+// Copyright (C) The Arvados Authors. All rights reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+
/* Deals with parsing Manifest Text. */
// Inspired by the Manifest class in arvados/sdk/ruby/lib/arvados/keep.rb
package manifest
import (
+ "errors"
+ "fmt"
"git.curoverse.com/arvados.git/sdk/go/blockdigest"
- "log"
+ "path"
+ "regexp"
+ "sort"
+ "strconv"
"strings"
)
+var ErrInvalidToken = errors.New("Invalid token")
+
type Manifest struct {
Text string
+ Err error
+}
+
+type BlockLocator struct {
+ Digest blockdigest.BlockDigest
+ Size int
+ Hints []string
+}
+
+// FileSegment is a portion of a file that is contained within a
+// single block.
+type FileSegment struct {
+ Locator string
+ // Offset (within this block) of this data segment
+ Offset int
+ Len int
+}
+
+// FileStreamSegment is a portion of a file described as a segment of a stream.
+type FileStreamSegment struct {
+ SegPos uint64
+ SegLen uint64
+ Name string
}
// Represents a single line from a manifest.
type ManifestStream struct {
- StreamName string
- Blocks []string
- Files []string
+ StreamName string
+ Blocks []string
+ blockOffsets []uint64
+ FileStreamSegments []FileStreamSegment
+ Err error
+}
+
+// Array of segments referencing file content
+type segmentedFile []FileSegment
+
+// Map of files to list of file segments referencing file content
+type segmentedStream map[string]segmentedFile
+
+// Map of streams
+type segmentedManifest map[string]segmentedStream
+
+var escapeSeq = regexp.MustCompile(`\\([0-9]{3}|\\)`)
+
+func unescapeSeq(seq string) string {
+ if seq == `\\` {
+ return `\`
+ }
+ i, err := strconv.ParseUint(seq[1:], 8, 8)
+ if err != nil {
+ // Invalid escape sequence: can't unescape.
+ return seq
+ }
+ return string([]byte{byte(i)})
+}
+
+func EscapeName(s string) string {
+ raw := []byte(s)
+ escaped := make([]byte, 0, len(s))
+ for _, c := range raw {
+ if c <= 32 {
+ oct := fmt.Sprintf("\\%03o", c)
+ escaped = append(escaped, []byte(oct)...)
+ } else {
+ escaped = append(escaped, c)
+ }
+ }
+ return string(escaped)
+}
+
+func UnescapeName(s string) string {
+ return escapeSeq.ReplaceAllStringFunc(s, unescapeSeq)
+}
+
+func ParseBlockLocator(s string) (b BlockLocator, err error) {
+ if !blockdigest.LocatorPattern.MatchString(s) {
+ err = fmt.Errorf("String \"%s\" does not match BlockLocator pattern "+
+ "\"%s\".",
+ s,
+ blockdigest.LocatorPattern.String())
+ } else {
+ tokens := strings.Split(s, "+")
+ var blockSize int64
+ var blockDigest blockdigest.BlockDigest
+ // We expect both of the following to succeed since LocatorPattern
+ // restricts the strings appropriately.
+ blockDigest, err = blockdigest.FromString(tokens[0])
+ if err != nil {
+ return
+ }
+ blockSize, err = strconv.ParseInt(tokens[1], 10, 0)
+ if err != nil {
+ return
+ }
+ b.Digest = blockDigest
+ b.Size = int(blockSize)
+ b.Hints = tokens[2:]
+ }
+ return
+}
+
+func parseFileStreamSegment(tok string) (ft FileStreamSegment, err error) {
+ parts := strings.SplitN(tok, ":", 3)
+ if len(parts) != 3 {
+ err = ErrInvalidToken
+ return
+ }
+ ft.SegPos, err = strconv.ParseUint(parts[0], 10, 64)
+ if err != nil {
+ return
+ }
+ ft.SegLen, err = strconv.ParseUint(parts[1], 10, 64)
+ if err != nil {
+ return
+ }
+ ft.Name = UnescapeName(parts[2])
+ return
+}
+
+func (s *ManifestStream) FileSegmentIterByName(filepath string) <-chan *FileSegment {
+ ch := make(chan *FileSegment, 64)
+ go func() {
+ s.sendFileSegmentIterByName(filepath, ch)
+ close(ch)
+ }()
+ return ch
+}
+
+func firstBlock(offsets []uint64, range_start uint64) int {
+ // range_start/block_start is the inclusive lower bound
+ // range_end/block_end is the exclusive upper bound
+
+ hi := len(offsets) - 1
+ var lo int
+ i := ((hi + lo) / 2)
+ block_start := offsets[i]
+ block_end := offsets[i+1]
+
+ // perform a binary search for the first block
+ // assumes that all of the blocks are contiguous, so range_start is guaranteed
+ // to either fall into the range of a block or be outside the block range entirely
+ for !(range_start >= block_start && range_start < block_end) {
+ if lo == i {
+ // must be out of range, fail
+ return -1
+ }
+ if range_start > block_start {
+ lo = i
+ } else {
+ hi = i
+ }
+ i = ((hi + lo) / 2)
+ block_start = offsets[i]
+ block_end = offsets[i+1]
+ }
+ return i
+}
+
+func (s *ManifestStream) sendFileSegmentIterByName(filepath string, ch chan<- *FileSegment) {
+ // This is what streamName+"/"+fileName will look like:
+ target := fixStreamName(filepath)
+ for _, fTok := range s.FileStreamSegments {
+ wantPos := fTok.SegPos
+ wantLen := fTok.SegLen
+ name := fTok.Name
+
+ if s.StreamName+"/"+name != target {
+ continue
+ }
+ if wantLen == 0 {
+ ch <- &FileSegment{Locator: "d41d8cd98f00b204e9800998ecf8427e+0", Offset: 0, Len: 0}
+ continue
+ }
+
+ // Binary search to determine first block in the stream
+ i := firstBlock(s.blockOffsets, wantPos)
+ if i == -1 {
+ // Shouldn't happen, file segments are checked in parseManifestStream
+ panic(fmt.Sprintf("File segment %v extends past end of stream", fTok))
+ }
+ for ; i < len(s.Blocks); i++ {
+ blockPos := s.blockOffsets[i]
+ blockEnd := s.blockOffsets[i+1]
+ if blockEnd <= wantPos {
+ // Shouldn't happen, FirstBlock() should start
+ // us on the right block, so if this triggers
+ // that means there is a bug.
+ panic(fmt.Sprintf("Block end %v comes before start of file segment %v", blockEnd, wantPos))
+ }
+ if blockPos >= wantPos+wantLen {
+ // current block comes after current file span
+ break
+ }
+
+ fseg := FileSegment{
+ Locator: s.Blocks[i],
+ Offset: 0,
+ Len: int(blockEnd - blockPos),
+ }
+ if blockPos < wantPos {
+ fseg.Offset = int(wantPos - blockPos)
+ fseg.Len -= fseg.Offset
+ }
+ if blockEnd > wantPos+wantLen {
+ fseg.Len = int(wantPos+wantLen-blockPos) - fseg.Offset
+ }
+ ch <- &fseg
+ }
+ }
}
func parseManifestStream(s string) (m ManifestStream) {
tokens := strings.Split(s, " ")
- m.StreamName = tokens[0]
+
+ m.StreamName = UnescapeName(tokens[0])
+ if m.StreamName != "." && !strings.HasPrefix(m.StreamName, "./") {
+ m.Err = fmt.Errorf("Invalid stream name: %s", m.StreamName)
+ return
+ }
+
tokens = tokens[1:]
var i int
- for i = range tokens {
+ for i = 0; i < len(tokens); i++ {
if !blockdigest.IsBlockLocator(tokens[i]) {
break
}
}
m.Blocks = tokens[:i]
- m.Files = tokens[i:]
+ fileTokens := tokens[i:]
+
+ if len(m.Blocks) == 0 {
+ m.Err = fmt.Errorf("No block locators found")
+ return
+ }
+
+ m.blockOffsets = make([]uint64, len(m.Blocks)+1)
+ var streamoffset uint64
+ for i, b := range m.Blocks {
+ bl, err := ParseBlockLocator(b)
+ if err != nil {
+ m.Err = err
+ return
+ }
+ m.blockOffsets[i] = streamoffset
+ streamoffset += uint64(bl.Size)
+ }
+ m.blockOffsets[len(m.Blocks)] = streamoffset
+
+ if len(fileTokens) == 0 {
+ m.Err = fmt.Errorf("No file tokens found")
+ return
+ }
+
+ for _, ft := range fileTokens {
+ pft, err := parseFileStreamSegment(ft)
+ if err != nil {
+ m.Err = fmt.Errorf("Invalid file token: %s", ft)
+ break
+ }
+ if pft.SegPos+pft.SegLen > streamoffset {
+ m.Err = fmt.Errorf("File segment %s extends past end of stream %d", ft, streamoffset)
+ break
+ }
+ m.FileStreamSegments = append(m.FileStreamSegments, pft)
+ }
+
+ return
+}
+
+func fixStreamName(sn string) string {
+ sn = path.Clean(sn)
+ if strings.HasPrefix(sn, "/") {
+ sn = "." + sn
+ } else if sn != "." {
+ sn = "./" + sn
+ }
+ return sn
+}
+
+func splitPath(srcpath string) (streamname, filename string) {
+ pathIdx := strings.LastIndex(srcpath, "/")
+ if pathIdx >= 0 {
+ streamname = srcpath[0:pathIdx]
+ filename = srcpath[pathIdx+1:]
+ } else {
+ streamname = srcpath
+ filename = ""
+ }
+ return
+}
+
+func (m *Manifest) segment() (*segmentedManifest, error) {
+ files := make(segmentedManifest)
+
+ for stream := range m.StreamIter() {
+ if stream.Err != nil {
+ // Stream has an error
+ return nil, stream.Err
+ }
+ currentStreamfiles := make(map[string]bool)
+ for _, f := range stream.FileStreamSegments {
+ sn := stream.StreamName
+ if strings.HasSuffix(sn, "/") {
+ sn = sn[0 : len(sn)-1]
+ }
+ path := sn + "/" + f.Name
+ streamname, filename := splitPath(path)
+ if files[streamname] == nil {
+ files[streamname] = make(segmentedStream)
+ }
+ if !currentStreamfiles[path] {
+ segs := files[streamname][filename]
+ for seg := range stream.FileSegmentIterByName(path) {
+ if seg.Len > 0 {
+ segs = append(segs, *seg)
+ }
+ }
+ files[streamname][filename] = segs
+ currentStreamfiles[path] = true
+ }
+ }
+ }
+
+ return &files, nil
+}
+
+func (stream segmentedStream) normalizedText(name string) string {
+ var sortedfiles []string
+ for k, _ := range stream {
+ sortedfiles = append(sortedfiles, k)
+ }
+ sort.Strings(sortedfiles)
+
+ stream_tokens := []string{EscapeName(name)}
+
+ blocks := make(map[blockdigest.BlockDigest]int64)
+ var streamoffset int64
+
+ // Go through each file and add each referenced block exactly once.
+ for _, streamfile := range sortedfiles {
+ for _, segment := range stream[streamfile] {
+ b, _ := ParseBlockLocator(segment.Locator)
+ if _, ok := blocks[b.Digest]; !ok {
+ stream_tokens = append(stream_tokens, segment.Locator)
+ blocks[b.Digest] = streamoffset
+ streamoffset += int64(b.Size)
+ }
+ }
+ }
+
+ if len(stream_tokens) == 1 {
+ stream_tokens = append(stream_tokens, "d41d8cd98f00b204e9800998ecf8427e+0")
+ }
+
+ for _, streamfile := range sortedfiles {
+ // Add in file segments
+ span_start := int64(-1)
+ span_end := int64(0)
+ fout := EscapeName(streamfile)
+ for _, segment := range stream[streamfile] {
+ // Collapse adjacent segments
+ b, _ := ParseBlockLocator(segment.Locator)
+ streamoffset = blocks[b.Digest] + int64(segment.Offset)
+ if span_start == -1 {
+ span_start = streamoffset
+ span_end = streamoffset + int64(segment.Len)
+ } else {
+ if streamoffset == span_end {
+ span_end += int64(segment.Len)
+ } else {
+ stream_tokens = append(stream_tokens, fmt.Sprintf("%d:%d:%s", span_start, span_end-span_start, fout))
+ span_start = streamoffset
+ span_end = streamoffset + int64(segment.Len)
+ }
+ }
+ }
+
+ if span_start != -1 {
+ stream_tokens = append(stream_tokens, fmt.Sprintf("%d:%d:%s", span_start, span_end-span_start, fout))
+ }
+
+ if len(stream[streamfile]) == 0 {
+ stream_tokens = append(stream_tokens, fmt.Sprintf("0:0:%s", fout))
+ }
+ }
+
+ return strings.Join(stream_tokens, " ") + "\n"
+}
+
+func (m segmentedManifest) manifestTextForPath(srcpath, relocate string) string {
+ srcpath = fixStreamName(srcpath)
+
+ var suffix string
+ if strings.HasSuffix(relocate, "/") {
+ suffix = "/"
+ }
+ relocate = fixStreamName(relocate) + suffix
+
+ streamname, filename := splitPath(srcpath)
+
+ if stream, ok := m[streamname]; ok {
+ // check if it refers to a single file in a stream
+ filesegs, okfile := stream[filename]
+ if okfile {
+ newstream := make(segmentedStream)
+ relocate_stream, relocate_filename := splitPath(relocate)
+ if relocate_filename == "" {
+ relocate_filename = filename
+ }
+ newstream[relocate_filename] = filesegs
+ return newstream.normalizedText(relocate_stream)
+ }
+ }
+
+ // Going to extract multiple streams
+ prefix := srcpath + "/"
+
+ if strings.HasSuffix(relocate, "/") {
+ relocate = relocate[0 : len(relocate)-1]
+ }
+
+ var sortedstreams []string
+ for k, _ := range m {
+ sortedstreams = append(sortedstreams, k)
+ }
+ sort.Strings(sortedstreams)
+
+ manifest := ""
+ for _, k := range sortedstreams {
+ if strings.HasPrefix(k, prefix) || k == srcpath {
+ manifest += m[k].normalizedText(relocate + k[len(srcpath):])
+ }
+ }
+ return manifest
+}
+
+// Extract extracts some or all of the manifest and returns the extracted
+// portion as a normalized manifest. This is a swiss army knife function that
+// can be several ways:
+//
+// If 'srcpath' and 'relocate' are '.' it simply returns an equivalent manifest
+// in normalized form.
+//
+// Extract(".", ".") // return entire normalized manfest text
+//
+// If 'srcpath' points to a single file, it will return manifest text for just that file.
+// The value of "relocate" is can be used to rename the file or set the file stream.
+//
+// Extract("./foo", ".") // extract file "foo" and put it in stream "."
+// Extract("./foo", "./bar") // extract file "foo", rename it to "bar" in stream "."
+// Extract("./foo", "./bar/") // extract file "foo", rename it to "./bar/foo"
+// Extract("./foo", "./bar/baz") // extract file "foo", rename it to "./bar/baz")
+//
+// Otherwise it will return the manifest text for all streams with the prefix in "srcpath" and place
+// them under the path in "relocate".
+//
+// Extract("./stream", ".") // extract "./stream" to "." and "./stream/subdir" to "./subdir")
+// Extract("./stream", "./bar") // extract "./stream" to "./bar" and "./stream/subdir" to "./bar/subdir")
+func (m Manifest) Extract(srcpath, relocate string) (ret Manifest) {
+ segmented, err := m.segment()
+ if err != nil {
+ ret.Err = err
+ return
+ }
+ ret.Text = segmented.manifestTextForPath(srcpath, relocate)
return
}
return ch
}
-// Blocks may appear mulitple times within the same manifest if they
+func (m *Manifest) FileSegmentIterByName(filepath string) <-chan *FileSegment {
+ ch := make(chan *FileSegment, 64)
+ filepath = fixStreamName(filepath)
+ go func() {
+ for stream := range m.StreamIter() {
+ if !strings.HasPrefix(filepath, stream.StreamName+"/") {
+ continue
+ }
+ stream.sendFileSegmentIterByName(filepath, ch)
+ }
+ close(ch)
+ }()
+ return ch
+}
+
+// Blocks may appear multiple times within the same manifest if they
// are used by multiple files. In that case this Iterator will output
// the same block multiple times.
+//
+// In order to detect parse errors, caller must check m.Err after the returned channel closes.
func (m *Manifest) BlockIterWithDuplicates() <-chan blockdigest.BlockLocator {
blockChannel := make(chan blockdigest.BlockLocator)
go func(streamChannel <-chan ManifestStream) {
- for m := range streamChannel {
- for _, block := range m.Blocks {
+ for ms := range streamChannel {
+ if ms.Err != nil {
+ m.Err = ms.Err
+ continue
+ }
+ for _, block := range ms.Blocks {
if b, err := blockdigest.ParseBlockLocator(block); err == nil {
blockChannel <- b
} else {
- log.Printf("ERROR: Failed to parse block: %v", err)
+ m.Err = err
}
}
}
projects / arvados.git / blobdiff