added parents to nodehandle

btrfs/Cargo.toml

@@ -21,6 +21,7 @@ zerocopy = "0.6.1"
 crc = "3.0.1"
 thiserror = { version = "1.0", package = "thiserror-core", default-features = false }
 num_enum = {version = "0.5.11", default-features = false}
+replace_with = "0.1.7"
 
 [dev-dependencies]
 env_logger = "*"

btrfs/src/v2/tree.rs

@@ -60,10 +60,12 @@ type BoxedNode = Rc<Node>;
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct NodeHandle {
+    parents: Vec<(BoxedNode, u32)>,
     node: BoxedNode,
     idx: u32,
 }
 
+#[derive(Debug)]
 pub struct Range<R: super::Read> {
     volume: Rc<Volume<R>>,
     parents: Vec<NodeHandle>,
@@ -271,6 +273,65 @@ impl RootOrEdge {
         .clone()
     }
 
+    pub fn into_next_leaf_any<R, F>(
+        self,
+        volume: &super::volume::Volume<R>,
+        f: F,
+    ) -> core::result::Result<Self, Self>
+    where
+        F: Fn(
+            NodeHandle,
+            &super::volume::Volume<R>,
+        ) -> core::result::Result<NodeHandle, NodeHandle>,
+        R: super::Read,
+    {
+        let mut node = match self {
+            RootOrEdge::Root(root) => {
+                // use self if is leaf already, otherwise forward to next leaf
+                if root.node.inner.is_leaf() {
+                    return Ok(Self::Edge(root));
+                } else {
+                    root
+                }
+            }
+            RootOrEdge::Edge(edge) => edge,
+        };
+
+        let leaf = loop {
+            match f(node, volume) {
+                Ok(next) => {
+                    if next.node.inner.is_leaf() {
+                        break Ok(next);
+                    } else {
+                        node = next;
+                    }
+                }
+                Err(last) => {
+                    break Err(Self::Edge(last));
+                }
+            }
+        };
+
+        // turn leaf into Self::Edge
+        leaf.map(|leaf| Self::Edge(leaf))
+    }
+
+    /// returns the next RootOrEdge, or the end of the tree as Err
+    pub fn into_next_leaf<R: super::Read>(
+        self,
+        volume: &super::volume::Volume<R>,
+    ) -> core::result::Result<Self, Self> {
+        self.into_next_leaf_any(volume, NodeHandle::into_next)
+    }
+
+    /// returns the next RootOrEdge, or the end of the tree as Err, in reverse direction
+    pub fn into_next_back_leaf<R: super::Read>(
+        self,
+        volume: &super::volume::Volume<R>,
+    ) -> core::result::Result<Self, Self> {
+        self.into_next_leaf_any(volume, NodeHandle::into_next_back)
+    }
+
     pub fn as_handle(&self) -> &NodeHandle {
         match self {
             RootOrEdge::Root(handle) => handle,
@@ -320,6 +381,7 @@ impl Node {
         }
     }
 
+    // TODO: move this to nodehandle
     pub fn find_key<K: PartialEq<Key> + PartialOrd<Key>>(self: &Rc<Self>, key: &K) -> SearchResult {
         match &self.inner {
             BTreeNode::Internal(node) => {
@@ -327,12 +389,14 @@ impl Node {
                     match key.partial_cmp(&child.key) {
                         Some(core::cmp::Ordering::Less) => {
                             return SearchResult::Edge(NodeHandle {
+                                parents: Default::default(),
                                 node: self.clone(),
                                 idx: if i == 0 { 0 } else { i as u32 - 1 },
                             });
                         }
                         Some(core::cmp::Ordering::Equal) | None => {
                             return SearchResult::Edge(NodeHandle {
+                                parents: Default::default(),
                                 node: self.clone(),
                                 idx: i as u32,
                             });
@@ -342,6 +406,7 @@ impl Node {
                 }
 
                 SearchResult::Edge(NodeHandle {
+                    parents: Default::default(),
                     node: self.clone(),
                     idx: node.children.len() as u32 - 1,
                 })
@@ -356,6 +421,7 @@ impl Node {
                     // } else
                     if key.eq(&child.key) {
                         return SearchResult::Leaf(NodeHandle {
+                            parents: Default::default(),
                             node: self.clone(),
                             idx: i as u32,
                         });
@@ -364,6 +430,7 @@ impl Node {
 
                 log::debug!("key definitely not found!");
                 SearchResult::Edge(NodeHandle {
+                    parents: Default::default(),
                     node: self.clone(),
                     idx: node.items.len() as u32 - 1,
                 })
@@ -484,29 +551,53 @@ where
     type Item = (Item, TreeItem);
 
     fn next(&mut self) -> Option<Self::Item> {
-        let handle = match &self.start {
+        if !self.is_empty() {
-            RootOrEdge::Root(_) => {
+            replace_with::replace_with_or_abort(&mut self.start, |start| {
-                self.init_start().expect("error");
+                match start.into_next_leaf(&self.volume) {
-                match &self.start.node.inner {
+                    Ok(next) => next,
-                    BTreeNode::Internal(_) => None,
+                    Err(next) => next,
-                    BTreeNode::Leaf(_) => Some(self.start.into_handle()),
                 }
-            }
+            });
-            RootOrEdge::Edge(_) => self
-                .advance()
-                .expect("cant advance range")
-                .map(|_| self.start.into_handle()),
-        };
 
-        handle
+            let item = self.start.as_handle().parse_item().expect("range item");
-            .map(|handle| handle.parse_item())?
+
-            .expect("failed to parse item")
+            item
+        } else {
+            None
+        }
+    }
+}
+
+impl<R> DoubleEndedIterator for Range<R>
+where
+    R: super::Read,
+{
+    fn next_back(&mut self) -> Option<Self::Item> {
+        if !self.is_empty() {
+            replace_with::replace_with_or_abort(&mut self.end, |end| {
+                match end.into_next_back_leaf(&self.volume) {
+                    Ok(next) => next,
+                    Err(next) => next,
+                }
+            });
+
+            let item = self.start.as_handle().parse_item().expect("range item");
+
+            item
+        } else {
+            None
+        }
     }
 }
 
 impl NodeHandle {
     pub fn start(node: BoxedNode) -> Self {
-        Self { node, idx: 0 }
+        let parents = Vec::with_capacity(node.inner.header().level as usize);
+        Self {
+            node,
+            parents,
+            idx: 0,
+        }
     }
 
     pub fn parse_item(&self) -> Result<Option<(Item, TreeItem)>> {
@@ -528,6 +619,123 @@ impl NodeHandle {
         }
     }
 
+    // needs reference to volume to be able to read children key_ptrs
+    // this is a live reference so if in the future I want to have a &mut to something in Volume
+    // greppable: volume ref
+    pub fn into_next_back<R: super::Read>(
+        self,
+        volume: &super::volume::Volume<R>,
+    ) -> core::result::Result<Self, Self> {
+        let Self {
+            mut parents,
+            node,
+            idx,
+        } = self;
+
+        if idx < 1 {
+            // go up
+            match parents.pop() {
+                Some((node, idx)) => Self { node, idx, parents }.into_next_back(volume),
+                None => Err(Self { node, idx, parents }),
+            }
+        } else {
+            match &node.inner {
+                BTreeNode::Internal(internal) => {
+                    let child_ptr = *internal
+                        .children
+                        .get(idx as usize)
+                        .expect("no children in node");
+                    let node = match volume
+                        .read_keyptr(&child_ptr)
+                        .and_then(|bytes| Node::from_bytes(bytes))
+                        .map(|node| Rc::new(node))
+                    {
+                        Ok(child) => {
+                            parents.push((node, idx));
+                            Ok(Self {
+                                parents,
+                                idx: child.inner.header().nritems.get() - 1,
+                                node: child,
+                            })
+                        }
+                        Err(_) => Err(Self { parents, node, idx }),
+                    };
+
+                    // TODO: better error or panic here? this would return self, indicating the end of the tree, even though we simply failed to retrieve the next node
+                    node
+                }
+
+                BTreeNode::Leaf(_) => Ok(Self {
+                    idx: idx - 1,
+                    parents,
+                    node,
+                }),
+            }
+        }
+    }
+
+    // needs reference to volume to be able to read children key_ptrs
+    // this is a live reference so if in the future I want to have a &mut to something in Volume
+    // greppable: volume ref
+    /// returns Ok(next) or Err(self) if self is already the last node
+    pub fn into_next<R: super::Read>(
+        self,
+        volume: &super::volume::Volume<R>,
+    ) -> core::result::Result<Self, Self> {
+        let Self {
+            mut parents,
+            node,
+            idx,
+        } = self;
+
+        let header = node.inner.header();
+
+        if idx + 1 >= header.nritems.get() {
+            // go up
+            match parents.pop() {
+                Some((node, idx)) => Self {
+                    node,
+                    idx: idx + 1,
+                    parents,
+                }
+                .into_next(volume),
+                None => Err(Self { node, idx, parents }),
+            }
+        } else {
+            match &node.inner {
+                BTreeNode::Internal(internal) => {
+                    let child_ptr = *internal
+                        .children
+                        .get(idx as usize)
+                        .expect("no children in node");
+                    let node = match volume
+                        .read_keyptr(&child_ptr)
+                        .and_then(|bytes| Node::from_bytes(bytes))
+                        .map(|node| Rc::new(node))
+                    {
+                        Ok(child) => {
+                            parents.push((node, idx));
+                            Ok(Self {
+                                parents,
+                                idx: 0,
+                                node: child,
+                            })
+                        }
+                        Err(_) => Err(Self { parents, node, idx }),
+                    };
+
+                    // TODO: better error or panic here? this would return self, indicating the end of the tree, even though we simply failed to retrieve the next node
+                    node
+                }
+                BTreeNode::Leaf(_) => Ok(Self {
+                    idx: idx + 1,
+                    parents,
+                    node,
+                }),
+            }
+        }
+    }
+
     // returns the next node in ascending sequential order
     pub fn advance_down(self) -> NodeHandleAdvanceResult {
         let header = self.node.inner.header();
@@ -548,7 +756,9 @@ impl NodeHandle {
     }
 
     pub fn end(node: BoxedNode) -> Self {
+        let parents = Vec::with_capacity(node.inner.header().level as usize);
         Self {
+            parents,
             idx: node.inner.header().nritems.get() - 1,
             node,
         }

btrfs/src/v2/volume.rs

@@ -117,6 +117,7 @@ impl<R: super::Read> Volume<R> {
     }
 
     fn parse_chunk_tree(mut self) -> Result<Self> {
+        log::debug!("parsing chunk tree");
         let this = Rc::new(self);
 
         let chunk_tree =
@@ -124,9 +125,12 @@ impl<R: super::Read> Volume<R> {
 
         let chunks = chunk_tree
             .iter()
-            .filter_map(|(item, v)| match v {
+            .filter_map(|(item, v)| {
+                log::debug!("{:?}", item);
+                match v {
                     TreeItem::Chunk(chunk) => Some((item, chunk)),
                     _ => None,
+                }
             })
             .collect::<Vec<_>>();
 
@@ -366,6 +370,7 @@ mod tests {
         let vol = Volume::new(file).expect("volume");
         let v2 = vol.into_volume2().expect("volume2");
 
+        log::info!("roots:");
         for (id, v) in v2.roots.iter() {
             log::info!("[{id:?}] {v:#?}");
         }
@@ -378,8 +383,12 @@ mod tests {
         let v2 = vol.into_volume2().expect("volume2");
         let fs = v2.default_subvolume().expect("default subvol");
 
-        for (id, entry) in fs.fs_root.iter() {
+        log::info!("fs_root:");
-            log::info!("[{id:?}] {entry:#?}");
+        for (_id, entry) in fs.fs_root.iter() {
+            if let Some(dir) = entry.as_dir_index() {
+                log::info!("{}", dir.name_as_string_lossy());
+            }
+            // log::info!("[{id:?}] {entry:#?}");
         }
     }
 }