s3manager

Documentation

Overview

Package s3manager provides utilities to upload and download objects from S3 concurrently. Helpful for when working with large objects.

Index

• Constants
• type Downloader
  • func NewDownloader(c client.ConfigProvider, options ...func(*Downloader)) *Downloader
  • func NewDownloaderWithClient(svc s3iface.S3API, options ...func(*Downloader)) *Downloader
  • func (d Downloader) Download(w io.WriterAt, input *s3.GetObjectInput, options ...func(*Downloader)) (n int64, err error)
• type MultiUploadFailure
• type UploadInput
• type UploadOutput
• type Uploader
  • func NewUploader(c client.ConfigProvider, options ...func(*Uploader)) *Uploader
  • func NewUploaderWithClient(svc s3iface.S3API, options ...func(*Uploader)) *Uploader
  • func (u Uploader) Upload(input *UploadInput, options ...func(*Uploader)) (*UploadOutput, error)

Constants

const DefaultDownloadConcurrency = 5

DefaultDownloadConcurrency is the default number of goroutines to spin up when using Download().

const DefaultDownloadPartSize = 1024 * 1024 * 5

DefaultDownloadPartSize is the default range of bytes to get at a time when using Download().

const DefaultUploadConcurrency = 5

DefaultUploadConcurrency is the default number of goroutines to spin up when using Upload().

const DefaultUploadPartSize = MinUploadPartSize

DefaultUploadPartSize is the default part size to buffer chunks of a payload into.

const MaxUploadParts = 10000

MaxUploadParts is the maximum allowed number of parts in a multi-part upload on Amazon S3.

const MinUploadPartSize int64 = 1024 * 1024 * 5

MinUploadPartSize is the minimum allowed part size when uploading a part to Amazon S3.

Types

type Downloader

type Downloader struct {
	// The buffer size (in bytes) to use when buffering data into chunks and
	// sending them as parts to S3. The minimum allowed part size is 5MB, and
	// if this value is set to zero, the DefaultPartSize value will be used.
	PartSize int64

	// The number of goroutines to spin up in parallel when sending parts.
	// If this is set to zero, the DefaultDownloadConcurrency value will be used.
	Concurrency int

	// An S3 client to use when performing downloads.
	S3 s3iface.S3API
}

The Downloader structure that calls Download(). It is safe to call Download() on this structure for multiple objects and across concurrent goroutines. Mutating the Downloader's properties is not safe to be done concurrently.

func NewDownloader

func NewDownloader(c client.ConfigProvider, options ...func(*Downloader)) *Downloader

NewDownloader creates a new Downloader instance to downloads objects from S3 in concurrent chunks. Pass in additional functional options to customize the downloader behavior. Requires a client.ConfigProvider in order to create a S3 service client. The session.Session satisfies the client.ConfigProvider interface.

Example:

// The session the S3 Downloader will use
sess, err := session.NewSession()

// Create a downloader with the session and default options
downloader := s3manager.NewDownloader(sess)

// Create a downloader with the session and custom options
downloader := s3manager.NewDownloader(sess, func(d *s3manager.Downloader) {
     d.PartSize = 64 * 1024 * 1024 // 64MB per part
})

func NewDownloaderWithClient

func NewDownloaderWithClient(svc s3iface.S3API, options ...func(*Downloader)) *Downloader

NewDownloaderWithClient creates a new Downloader instance to downloads objects from S3 in concurrent chunks. Pass in additional functional options to customize the downloader behavior. Requires a S3 service client to make S3 API calls.

Example:

// The session the S3 Downloader will use
sess, err := session.NewSession()

// The S3 client the S3 Downloader will use
s3Svc := s3.new(sess)

// Create a downloader with the s3 client and default options
downloader := s3manager.NewDownloaderWithClient(s3Svc)

// Create a downloader with the s3 client and custom options
downloader := s3manager.NewDownloaderWithClient(s3Svc, func(d *s3manager.Downloader) {
     d.PartSize = 64 * 1024 * 1024 // 64MB per part
})

func (Downloader) Download

func (d Downloader) Download(w io.WriterAt, input *s3.GetObjectInput, options ...func(*Downloader)) (n int64, err error)

Download downloads an object in S3 and writes the payload into w using concurrent GET requests.

Additional functional options can be provided to configure the individual download. These options are copies of the Downloader instance Download is called from. Modifying the options will not impact the original Downloader instance.

It is safe to call this method concurrently across goroutines.

The w io.WriterAt can be satisfied by an os.File to do multipart concurrent downloads, or in memory []byte wrapper using aws.WriteAtBuffer.

type MultiUploadFailure

type MultiUploadFailure interface {
	awserr.Error

	// Returns the upload id for the S3 multipart upload that failed.
	UploadID() string
}

A MultiUploadFailure wraps a failed S3 multipart upload. An error returned will satisfy this interface when a multi part upload failed to upload all chucks to S3. In the case of a failure the UploadID is needed to operate on the chunks, if any, which were uploaded.

Example:

u := s3manager.NewUploader(opts)
output, err := u.upload(input)
if err != nil {
    if multierr, ok := err.(s3manager.MultiUploadFailure); ok {
        // Process error and its associated uploadID
        fmt.Println("Error:", multierr.Code(), multierr.Message(), multierr.UploadID())
    } else {
        // Process error generically
        fmt.Println("Error:", err.Error())
    }
}

type UploadInput

type UploadInput struct {
	// The canned ACL to apply to the object.
	ACL *string `location:"header" locationName:"x-amz-acl" type:"string"`

	Bucket *string `location:"uri" locationName:"Bucket" type:"string" required:"true"`

	// Specifies caching behavior along the request/reply chain.
	CacheControl *string `location:"header" locationName:"Cache-Control" type:"string"`

	// Specifies presentational information for the object.
	ContentDisposition *string `location:"header" locationName:"Content-Disposition" type:"string"`

	// Specifies what content encodings have been applied to the object and thus
	// what decoding mechanisms must be applied to obtain the media-type referenced
	// by the Content-Type header field.
	ContentEncoding *string `location:"header" locationName:"Content-Encoding" type:"string"`

	// The language the content is in.
	ContentLanguage *string `location:"header" locationName:"Content-Language" type:"string"`

	// A standard MIME type describing the format of the object data.
	ContentType *string `location:"header" locationName:"Content-Type" type:"string"`

	// The date and time at which the object is no longer cacheable.
	Expires *time.Time `location:"header" locationName:"Expires" type:"timestamp" timestampFormat:"rfc822"`

	// Gives the grantee READ, READ_ACP, and WRITE_ACP permissions on the object.
	GrantFullControl *string `location:"header" locationName:"x-amz-grant-full-control" type:"string"`

	// Allows grantee to read the object data and its metadata.
	GrantRead *string `location:"header" locationName:"x-amz-grant-read" type:"string"`

	// Allows grantee to read the object ACL.
	GrantReadACP *string `location:"header" locationName:"x-amz-grant-read-acp" type:"string"`

	// Allows grantee to write the ACL for the applicable object.
	GrantWriteACP *string `location:"header" locationName:"x-amz-grant-write-acp" type:"string"`

	Key *string `location:"uri" locationName:"Key" type:"string" required:"true"`

	// A map of metadata to store with the object in S3.
	Metadata map[string]*string `location:"headers" locationName:"x-amz-meta-" type:"map"`

	// Confirms that the requester knows that she or he will be charged for the
	// request. Bucket owners need not specify this parameter in their requests.
	// Documentation on downloading objects from requester pays buckets can be found
	// at http://docs.aws.amazon.com/AmazonS3/latest/dev/ObjectsinRequesterPaysBuckets.html
	RequestPayer *string `location:"header" locationName:"x-amz-request-payer" type:"string"`

	// Specifies the algorithm to use to when encrypting the object (e.g., AES256,
	// aws:kms).
	SSECustomerAlgorithm *string `location:"header" locationName:"x-amz-server-side-encryption-customer-algorithm" type:"string"`

	// Specifies the customer-provided encryption key for Amazon S3 to use in encrypting
	// data. This value is used to store the object and then it is discarded; Amazon
	// does not store the encryption key. The key must be appropriate for use with
	// the algorithm specified in the x-amz-server-side​-encryption​-customer-algorithm
	// header.
	SSECustomerKey *string `location:"header" locationName:"x-amz-server-side-encryption-customer-key" type:"string"`

	// Specifies the 128-bit MD5 digest of the encryption key according to RFC 1321.
	// Amazon S3 uses this header for a message integrity check to ensure the encryption
	// key was transmitted without error.
	SSECustomerKeyMD5 *string `location:"header" locationName:"x-amz-server-side-encryption-customer-key-MD5" type:"string"`

	// Specifies the AWS KMS key ID to use for object encryption. All GET and PUT
	// requests for an object protected by AWS KMS will fail if not made via SSL
	// or using SigV4. Documentation on configuring any of the officially supported
	// AWS SDKs and CLI can be found at http://docs.aws.amazon.com/AmazonS3/latest/dev/UsingAWSSDK.html#specify-signature-version
	SSEKMSKeyId *string `location:"header" locationName:"x-amz-server-side-encryption-aws-kms-key-id" type:"string"`

	// The Server-side encryption algorithm used when storing this object in S3
	// (e.g., AES256, aws:kms).
	ServerSideEncryption *string `location:"header" locationName:"x-amz-server-side-encryption" type:"string"`

	// The type of storage to use for the object. Defaults to 'STANDARD'.
	StorageClass *string `location:"header" locationName:"x-amz-storage-class" type:"string"`

	// If the bucket is configured as a website, redirects requests for this object
	// to another object in the same bucket or to an external URL. Amazon S3 stores
	// the value of this header in the object metadata.
	WebsiteRedirectLocation *string `location:"header" locationName:"x-amz-website-redirect-location" type:"string"`

	// The readable body payload to send to S3.
	Body io.Reader
}

UploadInput contains all input for upload requests to Amazon S3.

type UploadOutput

type UploadOutput struct {
	// The URL where the object was uploaded to.
	Location string

	// The version of the object that was uploaded. Will only be populated if
	// the S3 Bucket is versioned. If the bucket is not versioned this field
	// will not be set.
	VersionID *string

	// The ID for a multipart upload to S3. In the case of an error the error
	// can be cast to the MultiUploadFailure interface to extract the upload ID.
	UploadID string
}

UploadOutput represents a response from the Upload() call.

type Uploader

type Uploader struct {
	// The buffer size (in bytes) to use when buffering data into chunks and
	// sending them as parts to S3. The minimum allowed part size is 5MB, and
	// if this value is set to zero, the DefaultPartSize value will be used.
	PartSize int64

	// The number of goroutines to spin up in parallel when sending parts.
	// If this is set to zero, the DefaultUploadConcurrency value will be used.
	Concurrency int

	// Setting this value to true will cause the SDK to avoid calling
	// AbortMultipartUpload on a failure, leaving all successfully uploaded
	// parts on S3 for manual recovery.
	//
	// Note that storing parts of an incomplete multipart upload counts towards
	// space usage on S3 and will add additional costs if not cleaned up.
	LeavePartsOnError bool

	// MaxUploadParts is the max number of parts which will be uploaded to S3.
	// Will be used to calculate the partsize of the object to be uploaded.
	// E.g: 5GB file, with MaxUploadParts set to 100, will upload the file
	// as 100, 50MB parts.
	// With a limited of s3.MaxUploadParts (10,000 parts).
	MaxUploadParts int

	// The client to use when uploading to S3.
	S3 s3iface.S3API
}

The Uploader structure that calls Upload(). It is safe to call Upload() on this structure for multiple objects and across concurrent goroutines. Mutating the Uploader's properties is not safe to be done concurrently.

func NewUploader

func NewUploader(c client.ConfigProvider, options ...func(*Uploader)) *Uploader

NewUploader creates a new Uploader instance to upload objects to S3. Pass In additional functional options to customize the uploader's behavior. Requires a client.ConfigProvider in order to create a S3 service client. The session.Session satisfies the client.ConfigProvider interface.

Example:

// The session the S3 Uploader will use
sess, err := session.NewSession()

// Create an uploader with the session and default options
uploader := s3manager.NewUploader(sess)

// Create an uploader with the session and custom options
uploader := s3manager.NewUploader(session, func(u *s3manager.Uploader) {
     u.PartSize = 64 * 1024 * 1024 // 64MB per part
})

func NewUploaderWithClient

func NewUploaderWithClient(svc s3iface.S3API, options ...func(*Uploader)) *Uploader

NewUploaderWithClient creates a new Uploader instance to upload objects to S3. Pass in additional functional options to customize the uploader's behavior. Requires a S3 service client to make S3 API calls.

Example:

// The session the S3 Uploader will use
sess, err := session.NewSession()

// S3 service client the Upload manager will use.
s3Svc := s3.New(sess)

// Create an uploader with S3 client and default options
uploader := s3manager.NewUploaderWithClient(s3Svc)

// Create an uploader with S3 client and custom options
uploader := s3manager.NewUploaderWithClient(s3Svc, func(u *s3manager.Uploader) {
     u.PartSize = 64 * 1024 * 1024 // 64MB per part
})

func (Uploader) Upload

func (u Uploader) Upload(input *UploadInput, options ...func(*Uploader)) (*UploadOutput, error)

Upload uploads an object to S3, intelligently buffering large files into smaller chunks and sending them in parallel across multiple goroutines. You can configure the buffer size and concurrency through the Uploader's parameters.

Additional functional options can be provided to configure the individual upload. These options are copies of the Uploader instance Upload is called from. Modifying the options will not impact the original Uploader instance.

It is safe to call this method concurrently across goroutines.

Example:

// Upload input parameters
upParams := &s3manager.UploadInput{
    Bucket: &bucketName,
    Key:    &keyName,
    Body:   file,
}

// Perform an upload.
result, err := uploader.Upload(upParams)

// Perform upload with options different than the those in the Uploader.
result, err := uploader.Upload(upParams, func(u *s3manager.Uploader) {
     u.PartSize = 10 * 1024 * 1024 // 10MB part size
     u.LeavePartsOnError = true    // Don't delete the parts if the upload fails.
})