1 files changed, 314 insertions, 0 deletions
diff --git a/vendor/github.com/containerd/stargz-snapshotter/estargz/types.go b/vendor/github.com/containerd/stargz-snapshotter/estargz/types.go
new file mode 100644
index 000000000..1b1075a64
--- /dev/null
+++ b/vendor/github.com/containerd/stargz-snapshotter/estargz/types.go
@@ -0,0 +1,314 @@
+/*
+   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"
+	"hash"
+	"io"
+	"os"
+	"path"
+	"time"
+
+	digest "github.com/opencontainers/go-digest"
+)
+
+const (
+	// TOCTarName is the name of the JSON file in the tar archive in the
+	// table of contents gzip stream.
+	TOCTarName = "stargz.index.json"
+
+	// FooterSize is the number of bytes in the footer
+	//
+	// The footer is an empty gzip stream with no compression and an Extra
+	// header of the form "%016xSTARGZ", where the 64 bit hex-encoded
+	// number is the offset to the gzip stream of JSON TOC.
+	//
+	// 51 comes from:
+	//
+	// 10 bytes  gzip header
+	// 2  bytes  XLEN (length of Extra field) = 26 (4 bytes header + 16 hex digits + len("STARGZ"))
+	// 2  bytes  Extra: SI1 = 'S', SI2 = 'G'
+	// 2  bytes  Extra: LEN = 22 (16 hex digits + len("STARGZ"))
+	// 22 bytes  Extra: subfield = fmt.Sprintf("%016xSTARGZ", offsetOfTOC)
+	// 5  bytes  flate header
+	// 8  bytes  gzip footer
+	// (End of the eStargz blob)
+	//
+	// NOTE: For Extra fields, subfield IDs SI1='S' SI2='G' is used for eStargz.
+	FooterSize = 51
+
+	// legacyFooterSize is the number of bytes in the legacy stargz footer.
+	//
+	// 47 comes from:
+	//
+	//   10 byte gzip header +
+	//   2 byte (LE16) length of extra, encoding 22 (16 hex digits + len("STARGZ")) == "\x16\x00" +
+	//   22 bytes of extra (fmt.Sprintf("%016xSTARGZ", tocGzipOffset))
+	//   5 byte flate header
+	//   8 byte gzip footer (two little endian uint32s: digest, size)
+	legacyFooterSize = 47
+
+	// TOCJSONDigestAnnotation is an annotation for an image layer. This stores the
+	// digest of the TOC JSON.
+	// This annotation is valid only when it is specified in `.[]layers.annotations`
+	// of an image manifest.
+	TOCJSONDigestAnnotation = "containerd.io/snapshot/stargz/toc.digest"
+
+	// StoreUncompressedSizeAnnotation is an additional annotation key for eStargz to enable lazy
+	// pulling on containers/storage. Stargz Store is required to expose the layer's uncompressed size
+	// to the runtime but current OCI image doesn't ship this information by default. So we store this
+	// to the special annotation.
+	StoreUncompressedSizeAnnotation = "io.containers.estargz.uncompressed-size"
+
+	// PrefetchLandmark is a file entry which indicates the end position of
+	// prefetch in the stargz file.
+	PrefetchLandmark = ".prefetch.landmark"
+
+	// NoPrefetchLandmark is a file entry which indicates that no prefetch should
+	// occur in the stargz file.
+	NoPrefetchLandmark = ".no.prefetch.landmark"
+
+	landmarkContents = 0xf
+)
+
+// JTOC is the JSON-serialized table of contents index of the files in the stargz file.
+type JTOC struct {
+	Version int         `json:"version"`
+	Entries []*TOCEntry `json:"entries"`
+}
+
+// TOCEntry is an entry in the stargz file's TOC (Table of Contents).
+type TOCEntry struct {
+	// Name is the tar entry's name. It is the complete path
+	// stored in the tar file, not just the base name.
+	Name string `json:"name"`
+
+	// Type is one of "dir", "reg", "symlink", "hardlink", "char",
+	// "block", "fifo", or "chunk".
+	// The "chunk" type is used for regular file data chunks past the first
+	// TOCEntry; the 2nd chunk and on have only Type ("chunk"), Offset,
+	// ChunkOffset, and ChunkSize populated.
+	Type string `json:"type"`
+
+	// Size, for regular files, is the logical size of the file.
+	Size int64 `json:"size,omitempty"`
+
+	// ModTime3339 is the modification time of the tar entry. Empty
+	// means zero or unknown. Otherwise it's in UTC RFC3339
+	// format. Use the ModTime method to access the time.Time value.
+	ModTime3339 string `json:"modtime,omitempty"`
+	modTime     time.Time
+
+	// LinkName, for symlinks and hardlinks, is the link target.
+	LinkName string `json:"linkName,omitempty"`
+
+	// Mode is the permission and mode bits.
+	Mode int64 `json:"mode,omitempty"`
+
+	// UID is the user ID of the owner.
+	UID int `json:"uid,omitempty"`
+
+	// GID is the group ID of the owner.
+	GID int `json:"gid,omitempty"`
+
+	// Uname is the username of the owner.
+	//
+	// In the serialized JSON, this field may only be present for
+	// the first entry with the same UID.
+	Uname string `json:"userName,omitempty"`
+
+	// Gname is the group name of the owner.
+	//
+	// In the serialized JSON, this field may only be present for
+	// the first entry with the same GID.
+	Gname string `json:"groupName,omitempty"`
+
+	// Offset, for regular files, provides the offset in the
+	// stargz file to the file's data bytes. See ChunkOffset and
+	// ChunkSize.
+	Offset int64 `json:"offset,omitempty"`
+
+	nextOffset int64 // the Offset of the next entry with a non-zero Offset
+
+	// DevMajor is the major device number for "char" and "block" types.
+	DevMajor int `json:"devMajor,omitempty"`
+
+	// DevMinor is the major device number for "char" and "block" types.
+	DevMinor int `json:"devMinor,omitempty"`
+
+	// NumLink is the number of entry names pointing to this entry.
+	// Zero means one name references this entry.
+	NumLink int
+
+	// Xattrs are the extended attribute for the entry.
+	Xattrs map[string][]byte `json:"xattrs,omitempty"`
+
+	// Digest stores the OCI checksum for regular files payload.
+	// It has the form "sha256:abcdef01234....".
+	Digest string `json:"digest,omitempty"`
+
+	// ChunkOffset is non-zero if this is a chunk of a large,
+	// regular file. If so, the Offset is where the gzip header of
+	// ChunkSize bytes at ChunkOffset in Name begin.
+	//
+	// In serialized form, a "chunkSize" JSON field of zero means
+	// that the chunk goes to the end of the file. After reading
+	// from the stargz TOC, though, the ChunkSize is initialized
+	// to a non-zero file for when Type is either "reg" or
+	// "chunk".
+	ChunkOffset int64 `json:"chunkOffset,omitempty"`
+	ChunkSize   int64 `json:"chunkSize,omitempty"`
+
+	// ChunkDigest stores an OCI digest of the chunk. This must be formed
+	// as "sha256:0123abcd...".
+	ChunkDigest string `json:"chunkDigest,omitempty"`
+
+	children map[string]*TOCEntry
+}
+
+// ModTime returns the entry's modification time.
+func (e *TOCEntry) ModTime() time.Time { return e.modTime }
+
+// NextOffset returns the position (relative to the start of the
+// stargz file) of the next gzip boundary after e.Offset.
+func (e *TOCEntry) NextOffset() int64 { return e.nextOffset }
+
+func (e *TOCEntry) addChild(baseName string, child *TOCEntry) {
+	if e.children == nil {
+		e.children = make(map[string]*TOCEntry)
+	}
+	if child.Type == "dir" {
+		e.NumLink++ // Entry ".." in the subdirectory links to this directory
+	}
+	e.children[baseName] = child
+}
+
+// isDataType reports whether TOCEntry is a regular file or chunk (something that
+// contains regular file data).
+func (e *TOCEntry) isDataType() bool { return e.Type == "reg" || e.Type == "chunk" }
+
+// Stat returns a FileInfo value representing e.
+func (e *TOCEntry) Stat() os.FileInfo { return fileInfo{e} }
+
+// ForeachChild calls f for each child item. If f returns false, iteration ends.
+// If e is not a directory, f is not called.
+func (e *TOCEntry) ForeachChild(f func(baseName string, ent *TOCEntry) bool) {
+	for name, ent := range e.children {
+		if !f(name, ent) {
+			return
+		}
+	}
+}
+
+// LookupChild returns the directory e's child by its base name.
+func (e *TOCEntry) LookupChild(baseName string) (child *TOCEntry, ok bool) {
+	child, ok = e.children[baseName]
+	return
+}
+
+// fileInfo implements os.FileInfo using the wrapped *TOCEntry.
+type fileInfo struct{ e *TOCEntry }
+
+var _ os.FileInfo = fileInfo{}
+
+func (fi fileInfo) Name() string       { return path.Base(fi.e.Name) }
+func (fi fileInfo) IsDir() bool        { return fi.e.Type == "dir" }
+func (fi fileInfo) Size() int64        { return fi.e.Size }
+func (fi fileInfo) ModTime() time.Time { return fi.e.ModTime() }
+func (fi fileInfo) Sys() interface{}   { return fi.e }
+func (fi fileInfo) Mode() (m os.FileMode) {
+	// TOCEntry.Mode is tar.Header.Mode so we can understand the these bits using `tar` pkg.
+	m = (&tar.Header{Mode: fi.e.Mode}).FileInfo().Mode() &
+		(os.ModePerm | os.ModeSetuid | os.ModeSetgid | os.ModeSticky)
+	switch fi.e.Type {
+	case "dir":
+		m |= os.ModeDir
+	case "symlink":
+		m |= os.ModeSymlink
+	case "char":
+		m |= os.ModeDevice | os.ModeCharDevice
+	case "block":
+		m |= os.ModeDevice
+	case "fifo":
+		m |= os.ModeNamedPipe
+	}
+	return m
+}
+
+// TOCEntryVerifier holds verifiers that are usable for verifying chunks contained
+// in a eStargz blob.
+type TOCEntryVerifier interface {
+
+	// Verifier provides a content verifier that can be used for verifying the
+	// contents of the specified TOCEntry.
+	Verifier(ce *TOCEntry) (digest.Verifier, error)
+}
+
+// Compression provides the compression helper to be used creating and parsing eStargz.
+// This package provides gzip-based Compression by default, but any compression
+// algorithm (e.g. zstd) can be used as long as it implements Compression.
+type Compression interface {
+	Compressor
+	Decompressor
+}
+
+// Compressor represents the helper mothods to be used for creating eStargz.
+type Compressor interface {
+	// Writer returns WriteCloser to be used for writing a chunk to eStargz.
+	// Everytime a chunk is written, the WriteCloser is closed and Writer is
+	// called again for writing the next chunk.
+	Writer(w io.Writer) (io.WriteCloser, error)
+
+	// WriteTOCAndFooter is called to write JTOC to the passed Writer.
+	// diffHash calculates the DiffID (uncompressed sha256 hash) of the blob
+	// WriteTOCAndFooter can optionally write anything that affects DiffID calculation
+	// (e.g. uncompressed TOC JSON).
+	//
+	// This function returns tocDgst that represents the digest of TOC that will be used
+	// to verify this blob when it's parsed.
+	WriteTOCAndFooter(w io.Writer, off int64, toc *JTOC, diffHash hash.Hash) (tocDgst digest.Digest, err error)
+}
+
+// Deompressor represents the helper mothods to be used for parsing eStargz.
+type Decompressor interface {
+	// Reader returns ReadCloser to be used for decompressing file payload.
+	Reader(r io.Reader) (io.ReadCloser, error)
+
+	// FooterSize returns the size of the footer of this blob.
+	FooterSize() int64
+
+	// ParseFooter parses the footer and returns the offset and (compressed) size of TOC.
+	//
+	// Here, tocSize is optional. If tocSize <= 0, it's by default the size of the range
+	// from tocOffset until the beginning of the footer (blob size - tocOff - FooterSize).
+	ParseFooter(p []byte) (tocOffset, tocSize int64, err error)
+
+	// ParseTOC parses TOC from the passed reader. The reader provides the partial contents
+	// of the underlying blob that has the range specified by ParseFooter method.
+	//
+	// This function returns tocDgst that represents the digest of TOC that will be used
+	// to verify this blob. This must match to the value returned from
+	// Compressor.WriteTOCAndFooter that is used when creating this blob.
+	ParseTOC(r io.Reader) (toc *JTOC, tocDgst digest.Digest, err error)
+}