From 777d5e01a34b8ebe6f1a5751b593266f93e88499 Mon Sep 17 00:00:00 2001
From: Chuyan Zhang <me@zcy.moe>
Date: Sat, 25 Nov 2023 19:36:31 -0800
Subject: Add dir entry operations

---
 src/memory/cached_block.rs | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

(limited to 'src/memory/cached_block.rs')

diff --git a/src/memory/cached_block.rs b/src/memory/cached_block.rs
index 77cdf61..783e987 100644
--- a/src/memory/cached_block.rs
+++ b/src/memory/cached_block.rs
@@ -70,6 +70,7 @@ impl<T: Block> BlockCache<T> {
     }
 
     /// 从 LRU cache 里获取一个 block 的引用, 如果没有在 cache 中会加载.
+    /// 这个函数不应该返回 None
     pub(crate) fn get_block<U: Block>(&mut self, index: usize) -> Option<&CachedBlock<U>> {
         if !self.cache.contains(&index) {
             self.load_block(index);
@@ -78,11 +79,15 @@ impl<T: Block> BlockCache<T> {
     }
 
     /// 从 LRU cache 里获取一个 block 的可变引用, 如果没有在 cache 中会加载.
+    /// 这个函数不应该返回 None
     pub(crate) fn get_block_mut<U: Block>(&mut self, index: usize) -> Option<&mut CachedBlock<U>> {
         if !self.cache.contains(&index) {
             self.load_block(index);
         }
-        self.cache.get_mut(&index).map(convert_mut::<T, U>)
+        self.cache.get_mut(&index).map(|block| {
+            block.dirty = true;
+            convert_mut::<T, U>(block)
+        })
     }
 
     /// 从 LRU cache 中读取一个 block 的引用, *不会* 影响 LRU cache 的结构, 如果没有在 cache 中不会加载.
@@ -97,7 +102,8 @@ impl<T: Block> BlockCache<T> {
 
     pub(crate) fn update_block<U: Block>(&mut self, block: CachedBlock<U>) -> bool {
         if self.cache.contains(&block.index) {
-            let data_block = convert::<U, T>(&block).clone();
+            let mut data_block = convert::<U, T>(&block).clone();
+            data_block.dirty = true; // TODO 需要把显式写回的都标记为 dirty 吗
             self.cache.push(block.index, data_block);
             true
         } else {
@@ -123,25 +129,29 @@ impl AyaFS {
     pub(crate) fn get_block<T: Block>(&mut self, index: usize) -> Option<&CachedBlock<T>> {
         self.data_bitmap
             .query(index)
-            .and_then(|| self.cached_blocks.get_block::<T>(index))
+            .then(|| self.cached_blocks.get_block::<T>(index).unwrap())
+        // 返回 None 当且仅当 data_bitmap 中这个 block 为 invalid
     }
 
     pub(crate) fn get_block_mut<T: Block>(&mut self, index: usize) -> Option<&mut CachedBlock<T>> {
         self.data_bitmap
             .query(index)
-            .and_then(|| self.cached_blocks.get_block_mut::<T>(index))
+            .then(|| self.cached_blocks.get_block_mut::<T>(index).unwrap())
+        // 返回 None 当且仅当 data_bitmap 中这个 block 为 invalid
     }
 
     pub(crate) fn peek_block<T: Block>(&self, index: usize) -> Option<&CachedBlock<T>> {
         self.data_bitmap
             .query(index)
-            .and_then(|| self.cached_blocks.peek_block::<T>(index))
+            .then(|| self.cached_blocks.peek_block::<T>(index).unwrap())
+        // 返回 None 当且仅当 data_bitmap 中这个 block 为 invalid
     }
 
     pub(crate) fn peek_block_mut<T: Block>(&mut self, index: usize) -> Option<&mut CachedBlock<T>> {
         self.data_bitmap
             .query(index)
-            .and_then(|| self.cached_blocks.peek_block_mut::<T>(index))
+            .then(|| self.cached_blocks.peek_block_mut::<T>(index).unwrap())
+        // 返回 None 当且仅当 data_bitmap 中这个 block 为 invalid
     }
 
     pub(crate) fn update_block<T: Block>(&mut self, block: CachedBlock<T>) -> bool {
-- 
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