idk

btrfs/src/structs.rs

@@ -328,6 +328,22 @@ pub enum ExtentData {
     Other(ExtentData2),
 }
 
+impl ExtentData {
+    pub fn header(&self) -> &ExtentData1 {
+        match self {
+            ExtentData::Inline { header, .. } => header,
+            ExtentData::Other(extent) => extent.extent_data1(),
+        }
+    }
+
+    pub fn len(&self) -> u64 {
+        match self {
+            ExtentData::Inline { data, .. } => data.len() as u64,
+            ExtentData::Other(extent) => extent.num_bytes(),
+        }
+    }
+}
+
 impl Parseable for ExtentData {
     fn parse(bytes: &[u8]) -> Result<Self> {
         let header = ExtentData1::parse(bytes)?;
@@ -966,6 +982,10 @@ where
         &self.name
     }
 
+    pub fn into_name(self) -> Vec<u8> {
+        self.name
+    }
+
     pub fn name_as_str(&self) -> core::result::Result<&str, core::str::Utf8Error> {
         core::str::from_utf8(&self.name)
     }
@@ -1107,9 +1127,7 @@ impl TreeItem {
             None
         }
     }
-}
 
-impl TreeItem {
     pub fn as_chunk(&self) -> Option<&Chunk> {
         if let Self::Chunk(v) = self {
             Some(v)
@@ -1157,6 +1175,62 @@ impl TreeItem {
             None
         }
     }
+
+    pub fn try_into_chunk(self) -> core::result::Result<Chunk, Self> {
+        if let Self::Chunk(v) = self {
+            Ok(v)
+        } else {
+            Err(self)
+        }
+    }
+
+    pub fn try_into_root(self) -> core::result::Result<RootItem, Self> {
+        if let Self::Root(v) = self {
+            Ok(v)
+        } else {
+            Err(self)
+        }
+    }
+
+    pub fn try_into_extent_data(self) -> core::result::Result<ExtentData, Self> {
+        if let Self::ExtentData(v) = self {
+            Ok(v)
+        } else {
+            Err(self)
+        }
+    }
+
+    pub fn try_into_dir_item(self) -> core::result::Result<Vec<DirItemEntry>, Self> {
+        if let Self::DirItem(v) = self {
+            Ok(v)
+        } else {
+            Err(self)
+        }
+    }
+
+    pub fn try_into_dir_index(self) -> core::result::Result<DirItemEntry, Self> {
+        if let Self::DirIndex(v) = self {
+            Ok(v)
+        } else {
+            Err(self)
+        }
+    }
+
+    pub fn try_into_inode_item(self) -> core::result::Result<INodeItem, Self> {
+        if let Self::INodeItem(v) = self {
+            Ok(v)
+        } else {
+            Err(self)
+        }
+    }
+
+    pub fn try_into_inode_ref(self) -> core::result::Result<INodeRefEntry, Self> {
+        if let Self::INodeRef(v) = self {
+            Ok(v)
+        } else {
+            Err(self)
+        }
+    }
 }
 
 #[derive(Debug, Clone)]

btrfs/src/v2/mod.rs

@@ -1,3 +1,9 @@
+use core::{
+    cmp::Ordering,
+    fmt::Debug,
+    ops::{Bound, RangeBounds},
+};
+
 use crate::Error;
 
 pub mod error {
@@ -65,3 +71,275 @@ impl Read for std::fs::File {
 pub mod file;
 pub mod tree;
 pub mod volume;
+
+pub fn cmp_start_bound<T: PartialOrd>(
+    rhs: &core::ops::Bound<T>,
+    lhs: &core::ops::Bound<T>,
+) -> Option<core::cmp::Ordering> {
+    match rhs {
+        core::ops::Bound::Included(r) => match lhs {
+            core::ops::Bound::Included(l) => r.partial_cmp(&l),
+            core::ops::Bound::Excluded(l) => match r.partial_cmp(&l) {
+                Some(core::cmp::Ordering::Equal) => Some(core::cmp::Ordering::Less),
+                i => i,
+            },
+            core::ops::Bound::Unbounded => Some(core::cmp::Ordering::Greater),
+        },
+        core::ops::Bound::Excluded(r) => match lhs {
+            core::ops::Bound::Excluded(l) => r.partial_cmp(&l),
+            core::ops::Bound::Included(l) => match r.partial_cmp(&l) {
+                Some(core::cmp::Ordering::Equal) => Some(core::cmp::Ordering::Greater),
+                i => i,
+            },
+            core::ops::Bound::Unbounded => Some(core::cmp::Ordering::Greater),
+        },
+        core::ops::Bound::Unbounded => match lhs {
+            core::ops::Bound::Unbounded => Some(core::cmp::Ordering::Equal),
+            _ => Some(core::cmp::Ordering::Less),
+        },
+    }
+}
+
+pub fn cmp_end_bound<T: PartialOrd>(
+    rhs: &core::ops::Bound<T>,
+    lhs: &core::ops::Bound<T>,
+) -> Option<core::cmp::Ordering> {
+    match rhs {
+        core::ops::Bound::Included(r) => match lhs {
+            core::ops::Bound::Included(l) => r.partial_cmp(&l),
+            core::ops::Bound::Excluded(l) => match r.partial_cmp(&l) {
+                Some(core::cmp::Ordering::Equal) => Some(core::cmp::Ordering::Greater),
+                i => i,
+            },
+            core::ops::Bound::Unbounded => Some(core::cmp::Ordering::Less),
+        },
+        core::ops::Bound::Excluded(r) => match lhs {
+            core::ops::Bound::Excluded(l) => r.partial_cmp(&l),
+            core::ops::Bound::Included(l) => match r.partial_cmp(&l) {
+                Some(core::cmp::Ordering::Equal) => Some(core::cmp::Ordering::Greater),
+                i => i,
+            },
+            core::ops::Bound::Unbounded => Some(core::cmp::Ordering::Less),
+        },
+        core::ops::Bound::Unbounded => match lhs {
+            core::ops::Bound::Unbounded => Some(core::cmp::Ordering::Equal),
+            _ => Some(core::cmp::Ordering::Greater),
+        },
+    }
+}
+
+#[derive(Debug, PartialEq, Eq)]
+struct StartBound<T: PartialOrd>(Bound<T>);
+impl<T: PartialOrd> PartialOrd for StartBound<T> {
+    fn partial_cmp(&self, other: &Self) -> Option<core::cmp::Ordering> {
+        cmp_start_bound(&self.0, &other.0)
+    }
+}
+impl<T: Ord> Ord for StartBound<T> {
+    fn cmp(&self, other: &Self) -> core::cmp::Ordering {
+        self.partial_cmp(other).unwrap()
+    }
+}
+
+#[derive(Debug, PartialEq, Eq)]
+struct EndBound<T: PartialOrd>(Bound<T>);
+
+impl<T: PartialOrd> PartialOrd for EndBound<T> {
+    fn partial_cmp(&self, other: &Self) -> Option<core::cmp::Ordering> {
+        cmp_end_bound(&self.0, &other.0)
+    }
+}
+impl<T: Ord> Ord for EndBound<T> {
+    fn cmp(&self, other: &Self) -> core::cmp::Ordering {
+        // safety: partial_cmp only returns None when returning T::partial_cmp
+        self.partial_cmp(other).unwrap()
+    }
+}
+
+pub fn range_countains_bound<T: Ord + Debug, R: RangeBounds<T>>(
+    range: R,
+    bound: Bound<&T>,
+) -> bool {
+    let start = &StartBound(bound);
+    let end = &EndBound(bound);
+    let r_start = &StartBound(range.start_bound());
+    let r_end = &EndBound(range.end_bound());
+    log::info!(
+        "start: {start:?} <=> {r_start:?}: {:?} {:?}",
+        start.cmp(r_start),
+        r_start.cmp(start)
+    );
+    log::info!(
+        "end: {end:?} <=> {r_end:?}: {:?} {:?}",
+        end.cmp(r_end),
+        r_end.cmp(end)
+    );
+    (start.cmp(r_start).is_ge() || r_start.cmp(start).is_le())
+        && (end.cmp(r_end).is_ge() || r_end.cmp(end).is_le())
+}
+
+#[cfg(test)]
+mod bound_ord_tests {
+    use core::{cmp::Ordering, ops::RangeBounds};
+
+    use super::*;
+    use test_log::test;
+
+    #[test]
+    fn start_bound_ord() {
+        assert_eq!(
+            cmp_start_bound(&Bound::Unbounded, &Bound::Included(0)),
+            Some(Ordering::Less)
+        );
+        assert_eq!(
+            cmp_start_bound::<i32>(&Bound::Unbounded, &Bound::Unbounded),
+            Some(Ordering::Equal)
+        );
+        assert_eq!(
+            cmp_start_bound(&Bound::Included(0), &Bound::Included(0)),
+            Some(Ordering::Equal)
+        );
+        assert_eq!(
+            cmp_start_bound(&Bound::Excluded(0), &Bound::Included(0)),
+            Some(Ordering::Greater)
+        );
+        assert_ne!(
+            cmp_start_bound(&Bound::Excluded(0), &Bound::Included(1)),
+            Some(Ordering::Greater)
+        );
+        // This is actually WRONG and is why we have to test both ways because I
+        // can't think of a way to actually determine how the 2 bounds are
+        // ordered without knowing the smallest discrete step size of T.
+        //
+        // In this case technically they should be equal, but for floats (which
+        // arent ord anyways?) this would be wrong
+        assert_eq!(
+            cmp_start_bound(&Bound::Included(1), &Bound::Excluded(0)),
+            Some(Ordering::Greater)
+        );
+
+        assert_eq!(
+            cmp_start_bound(&Bound::Included(0), &Bound::Excluded(1)),
+            Some(Ordering::Less)
+        );
+    }
+
+    #[test]
+    fn end_bound_ord() {
+        assert_eq!(
+            cmp_end_bound::<i32>(&Bound::Unbounded, &Bound::Unbounded),
+            Some(Ordering::Equal)
+        );
+        assert_eq!(
+            cmp_end_bound(&Bound::Unbounded, &Bound::Included(0)),
+            Some(Ordering::Greater)
+        );
+        assert_eq!(
+            cmp_end_bound(&Bound::Included(0), &Bound::Included(0)),
+            Some(Ordering::Equal)
+        );
+        assert_eq!(
+            cmp_end_bound(&Bound::Excluded(0), &Bound::Included(0)),
+            Some(Ordering::Greater)
+        );
+        assert_ne!(
+            cmp_end_bound(&Bound::Excluded(0), &Bound::Included(1)),
+            Some(Ordering::Greater)
+        );
+        // This is actually WRONG and is why we have to test both ways because I
+        // can't think of a way to actually determine how the 2 bounds are
+        // ordered without knowing the smallest discrete step size of T.
+        //
+        // In this case technically they should be equal, but for floats (which
+        // arent ord anyways?) this would be wrong
+        assert_eq!(
+            cmp_end_bound(&Bound::Included(1), &Bound::Excluded(0)),
+            Some(Ordering::Greater)
+        );
+
+        assert_eq!(
+            cmp_end_bound(&Bound::Included(0), &Bound::Excluded(1)),
+            Some(Ordering::Less)
+        );
+    }
+
+    #[test]
+    fn test_bound_ord() {
+        let r1 = 0..4;
+        let r2 = 2..3;
+
+        assert_eq!(
+            cmp_start_bound(&r1.start_bound(), &r2.start_bound()),
+            Some(core::cmp::Ordering::Less)
+        );
+        assert_eq!(
+            cmp_end_bound(&r1.end_bound(), &r2.end_bound()),
+            Some(core::cmp::Ordering::Greater)
+        );
+
+        assert_eq!(
+            cmp_start_bound(&r2.start_bound(), &r1.start_bound()),
+            Some(core::cmp::Ordering::Greater)
+        );
+        assert_eq!(
+            cmp_end_bound(&r2.end_bound(), &r1.end_bound()),
+            Some(core::cmp::Ordering::Less)
+        );
+
+        let r1 = 0..=8;
+        let r2 = 0..9;
+
+        assert_eq!(
+            cmp_start_bound(&r1.start_bound(), &r2.start_bound()),
+            Some(core::cmp::Ordering::Equal)
+        );
+        assert_eq!(
+            cmp_end_bound(&r1.end_bound(), &r2.end_bound()),
+            Some(core::cmp::Ordering::Less)
+        );
+        assert_eq!(
+            cmp_end_bound(&r2.end_bound(), &r1.end_bound()),
+            Some(core::cmp::Ordering::Greater)
+        );
+    }
+}
+
+pub fn ranges_intersect<T, R1, R2>(rhs: R1, lhs: R2) -> ()
+where
+    T: Ord,
+    R1: core::ops::RangeBounds<T>,
+    R2: core::ops::RangeBounds<T>,
+{
+    let a = rhs.start_bound();
+    let b = rhs.end_bound();
+    let x = lhs.start_bound();
+    let y = lhs.end_bound();
+
+    // check that a <=> x is different than b <=> x
+
+    // a <=> x
+    match a {
+        Bound::Included(a) => match x {
+            Bound::Included(x) => a.partial_cmp(x),
+            Bound::Excluded(x) => match a.partial_cmp(x) {
+                Some(Ordering::Equal) => Some(Ordering::Less),
+                ord => ord,
+            },
+            Bound::Unbounded => Some(Ordering::Greater),
+        },
+        Bound::Excluded(a) => match x {
+            Bound::Included(x) => match a.partial_cmp(x) {
+                Some(Ordering::Equal) => Some(Ordering::Greater),
+                ord => ord,
+            },
+            Bound::Excluded(x) => a.partial_cmp(x),
+            Bound::Unbounded => Some(Ordering::Less),
+        },
+        Bound::Unbounded => match x {
+            Bound::Unbounded => Some(Ordering::Equal),
+            _ => Some(Ordering::Less),
+        },
+    };
+
+    todo!()
+}

btrfs/src/v2/volume.rs

@@ -1,4 +1,5 @@
 use core::mem::size_of;
+use core::ops::{Range, RangeBounds};
 
 use alloc::collections::btree_map::Entry;
 use alloc::{collections::BTreeMap, rc::Rc, vec, vec::Vec};
@@ -370,21 +371,30 @@ impl<R: super::Read> Fs<R> {
         }
     }
 
-    pub fn get_inode_children(&self, inode: &INode) -> Result<Vec<INode>> {
+    pub fn get_inode_children_inodes<'a>(
+        &self,
+        inode: &'a INode,
+    ) -> Result<impl Iterator<Item = INode> + 'a>
+    where
+        R: 'a,
+    {
+        self.get_inode_children(inode).map(|children| {
+            children.map(|child| {
+                let id: u64 = child.item().location.id().into();
+
+                inode.clone().into_child(id, child.into_name())
+            })
+        })
+    }
+
+    pub fn get_inode_children(&self, inode: &INode) -> Result<impl Iterator<Item = DirItemEntry>> {
         let key = PartialKey::new(Some(inode.id()), Some(ObjectType::DirIndex), None);
 
         let children = self.fs_root.find_range(&key)?;
 
-        let children = children
-            .map(|(_, v)| {
-                let dir_item = v.as_dir_index().expect("dir index");
-                let id: u64 = dir_item.item().location.id().into();
+        let a = children.map(|(_, v)| v.try_into_dir_index().expect("dir index"));
 
-                inode.clone().into_child(id, dir_item.name().clone())
-            })
-            .collect::<Vec<_>>();
-
-        Ok(children)
+        Ok(a)
     }
 
     pub fn get_inode_parent(&self, inode: &INode) -> Result<INode> {
@@ -420,14 +430,15 @@ impl<R: super::Read> Fs<R> {
                         inode = self.get_inode_parent(&inode)?;
                     }
                     crate::path::Segment::File(child_name) => {
-                        inode = self
-                            .get_inode_children(&inode)?
-                            .iter()
+                        let child = self
+                            .get_inode_children_inodes(&inode)?
                             .find(|child| {
                                 child.path.last().map(|bytes| bytes.as_slice()) == Some(child_name)
                             })
                             .ok_or(Error::INodeNotFound)?
-                            .clone()
+                            .clone();
+                        // silly borrow checker
+                        inode = child;
                     }
                     _ => unreachable!(),
                 }
@@ -496,7 +507,7 @@ impl<R: super::Read> Fs<R> {
         }
     }
 
-    fn get_inode_extents(&self, inode_id: u64) -> Result<Option<Vec<(u64, ExtentData)>>> {
+    fn get_inode_extents(&self, inode_id: u64) -> Result<Vec<(u64, ExtentData)>> {
         if let Some(dir_entry) = self.get_inode_dir_index(inode_id)? {
             if dir_entry.item().ty() == DirItemType::RegFile {
                 let key =
@@ -513,11 +524,81 @@ impl<R: super::Read> Fs<R> {
                     })
                     .collect::<Vec<_>>();
 
-                return Ok(Some(extents));
+                Ok(extents)
+            } else {
+                Ok(vec![])
+            }
+        } else {
+            Err(Error::INodeNotFound)
         }
     }
 
-        Ok(None)
+    fn read_inode_raw<I: RangeBounds<u64>>(&self, inode: &INode, range: I) -> Result<Vec<u8>> {
+        let mut contents = Vec::new();
+        let extents = self.get_inode_extents(inode.id)?;
+
+        let start = match range.start_bound() {
+            core::ops::Bound::Included(v) => *v,
+            core::ops::Bound::Excluded(v) => *v + 1,
+            core::ops::Bound::Unbounded => 0,
+        };
+
+        let end = match range.end_bound() {
+            core::ops::Bound::Included(v) => Some(*v + 1),
+            core::ops::Bound::Excluded(v) => Some(*v),
+            core::ops::Bound::Unbounded => None,
+        };
+
+        for (offset, extent) in extents.into_iter().filter(|(offset, extent)| {
+            let extent_start = *offset;
+            let extent_end = extent_start + extent.len();
+
+            let range_len = end.map(|end| end - start);
+
+            let start2 = start.min(extent_start);
+            let end = end.map(|end| end.max(extent_end));
+            let len = end.map(|end| (end - start2));
+
+            if let (Some(len), Some(range_len)) = (len, range_len) {
+                range_len + range_len < len
+            } else {
+                start2 < extent_end
+            }
+        }) {
+            //
+            let start = start.saturating_sub(offset);
+
+            let end = end.map(|end| end - offset);
+
+            log::info!("reading {}..{:?} from extent.", start, end);
+
+            let data: alloc::borrow::Cow<[u8]> = match &extent {
+                ExtentData::Inline { data, .. } => {
+                    // TODO: handle compression and encryption
+                    let data = if let Some(end) = end {
+                        &data[start as usize..end as usize]
+                    } else {
+                        &data[start as usize..]
+                    };
+
+                    data.into()
+                }
+                ExtentData::Other(extent) => {
+                    let address = extent.address() + extent.offset() + start;
+                    let data = self
+                        .volume
+                        .inner
+                        .read_range(address..address + end.unwrap_or(extent.num_bytes()))
+                        .expect("bytes");
+                    data.into()
+                }
+            };
+
+            log::info!("reading {} bytes from file", data.len());
+            contents.extend_from_slice(&data);
+        }
+
+        Ok(contents)
     }
 
     fn find_inode_ref(&self, inode_id: u64) -> Result<Option<(Item, INodeRefEntry)>> {
@@ -674,7 +755,6 @@ mod tests {
             log::info!("inode: {inode_item:#?}");
             let extents = fs.get_inode_extents(inode_id)?;
 
-            if let Some(extents) = extents {
             for (_, extent) in extents {
                 match extent {
                     ExtentData::Inline { header, data } => {
@@ -684,7 +764,6 @@ mod tests {
                 }
             }
         }
-        }
         log::info!("range: [end]");
 
         Ok(())
@@ -698,11 +777,11 @@ mod tests {
         let fs = v2.default_subvolume().expect("default subvol");
 
         let root_dir = fs.get_root_dir();
-        let children = fs.get_inode_children(&root_dir)?;
+        let children = fs.get_inode_children(&root_dir)?.collect::<Vec<_>>();
         log::info!("chidlren: {:?}", children);
 
         let home = fs.get_inode_by_path(b"/home/user")?;
-        let children = fs.get_inode_children(&home)?;
+        let children = fs.get_inode_children(&home)?.collect::<Vec<_>>();
         log::info!("chidlren: {:?}", children);
 
         let hii = fs.get_inode_by_path(b"/home/user/hii.txt")?;
@@ -711,7 +790,6 @@ mod tests {
         let extents = fs.get_inode_extents(hii.id)?;
         assert_eq!(hii, hii2);
 
-        if let Some(extents) = extents {
         for (_offset, extent) in extents {
             match extent {
                 ExtentData::Inline { header, data } => {
@@ -720,38 +798,22 @@ mod tests {
                 _ => {}
             }
         }
-        }
 
         let btrfs = fs.get_inode_by_path(b"/home/user/btrfs")?;
-        let children = fs.get_inode_children(&btrfs)?;
+        let children = fs.get_inode_children_inodes(&btrfs)?.collect::<Vec<_>>();
         log::info!("chidlren: {:?}", children);
 
-        let home = fs.get_inode_by_path(b"/home/user/btrfs/CMakeLists.txt")?;
-        let extents = fs.get_inode_extents(home.id)?;
+        for child in children {
+            let file_contents = fs.read_inode_raw(&child, ..).expect("file contents");
+            log::info!("{}", String::from_utf8_lossy(&file_contents));
+        }
 
-        if let Some(extents) = extents {
-            for (offset, extent) in extents {
-                log::info!("extent {:x}..", offset);
-                match extent {
-                    ExtentData::Inline { header, data } => {
-                        log::info!("{header:?}\n{}", String::from_utf8_lossy(&data));
-                    }
-                    ExtentData::Other(extent) => {
-                        let address = extent.address() + extent.offset();
-                        let data = fs
-                            .volume
-                            .inner
-                            .read_range(address..address + extent.num_bytes())
-                            .expect("bytes");
-                        log::info!(
-                            "{:?}\n{}",
-                            extent.extent_data1(),
-                            String::from_utf8_lossy(&data)
-                        );
-                    }
-                }
-            }
-        }
+        let cmake_list = fs.get_inode_by_path(b"/home/user/btrfs/CMakeLists.txt")?;
+        let file_contents = fs
+            .read_inode_raw(&cmake_list, ..100)
+            .expect("file contents");
+        log::info!("cmakelists file:");
+        log::info!("{}", String::from_utf8_lossy(&file_contents));
 
         Ok(())
     }