Golang storage.Client類代碼示例

func ExampleBucketHandle_List() {
	ctx := context.Background()
	var client *storage.Client // See Example (Auth)

	var query *storage.Query
	for {
		// If you are using this package on the App Engine Flex runtime,
		// you can init a bucket client with your app's default bucket name.
		// See http://godoc.org/google.golang.org/appengine/file#DefaultBucketName.
		objects, err := client.Bucket("bucketname").List(ctx, query)
		if err != nil {
			log.Fatal(err)
		}
		for _, obj := range objects.Results {
			log.Printf("object name: %s, size: %v", obj.Name, obj.Size)
		}
		// If there are more results, objects.Next will be non-nil.
		if objects.Next == nil {
			break
		}
		query = objects.Next
	}

	log.Println("paginated through all object items in the bucket you specified.")
}

func (s *shard) createOutputFile(c context.Context) (io.WriteCloser, error) {
	c, _ = context.WithTimeout(c, time.Duration(10)*time.Minute)
	// for development we can't use the appengine default credentials so
	// instead need to create our own oauth token source to access storage

	// TODO: maybe give job a chance to generate this - it could also
	// create the writer (?). The only reason we're doing it is to prevent
	// duplication and also handle the file rollup operations
	var client *cstorage.Client
	if appengine.IsDevAppServer() {
		jsonKey, err := ioutil.ReadFile("service-account.json")
		if err != nil {
			return nil, err
		}
		conf, err := google.JWTConfigFromJSON(jsonKey, cstorage.ScopeReadWrite)
		if err != nil {
			return nil, err
		}
		client, err = cstorage.NewClient(c, option.WithTokenSource(conf.TokenSource(c)))
		if err != nil {
			return nil, err
		}
	} else {
		var err error
		client, err = cstorage.NewClient(c)
		if err != nil {
			return nil, err
		}
	}

	o := client.Bucket(s.job.Bucket).Object(s.sliceFilename(s.Sequence)).NewWriter(c)

	// TODO: wrap writer to count bytes and continue slice if we get close to 10Mb limit (?)
	return o, nil
}

func addObjectACL(client *storage.Client, bucket, object string) error {
	ctx := context.Background()

	acl := client.Bucket(bucket).Object(object).ACL()
	if err := acl.Set(ctx, storage.AllAuthenticatedUsers, storage.RoleReader); err != nil {
		return err
	}
	return nil
}

func deleteDefaultBucketACL(client *storage.Client, bucket string) error {
	ctx := context.Background()

	acl := client.Bucket(bucket).DefaultObjectACL()
	if err := acl.Delete(ctx, storage.AllAuthenticatedUsers); err != nil {
		return err
	}
	return nil
}

func delete(client *storage.Client, bucketName string) error {
	ctx := context.Background()
	// [START delete_bucket]
	if err := client.Bucket(bucketName).Delete(ctx); err != nil {
		return err
	}
	// [END delete_bucket]
	return nil
}

func create(client *storage.Client, projectID, bucketName string) error {
	ctx := context.Background()
	// [START create_bucket]
	if err := client.Bucket(bucketName).Create(ctx, projectID, nil); err != nil {
		return err
	}
	// [END create_bucket]
	return nil
}

func makePublic(client *storage.Client, bucket, object string) error {
	ctx := context.Background()
	// [START public]
	acl := client.Bucket(bucket).Object(object).ACL()
	if err := acl.Set(ctx, storage.AllUsers, storage.RoleReader); err != nil {
		return err
	}
	// [END public]
	return nil
}

func attrs(client *storage.Client, bucket, object string) (*storage.ObjectAttrs, error) {
	ctx := context.Background()
	// [START get_metadata]
	o := client.Bucket(bucket).Object(object)
	attrs, err := o.Attrs(ctx)
	if err != nil {
		return nil, err
	}
	return attrs, nil
	// [END get_metadata]
}

func objectACL(client *storage.Client, bucket, object string) error {
	ctx := context.Background()

	rules, err := client.Bucket(bucket).Object(object).ACL().List(ctx)
	if err != nil {
		return err
	}
	for _, rule := range rules {
		fmt.Printf("ACL rule: %v\n", rule)
	}
	return nil
}

func copyToBucket(client *storage.Client, dstBucket, srcBucket, srcObject string) error {
	ctx := context.Background()
	// [START copy_file]
	dstObject := srcObject + "-copy"
	src := client.Bucket(srcBucket).Object(srcObject)
	dst := client.Bucket(dstBucket).Object(dstObject)

	if _, err := dst.CopierFrom(src).Run(ctx); err != nil {
		return err
	}
	// [END copy_file]
	return nil
}

func createWithAttrs(client *storage.Client, projectID, bucketName string) error {
	ctx := context.Background()
	// [START create_bucket_with_storageclass_and_location]
	bucket := client.Bucket(bucketName)
	if err := bucket.Create(ctx, projectID, &storage.BucketAttrs{
		StorageClass: "COLDLINE",
		Location:     "asia",
	}); err != nil {
		return err
	}
	// [END create_bucket_with_storageclass_and_location]
	return nil
}

func objectACLFiltered(client *storage.Client, bucket, object string, entity storage.ACLEntity) error {
	ctx := context.Background()

	rules, err := client.Bucket(bucket).ACL().List(ctx)
	if err != nil {
		return err
	}
	for _, r := range rules {
		if r.Entity == entity {
			fmt.Printf("ACL rule role: %v\n", r.Role)
		}
	}
	return nil
}

// Gets a single object's bytes based on bucket and name parameters
func GetObject(gc *storage.Client, bucket, name string) (*bytes.Buffer, error) {

	rc, err := gc.Bucket(bucket).Object(name).NewReader(context.Background())
	if err != nil {
		if err == storage.ErrObjectNotExist {
			return nil, cloudstorage.ObjectNotFound
		}
		return nil, err
	}
	by, err := ioutil.ReadAll(rc)
	if err != nil {
		return nil, err
	}
	return bytes.NewBuffer(by), nil
}

func writeEncryptedObject(client *storage.Client, bucket, object string, secretKey []byte) error {
	ctx := context.Background()

	// [START storage_upload_encrypted_file]
	obj := client.Bucket(bucket).Object(object)
	// Encrypt the object's contents.
	wc := obj.Key(secretKey).NewWriter(ctx)
	if _, err := wc.Write([]byte("top secret")); err != nil {
		return err
	}
	if err := wc.Close(); err != nil {
		return err
	}
	// [END storage_upload_encrypted_file]
	return nil
}

func read(client *storage.Client, bucket, object string) ([]byte, error) {
	ctx := context.Background()
	// [START download_file]
	rc, err := client.Bucket(bucket).Object(object).NewReader(ctx)
	if err != nil {
		return nil, err
	}
	defer rc.Close()

	data, err := ioutil.ReadAll(rc)
	if err != nil {
		return nil, err
	}
	return data, nil
	// [END download_file]
}