Check the good stuff

- Create a new snapshot version number as this method is not backwards
compatible.
- This has some breakages with restoring. Namely if the root file
is not marked for download any hardlinked files that need to be restored
will not be linked, they will be restored as a regular file

duplicacy/duplicacy_main.go

@@ -2262,7 +2262,7 @@ func main() {
 	app.Name = "duplicacy"
 	app.HelpName = "duplicacy"
 	app.Usage = "A new generation cloud backup tool based on lock-free deduplication"
-	app.Version = "3.2.0" + " (" + GitCommit + ")"
+	app.Version = "3.2.1" + " (" + GitCommit + ")"
 
 	// Exit with code 2 if an invalid command is provided
 	app.CommandNotFound = func(context *cli.Context, command string) {

src/duplicacy_b2client.go

@@ -396,7 +396,7 @@ type B2ListFileNamesOutput struct {
 
 func (client *B2Client) ListFileNames(threadIndex int, startFileName string, singleFile bool, includeVersions bool) (files []*B2Entry, err error) {
 
-	maxFileCount := 1000
+	maxFileCount := 10_000
 	if singleFile {
 		if includeVersions {
 			maxFileCount = 4

src/duplicacy_backupmanager.go

@@ -304,7 +304,24 @@ func (manager *BackupManager) Backup(top string, quickMode bool, threads int, ta
 			remoteEntry = nil
 		}
 
-		if compareResult == 0  {
+		if localEntry.IsHardlinkedFrom() {
+			// FIXME: Sanity check?
+			// FIXME: perhaps we can make size = 0 an initial invariant of the link?
+			//
+			// Note that if the initial size was 0 then this original logic doesn't change!
+			localEntry.Size = 0
+			// targetEntry, ok := localEntryList.HardLinkTable[localEntry.Link]
+			// if !ok {
+			// 	LOG_ERROR("BACKUP_CREATE", "Hard link %s not found in entry cache for path %s", localEntry.Link, localEntry.Path)
+			// }
+			// localEntry.Size = targetEntry.Size
+			// localEntry.Hash = targetEntry.Hash
+			// localEntry.StartChunk = targetEntry.StartChunk
+			// localEntry.StartOffset = targetEntry.StartOffset
+			// localEntry.EndChunk = targetEntry.EndChunk
+			// localEntry.EndOffset = targetEntry.EndOffset
+			// LOG_DEBUG("BACKUP_CREATE", "Hard link %s to %s in initial listing", localEntry.Link, targetEntry.Path)
+		} else if compareResult == 0  {
 			// No need to check if it is in hash mode -- in that case remote listing is nil
 			if localEntry.IsSameAs(remoteEntry) && localEntry.IsFile() {
 				if localEntry.Size > 0 {
@@ -709,7 +726,7 @@ func (manager *BackupManager) Restore(top string, revision int, inPlace bool, qu
 	localListingOK := true
 
 	hardLinkTable := make(map[string]hardLinkEntry)
-	hardLinks := make([]*Entry, 0)
+	//hardLinks := make([]*Entry, 0)
 
 	for remoteEntry := range remoteListingChannel {
 
@@ -745,22 +762,28 @@ func (manager *BackupManager) Restore(top string, revision int, inPlace bool, qu
 		}
 
 		if compareResult == 0 {
-			if quickMode && localEntry.IsFile() {
-				checkEntry := remoteEntry
-				if len(remoteEntry.Link) > 0 && remoteEntry.Link != "/" {
-					if e, ok := hardLinkTable[remoteEntry.Link]; !ok {
-						LOG_ERROR("RESTORE_LINK", "Source file %s for hardlink %s missing", remoteEntry.Link, remoteEntry.Path)
-					} else {
-						checkEntry = e.entry
-					}
-				}
-				if localEntry.IsSameAs(checkEntry) {
+			// if quickMode && localEntry.IsFile() {
+				if quickMode && localEntry.IsFile() && localEntry.IsSameAs(remoteEntry) {
 					LOG_TRACE("RESTORE_SKIP", "File %s unchanged (by size and timestamp)", localEntry.Path)
 					skippedFileSize += localEntry.Size
 					skippedFileCount++
 					localEntry = nil
 					continue
-				}
+				// checkEntry := remoteEntry
+				// if len(remoteEntry.Link) > 0 && remoteEntry.Link != "/" {
+				// 	if e, ok := hardLinkTable[remoteEntry.Link]; !ok {
+				// 		LOG_ERROR("RESTORE_LINK", "Source file %s for hardlink %s missing", remoteEntry.Link, remoteEntry.Path)
+				// 	} else {
+				// 		checkEntry = e.entry
+				// 	}
+				// }
+				// if localEntry.IsSameAs(checkEntry) {
+				// 	LOG_TRACE("RESTORE_SKIP", "File %s unchanged (by size and timestamp)", localEntry.Path)
+				// 	skippedFileSize += localEntry.Size
+				// 	skippedFileCount++
+				// 	localEntry = nil
+				// 	continue
+				// }
 			}
 			localEntry = nil
 		}
@@ -807,21 +830,21 @@ func (manager *BackupManager) Restore(top string, revision int, inPlace bool, qu
 			}
 			directoryEntries = append(directoryEntries, remoteEntry)
 		} else {
-			if remoteEntry.Link == "/" {
-				hardLinkTable[remoteEntry.Path] = hardLinkEntry{remoteEntry, true}
-			} else if len(remoteEntry.Link) > 0 {
-				if e, ok := hardLinkTable[remoteEntry.Link]; !ok {
-					LOG_ERROR("RESTORE_LINK", "Source file %s for hardlink %s missing", remoteEntry.Link, remoteEntry.Path)
-				} else if !e.willDownload {
-					origSourcePath := e.entry.Path
-					e.entry.Path = remoteEntry.Path
-					remoteEntry = e.entry
-					hardLinkTable[origSourcePath] = hardLinkEntry{remoteEntry, true}
-				} else {
-					hardLinks = append(hardLinks, remoteEntry)
-					continue
-				}
-			}
+			// if remoteEntry.Link == "/" {
+			// 	hardLinkTable[remoteEntry.Path] = hardLinkEntry{remoteEntry, true}
+			// } else if len(remoteEntry.Link) > 0 {
+			// 	if e, ok := hardLinkTable[remoteEntry.Link]; !ok {
+			// 		LOG_ERROR("RESTORE_LINK", "Source file %s for hardlink %s missing", remoteEntry.Link, remoteEntry.Path)
+			// 	} else if !e.willDownload {
+			// 		origSourcePath := e.entry.Path
+			// 		e.entry.Path = remoteEntry.Path
+			// 		remoteEntry = e.entry
+			// 		hardLinkTable[origSourcePath] = hardLinkEntry{remoteEntry, true}
+			// 	} else {
+			// 		hardLinks = append(hardLinks, remoteEntry)
+			// 		continue
+			// 	}
+			// }
 			// We can't download files here since fileEntries needs to be sorted
 			fileEntries = append(fileEntries, remoteEntry)
 			totalFileSize += remoteEntry.Size
@@ -877,11 +900,11 @@ func (manager *BackupManager) Restore(top string, revision int, inPlace bool, qu
 		stat, _ := os.Stat(fullPath)
 		if stat != nil {
 			if quickMode {
-				cmpFile := file
-				if file.IsFile() && len(file.Link) > 0 && file.Link != "/" {
-					cmpFile = hardLinkTable[file.Link].entry
-				}
-				if cmpFile.IsSameAsFileInfo(stat) {
+				// cmpFile := file
+				// if file.IsFile() && len(file.Link) > 0 && file.Link != "/" {
+				// 	cmpFile = hardLinkTable[file.Link].entry
+				// }
+				if file.IsSameAsFileInfo(stat) {
 					LOG_TRACE("RESTORE_SKIP", "File %s unchanged (by size and timestamp)", file.Path)
 					skippedFileSize += file.Size
 					skippedFileCount++
@@ -944,14 +967,14 @@ func (manager *BackupManager) Restore(top string, revision int, inPlace bool, qu
 		file.RestoreMetadata(fullPath, nil, setOwner)
 	}
 
-	for _, linkEntry := range hardLinks {
-		sourcePath := joinPath(top, hardLinkTable[linkEntry.Link].entry.Path)
-		fullPath := joinPath(top, linkEntry.Path)
-		LOG_INFO("DOWNLOAD_LINK", "Hard linking %s -> %s", fullPath, sourcePath)
-		if err := os.Link(sourcePath, fullPath); err != nil {
-			LOG_ERROR("DOWNLOAD_LINK", "Failed to create hard link %s -> %s", fullPath, sourcePath)
-		}
-	}
+	// for _, linkEntry := range hardLinks {
+	// 	sourcePath := joinPath(top, hardLinkTable[linkEntry.Link].entry.Path)
+	// 	fullPath := joinPath(top, linkEntry.Path)
+	// 	LOG_INFO("DOWNLOAD_LINK", "Hard linking %s -> %s", fullPath, sourcePath)
+	// 	if err := os.Link(sourcePath, fullPath); err != nil {
+	// 		LOG_ERROR("DOWNLOAD_LINK", "Failed to create hard link %s -> %s", fullPath, sourcePath)
+	// 	}
+	// }
 
 	if deleteMode && len(patterns) == 0 {
 		// Reverse the order to make sure directories are empty before being deleted
@@ -1105,6 +1128,9 @@ func (manager *BackupManager) UploadSnapshot(chunkOperator *ChunkOperator, top s
 	lastEndChunk := 0
 
 	uploadEntryInfoFunc := func(entry *Entry) error {
+		if entry.IsHardlinkRoot() {
+			entryList.HardLinkTable[entry.Path] = entry
+		}
 
 		if entry.IsFile() && entry.Size > 0 {
 			delta := entry.StartChunk - len(chunkHashes) + 1
@@ -1127,6 +1153,14 @@ func (manager *BackupManager) UploadSnapshot(chunkOperator *ChunkOperator, top s
 			entry.StartChunk -= lastEndChunk
 			lastEndChunk = entry.EndChunk
 			entry.EndChunk = delta
+		} else if entry.IsHardlinkedFrom() {
+			targetEntry, ok := entryList.HardLinkTable[entry.Link]
+			if !ok {
+				LOG_ERROR("SNAPSHOT_UPLOAD", "Unable to find hardlink target for %s to %s", entry.Path, entry.Link)
+			}
+			// FIXME: We will use a copy, so it is probably sufficient to skip rereading xattrs and such in the initial code
+			entry = entry.LinkTo(targetEntry)
+			LOG_DEBUG("SNAPSHOT_UPLOAD", "Uploading cloned hardlink entry for %s to %s", entry.Path, entry.Link)
 		}
 
 		buffer.Reset()

src/duplicacy_entry.go

@@ -4,6 +4,8 @@
 package duplicacy
 
 import (
+	"bytes"
+	"crypto/sha256"
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
@@ -15,13 +17,10 @@ import (
 	"sort"
 	"strconv"
 	"strings"
-	"time"
-	"bytes"
-	"crypto/sha256"
 	"syscall"
+	"time"
 
-    "github.com/vmihailenco/msgpack"
-
+	"github.com/vmihailenco/msgpack"
 )
 
 // This is the hidden directory in the repository for storing various files.
@@ -111,15 +110,36 @@ func (entry *Entry) Copy() *Entry {
 		UID: entry.UID,
 		GID: entry.GID,
 
-		StartChunk: entry.StartChunk,
+		StartChunk:  entry.StartChunk,
 		StartOffset: entry.StartOffset,
-		EndChunk: entry.EndChunk,
-		EndOffset: entry.EndOffset,
+		EndChunk:    entry.EndChunk,
+		EndOffset:   entry.EndOffset,
 
 		Attributes: entry.Attributes,
 	}
 }
 
+func (entry *Entry) LinkTo(target *Entry) *Entry {
+	return &Entry{
+		Path: entry.Path,
+		Size: target.Size,
+		Time: target.Time,
+		Mode: target.Mode,
+		Link: entry.Link,
+		Hash: target.Hash,
+
+		UID: target.UID,
+		GID: target.GID,
+
+		StartChunk:  target.StartChunk,
+		StartOffset: target.StartOffset,
+		EndChunk:    target.EndChunk,
+		EndOffset:   target.EndOffset,
+
+		Attributes: target.Attributes,
+	}
+}
+
 // CreateEntryFromJSON creates an entry from a json description.
 func (entry *Entry) UnmarshalJSON(description []byte) (err error) {
 
@@ -363,12 +383,12 @@ func (entry *Entry) EncodeMsgpack(encoder *msgpack.Encoder) error {
 
 	if entry.Attributes != nil {
 		attributes := make([]string, numberOfAttributes)
-        i := 0
-        for attribute := range *entry.Attributes {
-            attributes[i] = attribute
-            i++
-        }
-        sort.Strings(attributes)
+		i := 0
+		for attribute := range *entry.Attributes {
+			attributes[i] = attribute
+			i++
+		}
+		sort.Strings(attributes)
 		for _, attribute := range attributes {
 			err = encoder.EncodeString(attribute)
 			if err != nil {
@@ -381,7 +401,7 @@ func (entry *Entry) EncodeMsgpack(encoder *msgpack.Encoder) error {
 		}
 	}
 
-    return nil
+	return nil
 }
 
 func (entry *Entry) DecodeMsgpack(decoder *msgpack.Decoder) error {
@@ -493,14 +513,26 @@ func (entry *Entry) IsComplete() bool {
 	return entry.Size >= 0
 }
 
+func (entry *Entry) IsFileNotHardlink() bool {
+	return entry.IsFile() && (len(entry.Link) == 0 || entry.Link == "/")
+}
+
+func (entry *Entry) IsHardlinkedFrom() bool {
+	return entry.IsFile() && len(entry.Link) > 0 && entry.Link != "/"
+}
+
+func (entry *Entry) IsHardlinkRoot() bool {
+	return entry.IsFile() && entry.Link == "/"
+}
+
 func (entry *Entry) GetPermissions() os.FileMode {
 	return os.FileMode(entry.Mode) & fileModeMask
 }
 
 func (entry *Entry) GetParent() string {
 	path := entry.Path
-	if path != "" && path[len(path) - 1] == '/' {
-		path = path[:len(path) - 1]
+	if path != "" && path[len(path)-1] == '/' {
+		path = path[:len(path)-1]
 	}
 	i := strings.LastIndex(path, "/")
 	if i == -1 {
@@ -597,7 +629,7 @@ func ComparePaths(left string, right string) int {
 	for i := p; i < len(left); i++ {
 		c3 = left[i]
 		if c3 == '/' {
-			last1 = i == len(left) - 1
+			last1 = i == len(left)-1
 			break
 		}
 	}
@@ -607,7 +639,7 @@ func ComparePaths(left string, right string) int {
 	for i := p; i < len(right); i++ {
 		c4 = right[i]
 		if c4 == '/' {
-			last2 = i == len(right) - 1
+			last2 = i == len(right)-1
 			break
 		}
 	}
@@ -806,9 +838,8 @@ func ListEntries(top string, path string, patterns []string, nobackupFile string
 			if ok && stat != nil && stat.Nlink > 1 {
 				k := listEntryLinkKey{dev: uint64(stat.Dev), ino: uint64(stat.Ino)}
 				if path, ok := listingState.linkTable[k]; ok {
-					LOG_WARN("LIST_LINK", "Linking %s to %s", entry.Path, path)
+					LOG_DEBUG("LIST_HARDLINK", "Detected hardlink %s to %s", entry.Path, path)
 					entry.Link = path
-					entry.Size = 0
 				} else {
 					entry.Link = "/"
 					listingState.linkTable[k] = entry.Path

src/duplicacy_entrylist.go

@@ -62,6 +62,7 @@ type EntryList struct {
 	uploadedChunkIndex int                  // counter for upload chunks
 	uploadedChunkOffset int                 // the start offset for the current modified entry
 
+	HardLinkTable map[string]*Entry
 }
 
 // Create a new entry list
@@ -78,6 +79,7 @@ func CreateEntryList(snapshotID string, cachePath string, maximumInMemoryEntries
 		maximumInMemoryEntries: maximumInMemoryEntries,
 		cachePath: cachePath,
 		Token: string(token),
+		HardLinkTable: make(map[string]*Entry),
 	}
 
 	return entryList, nil
@@ -118,7 +120,7 @@ func (entryList *EntryList)AddEntry(entry *Entry) error {
 	if !entry.IsComplete() {
 		if entry.IsDir() || entry.IsLink() {
 			entry.Size = 0
-		} else {
+		} else if !entry.IsHardlinkedFrom() {
 			modifiedEntry := ModifiedEntry {
 				Path: entry.Path,
 				Size: -1,

src/duplicacy_snapshot.go

@@ -51,7 +51,7 @@ type Snapshot struct {
 // CreateEmptySnapshot creates an empty snapshot.
 func CreateEmptySnapshot(id string) (snapshto *Snapshot) {
 	return &Snapshot{
-		Version:   0x6a6c01,
+		Version:   1,
 		ID:        id,
 		Revision:  0,
 		StartTime: time.Now().Unix(),
@@ -161,7 +161,7 @@ func (snapshot *Snapshot)ListRemoteFiles(config *Config, chunkOperator *ChunkOpe
 				return
 			}
 		}
-	} else if snapshot.Version == 1 || snapshot.Version == 0x6a6c01 {
+	} else if snapshot.Version == 1 {
 		decoder := msgpack.NewDecoder(reader)
 
 		lastEndChunk := 0

src/duplicacy_utils_posix.go

@@ -2,13 +2,11 @@
 // Free for personal use and commercial trial
 // Commercial use requires per-user licenses available from https://duplicacy.com
 
+//go:build freebsd || netbsd || linux || solaris
 // +build freebsd netbsd linux solaris
 
 package duplicacy
 
-import (
-)
-
 func excludedByAttribute(attributes map[string][]byte) bool {
 	_, ok := attributes["user.duplicacy_exclude"]
 	return ok