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// Copyright (C) 2022 Luke Shumaker <lukeshu@lukeshu.com>
//
// SPDX-License-Identifier: GPL-2.0-or-later
package rebuildnodes
import (
"context"
"fmt"
"io"
"strings"
"github.com/datawire/dlib/dlog"
"git.lukeshu.com/btrfs-progs-ng/lib/btrfs"
"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsvol"
"git.lukeshu.com/btrfs-progs-ng/lib/btrfsprogs/btrfsinspect"
"git.lukeshu.com/btrfs-progs-ng/lib/containers"
"git.lukeshu.com/btrfs-progs-ng/lib/maps"
"git.lukeshu.com/btrfs-progs-ng/lib/slices"
)
func ShowLoops(ctx context.Context, out io.Writer, fs *btrfs.FS, nodeScanResults btrfsinspect.ScanDevicesResult) error {
scanData, err := ScanDevices(ctx, fs, nodeScanResults)
if err != nil {
return err
}
dlog.Info(ctx, "Collecting orphans...")
orphans := make(containers.Set[btrfsvol.LogicalAddr])
for node := range scanData.Nodes {
if len(scanData.EdgesTo[node]) == 0 {
orphans.Insert(node)
}
}
dlog.Info(ctx, "Walking graph...")
loopWalk(out, *scanData, 0)
for _, orphan := range maps.SortedKeys(orphans) {
loopWalk(out, *scanData, orphan)
}
return nil
}
func loopWalk(out io.Writer, scanData scanResult, stack ...btrfsvol.LogicalAddr) {
for _, kp := range scanData.EdgesFrom[stack[len(stack)-1]] {
childStack := append(stack, kp.ToNode)
if slices.Contains(kp.ToNode, stack) {
loopRender(out, scanData, childStack...)
} else {
loopWalk(out, scanData, childStack...)
}
}
}
func nodeRender(scanData scanResult, node btrfsvol.LogicalAddr) []string {
if node == 0 {
return []string{"root"}
} else if nodeData, ok := scanData.Nodes[node]; ok {
return []string{
fmt.Sprintf("{addr: %v,", node),
fmt.Sprintf(" level: %v,", nodeData.Level),
fmt.Sprintf(" gen: %v,", nodeData.Generation),
fmt.Sprintf(" num_items: %v,", nodeData.NumItems),
fmt.Sprintf(" min_item: {%d,%v,%d},",
nodeData.MinItem.ObjectID,
nodeData.MinItem.ItemType,
nodeData.MinItem.Offset),
fmt.Sprintf(" max_item: {%d,%v,%d}}",
nodeData.MaxItem.ObjectID,
nodeData.MaxItem.ItemType,
nodeData.MaxItem.Offset),
}
} else if nodeErr, ok := scanData.BadNodes[node]; ok {
return []string{
fmt.Sprintf("{addr:%v,", node),
fmt.Sprintf(" err:%q}", nodeErr.Error()),
}
} else {
panic("should not happen")
}
}
func edgeRender(scanData scanResult, kp kpData) []string {
a := fmt.Sprintf("[%d]={", kp.FromItem)
b := strings.Repeat(" ", len(a))
ret := []string{
a + fmt.Sprintf("ToNode: %v,", kp.ToNode),
b + fmt.Sprintf("ToLevel: %v,", kp.ToLevel),
b + fmt.Sprintf("ToGen: %v,", kp.ToGeneration),
b + fmt.Sprintf("ToKey: {%d,%v,%d}}",
kp.ToKey.ObjectID,
kp.ToKey.ItemType,
kp.ToKey.Offset),
}
var err error
if toNode, ok := scanData.Nodes[kp.ToNode]; !ok {
err = scanData.BadNodes[kp.ToNode]
} else {
err = checkNodeExpectations(kp, toNode)
}
if err != nil {
c := strings.Repeat(" ", len(a)-1)
ret = append(ret,
c+"^",
c+"`-err="+strings.ReplaceAll(err.Error(), "\n", "\n"+c+" "),
)
}
return ret
}
func loopRender(out io.Writer, scanData scanResult, stack ...btrfsvol.LogicalAddr) {
var lines []string
add := func(suffixes []string) {
curLen := 0
for _, line := range lines {
if len(line) > curLen {
curLen = len(line)
}
}
for i, suffix := range suffixes {
if len(lines) <= i {
lines = append(lines, "")
}
if len(lines[i]) < curLen {
if i == 0 {
lines[i] += strings.Repeat("-", curLen-len(lines[i])-1) + ">"
} else {
lines[i] += strings.Repeat(" ", curLen-len(lines[i]))
}
}
lines[i] += suffix
}
}
for i, node := range stack {
if i > 0 {
for _, kp := range scanData.EdgesTo[node] {
if kp.FromNode == stack[i-1] {
add(edgeRender(scanData, *kp))
break
}
}
}
add(nodeRender(scanData, node))
}
fmt.Fprintln(out, "loop:")
for _, line := range lines {
fmt.Fprintln(out, " "+line)
}
}
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