forked from TrueCloudLab/distribution
3178d8cfad
Note that the README currently contains details about the secure parameter which is part of a separate pull request. I feel confident adding it here since I am certain we will eventually add the secure parameter. Also note that encrypt now defaults to true and rootdirectory defaults to the empty string.
610 lines
16 KiB
Go
610 lines
16 KiB
Go
// Package s3 provides a storagedriver.StorageDriver implementation to
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// store blobs in Amazon S3 cloud storage.
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//
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// This package leverages the crowdmob/goamz client library for interfacing with
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// s3.
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//
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// Because s3 is a key, value store the Stat call does not support last modification
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// time for directories (directories are an abstraction for key, value stores)
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//
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// Keep in mind that s3 guarantees only eventual consistency, so do not assume
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// that a successful write will mean immediate access to the data written (although
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// in most regions a new object put has guaranteed read after write). The only true
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// guarantee is that once you call Stat and receive a certain file size, that much of
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// the file is already accessible.
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package s3
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import (
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"bytes"
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"fmt"
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"io"
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"io/ioutil"
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"net/http"
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"strconv"
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"strings"
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"time"
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"github.com/crowdmob/goamz/aws"
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"github.com/crowdmob/goamz/s3"
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"github.com/docker/distribution/storagedriver"
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"github.com/docker/distribution/storagedriver/factory"
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)
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const driverName = "s3"
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// minChunkSize defines the minimum multipart upload chunk size
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// S3 API requires multipart upload chunks to be at least 5MB
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const chunkSize = 5 * 1024 * 1024
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// listMax is the largest amount of objects you can request from S3 in a list call
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const listMax = 1000
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func init() {
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factory.Register(driverName, &s3DriverFactory{})
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}
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// s3DriverFactory implements the factory.StorageDriverFactory interface
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type s3DriverFactory struct{}
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func (factory *s3DriverFactory) Create(parameters map[string]interface{}) (storagedriver.StorageDriver, error) {
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return FromParameters(parameters)
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}
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// Driver is a storagedriver.StorageDriver implementation backed by Amazon S3
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// Objects are stored at absolute keys in the provided bucket
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type Driver struct {
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S3 *s3.S3
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Bucket *s3.Bucket
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Encrypt bool
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rootDirectory string
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}
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// FromParameters constructs a new Driver with a given parameters map
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// Required parameters:
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// - accesskey
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// - secretkey
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// - region
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// - bucket
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// - encrypt
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func FromParameters(parameters map[string]interface{}) (*Driver, error) {
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// Providing no values for these is valid in case the user is authenticating
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// with an IAM on an ec2 instance (in which case the instance credentials will
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// be summoned when GetAuth is called)
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accessKey, _ := parameters["accesskey"]
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secretKey, _ := parameters["secretkey"]
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regionName, ok := parameters["region"]
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if !ok || regionName.(string) == "" {
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return nil, fmt.Errorf("No region parameter provided")
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}
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region := aws.GetRegion(fmt.Sprint(regionName))
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if region.Name == "" {
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return nil, fmt.Errorf("Invalid region provided: %v", region)
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}
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bucket, ok := parameters["bucket"]
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if !ok || fmt.Sprint(bucket) == "" {
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return nil, fmt.Errorf("No bucket parameter provided")
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}
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encryptBool := true
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encrypt, ok := parameters["encrypt"]
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if ok {
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encryptBool, ok = encrypt.(bool)
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if !ok {
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return nil, fmt.Errorf("The encrypt parameter should be a boolean")
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}
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}
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rootDirectory, ok := parameters["rootdirectory"]
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if !ok {
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rootDirectory = ""
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}
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return New(fmt.Sprint(accessKey), fmt.Sprint(secretKey), fmt.Sprint(bucket), fmt.Sprint(rootDirectory), region, encryptBool)
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}
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// New constructs a new Driver with the given AWS credentials, region, encryption flag, and
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// bucketName
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func New(accessKey, secretKey, bucketName, rootDirectory string, region aws.Region, encrypt bool) (*Driver, error) {
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auth, err := aws.GetAuth(accessKey, secretKey, "", time.Time{})
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if err != nil {
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return nil, err
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}
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s3obj := s3.New(auth, region)
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bucket := s3obj.Bucket(bucketName)
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if _, err := bucket.List("", "", "", 1); err != nil {
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return nil, err
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}
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// TODO Currently multipart uploads have no timestamps, so this would be unwise
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// if you initiated a new s3driver while another one is running on the same bucket.
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// multis, _, err := bucket.ListMulti("", "")
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// if err != nil {
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// return nil, err
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// }
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// for _, multi := range multis {
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// err := multi.Abort()
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// //TODO appropriate to do this error checking?
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// if err != nil {
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// return nil, err
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// }
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// }
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return &Driver{s3obj, bucket, encrypt, rootDirectory}, nil
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}
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// Implement the storagedriver.StorageDriver interface
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// GetContent retrieves the content stored at "path" as a []byte.
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func (d *Driver) GetContent(path string) ([]byte, error) {
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if !storagedriver.PathRegexp.MatchString(path) {
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return nil, storagedriver.InvalidPathError{Path: path}
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}
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content, err := d.Bucket.Get(d.s3Path(path))
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if err != nil {
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return nil, parseError(path, err)
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}
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return content, nil
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}
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// PutContent stores the []byte content at a location designated by "path".
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func (d *Driver) PutContent(path string, contents []byte) error {
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if !storagedriver.PathRegexp.MatchString(path) {
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return storagedriver.InvalidPathError{Path: path}
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}
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return parseError(path, d.Bucket.Put(d.s3Path(path), contents, d.getContentType(), getPermissions(), d.getOptions()))
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}
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// ReadStream retrieves an io.ReadCloser for the content stored at "path" with a
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// given byte offset.
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func (d *Driver) ReadStream(path string, offset int64) (io.ReadCloser, error) {
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if !storagedriver.PathRegexp.MatchString(path) {
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return nil, storagedriver.InvalidPathError{Path: path}
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}
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if offset < 0 {
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return nil, storagedriver.InvalidOffsetError{Path: path, Offset: offset}
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}
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headers := make(http.Header)
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headers.Add("Range", "bytes="+strconv.FormatInt(offset, 10)+"-")
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resp, err := d.Bucket.GetResponseWithHeaders(d.s3Path(path), headers)
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if err != nil {
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if s3Err, ok := err.(*s3.Error); ok && s3Err.Code == "InvalidRange" {
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return ioutil.NopCloser(bytes.NewReader(nil)), nil
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}
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return nil, parseError(path, err)
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}
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return resp.Body, nil
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}
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// WriteStream stores the contents of the provided io.Reader at a
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// location designated by the given path. The driver will know it has
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// received the full contents when the reader returns io.EOF. The number
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// of successfully READ bytes will be returned, even if an error is
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// returned. May be used to resume writing a stream by providing a nonzero
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// offset. Offsets past the current size will write from the position
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// beyond the end of the file.
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func (d *Driver) WriteStream(path string, offset int64, reader io.Reader) (totalRead int64, err error) {
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if !storagedriver.PathRegexp.MatchString(path) {
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return 0, storagedriver.InvalidPathError{Path: path}
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}
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if offset < 0 {
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return 0, storagedriver.InvalidOffsetError{Path: path, Offset: offset}
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}
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partNumber := 1
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bytesRead := 0
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parts := []s3.Part{}
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var part s3.Part
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multi, err := d.Bucket.InitMulti(d.s3Path(path), d.getContentType(), getPermissions(), d.getOptions())
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if err != nil {
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return 0, err
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}
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buf := make([]byte, chunkSize)
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zeroBuf := make([]byte, chunkSize)
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// We never want to leave a dangling multipart upload, our only consistent state is
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// when there is a whole object at path. This is in order to remain consistent with
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// the stat call.
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//
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// Note that if the machine dies before executing the defer, we will be left with a dangling
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// multipart upload, which will eventually be cleaned up, but we will lose all of the progress
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// made prior to the machine crashing.
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defer func() {
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if len(parts) > 0 {
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if multi == nil {
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// Parts should be empty if the multi is not initialized
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panic("Unreachable")
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} else {
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if multi.Complete(parts) != nil {
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multi.Abort()
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}
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}
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}
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}()
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// Fills from 0 to total from current
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fromSmallCurrent := func(total int64) error {
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current, err := d.ReadStream(path, 0)
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if err != nil {
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return err
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}
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bytesRead = 0
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for int64(bytesRead) < total {
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//The loop should very rarely enter a second iteration
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nn, err := current.Read(buf[bytesRead:total])
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bytesRead += nn
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if err != nil {
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if err != io.EOF {
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return err
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}
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break
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}
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}
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return nil
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}
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// Fills from parameter to chunkSize from reader
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fromReader := func(from int64) error {
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bytesRead = 0
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for from+int64(bytesRead) < chunkSize {
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nn, err := reader.Read(buf[from+int64(bytesRead):])
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totalRead += int64(nn)
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bytesRead += nn
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if err != nil {
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if err != io.EOF {
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return err
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}
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break
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}
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}
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if bytesRead > 0 {
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part, err = multi.PutPart(int(partNumber), bytes.NewReader(buf[0:int64(bytesRead)+from]))
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if err != nil {
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return err
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}
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parts = append(parts, part)
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partNumber++
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}
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return nil
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}
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if offset > 0 {
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resp, err := d.Bucket.Head(d.s3Path(path), nil)
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if err != nil {
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if s3Err, ok := err.(*s3.Error); !ok || s3Err.Code != "NoSuchKey" {
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return 0, err
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}
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}
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currentLength := int64(0)
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if err == nil {
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currentLength = resp.ContentLength
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}
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if currentLength >= offset {
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if offset < chunkSize {
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// chunkSize > currentLength >= offset
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if err = fromSmallCurrent(offset); err != nil {
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return totalRead, err
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}
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if err = fromReader(offset); err != nil {
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return totalRead, err
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}
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if totalRead+offset < chunkSize {
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return totalRead, nil
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}
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} else {
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// currentLength >= offset >= chunkSize
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_, part, err = multi.PutPartCopy(partNumber,
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s3.CopyOptions{CopySourceOptions: "bytes=0-" + strconv.FormatInt(offset-1, 10)},
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d.Bucket.Name+"/"+d.s3Path(path))
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if err != nil {
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return 0, err
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}
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parts = append(parts, part)
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partNumber++
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}
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} else {
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// Fills between parameters with 0s but only when to - from <= chunkSize
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fromZeroFillSmall := func(from, to int64) error {
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bytesRead = 0
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for from+int64(bytesRead) < to {
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nn, err := bytes.NewReader(zeroBuf).Read(buf[from+int64(bytesRead) : to])
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bytesRead += nn
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if err != nil {
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return err
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}
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}
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return nil
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}
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// Fills between parameters with 0s, making new parts
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fromZeroFillLarge := func(from, to int64) error {
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bytesRead64 := int64(0)
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for to-(from+bytesRead64) >= chunkSize {
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part, err := multi.PutPart(int(partNumber), bytes.NewReader(zeroBuf))
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if err != nil {
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return err
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}
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bytesRead64 += chunkSize
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parts = append(parts, part)
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partNumber++
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}
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return fromZeroFillSmall(0, (to-from)%chunkSize)
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}
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// currentLength < offset
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if currentLength < chunkSize {
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if offset < chunkSize {
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// chunkSize > offset > currentLength
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if err = fromSmallCurrent(currentLength); err != nil {
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return totalRead, err
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}
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if err = fromZeroFillSmall(currentLength, offset); err != nil {
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return totalRead, err
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}
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if err = fromReader(offset); err != nil {
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return totalRead, err
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}
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if totalRead+offset < chunkSize {
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return totalRead, nil
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}
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} else {
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// offset >= chunkSize > currentLength
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if err = fromSmallCurrent(currentLength); err != nil {
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return totalRead, err
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}
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if err = fromZeroFillSmall(currentLength, chunkSize); err != nil {
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return totalRead, err
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}
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part, err = multi.PutPart(int(partNumber), bytes.NewReader(buf))
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if err != nil {
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return totalRead, err
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}
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parts = append(parts, part)
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partNumber++
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//Zero fill from chunkSize up to offset, then some reader
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if err = fromZeroFillLarge(chunkSize, offset); err != nil {
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return totalRead, err
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}
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if err = fromReader(offset % chunkSize); err != nil {
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return totalRead, err
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}
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if totalRead+(offset%chunkSize) < chunkSize {
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return totalRead, nil
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}
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}
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} else {
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// offset > currentLength >= chunkSize
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_, part, err = multi.PutPartCopy(partNumber,
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s3.CopyOptions{CopySourceOptions: "bytes=0-" + strconv.FormatInt(currentLength-1, 10)},
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d.Bucket.Name+"/"+d.s3Path(path))
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if err != nil {
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return 0, err
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}
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parts = append(parts, part)
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partNumber++
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//Zero fill from currentLength up to offset, then some reader
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if err = fromZeroFillLarge(currentLength, offset); err != nil {
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return totalRead, err
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}
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if err = fromReader((offset - currentLength) % chunkSize); err != nil {
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return totalRead, err
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}
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if totalRead+((offset-currentLength)%chunkSize) < chunkSize {
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return totalRead, nil
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}
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}
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}
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}
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for {
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if err = fromReader(0); err != nil {
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return totalRead, err
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}
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if int64(bytesRead) < chunkSize {
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break
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}
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}
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return totalRead, nil
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}
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// Stat retrieves the FileInfo for the given path, including the current size
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// in bytes and the creation time.
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func (d *Driver) Stat(path string) (storagedriver.FileInfo, error) {
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if !storagedriver.PathRegexp.MatchString(path) {
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return nil, storagedriver.InvalidPathError{Path: path}
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}
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listResponse, err := d.Bucket.List(d.s3Path(path), "", "", 1)
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if err != nil {
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return nil, err
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}
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fi := storagedriver.FileInfoFields{
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Path: path,
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}
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if len(listResponse.Contents) == 1 {
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if listResponse.Contents[0].Key != d.s3Path(path) {
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fi.IsDir = true
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} else {
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fi.IsDir = false
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fi.Size = listResponse.Contents[0].Size
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timestamp, err := time.Parse(time.RFC3339Nano, listResponse.Contents[0].LastModified)
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if err != nil {
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return nil, err
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}
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fi.ModTime = timestamp
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}
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} else if len(listResponse.CommonPrefixes) == 1 {
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fi.IsDir = true
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} else {
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return nil, storagedriver.PathNotFoundError{Path: path}
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}
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return storagedriver.FileInfoInternal{FileInfoFields: fi}, nil
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}
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// List returns a list of the objects that are direct descendants of the given path.
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func (d *Driver) List(path string) ([]string, error) {
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if !storagedriver.PathRegexp.MatchString(path) && path != "/" {
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return nil, storagedriver.InvalidPathError{Path: path}
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}
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if path != "/" && path[len(path)-1] != '/' {
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path = path + "/"
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}
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listResponse, err := d.Bucket.List(d.s3Path(path), "/", "", listMax)
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if err != nil {
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return nil, err
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}
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files := []string{}
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directories := []string{}
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for {
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for _, key := range listResponse.Contents {
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files = append(files, strings.Replace(key.Key, d.s3Path(""), "", 1))
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}
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for _, commonPrefix := range listResponse.CommonPrefixes {
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directories = append(directories, strings.Replace(commonPrefix[0:len(commonPrefix)-1], d.s3Path(""), "", 1))
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}
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if listResponse.IsTruncated {
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listResponse, err = d.Bucket.List(d.s3Path(path), "/", listResponse.NextMarker, listMax)
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if err != nil {
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return nil, err
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}
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} else {
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break
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}
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}
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return append(files, directories...), nil
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}
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// Move moves an object stored at sourcePath to destPath, removing the original
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// object.
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func (d *Driver) Move(sourcePath string, destPath string) error {
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if !storagedriver.PathRegexp.MatchString(sourcePath) {
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return storagedriver.InvalidPathError{Path: sourcePath}
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} else if !storagedriver.PathRegexp.MatchString(destPath) {
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return storagedriver.InvalidPathError{Path: destPath}
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}
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/* This is terrible, but aws doesn't have an actual move. */
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_, err := d.Bucket.PutCopy(d.s3Path(destPath), getPermissions(),
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s3.CopyOptions{Options: d.getOptions(), ContentType: d.getContentType()}, d.Bucket.Name+"/"+d.s3Path(sourcePath))
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if err != nil {
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return parseError(sourcePath, err)
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}
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|
|
return d.Delete(sourcePath)
|
|
}
|
|
|
|
// Delete recursively deletes all objects stored at "path" and its subpaths.
|
|
func (d *Driver) Delete(path string) error {
|
|
if !storagedriver.PathRegexp.MatchString(path) {
|
|
return storagedriver.InvalidPathError{Path: path}
|
|
}
|
|
|
|
listResponse, err := d.Bucket.List(d.s3Path(path), "", "", listMax)
|
|
if err != nil || len(listResponse.Contents) == 0 {
|
|
return storagedriver.PathNotFoundError{Path: path}
|
|
}
|
|
|
|
s3Objects := make([]s3.Object, listMax)
|
|
|
|
for len(listResponse.Contents) > 0 {
|
|
for index, key := range listResponse.Contents {
|
|
s3Objects[index].Key = key.Key
|
|
}
|
|
|
|
err := d.Bucket.DelMulti(s3.Delete{Quiet: false, Objects: s3Objects[0:len(listResponse.Contents)]})
|
|
if err != nil {
|
|
return nil
|
|
}
|
|
|
|
listResponse, err = d.Bucket.List(d.s3Path(path), "", "", listMax)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func (d *Driver) s3Path(path string) string {
|
|
return strings.TrimLeft(strings.TrimRight(d.rootDirectory, "/")+path, "/")
|
|
}
|
|
|
|
func parseError(path string, err error) error {
|
|
if s3Err, ok := err.(*s3.Error); ok && s3Err.Code == "NoSuchKey" {
|
|
return storagedriver.PathNotFoundError{Path: path}
|
|
}
|
|
|
|
return err
|
|
}
|
|
|
|
func hasCode(err error, code string) bool {
|
|
s3err, ok := err.(*aws.Error)
|
|
return ok && s3err.Code == code
|
|
}
|
|
|
|
func (d *Driver) getOptions() s3.Options {
|
|
return s3.Options{SSE: d.Encrypt}
|
|
}
|
|
|
|
func getPermissions() s3.ACL {
|
|
return s3.Private
|
|
}
|
|
|
|
func (d *Driver) getContentType() string {
|
|
return "application/octet-stream"
|
|
}
|