package s3manager
import (
"bytes"
"fmt"
"io"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/awserr"
"github.com/aws/aws-sdk-go/aws/client"
"github.com/aws/aws-sdk-go/aws/request"
"github.com/aws/aws-sdk-go/service/s3"
"github.com/aws/aws-sdk-go/service/s3/s3iface"
)
const (
// DefaultBatchSize is the batch size we initialize when constructing a batch delete client.
// This value is used when calling DeleteObjects. This represents how many objects to delete
// per DeleteObjects call.
DefaultBatchSize = 100
)
// BatchError will contain the key and bucket of the object that failed to
// either upload or download.
type BatchError struct {
Errors Errors
code string
message string
}
// Errors is a typed alias for a slice of errors to satisfy the error
// interface.
type Errors []Error
func (errs Errors) Error() string {
buf := bytes.NewBuffer(nil)
for i, err := range errs {
buf.WriteString(err.Error())
if i+1 < len(errs) {
buf.WriteString("\n")
}
}
return buf.String()
}
// Error will contain the original error, bucket, and key of the operation that failed
// during batch operations.
type Error struct {
OrigErr error
Bucket *string
Key *string
}
func newError(err error, bucket, key *string) Error {
return Error{
err,
bucket,
key,
}
}
func (err *Error) Error() string {
origErr := ""
if err.OrigErr != nil {
origErr = ":\n" + err.OrigErr.Error()
}
return fmt.Sprintf("failed to perform batch operation on %q to %q%s",
aws.StringValue(err.Key),
aws.StringValue(err.Bucket),
origErr,
)
}
// NewBatchError will return a BatchError that satisfies the awserr.Error interface.
func NewBatchError(code, message string, err []Error) awserr.Error {
return &BatchError{
Errors: err,
code: code,
message: message,
}
}
// Code will return the code associated with the batch error.
func (err *BatchError) Code() string {
return err.code
}
// Message will return the message associated with the batch error.
func (err *BatchError) Message() string {
return err.message
}
func (err *BatchError) Error() string {
return awserr.SprintError(err.Code(), err.Message(), "", err.Errors)
}
// OrigErr will return the original error. Which, in this case, will always be nil
// for batched operations.
func (err *BatchError) OrigErr() error {
return err.Errors
}
// BatchDeleteIterator is an interface that uses the scanner pattern to
// iterate through what needs to be deleted.
type BatchDeleteIterator interface {
Next() bool
Err() error
DeleteObject() BatchDeleteObject
}
// DeleteListIterator is an alternative iterator for the BatchDelete client. This will
// iterate through a list of objects and delete the objects.
//
// Example:
// iter := &s3manager.DeleteListIterator{
// Client: svc,
// Input: &s3.ListObjectsInput{
// Bucket: aws.String("bucket"),
// MaxKeys: aws.Int64(5),
// },
// Paginator: request.Pagination{
// NewRequest: func() (*request.Request, error) {
// var inCpy *ListObjectsInput
// if input != nil {
// tmp := *input
// inCpy = &tmp
// }
// req, _ := c.ListObjectsRequest(inCpy)
// return req, nil
// },
// },
// }
//
// batcher := s3manager.NewBatchDeleteWithClient(svc)
// if err := batcher.Delete(aws.BackgroundContext(), iter); err != nil {
// return err
// }
type DeleteListIterator struct {
Bucket *string
Paginator request.Pagination
objects []*s3.Object
}
// NewDeleteListIterator will return a new DeleteListIterator.
func NewDeleteListIterator(svc s3iface.S3API, input *s3.ListObjectsInput, opts ...func(*DeleteListIterator)) BatchDeleteIterator {
iter := &DeleteListIterator{
Bucket: input.Bucket,
Paginator: request.Pagination{
NewRequest: func() (*request.Request, error) {
var inCpy *s3.ListObjectsInput
if input != nil {
tmp := *input
inCpy = &tmp
}
req, _ := svc.ListObjectsRequest(inCpy)
return req, nil
},
},
}
for _, opt := range opts {
opt(iter)
}
return iter
}
// Next will use the S3API client to iterate through a list of objects.
func (iter *DeleteListIterator) Next() bool {
if len(iter.objects) > 0 {
iter.objects = iter.objects[1:]
}
if len(iter.objects) == 0 && iter.Paginator.Next() {
iter.objects = iter.Paginator.Page().(*s3.ListObjectsOutput).Contents
}
return len(iter.objects) > 0
}
// Err will return the last known error from Next.
func (iter *DeleteListIterator) Err() error {
return iter.Paginator.Err()
}
// DeleteObject will return the current object to be deleted.
func (iter *DeleteListIterator) DeleteObject() BatchDeleteObject {
return BatchDeleteObject{
Object: &s3.DeleteObjectInput{
Bucket: iter.Bucket,
Key: iter.objects[0].Key,
},
}
}
// BatchDelete will use the s3 package's service client to perform a batch
// delete.
type BatchDelete struct {
Client s3iface.S3API
BatchSize int
}
// NewBatchDeleteWithClient will return a new delete client that can delete a batched amount of
// objects.
//
// Example:
// batcher := s3manager.NewBatchDeleteWithClient(client, size)
//
// objects := []BatchDeleteObject{
// {
// Object: &s3.DeleteObjectInput {
// Key: aws.String("key"),
// Bucket: aws.String("bucket"),
// },
// },
// }
//
// if err := batcher.Delete(aws.BackgroundContext(), &s3manager.DeleteObjectsIterator{
// Objects: objects,
// }); err != nil {
// return err
// }
func NewBatchDeleteWithClient(client s3iface.S3API, options ...func(*BatchDelete)) *BatchDelete {
svc := &BatchDelete{
Client: client,
BatchSize: DefaultBatchSize,
}
for _, opt := range options {
opt(svc)
}
return svc
}
// NewBatchDelete will return a new delete client that can delete a batched amount of
// objects.
//
// Example:
// batcher := s3manager.NewBatchDelete(sess, size)
//
// objects := []BatchDeleteObject{
// {
// Object: &s3.DeleteObjectInput {
// Key: aws.String("key"),
// Bucket: aws.String("bucket"),
// },
// },
// }
//
// if err := batcher.Delete(aws.BackgroundContext(), &s3manager.DeleteObjectsIterator{
// Objects: objects,
// }); err != nil {
// return err
// }
func NewBatchDelete(c client.ConfigProvider, options ...func(*BatchDelete)) *BatchDelete {
client := s3.New(c)
return NewBatchDeleteWithClient(client, options...)
}
// BatchDeleteObject is a wrapper object for calling the batch delete operation.
type BatchDeleteObject struct {
Object *s3.DeleteObjectInput
// After will run after each iteration during the batch process. This function will
// be executed whether or not the request was successful.
After func() error
}
// DeleteObjectsIterator is an interface that uses the scanner pattern to iterate
// through a series of objects to be deleted.
type DeleteObjectsIterator struct {
Objects []BatchDeleteObject
index int
inc bool
}
// Next will increment the default iterator's index and ensure that there
// is another object to iterator to.
func (iter *DeleteObjectsIterator) Next() bool {
if iter.inc {
iter.index++
} else {
iter.inc = true
}
return iter.index < len(iter.Objects)
}
// Err will return an error. Since this is just used to satisfy the BatchDeleteIterator interface
// this will only return nil.
func (iter *DeleteObjectsIterator) Err() error {
return nil
}
// DeleteObject will return the BatchDeleteObject at the current batched index.
func (iter *DeleteObjectsIterator) DeleteObject() BatchDeleteObject {
object := iter.Objects[iter.index]
return object
}
// Delete will use the iterator to queue up objects that need to be deleted.
// Once the batch size is met, this will call the deleteBatch function.
func (d *BatchDelete) Delete(ctx aws.Context, iter BatchDeleteIterator) error {
var errs []Error
objects := []BatchDeleteObject{}
var input *s3.DeleteObjectsInput
for iter.Next() {
o := iter.DeleteObject()
if input == nil {
input = initDeleteObjectsInput(o.Object)
}
parity := hasParity(input, o)
if parity {
input.Delete.Objects = append(input.Delete.Objects, &s3.ObjectIdentifier{
Key: o.Object.Key,
VersionId: o.Object.VersionId,
})
objects = append(objects, o)
}
if len(input.Delete.Objects) == d.BatchSize || !parity {
if err := deleteBatch(ctx, d, input, objects); err != nil {
errs = append(errs, err...)
}
objects = objects[:0]
input = nil
if !parity {
objects = append(objects, o)
input = initDeleteObjectsInput(o.Object)
input.Delete.Objects = append(input.Delete.Objects, &s3.ObjectIdentifier{
Key: o.Object.Key,
VersionId: o.Object.VersionId,
})
}
}
}
// iter.Next() could return false (above) plus populate iter.Err()
if iter.Err() != nil {
errs = append(errs, newError(iter.Err(), nil, nil))
}
if input != nil && len(input.Delete.Objects) > 0 {
if err := deleteBatch(ctx, d, input, objects); err != nil {
errs = append(errs, err...)
}
}
if len(errs) > 0 {
return NewBatchError("BatchedDeleteIncomplete", "some objects have failed to be deleted.", errs)
}
return nil
}
func initDeleteObjectsInput(o *s3.DeleteObjectInput) *s3.DeleteObjectsInput {
return &s3.DeleteObjectsInput{
Bucket: o.Bucket,
MFA: o.MFA,
RequestPayer: o.RequestPayer,
Delete: &s3.Delete{},
}
}
const (
// ErrDeleteBatchFailCode represents an error code which will be returned
// only when DeleteObjects.Errors has an error that does not contain a code.
ErrDeleteBatchFailCode = "DeleteBatchError"
errDefaultDeleteBatchMessage = "failed to delete"
)
// deleteBatch will delete a batch of items in the objects parameters.
func deleteBatch(ctx aws.Context, d *BatchDelete, input *s3.DeleteObjectsInput, objects []BatchDeleteObject) []Error {
errs := []Error{}
if result, err := d.Client.DeleteObjectsWithContext(ctx, input); err != nil {
for i := 0; i < len(input.Delete.Objects); i++ {
errs = append(errs, newError(err, input.Bucket, input.Delete.Objects[i].Key))
}
} else if len(result.Errors) > 0 {
for i := 0; i < len(result.Errors); i++ {
code := ErrDeleteBatchFailCode
msg := errDefaultDeleteBatchMessage
if result.Errors[i].Message != nil {
msg = *result.Errors[i].Message
}
if result.Errors[i].Code != nil {
code = *result.Errors[i].Code
}
errs = append(errs, newError(awserr.New(code, msg, err), input.Bucket, result.Errors[i].Key))
}
}
for _, object := range objects {
if object.After == nil {
continue
}
if err := object.After(); err != nil {
errs = append(errs, newError(err, object.Object.Bucket, object.Object.Key))
}
}
return errs
}
func hasParity(o1 *s3.DeleteObjectsInput, o2 BatchDeleteObject) bool {
if o1.Bucket != nil && o2.Object.Bucket != nil {
if *o1.Bucket != *o2.Object.Bucket {
return false
}
} else if o1.Bucket != o2.Object.Bucket {
return false
}
if o1.MFA != nil && o2.Object.MFA != nil {
if *o1.MFA != *o2.Object.MFA {
return false
}
} else if o1.MFA != o2.Object.MFA {
return false
}
if o1.RequestPayer != nil && o2.Object.RequestPayer != nil {
if *o1.RequestPayer != *o2.Object.RequestPayer {
return false
}
} else if o1.RequestPayer != o2.Object.RequestPayer {
return false
}
return true
}
// BatchDownloadIterator is an interface that uses the scanner pattern to iterate
// through a series of objects to be downloaded.
type BatchDownloadIterator interface {
Next() bool
Err() error
DownloadObject() BatchDownloadObject
}
// BatchDownloadObject contains all necessary information to run a batch operation once.
type BatchDownloadObject struct {
Object *s3.GetObjectInput
Writer io.WriterAt
// After will run after each iteration during the batch process. This function will
// be executed whether or not the request was successful.
After func() error
}
// DownloadObjectsIterator implements the BatchDownloadIterator interface and allows for batched
// download of objects.
type DownloadObjectsIterator struct {
Objects []BatchDownloadObject
index int
inc bool
}
// Next will increment the default iterator's index and ensure that there
// is another object to iterator to.
func (batcher *DownloadObjectsIterator) Next() bool {
if batcher.inc {
batcher.index++
} else {
batcher.inc = true
}
return batcher.index < len(batcher.Objects)
}
// DownloadObject will return the BatchDownloadObject at the current batched index.
func (batcher *DownloadObjectsIterator) DownloadObject() BatchDownloadObject {
object := batcher.Objects[batcher.index]
return object
}
// Err will return an error. Since this is just used to satisfy the BatchDeleteIterator interface
// this will only return nil.
func (batcher *DownloadObjectsIterator) Err() error {
return nil
}
// BatchUploadIterator is an interface that uses the scanner pattern to
// iterate through what needs to be uploaded.
type BatchUploadIterator interface {
Next() bool
Err() error
UploadObject() BatchUploadObject
}
// UploadObjectsIterator implements the BatchUploadIterator interface and allows for batched
// upload of objects.
type UploadObjectsIterator struct {
Objects []BatchUploadObject
index int
inc bool
}
// Next will increment the default iterator's index and ensure that there
// is another object to iterator to.
func (batcher *UploadObjectsIterator) Next() bool {
if batcher.inc {
batcher.index++
} else {
batcher.inc = true
}
return batcher.index < len(batcher.Objects)
}
// Err will return an error. Since this is just used to satisfy the BatchUploadIterator interface
// this will only return nil.
func (batcher *UploadObjectsIterator) Err() error {
return nil
}
// UploadObject will return the BatchUploadObject at the current batched index.
func (batcher *UploadObjectsIterator) UploadObject() BatchUploadObject {
object := batcher.Objects[batcher.index]
return object
}
// BatchUploadObject contains all necessary information to run a batch operation once.
type BatchUploadObject struct {
Object *UploadInput
// After will run after each iteration during the batch process. This function will
// be executed whether or not the request was successful.
After func() error
}