1 files changed, 58 insertions, 0 deletions
diff --git a/cmd/btrfs-rec/inspect/rebuildmappings/process_blockgroups.go b/cmd/btrfs-rec/inspect/rebuildmappings/process_blockgroups.go
new file mode 100644
index 0000000..0e2d5a0
--- /dev/null
+++ b/cmd/btrfs-rec/inspect/rebuildmappings/process_blockgroups.go
@@ -0,0 +1,58 @@
+// Copyright (C) 2022  Luke Shumaker <lukeshu@lukeshu.com>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package rebuildmappings
+
+import (
+	"fmt"
+	"sort"
+
+	"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"
+)
+
+type BlockGroup struct {
+	LAddr btrfsvol.LogicalAddr
+	Size  btrfsvol.AddrDelta
+	Flags btrfsvol.BlockGroupFlags
+}
+
+func DedupBlockGroups(scanResults btrfsinspect.ScanDevicesResult) (map[btrfsvol.LogicalAddr]BlockGroup, error) {
+	// Dedup
+	bgsSet := make(containers.Set[BlockGroup])
+	for _, devResults := range scanResults {
+		for _, bg := range devResults.FoundBlockGroups {
+			bgsSet.Insert(BlockGroup{
+				LAddr: btrfsvol.LogicalAddr(bg.Key.ObjectID),
+				Size:  btrfsvol.AddrDelta(bg.Key.Offset),
+				Flags: bg.BG.Flags,
+			})
+		}
+	}
+
+	// Sort
+	bgsOrdered := maps.Keys(bgsSet)
+	sort.Slice(bgsOrdered, func(i, j int) bool {
+		return bgsOrdered[i].LAddr < bgsOrdered[j].LAddr
+	})
+
+	// Sanity check
+	var pos btrfsvol.LogicalAddr
+	for _, bg := range bgsOrdered {
+		if bg.LAddr < pos || bg.Size < 0 {
+			return nil, fmt.Errorf("found block groups are inconsistent")
+		}
+		pos = bg.LAddr.Add(bg.Size)
+	}
+
+	// Return.  We return a map instead of a slice in order to
+	// facilitate easy deletes.
+	bgsMap := make(map[btrfsvol.LogicalAddr]BlockGroup, len(bgsSet))
+	for bg := range bgsSet {
+		bgsMap[bg.LAddr] = bg
+	}
+	return bgsMap, nil
+}