From 76ac602c3d79bb39c133c81a38425a77bc0b8b1f Mon Sep 17 00:00:00 2001
From: Chuyan Zhang <me@zcy.moe>
Date: Sat, 25 Nov 2023 02:13:22 -0800
Subject: Some FUSE callbacks, some POSIX interface implementation

---
 src/disk/block.rs | 119 +++++++++++++++++++++++++-----------------------------
 1 file changed, 56 insertions(+), 63 deletions(-)

(limited to 'src/disk/block.rs')

diff --git a/src/disk/block.rs b/src/disk/block.rs
index d287ee6..0058b3e 100644
--- a/src/disk/block.rs
+++ b/src/disk/block.rs
@@ -1,7 +1,10 @@
 use crate::disk::inode::Inode;
+use std::ffi::{OsStr, OsString};
+use std::os::unix::ffi::OsStrExt;
 
 pub trait Block: Default + Clone {}
 
+#[repr(C)]
 #[derive(Clone)]
 pub struct DataBlock(pub(crate) [u8; 4096]);
 
@@ -13,6 +16,7 @@ impl Default for DataBlock {
 
 impl Block for DataBlock {}
 
+#[repr(C)]
 #[derive(Clone)]
 pub struct InodeBlock {
     pub(crate) inodes: [Inode; 16],
@@ -47,53 +51,70 @@ impl Block for InodeBlock {}
 
 const FULL_MAP: u32 = 0b111_111_111_111_111;
 
+#[repr(C)]
 #[derive(Clone)]
-pub struct DirectoryBlock {
-    entries: [[u8; 256]; 15],
-    inode_ids: [usize; 15],
-    occupancy_map: u32,
-    reserved: [u8; 132],
+pub struct DirectoryEntry {
+    pub inode: u32,
+    pub record_len: u16,
+    pub name_len: u8,
+    pub file_type: u8,
+    pub name: [u8; 256],
 }
 
-impl Default for DirectoryBlock {
+impl DirectoryEntry {
+    pub(crate) fn name(&self) -> OsString {
+        let name = &self.name[0..self.name_len as usize];
+        OsStr::from_bytes(name).to_os_string()
+    }
+}
+
+impl Default for DirectoryEntry {
     fn default() -> Self {
         Self {
-            entries: [[0; 256]; 15],
-            inode_ids: [0; 15],
-            occupancy_map: 0,
-            reserved: [0xFF; 132],
+            inode: 0,
+            record_len: 0,
+            name_len: 0,
+            file_type: 0x0,
+            name: [0; 256],
         }
     }
 }
 
-impl Block for DirectoryBlock {}
-
-impl DirectoryBlock {
-    fn vacant(&self) -> bool {
-        self.occupancy_map & FULL_MAP != FULL_MAP
-    }
-
-    fn first_free(&self) -> Option<usize> {
-        todo!()
-    }
-
-    fn mark_busy(&mut self, entry_id: usize) {
-        todo!()
-    }
+#[repr(C)]
+#[derive(Clone)]
+pub struct DirectoryBlock {
+    pub entries: [DirectoryEntry; 15],
+    reserved: [u8; 136],
+}
 
-    /// 需要判断 entry_name.len() <= 255
-    pub fn write_entry(&mut self, entry_name: &[u8], entry_inode_id: usize) -> Option<usize> {
-        if let Some(entry_id) = self.first_free() {
-            self.mark_busy(entry_id);
-            self.entries[entry_id].copy_from_slice(entry_name);
-            self.inode_ids[entry_id] = entry_inode_id;
-            Some(entry_id)
-        } else {
-            None
+impl Default for DirectoryBlock {
+    fn default() -> Self {
+        Self {
+            entries: [
+                DirectoryEntry::default(),
+                DirectoryEntry::default(),
+                DirectoryEntry::default(),
+                DirectoryEntry::default(),
+                DirectoryEntry::default(),
+                DirectoryEntry::default(),
+                DirectoryEntry::default(),
+                DirectoryEntry::default(),
+                DirectoryEntry::default(),
+                DirectoryEntry::default(),
+                DirectoryEntry::default(),
+                DirectoryEntry::default(),
+                DirectoryEntry::default(),
+                DirectoryEntry::default(),
+                DirectoryEntry::default(),
+            ],
+            reserved: [0xFF; 136],
         }
     }
 }
 
+impl Block for DirectoryBlock {}
+
+#[repr(C)]
 #[derive(Clone)]
 pub struct IndirectBlock {
     pub entries: [u32; 1024],
@@ -107,16 +128,7 @@ impl Default for IndirectBlock {
 
 impl Block for IndirectBlock {}
 
-impl IndirectBlock {
-    pub fn full(&self) -> bool {
-        todo!()
-    }
-
-    pub fn allocate(&mut self) -> Option<usize> {
-        todo!()
-    }
-}
-
+#[repr(C)]
 #[derive(Clone)]
 pub struct DoubleIndirectBlock {
     pub indirect: [u32; 1024],
@@ -132,16 +144,7 @@ impl Default for DoubleIndirectBlock {
 
 impl Block for DoubleIndirectBlock {}
 
-impl DoubleIndirectBlock {
-    pub fn full(&self) -> bool {
-        todo!()
-    }
-
-    pub fn allocate(&mut self) -> Option<usize> {
-        todo!()
-    }
-}
-
+#[repr(C)]
 #[derive(Clone)]
 pub struct TripleIndirectBlock {
     pub double_indirect: [u32; 1024],
@@ -156,13 +159,3 @@ impl Default for TripleIndirectBlock {
 }
 
 impl Block for TripleIndirectBlock {}
-
-impl TripleIndirectBlock {
-    pub fn full(&self) -> bool {
-        todo!()
-    }
-
-    pub fn allocate(&mut self) -> Option<usize> {
-        todo!()
-    }
-}
-- 
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