write btrfs-ls-trees

1 files changed, 73 insertions, 0 deletions

diff --git a/cmd/btrfs-ls-trees/main.go b/cmd/btrfs-ls-trees/main.go
new file mode 100644
index 0000000..c3156f5
--- /dev/null
+++ b/cmd/btrfs-ls-trees/main.go
@@ -0,0 +1,73 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"text/tabwriter"
+
+	"lukeshu.com/btrfs-tools/pkg/btrfs"
+	"lukeshu.com/btrfs-tools/pkg/btrfs/btrfsitem"
+	"lukeshu.com/btrfs-tools/pkg/btrfsmisc"
+	"lukeshu.com/btrfs-tools/pkg/util"
+)
+
+func main() {
+	if err := Main(os.Args[1:]...); err != nil {
+		fmt.Fprintf(os.Stderr, "%v: error: %v\n", os.Args[0], err)
+		os.Exit(1)
+	}
+}
+
+func Main(imgfilenames ...string) (err error) {
+	maybeSetErr := func(_err error) {
+		if _err != nil && err == nil {
+			err = _err
+		}
+	}
+
+	fs, err := btrfsmisc.Open(os.O_RDONLY, imgfilenames...)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		maybeSetErr(fs.Close())
+	}()
+
+	var treeErrCnt int
+	var treeItemCnt map[btrfsitem.Type]int
+	btrfsmisc.WalkFS(fs, btrfsmisc.WalkFSHandler{
+		PreTree: func(name string, laddr btrfs.LogicalAddr) {
+			treeErrCnt = 0
+			treeItemCnt = make(map[btrfsitem.Type]int)
+			fmt.Printf("tree laddr=%v name=%q\n", laddr, name)
+		},
+		Err: func(_ error) {
+			treeErrCnt++
+		},
+		WalkTreeHandler: btrfs.WalkTreeHandler{
+			Item: func(_ btrfs.WalkTreePath, item btrfs.Item) error {
+				typ := item.Head.Key.ItemType
+				treeItemCnt[typ] = treeItemCnt[typ] + 1
+				return nil
+			},
+		},
+		PostTree: func(name string, laddr btrfs.LogicalAddr) {
+			totalItems := 0
+			for _, cnt := range treeItemCnt {
+				totalItems += cnt
+			}
+			numWidth := len(strconv.Itoa(util.Max(treeErrCnt, totalItems)))
+
+			table := tabwriter.NewWriter(os.Stdout, 0, 8, 2, ' ', 0)
+			fmt.Fprintf(table, "        errors\t% *s\n", numWidth, strconv.Itoa(treeErrCnt))
+			for _, typ := range util.SortedMapKeys(treeItemCnt) {
+				fmt.Fprintf(table, "        %v items\t% *s\n", typ, numWidth, strconv.Itoa(treeItemCnt[typ]))
+			}
+			fmt.Fprintf(table, "        total items\t% *s\n", numWidth, strconv.Itoa(totalItems))
+			table.Flush()
+		},
+	})
+
+	return nil
+}