add prefix tree map to search for mount points

Signed-off-by: Julien CLEMENT <julien.clement@epita.fr>

src/drivers/atapi/mod.rs

@@ -58,7 +58,8 @@ static ATAPI_SIG: [u8; 4] = [
 ];
 
 lazy_static! {
-    pub static ref DRIVE: AsyncMutex<Option<ATABus>> = AsyncMutex::new(ATABus::discover_atapi_drive());
+    pub static ref DRIVE: AsyncMutex<Option<ATABus>> =
+        AsyncMutex::new(ATABus::discover_atapi_drive());
 }
 
 pub async fn init() {
@@ -328,4 +329,4 @@ pub async fn print_block(lba: u32) {
 
 pub async fn read_block(lba: u32) -> [u8; CD_SECTOR_SIZE] {
     DRIVE.lock().await.as_mut().unwrap().read_block(lba).await
-}
+}

src/fd/mod.rs

@@ -37,10 +37,7 @@ impl FDTable {
 
     pub fn unregister_fd(&mut self, fd: &dyn FileDescriptor) {
         self.table.remove(&fd.get_fd());
-        println!(
-            "Unregistered fd: {:?}",
-            fd.get_fd()
-        );
+        println!("Unregistered fd: {:?}", fd.get_fd());
     }
 
     pub fn register_fd(&mut self, fd: FDt) {

src/fs/iso/fd.rs

@@ -11,7 +11,7 @@ pub struct IsoFD {
     pub fd: FDId,
     offset: u32,
     lba: u32,
-    size: u32
+    size: u32,
 }
 
 impl IsoFD {

src/fs/iso/iso9660.rs

@@ -77,7 +77,7 @@ impl IsoDir {
     #[allow(unaligned_references)]
     pub fn get_idf(&self) -> &[u8] {
         let mut len: usize = self.idf_len as usize;
-        unsafe { 
+        unsafe {
             let mut idf = core::slice::from_raw_parts(self.idf.as_ptr(), len as usize);
             if len > 2 && idf[len - 2] == b';' && idf[len - 1] == b'1' {
                 len -= 2;

src/fs/iso/mod.rs

@@ -2,7 +2,7 @@ mod fd;
 pub mod iso9660;
 
 use crate::drivers::atapi::read_block;
-use crate::fd::{FDt};
+use crate::fd::FDt;
 use crate::utils::unserialize;
 
 use super::FileSystem;
@@ -31,20 +31,18 @@ impl FileSystem for IsoFS {
         }
 
         let root: &IsoDir = &voldesc.root_dir;
-        let mut curr_entry_block: [u8; iso9660::ISO_BLOCK_SIZE as usize] = read_block(root.data_blk.le).await;
+        let mut curr_entry_block: [u8; iso9660::ISO_BLOCK_SIZE as usize] =
+            read_block(root.data_blk.le).await;
 
         let mut curr_entry: &IsoDir = unserialize(curr_entry_block.as_ptr());
 
         let path_s: String = String::from(path);
         let path_split: Vec<&str> = path_s.split("/").collect();
-        let path_it = path_s
-            .split("/")
-            .filter(|p| p != &"");
+        let path_it = path_s.split("/").filter(|p| p != &"");
 
         for path_component in path_it {
             let mut found = false;
             while curr_entry.idf_len != 0 {
-
                 // Found entry
                 if curr_entry.matches(path_component) {
                     found = true;
@@ -76,7 +74,6 @@ impl FileSystem for IsoFS {
     }
 }
 
-
 pub async fn get_prim_vol_desc() -> IsoPrimVolDesc {
     let desc_block = read_block(iso9660::ISO_PRIM_VOLDESC_BLOCK).await;
     *unserialize::<IsoPrimVolDesc>(desc_block.as_ptr())

src/fs/mod.rs

@@ -3,10 +3,11 @@ pub mod iso;
 use crate::fd::FDt;
 use crate::utils::mutex::AsyncMutex;
 
-use alloc::{boxed::Box, sync::Arc};
+use alloc::{boxed::Box, string::String, sync::Arc, vec::Vec};
 use async_trait::async_trait;
 use core::cell::RefCell;
 use lazy_static::lazy_static;
+use prefix_tree_map::{PrefixTreeMap, PrefixTreeMapBuilder};
 
 pub type FSt = Arc<RefCell<dyn FileSystem>>;
 
@@ -20,20 +21,57 @@ pub trait FileSystem {
 }
 
 pub struct VirtualFS {
-    fs: FSt,
+    map_builder: PrefixTreeMapBuilder<String, String, FSt>,
+    map: Option<PrefixTreeMap<String, String, FSt>>,
 }
 
 impl VirtualFS {
     fn new() -> Self {
-        VirtualFS {
-            fs: Arc::new(RefCell::new(iso::IsoFS {})),
-        }
+        let mut res = VirtualFS {
+            map_builder: PrefixTreeMapBuilder::new(),
+            map: None,
+        };
+        let fs = Arc::new(RefCell::new(iso::IsoFS {}));
+        let fs2 = Arc::new(RefCell::new(iso::IsoFS {}));
+        res.mount("/", fs);
+        res.mount("/mnt/iso", fs2);
+        res
+    }
+
+    fn mount(&mut self, path: &str, fs: FSt) {
+        let path_s: String = String::from(path);
+        self.map_builder.insert_exact(
+            path_s
+                .split("/")
+                .filter(|p| p != &"")
+                .map(|s| String::from(s)),
+            fs,
+        );
+        self.map = Some(self.map_builder.clone().build());
     }
 }
 
 #[async_trait(?Send)]
 impl FileSystem for VirtualFS {
     async fn open(&mut self, path: &str, flags: u32) -> Option<FDt> {
-        self.fs.borrow_mut().open(path, flags).await
+        if let Some(map) = &self.map {
+            let path_s: String = String::from(path);
+            let mut path_split: Vec<String> = path_s
+                .split("/")
+                .filter(|p| p != &"")
+                .map(|s| String::from(s))
+                .collect();
+            loop {
+                if let Some(fs) = map.find_exact(&path_split) {
+                    // TODO, remove path prefix of the mount point
+                    return fs.borrow_mut().open(path, flags).await;
+                }
+                else {
+                    path_split.truncate(path_split.len() - 1);
+                }
+            }
+        } else {
+            None
+        }
     }
 }

src/utils/mod.rs

@@ -16,4 +16,4 @@ pub fn ref_raw_offset<T>(r: &T, off: isize) -> &T {
     unsafe {
         return &*ref_ptr.cast::<u8>().offset(off).cast::<T>();
     }
-}
+}