diff options
Diffstat (limited to 'lib/btrfs/btrfstree/btree.go')
| -rw-r--r-- | lib/btrfs/btrfstree/btree.go | 70 |
1 files changed, 36 insertions, 34 deletions
diff --git a/lib/btrfs/btrfstree/btree.go b/lib/btrfs/btrfstree/btree.go index e91fcc1..bc1bac2 100644 --- a/lib/btrfs/btrfstree/btree.go +++ b/lib/btrfs/btrfstree/btree.go @@ -22,30 +22,51 @@ type TreeSearcher interface { Search(key btrfsprim.Key, size uint32) int } +type TreeWalkHandler struct { + BadSuperblock func(error) + + // Callbacks for entire nodes. + // + // The return value from BadNode is whether to process the + // slots in this node or not; if no BadNode function is given, + // then it is not processed. + Node func(Path, *Node) + BadNode func(Path, *Node, error) bool + + // Callbacks for slots in nodes. + // + // The return value from KeyPointer is whether to recurse or + // not; if no KeyPointer function is given, then it is + // recursed. + KeyPointer func(Path, KeyPointer) bool + Item func(Path, Item) + BadItem func(Path, Item) +} + // 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. + // 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. + // 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() + // 000 (read superblock) (maybe cbs.BadSuperblock()) + // + // 001 (read node) + // 002 cbs.Node() or cbs.BadNode() + // if interior: + // for kp in node.items: + // 003a if cbs.PreKeyPointer == nil || cbs.PreKeyPointer() { + // 004b (recurse) + // else: + // for item in node.items: + // 003b cbs.Item() or cbs.BadItem() TreeWalk(ctx context.Context, treeID btrfsprim.ObjID, errHandle func(*TreeError), cbs TreeWalkHandler) TreeLookup(treeID btrfsprim.ObjID, key btrfsprim.Key) (Item, error) @@ -62,25 +83,6 @@ type TreeOperator interface { TreeSearchAll(treeID btrfsprim.ObjID, search TreeSearcher) ([]Item, error) } -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(Path) error - Node func(Path, *Node) error - BadNode func(Path, *Node, error) error - PostNode func(Path, *Node) error - // Callbacks for items on interior nodes - PreKeyPointer func(Path, KeyPointer) error - PostKeyPointer func(Path, KeyPointer) error - // Callbacks for items on leaf nodes - Item func(Path, Item) error - BadItem func(Path, Item) error -} - type TreeError struct { Path Path Err error |