diff options
| -rw-r--r-- | lib/btrfs/btrfstree/btree.go | 86 | ||||
| -rw-r--r-- | lib/btrfs/btrfstree/btree_tree.go | 72 |
2 files changed, 86 insertions, 72 deletions
diff --git a/lib/btrfs/btrfstree/btree.go b/lib/btrfs/btrfstree/btree.go new file mode 100644 index 0000000..2fd7c39 --- /dev/null +++ b/lib/btrfs/btrfstree/btree.go @@ -0,0 +1,86 @@ +// Copyright (C) 2022-2023 Luke Shumaker <lukeshu@lukeshu.com> +// +// SPDX-License-Identifier: GPL-2.0-or-later + +package btrfstree + +import ( + "context" + "fmt" + + "git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsprim" + "git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsvol" + "git.lukeshu.com/btrfs-progs-ng/lib/diskio" +) + +// TreeOperator is an interface for performing basic btree operations. +type TreeOperator interface { + // TreeWalk walks a tree, triggering callbacks for every node, + // key-pointer, and item; as well as for any errors encountered. + // + // If the tree is valid, then everything is walked in key-order; but if + // the tree is broken, then ordering is not guaranteed. + // + // Canceling the Context causes TreeWalk to return early; no + // values from the Context are used. + // + // The lifecycle of callbacks is: + // + // 001 .PreNode() + // 002 (read node) + // 003 .Node() (or .BadNode()) + // for item in node.items: + // if interior: + // 004 .PreKeyPointer() + // 005 (recurse) + // 006 .PostKeyPointer() + // else: + // 004 .Item() (or .BadItem()) + // 007 .PostNode() + TreeWalk(ctx context.Context, treeID btrfsprim.ObjID, errHandle func(*TreeError), cbs TreeWalkHandler) + + TreeLookup(treeID btrfsprim.ObjID, key btrfsprim.Key) (Item, error) + TreeSearch(treeID btrfsprim.ObjID, fn func(key btrfsprim.Key, size uint32) int) (Item, error) // size is math.MaxUint32 for key-pointers + + // If some items are able to be read, but there is an error reading the + // full set, then it might return *both* a list of items and an error. + // + // If no such item is found, an error that is io/fs.ErrNotExist is + // returned. + TreeSearchAll(treeID btrfsprim.ObjID, fn func(key btrfsprim.Key, size uint32) int) ([]Item, error) // size is math.MaxUint32 for key-pointers +} + +type TreeWalkHandler struct { + // Callbacks for entire nodes. + // + // If any of these return an error that is io/fs.SkipDir, the + // node immediately stops getting processed; if PreNode, Node, + // or BadNode return io/fs.SkipDir then key pointers and items + // within the node are not processed. + PreNode func(TreePath) error + Node func(TreePath, *diskio.Ref[btrfsvol.LogicalAddr, Node]) error + BadNode func(TreePath, *diskio.Ref[btrfsvol.LogicalAddr, Node], error) error + PostNode func(TreePath, *diskio.Ref[btrfsvol.LogicalAddr, Node]) error + // Callbacks for items on interior nodes + PreKeyPointer func(TreePath, KeyPointer) error + PostKeyPointer func(TreePath, KeyPointer) error + // Callbacks for items on leaf nodes + Item func(TreePath, Item) error + BadItem func(TreePath, Item) error +} + +type TreeError struct { + Path TreePath + Err error +} + +func (e *TreeError) Unwrap() error { return e.Err } + +func (e *TreeError) Error() string { + return fmt.Sprintf("%v: %v", e.Path, e.Err) +} + +type NodeSource interface { + Superblock() (*Superblock, error) + ReadNode(TreePath) (*diskio.Ref[btrfsvol.LogicalAddr, Node], error) +} diff --git a/lib/btrfs/btrfstree/btree_tree.go b/lib/btrfs/btrfstree/btree_tree.go index e75eb0b..afaaf92 100644 --- a/lib/btrfs/btrfstree/btree_tree.go +++ b/lib/btrfs/btrfstree/btree_tree.go @@ -20,78 +20,6 @@ import ( "git.lukeshu.com/btrfs-progs-ng/lib/slices" ) -// TreeOperator is an interface for performing basic btree operations. -type TreeOperator interface { - // TreeWalk walks a tree, triggering callbacks for every node, - // key-pointer, and item; as well as for any errors encountered. - // - // If the tree is valid, then everything is walked in key-order; but if - // the tree is broken, then ordering is not guaranteed. - // - // Canceling the Context causes TreeWalk to return early; no - // values from the Context are used. - // - // The lifecycle of callbacks is: - // - // 001 .PreNode() - // 002 (read node) - // 003 .Node() (or .BadNode()) - // for item in node.items: - // if interior: - // 004 .PreKeyPointer() - // 005 (recurse) - // 006 .PostKeyPointer() - // else: - // 004 .Item() (or .BadItem()) - // 007 .PostNode() - TreeWalk(ctx context.Context, treeID btrfsprim.ObjID, errHandle func(*TreeError), cbs TreeWalkHandler) - - TreeLookup(treeID btrfsprim.ObjID, key btrfsprim.Key) (Item, error) - TreeSearch(treeID btrfsprim.ObjID, fn func(key btrfsprim.Key, size uint32) int) (Item, error) // size is math.MaxUint32 for key-pointers - - // If some items are able to be read, but there is an error reading the - // full set, then it might return *both* a list of items and an error. - // - // If no such item is found, an error that is io/fs.ErrNotExist is - // returned. - TreeSearchAll(treeID btrfsprim.ObjID, fn func(key btrfsprim.Key, size uint32) int) ([]Item, error) // size is math.MaxUint32 for key-pointers -} - -type TreeWalkHandler struct { - // Callbacks for entire nodes. - // - // If any of these return an error that is io/fs.SkipDir, the - // node immediately stops getting processed; if PreNode, Node, - // or BadNode return io/fs.SkipDir then key pointers and items - // within the node are not processed. - PreNode func(TreePath) error - Node func(TreePath, *diskio.Ref[btrfsvol.LogicalAddr, Node]) error - BadNode func(TreePath, *diskio.Ref[btrfsvol.LogicalAddr, Node], error) error - PostNode func(TreePath, *diskio.Ref[btrfsvol.LogicalAddr, Node]) error - // Callbacks for items on interior nodes - PreKeyPointer func(TreePath, KeyPointer) error - PostKeyPointer func(TreePath, KeyPointer) error - // Callbacks for items on leaf nodes - Item func(TreePath, Item) error - BadItem func(TreePath, Item) error -} - -type TreeError struct { - Path TreePath - Err error -} - -func (e *TreeError) Unwrap() error { return e.Err } - -func (e *TreeError) Error() string { - return fmt.Sprintf("%v: %v", e.Path, e.Err) -} - -type NodeSource interface { - Superblock() (*Superblock, error) - ReadNode(TreePath) (*diskio.Ref[btrfsvol.LogicalAddr, Node], error) -} - type TreeOperatorImpl struct { NodeSource } |