From 95d8d84eef645b52d92fd3fb8fdea7aed1f6d474 Mon Sep 17 00:00:00 2001
From: Chuyan Zhang <me@zcy.moe>
Date: Fri, 17 Nov 2023 11:40:33 -0800
Subject: Layer 1 incomplete

---
 src/disk/data_block.rs | 94 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)
 create mode 100644 src/disk/data_block.rs

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

diff --git a/src/disk/data_block.rs b/src/disk/data_block.rs
new file mode 100644
index 0000000..2160b91
--- /dev/null
+++ b/src/disk/data_block.rs
@@ -0,0 +1,94 @@
+pub trait Block: Default {}
+
+#[derive(Default)]
+pub struct DataBlock([u8; 4096]);
+impl Block for DataBlock {}
+
+const FULL_MAP: u32 = 0b111_111_111_111_111;
+
+#[derive(Default)]
+pub struct DirectoryBlock {
+    entries: [[u8; 256]; 15],
+    inode_ids: [usize; 15],
+    occupancy_map: u32,
+    reserved: [u8; 132],
+}
+
+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!()
+    }
+
+    /// 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
+        }
+    }
+}
+
+#[derive(Default)]
+pub struct IndirectBlock {
+    pub entries: [u32; 1024],
+}
+
+impl Block for IndirectBlock {}
+
+impl IndirectBlock {
+    pub fn full(&self) -> bool {
+        todo!()
+    }
+
+    pub fn allocate(&mut self) -> Option<usize> {
+        todo!()
+    }
+}
+
+#[derive(Default)]
+pub struct DoubleIndirectBlock {
+    pub indirect: [u32; 1024],
+}
+
+impl Block for DoubleIndirectBlock {}
+
+impl DoubleIndirectBlock {
+    pub fn full(&self) -> bool {
+        todo!()
+    }
+
+    pub fn allocate(&mut self) -> Option<usize> {
+        todo!()
+    }
+}
+
+#[derive(Default)]
+pub struct TripleIndirectBlock {
+    pub double_indirect: [u32; 1024],
+}
+
+impl Block for TripleIndirectBlock {}
+
+impl TripleIndirectBlock {
+    pub fn full(&self) -> bool {
+        todo!()
+    }
+
+    pub fn allocate(&mut self) -> Option<usize> {
+        todo!()
+    }
+}
-- 
cgit v1.2.3-70-g09d2