44 lines
1.3 KiB
Rust
44 lines
1.3 KiB
Rust
use super::{
|
|
BlockDevice,
|
|
BLOCK_SZ,
|
|
BlockCache,
|
|
get_block_cache,
|
|
};
|
|
use alloc::sync::Arc;
|
|
use core::marker::PhantomData;
|
|
|
|
pub struct Dirty<T> {
|
|
block_cache: Arc<BlockCache>,
|
|
offset: usize,
|
|
phantom: PhantomData<T>,
|
|
}
|
|
|
|
impl<T> Dirty<T> where T: Sized {
|
|
pub fn new(block_id: usize, offset: usize, block_device: Arc<dyn BlockDevice>) -> Self {
|
|
Self {
|
|
block_cache: get_block_cache(block_id, block_device.clone()),
|
|
offset,
|
|
phantom: PhantomData,
|
|
}
|
|
}
|
|
pub fn get_mut(&mut self) -> &mut T {
|
|
let type_size = core::mem::size_of::<T>();
|
|
// assert that the struct is inside a block
|
|
assert!(self.offset + type_size <= BLOCK_SZ);
|
|
let start_addr = self.block_cache.start_addr(self.offset);
|
|
unsafe { &mut *(start_addr as *mut T) }
|
|
}
|
|
pub fn get_ref(&self) -> &T {
|
|
let type_size = core::mem::size_of::<T>();
|
|
// assert that the struct is inside a block
|
|
assert!(self.offset + type_size <= BLOCK_SZ);
|
|
let start_addr = self.block_cache.start_addr(self.offset);
|
|
unsafe { &*(start_addr as *const T) }
|
|
}
|
|
pub fn read<V>(&self, f: impl FnOnce(&T) -> V) -> V {
|
|
f(self.get_ref())
|
|
}
|
|
pub fn modify<V>(&mut self, f: impl FnOnce(&mut T) -> V) -> V {
|
|
f(self.get_mut())
|
|
}
|
|
}
|