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authorLuke Shumaker <lukeshu@lukeshu.com>2023-03-15 21:03:46 -0600
committerLuke Shumaker <lukeshu@lukeshu.com>2023-03-15 21:39:51 -0600
commitc42e8ea5d77a39d096d97600359bd91657da2f05 (patch)
tree528d075bd39efc1cdd9004492b23cecc542923ac /lib/btrfs/btrfsprim/key.go
parentdcf7632d5657973f87e17413849521738273fa61 (diff)
btrfsprim: Move Key to a separate file
Diffstat (limited to 'lib/btrfs/btrfsprim/key.go')
-rw-r--r--lib/btrfs/btrfsprim/key.go81
1 files changed, 81 insertions, 0 deletions
diff --git a/lib/btrfs/btrfsprim/key.go b/lib/btrfs/btrfsprim/key.go
new file mode 100644
index 0000000..55f7c05
--- /dev/null
+++ b/lib/btrfs/btrfsprim/key.go
@@ -0,0 +1,81 @@
+// Copyright (C) 2022-2023 Luke Shumaker <lukeshu@lukeshu.com>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package btrfsprim
+
+import (
+ "fmt"
+ "math"
+
+ "git.lukeshu.com/btrfs-progs-ng/lib/binstruct"
+ "git.lukeshu.com/btrfs-progs-ng/lib/containers"
+)
+
+type Key struct {
+ ObjectID ObjID `bin:"off=0x0, siz=0x8"` // Each tree has its own set of Object IDs.
+ ItemType ItemType `bin:"off=0x8, siz=0x1"`
+ Offset uint64 `bin:"off=0x9, siz=0x8"` // The meaning depends on the item type.
+ binstruct.End `bin:"off=0x11"`
+}
+
+// mimics print-tree.c:btrfs_print_key()
+func (key Key) Format(tree ObjID) string {
+ switch tree {
+ case UUID_TREE_OBJECTID:
+ return fmt.Sprintf("(%v %v %#08x)",
+ key.ObjectID.Format(tree),
+ key.ItemType,
+ key.Offset)
+ case ROOT_TREE_OBJECTID, QUOTA_TREE_OBJECTID:
+ return fmt.Sprintf("(%v %v %v)",
+ key.ObjectID.Format(tree),
+ key.ItemType,
+ ObjID(key.Offset).Format(tree))
+ default:
+ if key.Offset == math.MaxUint64 {
+ return fmt.Sprintf("(%v %v -1)",
+ key.ObjectID.Format(tree),
+ key.ItemType)
+ } else {
+ return fmt.Sprintf("(%v %v %v)",
+ key.ObjectID.Format(tree),
+ key.ItemType,
+ key.Offset)
+ }
+ }
+}
+
+func (key Key) String() string {
+ return key.Format(0)
+}
+
+var MaxKey = Key{
+ ObjectID: math.MaxUint64,
+ ItemType: math.MaxUint8,
+ Offset: math.MaxUint64,
+}
+
+func (key Key) Mm() Key {
+ switch {
+ case key.Offset > 0:
+ key.Offset--
+ case key.ItemType > 0:
+ key.ItemType--
+ case key.ObjectID > 0:
+ key.ObjectID--
+ }
+ return key
+}
+
+func (a Key) Compare(b Key) int {
+ if d := containers.NativeCompare(a.ObjectID, b.ObjectID); d != 0 {
+ return d
+ }
+ if d := containers.NativeCompare(a.ItemType, b.ItemType); d != 0 {
+ return d
+ }
+ return containers.NativeCompare(a.Offset, b.Offset)
+}
+
+var _ containers.Ordered[Key] = Key{}