Remove DirentBytes

Author: wyfcyx

easy-fs/src/layout.rs

@@ -407,10 +407,13 @@ pub struct DirEntry {
 
 pub const DIRENT_SZ: usize = 32;
 
-//pub type DirentBlock = [DirEntry; BLOCK_SZ / DIRENT_SZ];
-pub type DirentBytes = [u8; DIRENT_SZ];
-
 impl DirEntry {
+    pub fn empty() -> Self {
+        Self {
+            name: [0u8; NAME_LENGTH_LIMIT + 1],
+            inode_number: 0,
+        }
+    }
     pub fn new(name: &str, inode_number: u32) -> Self {
         let mut bytes = [0u8; NAME_LENGTH_LIMIT + 1];
         &mut bytes[..name.len()].copy_from_slice(name.as_bytes());
@@ -419,18 +422,20 @@ impl DirEntry {
             inode_number,
         }
     }
-    pub fn into_bytes(&self) -> &DirentBytes {
+    pub fn as_bytes(&self) -> &[u8] {
         unsafe {
-            &*(self as *const Self as usize as *const DirentBytes)
+            core::slice::from_raw_parts(
+                self as *const _ as usize as *const u8,
+                DIRENT_SZ,
+            )
         }
     }
-    pub fn from_bytes(bytes: &DirentBytes) -> &Self {
-        unsafe { &*(bytes.as_ptr() as usize as *const Self) }
-    }
-    #[allow(unused)]
-    pub fn from_bytes_mut(bytes: &mut DirentBytes) -> &mut Self {
+    pub fn as_bytes_mut(&mut self) -> &mut [u8] {
         unsafe {
-            &mut *(bytes.as_mut_ptr() as usize as *mut Self)
+            core::slice::from_raw_parts_mut(
+                self as *mut _ as usize as *mut u8,
+                DIRENT_SZ,
+            )
         }
     }
     pub fn name(&self) -> &str {

easy-fs/src/vfs.rs

@@ -3,7 +3,6 @@ use super::{
     DiskInode,
     DiskInodeType,
     DirEntry,
-    DirentBytes,
     EasyFileSystem,
     DIRENT_SZ,
     get_block_cache,
@@ -63,17 +62,16 @@ impl Inode {
         // assert it is a directory
         assert!(disk_inode.is_dir());
         let file_count = (disk_inode.size as usize) / DIRENT_SZ;
-        let mut dirent_space: DirentBytes = Default::default();
+        let mut dirent = DirEntry::empty();
         for i in 0..file_count {
             assert_eq!(
                 disk_inode.read_at(
                     DIRENT_SZ * i,
-                    &mut dirent_space,
+                    dirent.as_bytes_mut(),
                     &self.block_device,
                 ),
                 DIRENT_SZ,
             );
-            let dirent = DirEntry::from_bytes(&dirent_space);
             if dirent.name() == name {
                 return Some(dirent.inode_number() as u32);
             }
@@ -144,7 +142,7 @@ impl Inode {
             let dirent = DirEntry::new(name, new_inode_id);
             root_inode.write_at(
                 file_count * DIRENT_SZ,
-                dirent.into_bytes(),
+                dirent.as_bytes(),
                 &self.block_device,
             );
         });
@@ -164,16 +162,16 @@ impl Inode {
             let file_count = (disk_inode.size as usize) / DIRENT_SZ;
             let mut v: Vec<String> = Vec::new();
             for i in 0..file_count {
-                let mut dirent_bytes: DirentBytes = Default::default();
+                let mut dirent = DirEntry::empty();
                 assert_eq!(
                     disk_inode.read_at(
                         i * DIRENT_SZ,
-                        &mut dirent_bytes,
+                        dirent.as_bytes_mut(),
                         &self.block_device,
                     ),
                     DIRENT_SZ,
                 );
-                v.push(String::from(DirEntry::from_bytes(&dirent_bytes).name()));
+                v.push(String::from(dirent.name()));
             }
             v
         })