feat(ida): IDA内部改为使用XArray实现 (#934)

目前可以记录哪些ID已经分配,支持了ID释放的功能.

Signed-off-by: longjin <longjin@DragonOS.org>

kernel/crates/ida/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "ida"
+version = "0.1.0"
+edition = "2021"
+authors = ["longjin <longjin@dragonos.org>"]
+description = "一个基于XArray的ID分配器"
+
+[dependencies]
+kdepends = { path = "../kdepends" }

kernel/crates/ida/README.md

@@ -0,0 +1,3 @@
+# IDA
+
+一个基于XArray的ID分配器

kernel/crates/ida/src/lib.rs

@@ -0,0 +1,210 @@
+#![no_std]
+#![feature(core_intrinsics)]
+#![allow(internal_features)]
+#![allow(clippy::needless_return)]
+
+#[cfg(test)]
+#[macro_use]
+extern crate std;
+
+use core::cmp::min;
+use core::intrinsics::unlikely;
+use core::marker::PhantomData;
+use core::ops::Deref;
+
+struct EmptyIdaItemRef<'a> {
+    _marker: PhantomData<&'a EmptyIdaItem>,
+}
+
+impl<'a> Deref for EmptyIdaItemRef<'a> {
+    type Target = EmptyIdaItem;
+
+    fn deref(&self) -> &Self::Target {
+        &EmptyIdaItem
+    }
+}
+
+struct EmptyIdaItem;
+
+unsafe impl kdepends::xarray::ItemEntry for EmptyIdaItem {
+    type Ref<'a> = EmptyIdaItemRef<'a> where Self: 'a;
+
+    fn into_raw(self) -> *const () {
+        core::ptr::null()
+    }
+
+    unsafe fn from_raw(_raw: *const ()) -> Self {
+        EmptyIdaItem
+    }
+
+    unsafe fn raw_as_ref<'a>(_raw: *const ()) -> Self::Ref<'a> {
+        EmptyIdaItemRef {
+            _marker: PhantomData,
+        }
+    }
+}
+/// id分配器
+pub struct IdAllocator {
+    current_id: usize,
+    min_id: usize,
+    max_id: usize,
+    used: usize,
+    xarray: kdepends::xarray::XArray<EmptyIdaItem>,
+}
+
+impl IdAllocator {
+    /// 创建一个新的id分配器
+    pub const fn new(initial_id: usize, max_id: usize) -> Option<Self> {
+        if initial_id >= max_id {
+            return None;
+        }
+        Some(Self {
+            current_id: initial_id,
+            min_id: initial_id,
+            max_id,
+            used: 0,
+            xarray: kdepends::xarray::XArray::new(),
+        })
+    }
+
+    /// 可用的id数量
+    #[inline]
+    pub fn available(&self) -> usize {
+        self.max_id - self.min_id - self.used
+    }
+
+    /// 分配一个新的id
+    ///
+    /// ## 返回
+    ///
+    /// 如果分配成功，返回Some(id)，否则返回None
+    pub fn alloc(&mut self) -> Option<usize> {
+        if unlikely(self.available() == 0) {
+            return None;
+        }
+
+        if let Some(try1) = self.do_find_first_free_index(self.current_id, self.max_id) {
+            self.current_id = try1;
+            self.xarray.store(try1 as u64, EmptyIdaItem);
+            self.used += 1;
+            return Some(try1);
+        }
+
+        // 从头开始找
+        if let Some(try2) =
+            self.do_find_first_free_index(self.min_id, min(self.current_id, self.max_id))
+        {
+            self.current_id = try2;
+            self.xarray.store(try2 as u64, EmptyIdaItem);
+            self.used += 1;
+            return Some(try2);
+        }
+        return None;
+    }
+
+    /// 检查id是否存在
+    ///
+    /// ## 参数
+    ///
+    /// - `id`：要检查的id
+    ///
+    /// ## 返回
+    ///
+    /// 如果id存在，返回true，否则返回false
+    pub fn exists(&self, id: usize) -> bool {
+        if id < self.min_id || id >= self.max_id {
+            return false;
+        }
+        self.xarray.load(id as u64).is_some()
+    }
+
+    fn do_find_first_free_index(&self, start_id: usize, end: usize) -> Option<usize> {
+        (start_id..end).find(|&i| !self.exists(i))
+    }
+
+    /// 释放一个id
+    ///
+    /// ## 参数
+    ///
+    /// - `id`：要释放的id
+    pub fn free(&mut self, id: usize) {
+        if id < self.min_id || id >= self.max_id {
+            return;
+        }
+        if self.xarray.remove(id as u64).is_some() {
+            self.used -= 1;
+        }
+    }
+
+    /// 返回已经使用的id数量
+    pub fn used(&self) -> usize {
+        self.used
+    }
+}
+
+impl core::fmt::Debug for IdAllocator {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        f.debug_struct("IdAllocator")
+            .field("current_id", &self.current_id)
+            .field("min_id", &self.min_id)
+            .field("max_id", &self.max_id)
+            .field("used", &self.used)
+            .field("xarray", &"xarray<()>")
+            .finish()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn test_new_fail() {
+        assert_eq!(IdAllocator::new(10, 10).is_none(), true);
+        assert_eq!(IdAllocator::new(11, 10).is_none(), true);
+    }
+    #[test]
+    fn test_new_success() {
+        assert_eq!(IdAllocator::new(9, 10).is_some(), true);
+        assert_eq!(IdAllocator::new(0, 10).is_some(), true);
+    }
+
+    #[test]
+    fn test_id_allocator() {
+        let mut ida = IdAllocator::new(0, 10).unwrap();
+        assert_eq!(ida.alloc(), Some(0));
+        assert_eq!(ida.alloc(), Some(1));
+        assert_eq!(ida.alloc(), Some(2));
+        assert_eq!(ida.alloc(), Some(3));
+        assert_eq!(ida.alloc(), Some(4));
+        assert_eq!(ida.alloc(), Some(5));
+        assert_eq!(ida.alloc(), Some(6));
+        assert_eq!(ida.alloc(), Some(7));
+        assert_eq!(ida.alloc(), Some(8));
+        assert_eq!(ida.alloc(), Some(9));
+        assert_eq!(ida.alloc(), None);
+
+        for i in 0..10 {
+            assert_eq!(ida.exists(i), true);
+        }
+
+        ida.free(5);
+
+        for i in 0..10 {
+            if i == 5 {
+                assert_eq!(ida.exists(i), false);
+            } else {
+                assert_eq!(ida.exists(i), true);
+            }
+        }
+        assert_eq!(ida.used(), 9);
+        assert_eq!(ida.alloc(), Some(5));
+        assert_eq!(ida.alloc(), None);
+
+        assert_eq!(ida.used(), 10);
+        for i in 0..10 {
+            ida.free(i);
+        }
+
+        assert_eq!(ida.used(), 0);
+    }
+}

kernel/crates/kdepends/Cargo.toml

@@ -7,9 +7,10 @@ description = "需要导出的依赖项（为保持内核依赖版本与调试
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-ringbuffer = "0.15.0"
-memoffset = "0.9.0"
 crc = { path = "../crc" }
+memoffset = "0.9.0"
+ringbuffer = "0.15.0"
+xarray = { git = "https://git.mirrors.dragonos.org.cn/DragonOS-Community/xarray", rev = "de93b57c34", features = ["slab-friendly"] }
 
 # 一个无锁MPSC队列
 [dependencies.thingbuf]

kernel/crates/kdepends/src/lib.rs

@@ -7,3 +7,4 @@ pub extern crate memoffset;
 pub extern crate ringbuffer;
 
 pub extern crate crc;
+pub extern crate xarray;