Merge branch 'lukeshu/errs'

5 files changed, 169 insertions, 72 deletions

diff --git a/lib/btrfs/btrfsprim/itemtype.go b/lib/btrfs/btrfsprim/itemtype.go
index f33179a..682fecd 100644
--- a/lib/btrfs/btrfsprim/itemtype.go
+++ b/lib/btrfs/btrfsprim/itemtype.go
@@ -2,7 +2,10 @@
 
 package btrfsprim
 
-import "fmt"
+import (
+	"fmt"
+	"math"
+)
 
 type ItemType uint8
 
@@ -39,6 +42,8 @@ const (
 	UUID_RECEIVED_SUBVOL_KEY ItemType = 252
 	UUID_SUBVOL_KEY          ItemType = 251
 	XATTR_ITEM_KEY           ItemType = 24
+
+	MAX_KEY ItemType = math.MaxUint8
 )
 
 func (t ItemType) String() string {
diff --git a/lib/btrfs/btrfsprim/key.go b/lib/btrfs/btrfsprim/key.go
new file mode 100644
index 0000000..b07cc8c
--- /dev/null
+++ b/lib/btrfs/btrfsprim/key.go
@@ -0,0 +1,101 @@
+// 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"`
+}
+
+const MaxOffset uint64 = math.MaxUint64
+
+// 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--
+		key.Offset = MaxOffset
+	case key.ObjectID > 0:
+		key.ObjectID--
+		key.ItemType = MAX_KEY
+		key.Offset = MaxOffset
+	}
+	return key
+}
+
+func (key Key) Pp() Key {
+	switch {
+	case key.Offset < MaxOffset:
+		key.Offset++
+	case key.ItemType < MAX_KEY:
+		key.ItemType++
+		key.Offset = 0
+	case key.ObjectID < MAX_OBJECTID:
+		key.ObjectID++
+		key.ItemType = 0
+		key.Offset = 0
+	}
+	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{}
diff --git a/lib/btrfs/btrfsprim/key_test.go b/lib/btrfs/btrfsprim/key_test.go
new file mode 100644
index 0000000..6274b43
--- /dev/null
+++ b/lib/btrfs/btrfsprim/key_test.go
@@ -0,0 +1,59 @@
+// Copyright (C) 2023  Luke Shumaker <lukeshu@lukeshu.com>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package btrfsprim
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func k(objID ObjID, typ ItemType, offset uint64) Key {
+	return Key{
+		ObjectID: objID,
+		ItemType: typ,
+		Offset:   offset,
+	}
+}
+
+func eq(t *testing.T, act, exp Key) {
+	t.Helper()
+	assert.Equal(t, exp, act)
+}
+
+func ppEq(t *testing.T, in, exp Key) {
+	t.Helper()
+	eq(t, in.Pp(), exp)
+	if in != MaxKey {
+		eq(t, exp.Mm(), in)
+	}
+}
+
+func mmEq(t *testing.T, in, exp Key) {
+	t.Helper()
+	eq(t, in.Mm(), exp)
+	if in != (Key{}) {
+		eq(t, exp.Pp(), in)
+	}
+}
+
+func TestKey(t *testing.T) {
+	t.Parallel()
+
+	eq(t, MaxKey, k(18446744073709551615, 255, 18446744073709551615))
+
+	// pp
+	ppEq(t, k(0, 0, 0), k(0, 0, 1))
+	ppEq(t, k(0, 0, 18446744073709551615), k(0, 1, 0))
+	ppEq(t, k(0, 255, 0), k(0, 255, 1))
+	ppEq(t, k(0, 255, 18446744073709551615), k(1, 0, 0))
+	ppEq(t, MaxKey, k(18446744073709551615, 255, 18446744073709551615))
+
+	// mm
+	mmEq(t, MaxKey, k(18446744073709551615, 255, 18446744073709551614))
+	mmEq(t, k(18446744073709551615, 255, 0), k(18446744073709551615, 254, 18446744073709551615))
+	mmEq(t, k(18446744073709551615, 0, 0), k(18446744073709551614, 255, 18446744073709551615))
+	mmEq(t, k(0, 0, 0), k(0, 0, 0))
+}
diff --git a/lib/btrfs/btrfsprim/misc.go b/lib/btrfs/btrfsprim/misc.go
index ca2e313..38290d6 100644
--- a/lib/btrfs/btrfsprim/misc.go
+++ b/lib/btrfs/btrfsprim/misc.go
@@ -5,84 +5,13 @@
 package btrfsprim
 
 import (
-	"fmt"
-	"math"
 	"time"
 
 	"git.lukeshu.com/btrfs-progs-ng/lib/binstruct"
-	"git.lukeshu.com/btrfs-progs-ng/lib/containers"
 )
 
 type Generation uint64
 
-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{}
-
 type Time struct {
 	Sec           int64  `bin:"off=0x0, siz=0x8"` // Number of seconds since 1970-01-01T00:00:00Z.
 	NSec          uint32 `bin:"off=0x8, siz=0x4"` // Number of nanoseconds since the beginning of the second.
diff --git a/lib/btrfs/btrfsprim/objid.go b/lib/btrfs/btrfsprim/objid.go
index 1aea030..f364957 100644
--- a/lib/btrfs/btrfsprim/objid.go
+++ b/lib/btrfs/btrfsprim/objid.go
@@ -6,6 +6,7 @@ package btrfsprim
 
 import (
 	"fmt"
+	"math"
 )
 
 type ObjID uint64
@@ -52,6 +53,8 @@ const (
 
 	// ???
 	EMPTY_SUBVOL_DIR_OBJECTID ObjID = 2
+
+	MAX_OBJECTID ObjID = math.MaxUint64
 )
 
 var (