cmd/btrfs-rec: inspect ls-files: Move the code to a sub-package

2 files changed, 253 insertions, 222 deletions

diff --git a/cmd/btrfs-rec/inspect/lsfiles/lsfiles.go b/cmd/btrfs-rec/inspect/lsfiles/lsfiles.go
new file mode 100644
index 0000000..a713b8a
--- /dev/null
+++ b/cmd/btrfs-rec/inspect/lsfiles/lsfiles.go
@@ -0,0 +1,249 @@
+// Copyright (C) 2022-2023  Luke Shumaker <lukeshu@lukeshu.com>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+// Package lsfiles is the guts of the `btrfs-rec inspect ls-files`
+// command, which prints a tree-listing of all files in the
+// filesystem.
+package lsfiles
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"path"
+	"strings"
+
+	"github.com/datawire/dlib/derror"
+
+	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs"
+	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsitem"
+	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsprim"
+	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfstree"
+	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsvol"
+	"git.lukeshu.com/btrfs-progs-ng/lib/diskio"
+	"git.lukeshu.com/btrfs-progs-ng/lib/maps"
+	"git.lukeshu.com/btrfs-progs-ng/lib/textui"
+)
+
+func LsFiles(
+	out io.Writer,
+	fs interface {
+		btrfstree.TreeOperator
+		Superblock() (*btrfstree.Superblock, error)
+		diskio.ReaderAt[btrfsvol.LogicalAddr]
+	},
+) (err error) {
+	defer func() {
+		if _err := derror.PanicToError(recover()); _err != nil {
+			textui.Fprintf(out, "\n\n%+v\n", _err)
+			err = _err
+		}
+	}()
+
+	printSubvol(out, "", true, "/", btrfs.NewSubvolume(
+		fs,
+		btrfsprim.FS_TREE_OBJECTID,
+		false,
+	))
+
+	return nil
+}
+
+const (
+	tS = "    "
+	tl = "│   "
+	tT = "├── "
+	tL = "└── "
+)
+
+func printText(out io.Writer, prefix string, isLast bool, name, text string) {
+	first, rest := tT, tl
+	if isLast {
+		first, rest = tL, tS
+	}
+	for i, line := range strings.Split(textui.Sprintf("%q %s", name, text), "\n") {
+		_, _ = io.WriteString(out, prefix)
+		if i == 0 {
+			_, _ = io.WriteString(out, first)
+		} else {
+			_, _ = io.WriteString(out, rest)
+		}
+		_, _ = io.WriteString(out, line)
+		_, _ = io.WriteString(out, "\n")
+	}
+}
+
+func printSubvol(out io.Writer, prefix string, isLast bool, name string, subvol *btrfs.Subvolume) {
+	rootInode, err := subvol.GetRootInode()
+	if err != nil {
+		printText(out, prefix, isLast, name+"/", textui.Sprintf("subvol_id=%v err=%v",
+			subvol.TreeID, fmtErr(err)))
+		return
+	}
+	dir, err := subvol.LoadDir(rootInode)
+	if err != nil {
+		printText(out, prefix, isLast, name+"/", textui.Sprintf("subvol_id=%v err=%v",
+			subvol.TreeID, fmtErr(err)))
+		return
+	}
+	if name == "/" {
+		printDir(out, prefix, isLast, name, dir)
+		return
+	}
+	printText(out, prefix, isLast, name+"/", textui.Sprintf("subvol_id=%v", subvol.TreeID))
+	if isLast {
+		prefix += tS
+	} else {
+		prefix += tl
+	}
+	printDir(out, prefix, true, name, dir)
+}
+
+func fmtErr(err error) string {
+	errStr := err.Error()
+	if strings.Contains(errStr, "\n") {
+		errStr = "\\\n" + errStr
+	}
+	return errStr
+}
+
+func fmtInode(inode btrfs.BareInode) string {
+	var mode btrfsitem.StatMode
+	if inode.InodeItem == nil {
+		inode.Errs = append(inode.Errs, errors.New("missing INODE_ITEM"))
+	} else {
+		mode = inode.InodeItem.Mode
+	}
+	ret := textui.Sprintf("ino=%v mode=%v", inode.Inode, mode)
+	if len(inode.Errs) > 0 {
+		ret += " err=" + fmtErr(inode.Errs)
+	}
+	return ret
+}
+
+func printDir(out io.Writer, prefix string, isLast bool, name string, dir *btrfs.Dir) {
+	printText(out, prefix, isLast, name+"/", fmtInode(dir.BareInode))
+	if isLast {
+		prefix += tS
+	} else {
+		prefix += tl
+	}
+	for i, childName := range maps.SortedKeys(dir.ChildrenByName) {
+		printDirEntry(
+			out,
+			prefix,
+			i == len(dir.ChildrenByName)-1,
+			dir.SV,
+			path.Join(name, childName),
+			dir.ChildrenByName[childName])
+	}
+}
+
+func printDirEntry(out io.Writer, prefix string, isLast bool, subvol *btrfs.Subvolume, name string, entry btrfsitem.DirEntry) {
+	if len(entry.Data) != 0 {
+		panic(fmt.Errorf("TODO: I don't know how to handle dirent.data: %q", name))
+	}
+	switch entry.Type {
+	case btrfsitem.FT_DIR:
+		switch entry.Location.ItemType {
+		case btrfsitem.INODE_ITEM_KEY:
+			dir, err := subvol.LoadDir(entry.Location.ObjectID)
+			if err != nil {
+				printText(out, prefix, isLast, name, textui.Sprintf("%v err=%v", entry.Type, fmtErr(err)))
+				return
+			}
+			printDir(out, prefix, isLast, name, dir)
+		case btrfsitem.ROOT_ITEM_KEY:
+			printSubvol(out, prefix, isLast, name, subvol.NewChildSubvolume(entry.Location.ObjectID))
+		default:
+			panic(fmt.Errorf("TODO: I don't know how to handle an FT_DIR with location.ItemType=%v: %q",
+				entry.Location.ItemType, name))
+		}
+	case btrfsitem.FT_SYMLINK:
+		if entry.Location.ItemType != btrfsitem.INODE_ITEM_KEY {
+			panic(fmt.Errorf("TODO: I don't know how to handle an FT_SYMLINK with location.ItemType=%v: %q",
+				entry.Location.ItemType, name))
+		}
+		file, err := subvol.LoadFile(entry.Location.ObjectID)
+		if err != nil {
+			printText(out, prefix, isLast, name, textui.Sprintf("%v err=%v", entry.Type, fmtErr(err)))
+			return
+		}
+		printSymlink(out, prefix, isLast, name, file)
+	case btrfsitem.FT_REG_FILE:
+		if entry.Location.ItemType != btrfsitem.INODE_ITEM_KEY {
+			panic(fmt.Errorf("TODO: I don't know how to handle an FT_REG_FILE with location.ItemType=%v: %q",
+				entry.Location.ItemType, name))
+		}
+		file, err := subvol.LoadFile(entry.Location.ObjectID)
+		if err != nil {
+			printText(out, prefix, isLast, name, textui.Sprintf("%v err=%v", entry.Type, fmtErr(err)))
+			return
+		}
+		printFile(out, prefix, isLast, name, file)
+	case btrfsitem.FT_SOCK:
+		if entry.Location.ItemType != btrfsitem.INODE_ITEM_KEY {
+			panic(fmt.Errorf("TODO: I don't know how to handle an FT_SOCK with location.ItemType=%v: %q",
+				entry.Location.ItemType, name))
+		}
+		file, err := subvol.LoadFile(entry.Location.ObjectID)
+		if err != nil {
+			printText(out, prefix, isLast, name, textui.Sprintf("%v err=%v", entry.Type, fmtErr(err)))
+			return
+		}
+		printSocket(out, prefix, isLast, name, file)
+	case btrfsitem.FT_FIFO:
+		if entry.Location.ItemType != btrfsitem.INODE_ITEM_KEY {
+			panic(fmt.Errorf("TODO: I don't know how to handle an FT_FIFO with location.ItemType=%v: %q",
+				entry.Location.ItemType, name))
+		}
+		file, err := subvol.LoadFile(entry.Location.ObjectID)
+		if err != nil {
+			printText(out, prefix, isLast, name, textui.Sprintf("%v err=%v", entry.Type, fmtErr(err)))
+			return
+		}
+		printPipe(out, prefix, isLast, name, file)
+	default:
+		panic(fmt.Errorf("TODO: I don't know how to handle a fileType=%v: %q",
+			entry.Type, name))
+	}
+}
+
+func printSymlink(out io.Writer, prefix string, isLast bool, name string, file *btrfs.File) {
+	var tgt []byte
+	if file.InodeItem != nil {
+		var err error
+		tgt, err = io.ReadAll(io.NewSectionReader(file, 0, file.InodeItem.Size))
+		if err != nil {
+			file.Errs = append(file.Errs, err)
+		}
+	}
+	printText(out, prefix, isLast, name, textui.Sprintf(
+		"-> %q : %s",
+		tgt,
+		fmtInode(file.BareInode)))
+}
+
+func printFile(out io.Writer, prefix string, isLast bool, name string, file *btrfs.File) {
+	if file.InodeItem != nil {
+		if _, err := io.Copy(io.Discard, io.NewSectionReader(file, 0, file.InodeItem.Size)); err != nil {
+			file.Errs = append(file.Errs, err)
+		}
+	}
+	printText(out, prefix, isLast, name, fmtInode(file.BareInode))
+}
+
+func printSocket(out io.Writer, prefix string, isLast bool, name string, file *btrfs.File) {
+	if file.InodeItem != nil && file.InodeItem.Size > 0 {
+		panic(fmt.Errorf("TODO: I don't know how to handle a socket with size>0: %q", name))
+	}
+	printText(out, prefix, isLast, name, fmtInode(file.BareInode))
+}
+
+func printPipe(out io.Writer, prefix string, isLast bool, name string, file *btrfs.File) {
+	if file.InodeItem != nil && file.InodeItem.Size > 0 {
+		panic(fmt.Errorf("TODO: I don't know how to handle a pipe with size>0: %q", name))
+	}
+	printText(out, prefix, isLast, name, fmtInode(file.BareInode))
+}
diff --git a/cmd/btrfs-rec/inspect_lsfiles.go b/cmd/btrfs-rec/inspect_lsfiles.go
index e9fd057..04b5ec5 100644
--- a/cmd/btrfs-rec/inspect_lsfiles.go
+++ b/cmd/btrfs-rec/inspect_lsfiles.go
@@ -6,23 +6,14 @@ package main
 
 import (
 	"bufio"
-	"errors"
-	"fmt"
-	"io"
 	"os"
-	"path"
-	"strings"
 
-	"github.com/datawire/dlib/derror"
 	"github.com/datawire/ocibuild/pkg/cliutil"
 	"github.com/spf13/cobra"
 
+	"git.lukeshu.com/btrfs-progs-ng/cmd/btrfs-rec/inspect/lsfiles"
 	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs"
-	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsitem"
-	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsprim"
 	"git.lukeshu.com/btrfs-progs-ng/lib/btrfsutil"
-	"git.lukeshu.com/btrfs-progs-ng/lib/maps"
-	"git.lukeshu.com/btrfs-progs-ng/lib/textui"
 )
 
 func init() {
@@ -37,219 +28,10 @@ func init() {
 					err = _err
 				}
 			}()
-			defer func() {
-				if _err := derror.PanicToError(recover()); _err != nil {
-					textui.Fprintf(out, "\n\n%+v\n", _err)
-					err = _err
-				}
-			}()
-			ctx := cmd.Context()
 
-			printSubvol(out, "", true, "/", btrfs.NewSubvolume(
-				btrfsutil.NewOldRebuiltForrest(ctx, fs),
-				btrfsprim.FS_TREE_OBJECTID,
-				false,
-			))
-
-			return nil
+			return lsfiles.LsFiles(
+				out,
+				btrfsutil.NewOldRebuiltForrest(cmd.Context(), fs))
 		}),
 	})
 }
-
-const (
-	tS = "    "
-	tl = "│   "
-	tT = "├── "
-	tL = "└── "
-)
-
-func printText(out io.Writer, prefix string, isLast bool, name, text string) {
-	first, rest := tT, tl
-	if isLast {
-		first, rest = tL, tS
-	}
-	for i, line := range strings.Split(textui.Sprintf("%q %s", name, text), "\n") {
-		_, _ = io.WriteString(out, prefix)
-		if i == 0 {
-			_, _ = io.WriteString(out, first)
-		} else {
-			_, _ = io.WriteString(out, rest)
-		}
-		_, _ = io.WriteString(out, line)
-		_, _ = io.WriteString(out, "\n")
-	}
-}
-
-func printSubvol(out io.Writer, prefix string, isLast bool, name string, subvol *btrfs.Subvolume) {
-	rootInode, err := subvol.GetRootInode()
-	if err != nil {
-		printText(out, prefix, isLast, name+"/", textui.Sprintf("subvol_id=%v err=%v",
-			subvol.TreeID, fmtErr(err)))
-		return
-	}
-	dir, err := subvol.LoadDir(rootInode)
-	if err != nil {
-		printText(out, prefix, isLast, name+"/", textui.Sprintf("subvol_id=%v err=%v",
-			subvol.TreeID, fmtErr(err)))
-		return
-	}
-	if name == "/" {
-		printDir(out, prefix, isLast, name, dir)
-		return
-	}
-	printText(out, prefix, isLast, name+"/", textui.Sprintf("subvol_id=%v", subvol.TreeID))
-	if isLast {
-		prefix += tS
-	} else {
-		prefix += tl
-	}
-	printDir(out, prefix, true, name, dir)
-}
-
-func fmtErr(err error) string {
-	errStr := err.Error()
-	if strings.Contains(errStr, "\n") {
-		errStr = "\\\n" + errStr
-	}
-	return errStr
-}
-
-func fmtInode(inode btrfs.BareInode) string {
-	var mode btrfsitem.StatMode
-	if inode.InodeItem == nil {
-		inode.Errs = append(inode.Errs, errors.New("missing INODE_ITEM"))
-	} else {
-		mode = inode.InodeItem.Mode
-	}
-	ret := textui.Sprintf("ino=%v mode=%v", inode.Inode, mode)
-	if len(inode.Errs) > 0 {
-		ret += " err=" + fmtErr(inode.Errs)
-	}
-	return ret
-}
-
-func printDir(out io.Writer, prefix string, isLast bool, name string, dir *btrfs.Dir) {
-	printText(out, prefix, isLast, name+"/", fmtInode(dir.BareInode))
-	if isLast {
-		prefix += tS
-	} else {
-		prefix += tl
-	}
-	for i, childName := range maps.SortedKeys(dir.ChildrenByName) {
-		printDirEntry(
-			out,
-			prefix,
-			i == len(dir.ChildrenByName)-1,
-			dir.SV,
-			path.Join(name, childName),
-			dir.ChildrenByName[childName])
-	}
-}
-
-func printDirEntry(out io.Writer, prefix string, isLast bool, subvol *btrfs.Subvolume, name string, entry btrfsitem.DirEntry) {
-	if len(entry.Data) != 0 {
-		panic(fmt.Errorf("TODO: I don't know how to handle dirent.data: %q", name))
-	}
-	switch entry.Type {
-	case btrfsitem.FT_DIR:
-		switch entry.Location.ItemType {
-		case btrfsitem.INODE_ITEM_KEY:
-			dir, err := subvol.LoadDir(entry.Location.ObjectID)
-			if err != nil {
-				printText(out, prefix, isLast, name, textui.Sprintf("%v err=%v", entry.Type, fmtErr(err)))
-				return
-			}
-			printDir(out, prefix, isLast, name, dir)
-		case btrfsitem.ROOT_ITEM_KEY:
-			printSubvol(out, prefix, isLast, name, subvol.NewChildSubvolume(entry.Location.ObjectID))
-		default:
-			panic(fmt.Errorf("TODO: I don't know how to handle an FT_DIR with location.ItemType=%v: %q",
-				entry.Location.ItemType, name))
-		}
-	case btrfsitem.FT_SYMLINK:
-		if entry.Location.ItemType != btrfsitem.INODE_ITEM_KEY {
-			panic(fmt.Errorf("TODO: I don't know how to handle an FT_SYMLINK with location.ItemType=%v: %q",
-				entry.Location.ItemType, name))
-		}
-		file, err := subvol.LoadFile(entry.Location.ObjectID)
-		if err != nil {
-			printText(out, prefix, isLast, name, textui.Sprintf("%v err=%v", entry.Type, fmtErr(err)))
-			return
-		}
-		printSymlink(out, prefix, isLast, name, file)
-	case btrfsitem.FT_REG_FILE:
-		if entry.Location.ItemType != btrfsitem.INODE_ITEM_KEY {
-			panic(fmt.Errorf("TODO: I don't know how to handle an FT_REG_FILE with location.ItemType=%v: %q",
-				entry.Location.ItemType, name))
-		}
-		file, err := subvol.LoadFile(entry.Location.ObjectID)
-		if err != nil {
-			printText(out, prefix, isLast, name, textui.Sprintf("%v err=%v", entry.Type, fmtErr(err)))
-			return
-		}
-		printFile(out, prefix, isLast, name, file)
-	case btrfsitem.FT_SOCK:
-		if entry.Location.ItemType != btrfsitem.INODE_ITEM_KEY {
-			panic(fmt.Errorf("TODO: I don't know how to handle an FT_SOCK with location.ItemType=%v: %q",
-				entry.Location.ItemType, name))
-		}
-		file, err := subvol.LoadFile(entry.Location.ObjectID)
-		if err != nil {
-			printText(out, prefix, isLast, name, textui.Sprintf("%v err=%v", entry.Type, fmtErr(err)))
-			return
-		}
-		printSocket(out, prefix, isLast, name, file)
-	case btrfsitem.FT_FIFO:
-		if entry.Location.ItemType != btrfsitem.INODE_ITEM_KEY {
-			panic(fmt.Errorf("TODO: I don't know how to handle an FT_FIFO with location.ItemType=%v: %q",
-				entry.Location.ItemType, name))
-		}
-		file, err := subvol.LoadFile(entry.Location.ObjectID)
-		if err != nil {
-			printText(out, prefix, isLast, name, textui.Sprintf("%v err=%v", entry.Type, fmtErr(err)))
-			return
-		}
-		printPipe(out, prefix, isLast, name, file)
-	default:
-		panic(fmt.Errorf("TODO: I don't know how to handle a fileType=%v: %q",
-			entry.Type, name))
-	}
-}
-
-func printSymlink(out io.Writer, prefix string, isLast bool, name string, file *btrfs.File) {
-	var tgt []byte
-	if file.InodeItem != nil {
-		var err error
-		tgt, err = io.ReadAll(io.NewSectionReader(file, 0, file.InodeItem.Size))
-		if err != nil {
-			file.Errs = append(file.Errs, err)
-		}
-	}
-	printText(out, prefix, isLast, name, textui.Sprintf(
-		"-> %q : %s",
-		tgt,
-		fmtInode(file.BareInode)))
-}
-
-func printFile(out io.Writer, prefix string, isLast bool, name string, file *btrfs.File) {
-	if file.InodeItem != nil {
-		if _, err := io.Copy(io.Discard, io.NewSectionReader(file, 0, file.InodeItem.Size)); err != nil {
-			file.Errs = append(file.Errs, err)
-		}
-	}
-	printText(out, prefix, isLast, name, fmtInode(file.BareInode))
-}
-
-func printSocket(out io.Writer, prefix string, isLast bool, name string, file *btrfs.File) {
-	if file.InodeItem != nil && file.InodeItem.Size > 0 {
-		panic(fmt.Errorf("TODO: I don't know how to handle a socket with size>0: %q", name))
-	}
-	printText(out, prefix, isLast, name, fmtInode(file.BareInode))
-}
-
-func printPipe(out io.Writer, prefix string, isLast bool, name string, file *btrfs.File) {
-	if file.InodeItem != nil && file.InodeItem.Size > 0 {
-		panic(fmt.Errorf("TODO: I don't know how to handle a pipe with size>0: %q", name))
-	}
-	printText(out, prefix, isLast, name, fmtInode(file.BareInode))
-}