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-rw-r--r--src/memory/cached_block.rs201
-rw-r--r--src/memory/cached_inode.rs48
-rw-r--r--src/memory/mod.rs1
3 files changed, 208 insertions, 42 deletions
diff --git a/src/memory/cached_block.rs b/src/memory/cached_block.rs
index 0c401ff..9e266ef 100644
--- a/src/memory/cached_block.rs
+++ b/src/memory/cached_block.rs
@@ -1,7 +1,10 @@
-use and_then_some::BoolExt;
+use crate::block_device::{BlockDevice, BLOCK_SIZE};
+use crate::disk::block::Block;
use crate::AyaFS;
-use crate::block_device::BLOCK_SIZE;
-use crate::disk::data_block::{Block, DataBlock};
+use and_then_some::BoolExt;
+use lru::LruCache;
+use std::num::NonZeroUsize;
+use std::sync::Arc;
#[derive(Clone)]
pub struct CachedBlock<T: Block> {
@@ -28,39 +31,24 @@ pub fn convert<U: Block, T: Block>(input_block: &CachedBlock<U>) -> &CachedBlock
unsafe { &*block }
}
-impl AyaFS {
- pub(crate) fn update_block<T: Block>(&mut self, block: CachedBlock<T>) -> bool {
- if self.cached_blocks.contains(&block.index) {
- let data_block = convert::<T, DataBlock>(&block).clone();
- self.cached_blocks.push(block.index, data_block);
- true
- } else {
- false
- }
- }
- pub(crate) fn get_block<T: Block>(&mut self, index: usize) -> Option<&CachedBlock<T>> {
- self.load_block(index)
- .and_then(|| self.cached_blocks.get(&index).map(convert::<DataBlock, T>))
- }
+pub(crate) struct BlockCache<T: Block> {
+ device: Arc<dyn BlockDevice>,
+ cache: LruCache<usize, CachedBlock<T>>,
+}
- pub(crate) fn get_block_mut<T: Block>(&mut self, index: usize) -> Option<&mut CachedBlock<T>> {
- self.load_block(index).and_then(|| {
- self.cached_blocks
- .get_mut(&index)
- .map(convert_mut::<DataBlock, T>)
- })
+impl<T: Block> BlockCache<T> {
+ pub(crate) fn new(device: Arc<dyn BlockDevice>, cache_size: usize) -> Self {
+ Self {
+ device,
+ cache: LruCache::new(NonZeroUsize::new(cache_size).unwrap()),
+ }
}
pub(crate) fn load_block(&mut self, index: usize) -> bool {
- // 反正我自己保证所有实现了 Block trait 的数据结构都是 4K bytes 长, 来回 cast 没问题
- // 如果 block cache 里没有这个 block
- if self.cached_blocks.contains(&index) == false {
- if self.data_bitmap.query(index) == false {
- return false;
- } // 先看这个 block 是不是 valid, 不 valid 直接返回 None
- let block = DataBlock::default();
+ if self.cache.contains(&index) == false {
+ let block = T::default();
let buffer = unsafe {
- std::slice::from_raw_parts_mut(&block as *const DataBlock as *mut u8, BLOCK_SIZE)
+ std::slice::from_raw_parts_mut(&block as *const T as *mut u8, BLOCK_SIZE)
};
self.device.read(index, buffer);
let cached_block = CachedBlock {
@@ -68,17 +56,160 @@ impl AyaFS {
index,
dirty: false,
};
- if let Some((old_index, old_block)) = self.cached_blocks.push(index, cached_block) {
+ if let Some((old_index, old_block)) = self.cache.push(index, cached_block) {
assert_ne!(old_index, index); // 只有 block 不在 cache 里的时候才会插入
if old_block.dirty {
- let old_block_ptr = &old_block.block as *const DataBlock as *mut u8;
+ let old_block_ptr = &old_block.block as *const T as *mut u8;
let old_block_buffer =
unsafe { std::slice::from_raw_parts(old_block_ptr, BLOCK_SIZE) };
self.device.write(old_index, old_block_buffer);
}
- } // 如果 valid 就放到 block cache 里, 同时将（可能）被驱逐的 block 依据其是否为脏块进行写回
+ }
}
-
true
}
+
+ /// 从 LRU cache 里获取一个 block 的引用, 如果没有在 cache 中会加载.
+ pub(crate) fn get_block<U: Block>(&mut self, index: usize) -> Option<&CachedBlock<U>> {
+ self.load_block(index)
+ .and_then(|| self.cache.get(&index).map(convert::<T, U>))
+ }
+
+ /// 从 LRU cache 里获取一个 block 的可变引用, 如果没有在 cache 中会加载.
+ pub(crate) fn get_block_mut<U: Block>(&mut self, index: usize) -> Option<&mut CachedBlock<U>> {
+ self.load_block(index)
+ .and_then(|| self.cache.get_mut(&index).map(convert_mut::<T, U>))
+ }
+
+ /// 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.
+ pub(crate) fn peek_block<U: Block>(&self, index: usize) -> Option<&CachedBlock<U>> {
+ self.cache.peek(&index).map(convert::<T, U>)
+ }
+
+ /// 从 LRU cache 中读取一个 block 的可变引用, *不会* 影响 LRU cache 的结构, 如果没有在 cache 中不会加载.
+ pub(crate) fn peek_block_mut<U: Block>(&mut self, index: usize) -> Option<&mut CachedBlock<U>> {
+ self.cache.peek_mut(&index).map(convert_mut::<T, U>)
+ }
+
+ 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();
+ self.cache.push(block.index, data_block);
+ true
+ } else {
+ false
+ }
+ }
+
+ fn pop(&mut self, entry: &usize) -> Option<CachedBlock<T>> {
+ self.cache.pop(entry)
+ }
+}
+
+impl AyaFS {
+ pub(crate) fn load_block(&mut self, index: usize) -> bool {
+ if !self.data_bitmap.query(index) {
+ self.cached_blocks.pop(&index);
+ // deallocate 时只更新 bitmap 没有动 cache, lazy 地驱逐 cache 中的无效 entry.
+ return false;
+ }
+ self.cached_blocks.load_block(index)
+ }
+
+ 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))
+ }
+
+ 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))
+ }
+
+ 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))
+ }
+
+ 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))
+ }
+
+ pub(crate) fn update_block<T: Block>(&mut self, block: CachedBlock<T>) -> bool {
+ self.cached_blocks.update_block(block)
+ }
+
+ // pub(crate) fn update_block<T: Block>(&mut self, block: CachedBlock<T>) -> bool {
+ // if self.cached_blocks.contains(&block.index) {
+ // let data_block = convert::<T, DataBlock>(&block).clone();
+ // self.cached_blocks.push(block.index, data_block);
+ // true
+ // } else {
+ // false
+ // }
+ // }
+ //
+ // /// 从 LRU cache 里获取一个 block 的引用, 如果没有在 cache 中会加载.
+ // pub(crate) fn get_block<T: Block>(&mut self, index: usize) -> Option<&CachedBlock<T>> {
+ // self.load_block(index)
+ // .and_then(|| self.cached_blocks.get(&index).map(convert::<DataBlock, 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.
+ // pub(crate) fn get_block_mut<T: Block>(&mut self, index: usize) -> Option<&mut CachedBlock<T>> {
+ // self.load_block(index).and_then(|| {
+ // self.cached_blocks
+ // .get_mut(&index)
+ // .map(convert_mut::<DataBlock, T>)
+ // })
+ // }
+ //
+ // /// 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.
+ // pub(crate) fn peek_block<T: Block>(&self, index: usize) -> Option<&CachedBlock<T>> {
+ // self.cached_blocks.peek(&index).map(convert::<DataBlock, T>)
+ // }
+ //
+ // /// 从 LRU cache 中读取一个 block 的可变引用, *不会* 影响 LRU cache 的结构, 如果没有在 cache 中不会加载.
+ // pub(crate) fn peek_block_mut<T: Block>(&mut self, index: usize) -> Option<&mut CachedBlock<T>> {
+ // self.cached_blocks.peek_mut(&index).map(convert_mut::<DataBlock, T>)
+ // }
+ //
+ // pub(crate) fn load_block(&mut self, index: usize) -> bool {
+ // // 先看这个 block 是不是 valid, 不 valid 直接返回 false.
+ // if !self.data_bitmap.query(index) {
+ // self.cached_blocks.pop(&index);
+ // // deallocate 时只更新 bitmap 没有动 cache, lazy 地驱逐 cache 中的无效 entry.
+ // return false;
+ // }
+ //
+ // // 接下来这个 block 一定 valid. 如果 cache 里没有这个 block 就把它 load 到 cache 里
+ // if self.cached_blocks.contains(&index) == false {
+ // let block = DataBlock::default();
+ // let buffer = unsafe {
+ // std::slice::from_raw_parts_mut(&block as *const DataBlock as *mut u8, BLOCK_SIZE)
+ // };
+ // self.device.read(index, buffer);
+ // let cached_block = CachedBlock {
+ // block,
+ // index,
+ // dirty: false,
+ // };
+ // if let Some((old_index, old_block)) = self.cached_blocks.push(index, cached_block) {
+ // assert_ne!(old_index, index); // 只有 block 不在 cache 里的时候才会插入
+ // if old_block.dirty {
+ // let old_block_ptr = &old_block.block as *const DataBlock as *mut u8;
+ // let old_block_buffer =
+ // unsafe { std::slice::from_raw_parts(old_block_ptr, BLOCK_SIZE) };
+ // self.device.write(old_index, old_block_buffer);
+ // }
+ // }
+ // }
+ //
+ // true
+ // }
}
diff --git a/src/memory/cached_inode.rs b/src/memory/cached_inode.rs
index b51d279..b81bd2e 100644
--- a/src/memory/cached_inode.rs
+++ b/src/memory/cached_inode.rs
@@ -1,7 +1,7 @@
-use and_then_some::BoolExt;
+use crate::disk::block::{Block, InodeBlock};
+use crate::disk::inode::{Inode, InodeMode, INODE_SIZE};
use crate::AyaFS;
-use crate::disk::data_block::InodeBlock;
-use crate::disk::inode::{Inode, INODE_SIZE, InodeMode};
+use and_then_some::BoolExt;
impl AyaFS {
pub(crate) fn create_inode(
@@ -30,10 +30,24 @@ impl AyaFS {
})
}
+ pub(crate) fn update_inode(&mut self, inode_index: usize, inode: Inode) -> bool {
+ if self.inode_bitmap.query(inode_index) {
+ let (block_index, offset) = self.locate_inode(inode_index);
+ if let Some(cached_block) = self.cached_inodes.get_block_mut::<InodeBlock>(block_index)
+ {
+ cached_block.block.inodes[offset / INODE_SIZE] = inode;
+ }
+ true
+ } else {
+ false
+ }
+ }
+
pub(crate) fn get_inode(&mut self, inode_index: usize) -> Option<&Inode> {
self.inode_bitmap.query(inode_index).and_then(|| {
let (block_index, offset) = self.locate_inode(inode_index);
- self.get_block::<InodeBlock>(block_index)
+ self.cached_inodes
+ .get_block::<InodeBlock>(block_index)
.map(|cached_block| &cached_block.block.inodes[offset / INODE_SIZE])
})
}
@@ -41,11 +55,33 @@ impl AyaFS {
pub(crate) fn get_inode_mut(&mut self, inode_index: usize) -> Option<&mut Inode> {
self.inode_bitmap.query(inode_index).and_then(|| {
let (block_index, offset) = self.locate_inode(inode_index);
- self.get_block_mut::<InodeBlock>(block_index)
+ self.cached_inodes
+ .get_block_mut::<InodeBlock>(block_index)
+ .map(|cached_block| {
+ cached_block.dirty = true; // 保守一些, 只要返回了 &mut Inode 这个页一定标记为脏
+ &mut cached_block.block.inodes[offset / INODE_SIZE]
+ })
+ })
+ }
+
+ pub(crate) fn peek_inode(&self, inode_index: usize) -> Option<&Inode> {
+ self.inode_bitmap.query(inode_index).and_then(|| {
+ let (block_index, offset) = self.locate_inode(inode_index);
+ self.cached_inodes
+ .peek_block::<InodeBlock>(block_index)
+ .map(|cached_block| &cached_block.block.inodes[offset / INODE_SIZE])
+ })
+ }
+
+ pub(crate) fn peek_inode_mut(&mut self, inode_index: usize) -> Option<&mut Inode> {
+ self.inode_bitmap.query(inode_index).and_then(|| {
+ let (block_index, offset) = self.locate_inode(inode_index);
+ self.cached_inodes
+ .peek_block_mut::<InodeBlock>(block_index)
.map(|cached_block| {
cached_block.dirty = true; // 保守一些, 只要返回了 &mut Inode 这个页一定标记为脏
&mut cached_block.block.inodes[offset / INODE_SIZE]
})
})
}
-} \ No newline at end of file
+}
diff --git a/src/memory/mod.rs b/src/memory/mod.rs
index ffdf04c..3380d0f 100644
--- a/src/memory/mod.rs
+++ b/src/memory/mod.rs
@@ -1,5 +1,4 @@
/// In-memory data structures and logic.
/// This is where the crucial block and inode methods presented to upper calls implemented.
-
pub mod cached_block;
pub mod cached_inode;
generated by cgit v1.2.3-70-g09d2 (git 2.46.2) at 2024-10-16 18:51:06 +0000