownload-" + ticks; CreateQueueResponse createQueueResponse = sqsClient.CreateQueue(createQueueRequest); queueUrl = createQueueResponse.QueueUrl; Console.Write("QueueURL: "); Console.WriteLine(queueUrl); GetQueueAttributesRequest getQueueAttributesRequest = new GetQueueAttributesRequest(); getQueueAttributesRequest.AttributeNames = new List<string> { "QueueArn" }; getQueueAttributesRequest.QueueUrl = queueUrl; GetQueueAttributesResponse response = sqsClient.GetQueueAttributes(getQueueAttributesRequest); queueArn = response.QueueARN; Console.Write("QueueArn: "); Console.WriteLine(queueArn); // Setup the Amazon SNS topic to publish to the SQS queue. snsClient.Subscribe(new SubscribeRequest() { Protocol = "sqs", Endpoint = queueArn, TopicArn = topicArn }); // Add the policy to the queue so SNS can send messages to the queue. var policy = SQS_POLICY.Replace("{TopicArn}", topicArn).Replace("{QuernArn}", queueArn); sqsClient.SetQueueAttributes(new SetQueueAttributesRequest() { QueueUrl = queueUrl, Attributes = new Dictionary<string, string> { { QueueAttributeName.Policy, policy } } }); } static void DownloadAnArchive(string archiveId, AmazonGlacierClient client) { // Initiate job. InitiateJobRequest initJobRequest = new InitiateJobRequest() { VaultName = vaultName, JobParameters = new JobParameters() { Type = "archive-retrieval", ArchiveId = archiveId, Description = "This job is to download the archive.", SNSTopic = topicArn, } }; InitiateJobResponse initJobResponse = client.InitiateJob(initJobRequest); string jobId = initJobResponse.JobId; // Check queue for a message and if job completed successfully, download archive. ProcessQueue(jobId, client); } private static void ProcessQueue(string jobId, AmazonGlacierClient client) { var receiveMessageRequest = new ReceiveMessageRequest() { QueueUrl = queueUrl, MaxNumberOfMessages = 1 }; bool jobDone = false; while (!jobDone) { Console.WriteLine("Poll SQS queue"); ReceiveMessageResponse receiveMessageResponse = sqsClient.ReceiveMessage(receiveMessageRequest); if (receiveMessageResponse.Messages.Count == 0) { Thread.Sleep(10000 * 60); continue; } Console.WriteLine("Got message"); Message message = receiveMessageResponse.Messages[0]; Dictionary<string, string> outerLayer = JsonConvert.DeserializeObject<Dictionary<string, string>>(message.Body); Dictionary<string, object> fields = JsonConvert.DeserializeObject<Dictionary<string, object>>(outerLayer["Message"]); string statusCode = fields["StatusCode"] as string; if (string.Equals(statusCode, GlacierUtils.JOB_STATUS_SUCCEEDED, StringComparison.InvariantCultureIgnoreCase)) { long archiveSize = Convert.ToInt64(fields["ArchiveSizeInBytes"]); Console.WriteLine("Downloading job output"); DownloadOutput(jobId, archiveSize, client); // This where we save job output to the specified file location. } else if (string.Equals(statusCode, GlacierUtils.JOB_STATUS_FAILED, StringComparison.InvariantCultureIgnoreCase)) Console.WriteLine("Job failed... cannot download the archive."); jobDone = true; sqsClient.DeleteMessage(new DeleteMessageRequest() { QueueUrl = queueUrl, ReceiptHandle = message.ReceiptHandle }); } } private static void DownloadOutput(string jobId, long archiveSize, AmazonGlacierClient client) { long partSize = 4 * (long)Math.Pow(2, 20); // 4 MB. using (Stream fileToSave = new FileStream(fileName, FileMode.Create, FileAccess.Write)) { long currentPosition = 0; do { GetJobOutputRequest getJobOutputRequest = new GetJobOutputRequest() { JobId = jobId, VaultName = vaultName }; long endPosition = currentPosition + partSize - 1; if (endPosition > archiveSize) endPosition = archiveSize; getJobOutputRequest.SetRange(currentPosition, endPosition); GetJobOutputResponse getJobOutputResponse = client.GetJobOutput(getJobOutputRequest); using (Stream webStream = getJobOutputResponse.Body) { CopyStream(webStream, fileToSave); } currentPosition += partSize; } while (currentPosition < archiveSize); } } public static void CopyStream(Stream input, Stream output) { byte[] buffer = new byte[65536]; int length; while ((length = input.Read(buffer, 0, buffer.Length)) > 0) { output.Write(buffer, 0, length); } } } }