diff options
Diffstat (limited to 'vendor/github.com/goamz/goamz/s3/multi.go')
| -rw-r--r-- | vendor/github.com/goamz/goamz/s3/multi.go | 439 |
1 files changed, 439 insertions, 0 deletions
diff --git a/vendor/github.com/goamz/goamz/s3/multi.go b/vendor/github.com/goamz/goamz/s3/multi.go new file mode 100644 index 000000000..348ead300 --- /dev/null +++ b/vendor/github.com/goamz/goamz/s3/multi.go @@ -0,0 +1,439 @@ +package s3 + +import ( + "bytes" + "crypto/md5" + "encoding/base64" + "encoding/hex" + "encoding/xml" + "errors" + "io" + "sort" + "strconv" +) + +// Multi represents an unfinished multipart upload. +// +// Multipart uploads allow sending big objects in smaller chunks. +// After all parts have been sent, the upload must be explicitly +// completed by calling Complete with the list of parts. +// +// See http://goo.gl/vJfTG for an overview of multipart uploads. +type Multi struct { + Bucket *Bucket + Key string + UploadId string +} + +// That's the default. Here just for testing. +var listMultiMax = 1000 + +type listMultiResp struct { + NextKeyMarker string + NextUploadIdMarker string + IsTruncated bool + Upload []Multi + CommonPrefixes []string `xml:"CommonPrefixes>Prefix"` +} + +// ListMulti returns the list of unfinished multipart uploads in b. +// +// The prefix parameter limits the response to keys that begin with the +// specified prefix. You can use prefixes to separate a bucket into different +// groupings of keys (to get the feeling of folders, for example). +// +// The delim parameter causes the response to group all of the keys that +// share a common prefix up to the next delimiter in a single entry within +// the CommonPrefixes field. You can use delimiters to separate a bucket +// into different groupings of keys, similar to how folders would work. +// +// See http://goo.gl/ePioY for details. +func (b *Bucket) ListMulti(prefix, delim string) (multis []*Multi, prefixes []string, err error) { + params := map[string][]string{ + "uploads": {""}, + "max-uploads": {strconv.FormatInt(int64(listMultiMax), 10)}, + "prefix": {prefix}, + "delimiter": {delim}, + } + for attempt := b.S3.AttemptStrategy.Start(); attempt.Next(); { + req := &request{ + method: "GET", + bucket: b.Name, + params: params, + } + var resp listMultiResp + err := b.S3.query(req, &resp) + if shouldRetry(err) && attempt.HasNext() { + continue + } + if err != nil { + return nil, nil, err + } + for i := range resp.Upload { + multi := &resp.Upload[i] + multi.Bucket = b + multis = append(multis, multi) + } + prefixes = append(prefixes, resp.CommonPrefixes...) + if !resp.IsTruncated { + return multis, prefixes, nil + } + params["key-marker"] = []string{resp.NextKeyMarker} + params["upload-id-marker"] = []string{resp.NextUploadIdMarker} + attempt = b.S3.AttemptStrategy.Start() // Last request worked. + } + panic("unreachable") +} + +// Multi returns a multipart upload handler for the provided key +// inside b. If a multipart upload exists for key, it is returned, +// otherwise a new multipart upload is initiated with contType and perm. +func (b *Bucket) Multi(key, contType string, perm ACL) (*Multi, error) { + multis, _, err := b.ListMulti(key, "") + if err != nil && !hasCode(err, "NoSuchUpload") { + return nil, err + } + for _, m := range multis { + if m.Key == key { + return m, nil + } + } + return b.InitMulti(key, contType, perm) +} + +// InitMulti initializes a new multipart upload at the provided +// key inside b and returns a value for manipulating it. +// +// See http://goo.gl/XP8kL for details. +func (b *Bucket) InitMulti(key string, contType string, perm ACL) (*Multi, error) { + headers := map[string][]string{ + "Content-Type": {contType}, + "Content-Length": {"0"}, + "x-amz-acl": {string(perm)}, + } + params := map[string][]string{ + "uploads": {""}, + } + req := &request{ + method: "POST", + bucket: b.Name, + path: key, + headers: headers, + params: params, + } + var err error + var resp struct { + UploadId string `xml:"UploadId"` + } + for attempt := b.S3.AttemptStrategy.Start(); attempt.Next(); { + err = b.S3.query(req, &resp) + if !shouldRetry(err) { + break + } + } + if err != nil { + return nil, err + } + return &Multi{Bucket: b, Key: key, UploadId: resp.UploadId}, nil +} + +// PutPart sends part n of the multipart upload, reading all the content from r. +// Each part, except for the last one, must be at least 5MB in size. +// +// See http://goo.gl/pqZer for details. +func (m *Multi) PutPart(n int, r io.ReadSeeker) (Part, error) { + partSize, _, md5b64, err := seekerInfo(r) + if err != nil { + return Part{}, err + } + return m.putPart(n, r, partSize, md5b64) +} + +func (m *Multi) putPart(n int, r io.ReadSeeker, partSize int64, md5b64 string) (Part, error) { + headers := map[string][]string{ + "Content-Length": {strconv.FormatInt(partSize, 10)}, + "Content-MD5": {md5b64}, + } + params := map[string][]string{ + "uploadId": {m.UploadId}, + "partNumber": {strconv.FormatInt(int64(n), 10)}, + } + for attempt := m.Bucket.S3.AttemptStrategy.Start(); attempt.Next(); { + _, err := r.Seek(0, 0) + if err != nil { + return Part{}, err + } + req := &request{ + method: "PUT", + bucket: m.Bucket.Name, + path: m.Key, + headers: headers, + params: params, + payload: r, + } + err = m.Bucket.S3.prepare(req) + if err != nil { + return Part{}, err + } + resp, err := m.Bucket.S3.run(req, nil) + if shouldRetry(err) && attempt.HasNext() { + continue + } + if err != nil { + return Part{}, err + } + etag := resp.Header.Get("ETag") + if etag == "" { + return Part{}, errors.New("part upload succeeded with no ETag") + } + return Part{n, etag, partSize}, nil + } + panic("unreachable") +} + +func seekerInfo(r io.ReadSeeker) (size int64, md5hex string, md5b64 string, err error) { + _, err = r.Seek(0, 0) + if err != nil { + return 0, "", "", err + } + digest := md5.New() + size, err = io.Copy(digest, r) + if err != nil { + return 0, "", "", err + } + sum := digest.Sum(nil) + md5hex = hex.EncodeToString(sum) + md5b64 = base64.StdEncoding.EncodeToString(sum) + return size, md5hex, md5b64, nil +} + +type Part struct { + N int `xml:"PartNumber"` + ETag string + Size int64 +} + +type partSlice []Part + +func (s partSlice) Len() int { return len(s) } +func (s partSlice) Less(i, j int) bool { return s[i].N < s[j].N } +func (s partSlice) Swap(i, j int) { s[i], s[j] = s[j], s[i] } + +type listPartsResp struct { + NextPartNumberMarker string + IsTruncated bool + Part []Part +} + +// That's the default. Here just for testing. +var listPartsMax = 1000 + +// ListParts returns the list of previously uploaded parts in m, +// ordered by part number. +// +// See http://goo.gl/ePioY for details. +func (m *Multi) ListParts() ([]Part, error) { + params := map[string][]string{ + "uploadId": {m.UploadId}, + "max-parts": {strconv.FormatInt(int64(listPartsMax), 10)}, + } + var parts partSlice + for attempt := m.Bucket.S3.AttemptStrategy.Start(); attempt.Next(); { + req := &request{ + method: "GET", + bucket: m.Bucket.Name, + path: m.Key, + params: params, + } + var resp listPartsResp + err := m.Bucket.S3.query(req, &resp) + if shouldRetry(err) && attempt.HasNext() { + continue + } + if err != nil { + return nil, err + } + parts = append(parts, resp.Part...) + if !resp.IsTruncated { + sort.Sort(parts) + return parts, nil + } + params["part-number-marker"] = []string{resp.NextPartNumberMarker} + attempt = m.Bucket.S3.AttemptStrategy.Start() // Last request worked. + } + panic("unreachable") +} + +type ReaderAtSeeker interface { + io.ReaderAt + io.ReadSeeker +} + +// PutAll sends all of r via a multipart upload with parts no larger +// than partSize bytes, which must be set to at least 5MB. +// Parts previously uploaded are either reused if their checksum +// and size match the new part, or otherwise overwritten with the +// new content. +// PutAll returns all the parts of m (reused or not). +func (m *Multi) PutAll(r ReaderAtSeeker, partSize int64) ([]Part, error) { + old, err := m.ListParts() + if err != nil && !hasCode(err, "NoSuchUpload") { + return nil, err + } + reuse := 0 // Index of next old part to consider reusing. + current := 1 // Part number of latest good part handled. + totalSize, err := r.Seek(0, 2) + if err != nil { + return nil, err + } + first := true // Must send at least one empty part if the file is empty. + var result []Part +NextSection: + for offset := int64(0); offset < totalSize || first; offset += partSize { + first = false + if offset+partSize > totalSize { + partSize = totalSize - offset + } + section := io.NewSectionReader(r, offset, partSize) + _, md5hex, md5b64, err := seekerInfo(section) + if err != nil { + return nil, err + } + for reuse < len(old) && old[reuse].N <= current { + // Looks like this part was already sent. + part := &old[reuse] + etag := `"` + md5hex + `"` + if part.N == current && part.Size == partSize && part.ETag == etag { + // Checksum matches. Reuse the old part. + result = append(result, *part) + current++ + continue NextSection + } + reuse++ + } + + // Part wasn't found or doesn't match. Send it. + part, err := m.putPart(current, section, partSize, md5b64) + if err != nil { + return nil, err + } + result = append(result, part) + current++ + } + return result, nil +} + +type completeUpload struct { + XMLName xml.Name `xml:"CompleteMultipartUpload"` + Parts completeParts `xml:"Part"` +} + +type completePart struct { + PartNumber int + ETag string +} + +type completeParts []completePart + +func (p completeParts) Len() int { return len(p) } +func (p completeParts) Less(i, j int) bool { return p[i].PartNumber < p[j].PartNumber } +func (p completeParts) Swap(i, j int) { p[i], p[j] = p[j], p[i] } + +type completeResponse struct { + // The element name: should be either CompleteMultipartUploadResult or Error. + XMLName xml.Name + // If the element was error, then it should have the following: + Code string + Message string + RequestId string + HostId string +} + +// Complete assembles the given previously uploaded parts into the +// final object. This operation may take several minutes. +// +// The complete call to AMZ may still fail after returning HTTP 200, +// so even though it's unusued, the body of the reply must be demarshalled +// and checked to see whether or not the complete succeeded. +// +// See http://goo.gl/2Z7Tw for details. +func (m *Multi) Complete(parts []Part) error { + params := map[string][]string{ + "uploadId": {m.UploadId}, + } + c := completeUpload{} + for _, p := range parts { + c.Parts = append(c.Parts, completePart{p.N, p.ETag}) + } + sort.Sort(c.Parts) + data, err := xml.Marshal(&c) + if err != nil { + return err + } + + // Setting Content-Length prevents breakage on DreamObjects + for attempt := m.Bucket.S3.AttemptStrategy.Start(); attempt.Next(); { + req := &request{ + method: "POST", + bucket: m.Bucket.Name, + path: m.Key, + params: params, + payload: bytes.NewReader(data), + headers: map[string][]string{ + "Content-Length": []string{strconv.Itoa(len(data))}, + }, + } + + resp := &completeResponse{} + err := m.Bucket.S3.query(req, resp) + if shouldRetry(err) && attempt.HasNext() { + continue + } + if err == nil && resp.XMLName.Local == "Error" { + err = &Error{ + StatusCode: 200, + Code: resp.Code, + Message: resp.Message, + RequestId: resp.RequestId, + HostId: resp.HostId, + } + } + return err + } + panic("unreachable") +} + +// Abort deletes an unifinished multipart upload and any previously +// uploaded parts for it. +// +// After a multipart upload is aborted, no additional parts can be +// uploaded using it. However, if any part uploads are currently in +// progress, those part uploads might or might not succeed. As a result, +// it might be necessary to abort a given multipart upload multiple +// times in order to completely free all storage consumed by all parts. +// +// NOTE: If the described scenario happens to you, please report back to +// the goamz authors with details. In the future such retrying should be +// handled internally, but it's not clear what happens precisely (Is an +// error returned? Is the issue completely undetectable?). +// +// See http://goo.gl/dnyJw for details. +func (m *Multi) Abort() error { + params := map[string][]string{ + "uploadId": {m.UploadId}, + } + for attempt := m.Bucket.S3.AttemptStrategy.Start(); attempt.Next(); { + req := &request{ + method: "DELETE", + bucket: m.Bucket.Name, + path: m.Key, + params: params, + } + err := m.Bucket.S3.query(req, nil) + if shouldRetry(err) && attempt.HasNext() { + continue + } + return err + } + panic("unreachable") +} |