Cleanup, add node and header commands

src/node.rs

@@ -1,5 +1,4 @@
-use core::{mem, slice};
-use core::ops::{Deref, DerefMut};
+use core::{fmt, mem, ops, slice, str};
 
 use super::Extent;
 
@@ -7,19 +6,42 @@ use super::Extent;
 #[repr(packed)]
 pub struct Node {
     pub name: [u8; 256],
-    pub extents: [Extent; 16],
+    pub mode: u64,
+    pub next: u64,
+    pub extents: [Extent; 15],
 }
 
 impl Node {
-    pub fn new() -> Node {
+    pub fn default() -> Node {
         Node {
             name: [0; 256],
-            extents: [Extent::default(); 16]
+            mode: 0,
+            next: 0,
+            extents: [Extent::default(); 15]
         }
     }
+
+    pub fn name(&self) -> Result<&str, str::Utf8Error> {
+        let mut len = 0;
+
+        for &b in self.name.iter() {
+            if b == 0 {
+                break;
+            }
+            len += 1;
+        }
+
+        str::from_utf8(&self.name[..len])
+    }
 }
 
-impl Deref for Node {
+impl fmt::Debug for Node {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "Node {{ name: {:?}, mode: {:?}, next: {:?}, extents: {:?} }}", self.name(), self.mode, self.next, self.extents)
+    }
+}
+
+impl ops::Deref for Node {
     type Target = [u8];
     fn deref(&self) -> &[u8] {
         unsafe {
@@ -28,10 +50,15 @@ impl Deref for Node {
     }
 }
 
-impl DerefMut for Node {
+impl ops::DerefMut for Node {
     fn deref_mut(&mut self) -> &mut [u8] {
         unsafe {
             slice::from_raw_parts_mut(self as *mut Node as *mut u8, mem::size_of::<Node>()) as &mut [u8]
         }
     }
 }
+
+#[test]
+fn node_size_test(){
+    assert!(mem::size_of::<Node>() <= 512);
+}