From 310216f7db2111ab889adc846d070dfd0e0866a1 Mon Sep 17 00:00:00 2001
From: Zhijie Yang <zhijie.yang@canonical.com>
Date: Thu, 28 Nov 2024 12:32:42 +0100
Subject: [PATCH] feat: use LinkType to identify hard links for report.Add

---
 internal/fsutil/create.go   | 32 ++++++++++++++++++++++----------
 internal/manifest/report.go | 12 ++----------
 2 files changed, 24 insertions(+), 20 deletions(-)

diff --git a/internal/fsutil/create.go b/internal/fsutil/create.go
index 6b54e524..9d2f9b9f 100644
--- a/internal/fsutil/create.go
+++ b/internal/fsutil/create.go
@@ -26,12 +26,20 @@ type CreateOptions struct {
 	OverrideMode bool
 }
 
+// The following constants are used to distinguish different link types,
+// such as hard links and symlinks.
+const (
+	TypeSymlink = 1 << iota
+	TypeHardLink
+)
+
 type Entry struct {
-	Path   string
-	Mode   fs.FileMode
-	SHA256 string
-	Size   int
-	Link   string
+	Path     string
+	Mode     fs.FileMode
+	SHA256   string
+	Size     int
+	Link     string
+	LinkType int
 }
 
 // Create creates a filesystem entry according to the provided options and returns
@@ -45,6 +53,7 @@ func Create(options *CreateOptions) (*Entry, error) {
 
 	var err error
 	var hash string
+	var linkType int
 	if o.MakeParents {
 		if err := os.MkdirAll(filepath.Dir(o.Path), 0755); err != nil {
 			return nil, err
@@ -57,6 +66,7 @@ func Create(options *CreateOptions) (*Entry, error) {
 			// Creating the hard link does not involve reading the file.
 			// Therefore, its size and hash is not calculated here.
 			err = createHardLink(o)
+			linkType = TypeHardLink
 		} else {
 			err = createFile(o)
 			hash = hex.EncodeToString(rp.h.Sum(nil))
@@ -65,6 +75,7 @@ func Create(options *CreateOptions) (*Entry, error) {
 		err = createDir(o)
 	case fs.ModeSymlink:
 		err = createSymlink(o)
+		linkType = TypeSymlink
 	default:
 		err = fmt.Errorf("unsupported file type: %s", o.Path)
 	}
@@ -87,11 +98,12 @@ func Create(options *CreateOptions) (*Entry, error) {
 	}
 
 	entry := &Entry{
-		Path:   o.Path,
-		Mode:   mode,
-		SHA256: hash,
-		Size:   rp.size,
-		Link:   o.Link,
+		Path:     o.Path,
+		Mode:     mode,
+		SHA256:   hash,
+		Size:     rp.size,
+		Link:     o.Link,
+		LinkType: linkType,
 	}
 	return entry, nil
 }
diff --git a/internal/manifest/report.go b/internal/manifest/report.go
index 9814b7f9..1972e48e 100644
--- a/internal/manifest/report.go
+++ b/internal/manifest/report.go
@@ -61,7 +61,7 @@ func (r *Report) Add(slice *setup.Slice, fsEntry *fsutil.Entry) error {
 	}
 
 	hardLinkId := NON_HARD_LINK
-	if r.entryIsHardLink(fsEntry.Link) {
+	if fsEntry.LinkType == fsutil.TypeHardLink {
 		hardLinkId = r.getHardLinkId(fsEntry)
 	}
 
@@ -110,6 +110,7 @@ func (r *Report) getHardLinkId(fsEntry *fsutil.Entry) uint64 {
 			fsEntry.Link = ""
 		} else {
 			// The hard link links to a symlink
+			fmt.Println("FSENTRY:", fsEntry.Path, fsEntry.Link, "ENTRY:", entry.Path, entry.Link)
 			fsEntry.Link = entry.Link
 		}
 	}
@@ -151,12 +152,3 @@ func (r *Report) sanitizeAbsPath(path string, isDir bool) (relPath string, err e
 	}
 	return relPath, nil
 }
-
-// entryIsHardLink determines if a link is a hard link by checking if the link
-// has a prefix of the root dir, since hard links are created with absolute
-// paths prefixing the report's root dir, while symlinks are created either with
-// relative paths or absolute paths that do not have the report's root dir as a
-// prefix.
-func (r *Report) entryIsHardLink(link string) bool {
-	return link != "" && strings.HasPrefix(link, r.Root)
-}