變更物件儲存空間級別

本頁面說明如何透過重寫物件，變更 bucket 內物件的儲存空間級別。

• 如要瞭解如何在不重寫物件的情況下變更物件儲存空間級別，請參閱物件生命週期管理功能。
• 如要瞭解 Cloud Storage 如何自動管理物件的儲存空間級別，請參閱自動調整級別功能。

必要的角色

如要取得必要權限，透過重寫物件來變更物件的儲存空間級別，請要求管理員授予您值區的 Storage 物件使用者 (roles/storage.objectUser) 角色。

這個角色具備變更物件儲存空間類別所需的權限。如要查看確切的必要權限，請展開「Required permissions」(必要權限) 部分：

所需權限

• storage.objects.create
• storage.objects.delete
• storage.objects.get
• storage.objects.list

您或許還可透過其他預先定義的角色或自訂角色取得這些權限。

如需授予 bucket 角色的操作說明，請參閱「在 bucket 上設定及管理 IAM 政策」。

變更物件的的儲存空間級別

如要變更物件的儲存空間級別，請完成下列步驟：

控制台

無法透過 Google Cloud 控制台設定個別物件儲存空間級別。請改用 Google Cloud CLI。

指令列

使用 gcloud storage objects update 指令，並加上 --storage-class 旗標。例如：

gcloud storage objects update gs://BUCKET_NAME/OBJECT_NAME --storage-class=STORAGE_CLASS

其中：

• BUCKET_NAME 是 bucket 的名稱，其中包含要變更類別的物件。例如：my-bucket。
• OBJECT_NAME 是要變更類別的物件名稱。例如：pets/dog.png。
• STORAGE_CLASS 是物件的新儲存空間級別。例如：nearline。

用戶端程式庫

C++

詳情請參閱 Cloud Storage C++ API 參考文件。

如要向 Cloud Storage 進行驗證，請設定應用程式預設憑證。詳情請參閱「設定用戶端程式庫的驗證機制」。

namespace gcs = ::google::cloud::storage;
using ::google::cloud::StatusOr;
[](gcs::Client client, std::string const& bucket_name,
   std::string const& object_name, std::string const& storage_class) {
  StatusOr<gcs::ObjectMetadata> object_metadata =
      client.RewriteObjectBlocking(
          bucket_name, object_name, bucket_name, object_name,
          gcs::WithObjectMetadata(
              gcs::ObjectMetadata().set_storage_class(storage_class)));
  if (!object_metadata) throw std::move(object_metadata).status();

  std::cout << "Changed storage class of object " << object_metadata->name()
            << " in bucket " << object_metadata->bucket() << " to "
            << object_metadata->storage_class() << "\n";
}

C#

詳情請參閱 Cloud Storage C# API 參考文件。

如要向 Cloud Storage 進行驗證，請設定應用程式預設憑證。詳情請參閱「設定用戶端程式庫的驗證機制」。

using Google.Cloud.Storage.V1;
using System;

public class ChangeFileStorageClassSample
{
    public Google.Apis.Storage.v1.Data.Object ChangeFileStorageClass(
        string bucketName = "your-bucket-name",
        string objectName = "your-object-name",
        string storageClass = StorageClasses.Standard)
    {
        var storage = StorageClient.Create();

        // Changing storage class requires a rewrite operation, which can only be done
        // by the underlying service
        var obj = new Google.Apis.Storage.v1.Data.Object { StorageClass = storageClass };
        storage.Service.Objects.Rewrite(obj, bucketName, objectName, bucketName, objectName).Execute();

        var file = storage.GetObject(bucketName, objectName);
        Console.WriteLine($"Object {objectName} in bucket {bucketName} had" +
            $" its storage class set to {storageClass}.");

        return file;
    }
}

Go

詳情請參閱 Cloud Storage Go API 參考文件。

如要向 Cloud Storage 進行驗證，請設定應用程式預設憑證。詳情請參閱「設定用戶端程式庫的驗證機制」。

import (
	"context"
	"fmt"
	"io"
	"time"

	"cloud.google.com/go/storage"
)

// changeObjectStorageClass changes the storage class of a single object.
func changeObjectStorageClass(w io.Writer, bucket, object string) error {
	// bucket := "bucket-name"
	// object := "object-name"
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("storage.NewClient: %w", err)
	}
	defer client.Close()

	ctx, cancel := context.WithTimeout(ctx, time.Second*10)
	defer cancel()

	o := client.Bucket(bucket).Object(object)

	// Optional: set a generation-match precondition to avoid potential race
	// conditions and data corruptions. The request to copy is aborted if the
	// object's generation number does not match your precondition.
	attrs, err := o.Attrs(ctx)
	if err != nil {
		return fmt.Errorf("object.Attrs: %w", err)
	}
	o = o.If(storage.Conditions{GenerationMatch: attrs.Generation})

	// See the StorageClass documentation for other valid storage classes:
	// https://cloud.google.com/storage/docs/storage-classes
	newStorageClass := "COLDLINE"
	// You can't change an object's storage class directly, the only way is
	// to rewrite the object with the desired storage class.
	copier := o.CopierFrom(o)
	copier.StorageClass = newStorageClass
	if _, err := copier.Run(ctx); err != nil {
		return fmt.Errorf("copier.Run: %w", err)
	}
	fmt.Fprintf(w, "Object %v in bucket %v had its storage class set to %v\n", object, bucket, newStorageClass)
	return nil
}

Java

詳情請參閱 Cloud Storage Java API 參考文件。

如要向 Cloud Storage 進行驗證，請設定應用程式預設憑證。詳情請參閱「設定用戶端程式庫的驗證機制」。

import com.google.cloud.storage.Blob;
import com.google.cloud.storage.BlobId;
import com.google.cloud.storage.BlobInfo;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageClass;
import com.google.cloud.storage.StorageOptions;

public class ChangeObjectStorageClass {
  public static void changeObjectStorageClass(
      String projectId, String bucketName, String objectName) {
    // The ID of your GCP project
    // String projectId = "your-project-id";

    // The ID of your GCS bucket
    // String bucketName = "your-unique-bucket-name";

    // The ID of your GCS object
    // String objectName = "your-object-name";

    Storage storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();
    BlobId blobId = BlobId.of(bucketName, objectName);
    Blob sourceBlob = storage.get(blobId);
    if (sourceBlob == null) {
      System.out.println("The object " + objectName + " wasn't found in " + bucketName);
      return;
    }

    // See the StorageClass documentation for other valid storage classes:
    // https://googleapis.dev/java/google-cloud-clients/latest/com/google/cloud/storage/StorageClass.html
    StorageClass storageClass = StorageClass.COLDLINE;

    // You can't change an object's storage class directly, the only way is to rewrite the object
    // with the desired storage class

    BlobInfo targetBlob = BlobInfo.newBuilder(blobId).setStorageClass(storageClass).build();

    // Optional: set a generation-match precondition to avoid potential race
    // conditions and data corruptions. The request to upload returns a 412 error if
    // the object's generation number does not match your precondition.
    Storage.BlobSourceOption precondition =
        Storage.BlobSourceOption.generationMatch(sourceBlob.getGeneration());

    Storage.CopyRequest request =
        Storage.CopyRequest.newBuilder()
            .setSource(blobId)
            .setSourceOptions(precondition) // delete this line to run without preconditions
            .setTarget(targetBlob)
            .build();
    Blob updatedBlob = storage.copy(request).getResult();

    System.out.println(
        "Object "
            + objectName
            + " in bucket "
            + bucketName
            + " had its storage class set to "
            + updatedBlob.getStorageClass().name());
  }
}

Node.js

詳情請參閱「Cloud Storage Node.js API 參考文件」。

如要向 Cloud Storage 進行驗證，請設定應用程式預設憑證。詳情請參閱「設定用戶端程式庫的驗證機制」。

// Imports the Google Cloud client library
const {Storage} = require('@google-cloud/storage');

// Creates a client
const storage = new Storage();

/**
 * TODO(developer): Uncomment the following lines before running the sample.
 */
// The ID of your GCS bucket
// const bucketName = 'your-unique-bucket-name';

// The ID of your GCS file
// const fileName = 'your-file-name';

// The name of a storage class
// See the StorageClass documentation for other valid storage classes:
// https://googleapis.dev/java/google-cloud-clients/latest/com/google/cloud/storage/StorageClass.html
// const storageClass = 'coldline';

async function fileChangeStorageClass() {
  // Optional:
  // Set a generation-match precondition to avoid potential race conditions
  // and data corruptions. The request to copy is aborted if the object's
  // generation number does not match your precondition. For a destination
  // object that does not yet exist, set the ifGenerationMatch precondition to 0
  // If the destination object already exists in your bucket, set instead a
  // generation-match precondition using its generation number.
  const setStorageClassOptions = {
    ifGenerationMatch: generationMatchPrecondition,
  };

  await storage
    .bucket(bucketName)
    .file(fileName)
    .setStorageClass(storageClass, setStorageClassOptions);

  console.log(`${fileName} has been set to ${storageClass}`);
}

fileChangeStorageClass().catch(console.error);

PHP

詳情請參閱「Cloud Storage PHP API 參考文件」。

如要向 Cloud Storage 進行驗證，請設定應用程式預設憑證。詳情請參閱「設定用戶端程式庫的驗證機制」。

use Google\Cloud\Storage\StorageClient;

/**
 * Change the storage class of the given file.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 *        (e.g. 'my-bucket')
 * @param string $objectName The name of your Cloud Storage object.
 *        (e.g. 'my-object')
 * @param string $storageClass The storage class of the new object.
 *        (e.g. 'COLDLINE')
 */
function change_file_storage_class(string $bucketName, string $objectName, string $storageClass): void
{
    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    $object = $bucket->object($objectName);

    // Storage class cannot be changed directly. But we can rewrite the object
    // using the new storage class.

    $newObject = $object->rewrite($bucket, [
        'storageClass' => $storageClass,
    ]);

    printf(
        'Object %s in bucket %s had its storage class set to %s',
        $objectName,
        $bucketName,
        $newObject->info()['storageClass']
    );
}

Python

詳情請參閱「Cloud Storage Python API 參考文件」。

如要向 Cloud Storage 進行驗證，請設定應用程式預設憑證。詳情請參閱「設定用戶端程式庫的驗證機制」。

from google.cloud import storage


def change_file_storage_class(bucket_name, blob_name):
    """Change the default storage class of the blob"""
    # bucket_name = "your-bucket-name"
    # blob_name = "your-object-name"

    storage_client = storage.Client()

    bucket = storage_client.bucket(bucket_name)
    blob = bucket.blob(blob_name)
    generation_match_precondition = None

    # Optional: set a generation-match precondition to avoid potential race
    # conditions and data corruptions. The request is aborted if the
    # object's generation number does not match your precondition.
    blob.reload()  # Fetch blob metadata to use in generation_match_precondition.
    generation_match_precondition = blob.generation

    blob.update_storage_class("NEARLINE", if_generation_match=generation_match_precondition)

    print(
        "Blob {} in bucket {} had its storage class set to {}".format(
            blob_name,
            bucket_name,
            blob.storage_class
        )
    )
    return blob

Ruby

詳情請參閱 Cloud Storage Ruby API 參考文件。

如要向 Cloud Storage 進行驗證，請設定應用程式預設憑證。詳情請參閱「設定用戶端程式庫的驗證機制」。

def change_file_storage_class bucket_name:, file_name:
  # The ID of your GCS bucket
  # bucket_name = "your-unique-bucket-name"

  # The ID of your GCS object
  # file_name = "your-file-name"

  require "google/cloud/storage"

  storage = Google::Cloud::Storage.new
  bucket = storage.bucket bucket_name, skip_lookup: true

  file = bucket.file file_name

  file.storage_class = "NEARLINE"

  puts "File #{file_name} in bucket #{bucket_name} had its storage class set to #{file.storage_class}"
end

Rust

use google_cloud_storage::builder_ext::RewriteObjectExt;
use google_cloud_storage::client::StorageControl;
use google_cloud_storage::model::Object;

pub async fn sample(client: &StorageControl, bucket_id: &str) -> anyhow::Result<()> {
    const NAME: &str = "update-storage-class";
    let updated = client
        .rewrite_object()
        .set_source_bucket(format!("projects/_/buckets/{bucket_id}"))
        .set_source_object(NAME)
        .set_destination_bucket(format!("projects/_/buckets/{bucket_id}"))
        .set_destination_name(NAME)
        // For other valid storage classes, refer to the documentation:
        // https://cloud.google.com/storage/docs/storage-classes
        .set_destination(Object::new().set_storage_class("NEARLINE"))
        .rewrite_until_done()
        .await?;
    println!(
        "successfully updated storage class for object {NAME} in bucket {bucket_id}: {updated:?}"
    );
    Ok(())
}

REST API

JSON API

注意：您要透過原始物件保留的 ACL 必須包含在您在要求主體中提供的物件資源中。

1. 安裝並初始化 gcloud CLI，以便為 Authorization 標頭產生存取權杖。

2. 建立包含下列資訊的 JSON 檔案：

   {
     "storageClass": "STORAGE_CLASS"
   }

   其中：

   • STORAGE_CLASS 是物件的新儲存空間級別。例如：nearline。

3. 使用 cURL 呼叫 JSON API，並傳送 POST 物件要求：

   curl -X POST --data-binary @JSON_FILE_NAME \
     -H "Authorization: Bearer $(gcloud auth print-access-token)" \
     -H "Content-Type: application/json" \
     "https://storage.googleapis.com/storage/v1/b/BUCKET_NAME/o/OBJECT_NAME/rewriteTo/b/BUCKET_NAME/o/OBJECT_NAME"

   其中：

   • JSON_FILE_NAME 是您在步驟 2 建立的 JSON 檔案路徑。
   • BUCKET_NAME 是包含原始物件的 bucket 名稱。例如：my-bucket。
   • OBJECT_NAME 是物件的網址編碼名稱。例如 pets/dog.png，網址編碼為 pets%2Fdog.png。

XML API

注意：您要保留的原始物件中繼資料 (例如自訂中繼資料) 必須包含在您於要求內提供的標頭中。此外，物件的任何 ACL 如果與其包含值區的預設物件 ACL 不同，則在物件上傳後必須重新套用 ACL。

1. 安裝並初始化 gcloud CLI，以便為 Authorization 標頭產生存取權杖。

2. 使用 cURL 透過 PUT 物件要求呼叫 XML API：

   curl -X PUT --data-binary @OBJECT \
     -H "Authorization: Bearer $(gcloud auth print-access-token)" \
     -H "Content-Type: OBJECT_CONTENT_TYPE" \
     -H "x-goog-storage-class: STORAGE_CLASS" \
     "https://storage.googleapis.com/BUCKET_NAME/OBJECT_NAME"

   其中：

   • OBJECT 是要變更儲存空間級別的物件本機路徑 (使用 XML API 變更儲存空間級別時，必須重新上傳物件)。例如：Desktop/dog.png。
   • OBJECT_CONTENT_TYPE 是物件的內容類型。例如：image/png。
   • STORAGE_CLASS 是物件的新儲存空間級別。例如：nearline。
   • BUCKET_NAME 是 bucket 名稱，內含您要重寫的物件。例如：my-bucket。
   • OBJECT_NAME 是您要重新編寫的物件名稱，並經過網址編碼。例如 pets/dog.png，網址編碼為 pets%2Fdog.png。

注意： 本指南涉及重寫資料，這是 A 級作業，可能產生額外費用，具體取決於資料的保存時間、位置和儲存空間類別。詳情請參閱 Cloud Storage 定價。另請注意，如果已為值區啟用物件版本管理，原始物件會保留在值區中，直到明確刪除為止。

後續步驟

• 瞭解可用的儲存空間級別。
• 使用物件生命週期管理功能變更物件儲存空間級別。
• 探索其他 Cloud Storage 資料生命週期功能。
• 瞭解物件中繼資料。
• 瞭解如何使用要求前提條件，避免競爭狀況。