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authordependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>2021-09-13 12:29:39 +0000
committerGitHub <noreply@github.com>2021-09-13 12:29:39 +0000
commiteec59cea2c20cf5e515bdcbc8c35eba3e07da607 (patch)
tree71ec92fd12f16d15f25facd599ef097c2650c5f9 /vendor/github.com/containerd/stargz-snapshotter/estargz/gzip.go
parent0f3d3bd21da0b67542c44c832f0e1642c5f639cf (diff)
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Bump github.com/containers/storage from 1.35.0 to 1.36.0
Bumps [github.com/containers/storage](https://github.com/containers/storage) from 1.35.0 to 1.36.0. - [Release notes](https://github.com/containers/storage/releases) - [Changelog](https://github.com/containers/storage/blob/main/docs/containers-storage-changes.md) - [Commits](https://github.com/containers/storage/compare/v1.35.0...v1.36.0) --- updated-dependencies: - dependency-name: github.com/containers/storage dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <support@github.com>
Diffstat (limited to 'vendor/github.com/containerd/stargz-snapshotter/estargz/gzip.go')
-rw-r--r--vendor/github.com/containerd/stargz-snapshotter/estargz/gzip.go216
1 files changed, 216 insertions, 0 deletions
diff --git a/vendor/github.com/containerd/stargz-snapshotter/estargz/gzip.go b/vendor/github.com/containerd/stargz-snapshotter/estargz/gzip.go
new file mode 100644
index 000000000..efc435e09
--- /dev/null
+++ b/vendor/github.com/containerd/stargz-snapshotter/estargz/gzip.go
@@ -0,0 +1,216 @@
+/*
+ Copyright The containerd Authors.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+
+/*
+ Copyright 2019 The Go Authors. All rights reserved.
+ Use of this source code is governed by a BSD-style
+ license that can be found in the LICENSE file.
+*/
+
+package estargz
+
+import (
+ "archive/tar"
+ "bytes"
+ "compress/gzip"
+ "encoding/binary"
+ "encoding/json"
+ "fmt"
+ "hash"
+ "io"
+ "strconv"
+
+ digest "github.com/opencontainers/go-digest"
+ "github.com/pkg/errors"
+)
+
+type gzipCompression struct {
+ *gzipCompressor
+ *GzipDecompressor
+}
+
+func newGzipCompressionWithLevel(level int) Compression {
+ return &gzipCompression{
+ &gzipCompressor{level},
+ &GzipDecompressor{},
+ }
+}
+
+func NewGzipCompressorWithLevel(level int) Compressor {
+ return &gzipCompressor{level}
+}
+
+type gzipCompressor struct {
+ compressionLevel int
+}
+
+func (gc *gzipCompressor) Writer(w io.Writer) (io.WriteCloser, error) {
+ return gzip.NewWriterLevel(w, gc.compressionLevel)
+}
+
+func (gc *gzipCompressor) WriteTOCAndFooter(w io.Writer, off int64, toc *JTOC, diffHash hash.Hash) (digest.Digest, error) {
+ tocJSON, err := json.MarshalIndent(toc, "", "\t")
+ if err != nil {
+ return "", err
+ }
+ gz, _ := gzip.NewWriterLevel(w, gc.compressionLevel)
+ gw := io.Writer(gz)
+ if diffHash != nil {
+ gw = io.MultiWriter(gz, diffHash)
+ }
+ tw := tar.NewWriter(gw)
+ if err := tw.WriteHeader(&tar.Header{
+ Typeflag: tar.TypeReg,
+ Name: TOCTarName,
+ Size: int64(len(tocJSON)),
+ }); err != nil {
+ return "", err
+ }
+ if _, err := tw.Write(tocJSON); err != nil {
+ return "", err
+ }
+
+ if err := tw.Close(); err != nil {
+ return "", err
+ }
+ if err := gz.Close(); err != nil {
+ return "", err
+ }
+ if _, err := w.Write(gzipFooterBytes(off)); err != nil {
+ return "", err
+ }
+ return digest.FromBytes(tocJSON), nil
+}
+
+// gzipFooterBytes returns the 51 bytes footer.
+func gzipFooterBytes(tocOff int64) []byte {
+ buf := bytes.NewBuffer(make([]byte, 0, FooterSize))
+ gz, _ := gzip.NewWriterLevel(buf, gzip.NoCompression) // MUST be NoCompression to keep 51 bytes
+
+ // Extra header indicating the offset of TOCJSON
+ // https://tools.ietf.org/html/rfc1952#section-2.3.1.1
+ header := make([]byte, 4)
+ header[0], header[1] = 'S', 'G'
+ subfield := fmt.Sprintf("%016xSTARGZ", tocOff)
+ binary.LittleEndian.PutUint16(header[2:4], uint16(len(subfield))) // little-endian per RFC1952
+ gz.Header.Extra = append(header, []byte(subfield)...)
+ gz.Close()
+ if buf.Len() != FooterSize {
+ panic(fmt.Sprintf("footer buffer = %d, not %d", buf.Len(), FooterSize))
+ }
+ return buf.Bytes()
+}
+
+type GzipDecompressor struct{}
+
+func (gz *GzipDecompressor) Reader(r io.Reader) (io.ReadCloser, error) {
+ return gzip.NewReader(r)
+}
+
+func (gz *GzipDecompressor) ParseTOC(r io.Reader) (toc *JTOC, tocDgst digest.Digest, err error) {
+ return parseTOCEStargz(r)
+}
+
+func (gz *GzipDecompressor) ParseFooter(p []byte) (tocOffset, tocSize int64, err error) {
+ if len(p) != FooterSize {
+ return 0, 0, fmt.Errorf("invalid length %d cannot be parsed", len(p))
+ }
+ zr, err := gzip.NewReader(bytes.NewReader(p))
+ if err != nil {
+ return 0, 0, err
+ }
+ defer zr.Close()
+ extra := zr.Header.Extra
+ si1, si2, subfieldlen, subfield := extra[0], extra[1], extra[2:4], extra[4:]
+ if si1 != 'S' || si2 != 'G' {
+ return 0, 0, fmt.Errorf("invalid subfield IDs: %q, %q; want E, S", si1, si2)
+ }
+ if slen := binary.LittleEndian.Uint16(subfieldlen); slen != uint16(16+len("STARGZ")) {
+ return 0, 0, fmt.Errorf("invalid length of subfield %d; want %d", slen, 16+len("STARGZ"))
+ }
+ if string(subfield[16:]) != "STARGZ" {
+ return 0, 0, fmt.Errorf("STARGZ magic string must be included in the footer subfield")
+ }
+ tocOffset, err = strconv.ParseInt(string(subfield[:16]), 16, 64)
+ if err != nil {
+ return 0, 0, errors.Wrapf(err, "legacy: failed to parse toc offset")
+ }
+ return tocOffset, 0, nil
+}
+
+func (gz *GzipDecompressor) FooterSize() int64 {
+ return FooterSize
+}
+
+type legacyGzipDecompressor struct{}
+
+func (gz *legacyGzipDecompressor) Reader(r io.Reader) (io.ReadCloser, error) {
+ return gzip.NewReader(r)
+}
+
+func (gz *legacyGzipDecompressor) ParseTOC(r io.Reader) (toc *JTOC, tocDgst digest.Digest, err error) {
+ return parseTOCEStargz(r)
+}
+
+func (gz *legacyGzipDecompressor) ParseFooter(p []byte) (tocOffset, tocSize int64, err error) {
+ if len(p) != legacyFooterSize {
+ return 0, 0, fmt.Errorf("legacy: invalid length %d cannot be parsed", len(p))
+ }
+ zr, err := gzip.NewReader(bytes.NewReader(p))
+ if err != nil {
+ return 0, 0, errors.Wrapf(err, "legacy: failed to get footer gzip reader")
+ }
+ defer zr.Close()
+ extra := zr.Header.Extra
+ if len(extra) != 16+len("STARGZ") {
+ return 0, 0, fmt.Errorf("legacy: invalid stargz's extra field size")
+ }
+ if string(extra[16:]) != "STARGZ" {
+ return 0, 0, fmt.Errorf("legacy: magic string STARGZ not found")
+ }
+ tocOffset, err = strconv.ParseInt(string(extra[:16]), 16, 64)
+ if err != nil {
+ return 0, 0, errors.Wrapf(err, "legacy: failed to parse toc offset")
+ }
+ return tocOffset, 0, nil
+}
+
+func (gz *legacyGzipDecompressor) FooterSize() int64 {
+ return legacyFooterSize
+}
+
+func parseTOCEStargz(r io.Reader) (toc *JTOC, tocDgst digest.Digest, err error) {
+ zr, err := gzip.NewReader(r)
+ if err != nil {
+ return nil, "", fmt.Errorf("malformed TOC gzip header: %v", err)
+ }
+ defer zr.Close()
+ zr.Multistream(false)
+ tr := tar.NewReader(zr)
+ h, err := tr.Next()
+ if err != nil {
+ return nil, "", fmt.Errorf("failed to find tar header in TOC gzip stream: %v", err)
+ }
+ if h.Name != TOCTarName {
+ return nil, "", fmt.Errorf("TOC tar entry had name %q; expected %q", h.Name, TOCTarName)
+ }
+ dgstr := digest.Canonical.Digester()
+ toc = new(JTOC)
+ if err := json.NewDecoder(io.TeeReader(tr, dgstr.Hash())).Decode(&toc); err != nil {
+ return nil, "", fmt.Errorf("error decoding TOC JSON: %v", err)
+ }
+ return toc, dgstr.Digest(), nil
+}