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Vendor integration dependencies.

This commit is contained in:
Timo Reimann 2017-02-07 22:33:23 +01:00
parent dd5e3fba01
commit 55b57c736b
2451 changed files with 731611 additions and 0 deletions

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package asm
import (
"bytes"
"fmt"
"hash"
"hash/crc64"
"io"
"sync"
"github.com/vbatts/tar-split/tar/storage"
)
// NewOutputTarStream returns an io.ReadCloser that is an assembled tar archive
// stream.
//
// It takes a storage.FileGetter, for mapping the file payloads that are to be read in,
// and a storage.Unpacker, which has access to the rawbytes and file order
// metadata. With the combination of these two items, a precise assembled Tar
// archive is possible.
func NewOutputTarStream(fg storage.FileGetter, up storage.Unpacker) io.ReadCloser {
// ... Since these are interfaces, this is possible, so let's not have a nil pointer
if fg == nil || up == nil {
return nil
}
pr, pw := io.Pipe()
go func() {
err := WriteOutputTarStream(fg, up, pw)
if err != nil {
pw.CloseWithError(err)
} else {
pw.Close()
}
}()
return pr
}
// WriteOutputTarStream writes assembled tar archive to a writer.
func WriteOutputTarStream(fg storage.FileGetter, up storage.Unpacker, w io.Writer) error {
// ... Since these are interfaces, this is possible, so let's not have a nil pointer
if fg == nil || up == nil {
return nil
}
var copyBuffer []byte
var crcHash hash.Hash
var crcSum []byte
var multiWriter io.Writer
for {
entry, err := up.Next()
if err != nil {
if err == io.EOF {
return nil
}
return err
}
switch entry.Type {
case storage.SegmentType:
if _, err := w.Write(entry.Payload); err != nil {
return err
}
case storage.FileType:
if entry.Size == 0 {
continue
}
fh, err := fg.Get(entry.GetName())
if err != nil {
return err
}
if crcHash == nil {
crcHash = crc64.New(storage.CRCTable)
crcSum = make([]byte, 8)
multiWriter = io.MultiWriter(w, crcHash)
copyBuffer = byteBufferPool.Get().([]byte)
defer byteBufferPool.Put(copyBuffer)
} else {
crcHash.Reset()
}
if _, err := copyWithBuffer(multiWriter, fh, copyBuffer); err != nil {
fh.Close()
return err
}
if !bytes.Equal(crcHash.Sum(crcSum[:0]), entry.Payload) {
// I would rather this be a comparable ErrInvalidChecksum or such,
// but since it's coming through the PipeReader, the context of
// _which_ file would be lost...
fh.Close()
return fmt.Errorf("file integrity checksum failed for %q", entry.GetName())
}
fh.Close()
}
}
}
var byteBufferPool = &sync.Pool{
New: func() interface{} {
return make([]byte, 32*1024)
},
}
// copyWithBuffer is taken from stdlib io.Copy implementation
// https://github.com/golang/go/blob/go1.5.1/src/io/io.go#L367
func copyWithBuffer(dst io.Writer, src io.Reader, buf []byte) (written int64, err error) {
for {
nr, er := src.Read(buf)
if nr > 0 {
nw, ew := dst.Write(buf[0:nr])
if nw > 0 {
written += int64(nw)
}
if ew != nil {
err = ew
break
}
if nr != nw {
err = io.ErrShortWrite
break
}
}
if er == io.EOF {
break
}
if er != nil {
err = er
break
}
}
return written, err
}

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package asm
import (
"io"
"io/ioutil"
"github.com/vbatts/tar-split/archive/tar"
"github.com/vbatts/tar-split/tar/storage"
)
// NewInputTarStream wraps the Reader stream of a tar archive and provides a
// Reader stream of the same.
//
// In the middle it will pack the segments and file metadata to storage.Packer
// `p`.
//
// The the storage.FilePutter is where payload of files in the stream are
// stashed. If this stashing is not needed, you can provide a nil
// storage.FilePutter. Since the checksumming is still needed, then a default
// of NewDiscardFilePutter will be used internally
func NewInputTarStream(r io.Reader, p storage.Packer, fp storage.FilePutter) (io.Reader, error) {
// What to do here... folks will want their own access to the Reader that is
// their tar archive stream, but we'll need that same stream to use our
// forked 'archive/tar'.
// Perhaps do an io.TeeReader that hands back an io.Reader for them to read
// from, and we'll MITM the stream to store metadata.
// We'll need a storage.FilePutter too ...
// Another concern, whether to do any storage.FilePutter operations, such that we
// don't extract any amount of the archive. But then again, we're not making
// files/directories, hardlinks, etc. Just writing the io to the storage.FilePutter.
// Perhaps we have a DiscardFilePutter that is a bit bucket.
// we'll return the pipe reader, since TeeReader does not buffer and will
// only read what the outputRdr Read's. Since Tar archives have padding on
// the end, we want to be the one reading the padding, even if the user's
// `archive/tar` doesn't care.
pR, pW := io.Pipe()
outputRdr := io.TeeReader(r, pW)
// we need a putter that will generate the crc64 sums of file payloads
if fp == nil {
fp = storage.NewDiscardFilePutter()
}
go func() {
tr := tar.NewReader(outputRdr)
tr.RawAccounting = true
for {
hdr, err := tr.Next()
if err != nil {
if err != io.EOF {
pW.CloseWithError(err)
return
}
// even when an EOF is reached, there is often 1024 null bytes on
// the end of an archive. Collect them too.
if b := tr.RawBytes(); len(b) > 0 {
_, err := p.AddEntry(storage.Entry{
Type: storage.SegmentType,
Payload: b,
})
if err != nil {
pW.CloseWithError(err)
return
}
}
break // not return. We need the end of the reader.
}
if hdr == nil {
break // not return. We need the end of the reader.
}
if b := tr.RawBytes(); len(b) > 0 {
_, err := p.AddEntry(storage.Entry{
Type: storage.SegmentType,
Payload: b,
})
if err != nil {
pW.CloseWithError(err)
return
}
}
var csum []byte
if hdr.Size > 0 {
var err error
_, csum, err = fp.Put(hdr.Name, tr)
if err != nil {
pW.CloseWithError(err)
return
}
}
entry := storage.Entry{
Type: storage.FileType,
Size: hdr.Size,
Payload: csum,
}
// For proper marshalling of non-utf8 characters
entry.SetName(hdr.Name)
// File entries added, regardless of size
_, err = p.AddEntry(entry)
if err != nil {
pW.CloseWithError(err)
return
}
if b := tr.RawBytes(); len(b) > 0 {
_, err = p.AddEntry(storage.Entry{
Type: storage.SegmentType,
Payload: b,
})
if err != nil {
pW.CloseWithError(err)
return
}
}
}
// it is allowable, and not uncommon that there is further padding on the
// end of an archive, apart from the expected 1024 null bytes.
remainder, err := ioutil.ReadAll(outputRdr)
if err != nil && err != io.EOF {
pW.CloseWithError(err)
return
}
_, err = p.AddEntry(storage.Entry{
Type: storage.SegmentType,
Payload: remainder,
})
if err != nil {
pW.CloseWithError(err)
return
}
pW.Close()
}()
return pR, nil
}

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/*
Package asm provides the API for streaming assembly and disassembly of tar
archives.
Using the `github.com/vbatts/tar-split/tar/storage` for Packing/Unpacking the
metadata for a stream, as well as an implementation of Getting/Putting the file
entries' payload.
*/
package asm

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/*
Package storage is for metadata of a tar archive.
Packing and unpacking the Entries of the stream. The types of streams are
either segments of raw bytes (for the raw headers and various padding) and for
an entry marking a file payload.
The raw bytes are stored precisely in the packed (marshalled) Entry, whereas
the file payload marker include the name of the file, size, and crc64 checksum
(for basic file integrity).
*/
package storage

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package storage
import "unicode/utf8"
// Entries is for sorting by Position
type Entries []Entry
func (e Entries) Len() int { return len(e) }
func (e Entries) Swap(i, j int) { e[i], e[j] = e[j], e[i] }
func (e Entries) Less(i, j int) bool { return e[i].Position < e[j].Position }
// Type of Entry
type Type int
const (
// FileType represents a file payload from the tar stream.
//
// This will be used to map to relative paths on disk. Only Size > 0 will get
// read into a resulting output stream (due to hardlinks).
FileType Type = 1 + iota
// SegmentType represents a raw bytes segment from the archive stream. These raw
// byte segments consist of the raw headers and various padding.
//
// Its payload is to be marshalled base64 encoded.
SegmentType
)
// Entry is the structure for packing and unpacking the information read from
// the Tar archive.
//
// FileType Payload checksum is using `hash/crc64` for basic file integrity,
// _not_ for cryptography.
// From http://www.backplane.com/matt/crc64.html, CRC32 has almost 40,000
// collisions in a sample of 18.2 million, CRC64 had none.
type Entry struct {
Type Type `json:"type"`
Name string `json:"name,omitempty"`
NameRaw []byte `json:"name_raw,omitempty"`
Size int64 `json:"size,omitempty"`
Payload []byte `json:"payload"` // SegmentType stores payload here; FileType stores crc64 checksum here;
Position int `json:"position"`
}
// SetName will check name for valid UTF-8 string, and set the appropriate
// field. See https://github.com/vbatts/tar-split/issues/17
func (e *Entry) SetName(name string) {
if utf8.ValidString(name) {
e.Name = name
} else {
e.NameRaw = []byte(name)
}
}
// SetNameBytes will check name for valid UTF-8 string, and set the appropriate
// field
func (e *Entry) SetNameBytes(name []byte) {
if utf8.Valid(name) {
e.Name = string(name)
} else {
e.NameRaw = name
}
}
// GetName returns the string for the entry's name, regardless of the field stored in
func (e *Entry) GetName() string {
if len(e.NameRaw) > 0 {
return string(e.NameRaw)
}
return e.Name
}
// GetNameBytes returns the bytes for the entry's name, regardless of the field stored in
func (e *Entry) GetNameBytes() []byte {
if len(e.NameRaw) > 0 {
return e.NameRaw
}
return []byte(e.Name)
}

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package storage
import (
"bytes"
"errors"
"hash/crc64"
"io"
"os"
"path/filepath"
)
// FileGetter is the interface for getting a stream of a file payload,
// addressed by name/filename. Presumably, the names will be scoped to relative
// file paths.
type FileGetter interface {
// Get returns a stream for the provided file path
Get(filename string) (output io.ReadCloser, err error)
}
// FilePutter is the interface for storing a stream of a file payload,
// addressed by name/filename.
type FilePutter interface {
// Put returns the size of the stream received, and the crc64 checksum for
// the provided stream
Put(filename string, input io.Reader) (size int64, checksum []byte, err error)
}
// FileGetPutter is the interface that groups both Getting and Putting file
// payloads.
type FileGetPutter interface {
FileGetter
FilePutter
}
// NewPathFileGetter returns a FileGetter that is for files relative to path
// relpath.
func NewPathFileGetter(relpath string) FileGetter {
return &pathFileGetter{root: relpath}
}
type pathFileGetter struct {
root string
}
func (pfg pathFileGetter) Get(filename string) (io.ReadCloser, error) {
return os.Open(filepath.Join(pfg.root, filename))
}
type bufferFileGetPutter struct {
files map[string][]byte
}
func (bfgp bufferFileGetPutter) Get(name string) (io.ReadCloser, error) {
if _, ok := bfgp.files[name]; !ok {
return nil, errors.New("no such file")
}
b := bytes.NewBuffer(bfgp.files[name])
return &readCloserWrapper{b}, nil
}
func (bfgp *bufferFileGetPutter) Put(name string, r io.Reader) (int64, []byte, error) {
crc := crc64.New(CRCTable)
buf := bytes.NewBuffer(nil)
cw := io.MultiWriter(crc, buf)
i, err := io.Copy(cw, r)
if err != nil {
return 0, nil, err
}
bfgp.files[name] = buf.Bytes()
return i, crc.Sum(nil), nil
}
type readCloserWrapper struct {
io.Reader
}
func (w *readCloserWrapper) Close() error { return nil }
// NewBufferFileGetPutter is a simple in-memory FileGetPutter
//
// Implication is this is memory intensive...
// Probably best for testing or light weight cases.
func NewBufferFileGetPutter() FileGetPutter {
return &bufferFileGetPutter{
files: map[string][]byte{},
}
}
// NewDiscardFilePutter is a bit bucket FilePutter
func NewDiscardFilePutter() FilePutter {
return &bitBucketFilePutter{}
}
type bitBucketFilePutter struct {
}
func (bbfp *bitBucketFilePutter) Put(name string, r io.Reader) (int64, []byte, error) {
c := crc64.New(CRCTable)
i, err := io.Copy(c, r)
return i, c.Sum(nil), err
}
// CRCTable is the default table used for crc64 sum calculations
var CRCTable = crc64.MakeTable(crc64.ISO)

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package storage
import (
"encoding/json"
"errors"
"io"
"path/filepath"
"unicode/utf8"
)
// ErrDuplicatePath occurs when a tar archive has more than one entry for the
// same file path
var ErrDuplicatePath = errors.New("duplicates of file paths not supported")
// Packer describes the methods to pack Entries to a storage destination
type Packer interface {
// AddEntry packs the Entry and returns its position
AddEntry(e Entry) (int, error)
}
// Unpacker describes the methods to read Entries from a source
type Unpacker interface {
// Next returns the next Entry being unpacked, or error, until io.EOF
Next() (*Entry, error)
}
/* TODO(vbatts) figure out a good model for this
type PackUnpacker interface {
Packer
Unpacker
}
*/
type jsonUnpacker struct {
seen seenNames
dec *json.Decoder
}
func (jup *jsonUnpacker) Next() (*Entry, error) {
var e Entry
err := jup.dec.Decode(&e)
if err != nil {
return nil, err
}
// check for dup name
if e.Type == FileType {
cName := filepath.Clean(e.GetName())
if _, ok := jup.seen[cName]; ok {
return nil, ErrDuplicatePath
}
jup.seen[cName] = struct{}{}
}
return &e, err
}
// NewJSONUnpacker provides an Unpacker that reads Entries (SegmentType and
// FileType) as a json document.
//
// Each Entry read are expected to be delimited by new line.
func NewJSONUnpacker(r io.Reader) Unpacker {
return &jsonUnpacker{
dec: json.NewDecoder(r),
seen: seenNames{},
}
}
type jsonPacker struct {
w io.Writer
e *json.Encoder
pos int
seen seenNames
}
type seenNames map[string]struct{}
func (jp *jsonPacker) AddEntry(e Entry) (int, error) {
// if Name is not valid utf8, switch it to raw first.
if e.Name != "" {
if !utf8.ValidString(e.Name) {
e.NameRaw = []byte(e.Name)
e.Name = ""
}
}
// check early for dup name
if e.Type == FileType {
cName := filepath.Clean(e.GetName())
if _, ok := jp.seen[cName]; ok {
return -1, ErrDuplicatePath
}
jp.seen[cName] = struct{}{}
}
e.Position = jp.pos
err := jp.e.Encode(e)
if err != nil {
return -1, err
}
// made it this far, increment now
jp.pos++
return e.Position, nil
}
// NewJSONPacker provides a Packer that writes each Entry (SegmentType and
// FileType) as a json document.
//
// The Entries are delimited by new line.
func NewJSONPacker(w io.Writer) Packer {
return &jsonPacker{
w: w,
e: json.NewEncoder(w),
seen: seenNames{},
}
}
/*
TODO(vbatts) perhaps have a more compact packer/unpacker, maybe using msgapck
(https://github.com/ugorji/go)
Even though, since our jsonUnpacker and jsonPacker just take
io.Reader/io.Writer, then we can get away with passing them a
gzip.Reader/gzip.Writer
*/