From 7f46573218dc46417608a700a6146950dfea1442 Mon Sep 17 00:00:00 2001
From: Aaron Kaiser <a_kaiser@posteo.de>
Date: Thu, 10 Oct 2024 16:37:04 +0200
Subject: [PATCH] feat: make size of SharedPtr dynamic

---
 src/sharedptr.rs | 41 ++++++++++++++++++++++++-----------------
 1 file changed, 24 insertions(+), 17 deletions(-)

diff --git a/src/sharedptr.rs b/src/sharedptr.rs
index 278192f..fe0cbd7 100644
--- a/src/sharedptr.rs
+++ b/src/sharedptr.rs
@@ -4,54 +4,61 @@ use std::ops::{Deref, DerefMut};
 use crate::allocator::ALLOCATOR;
 
 #[derive(Debug)]
-pub struct SharedPtr<const N: usize>(*mut u8);
+pub struct SharedPtr {
+    ptr: *mut u8,
+    size: usize
+}
 
-unsafe impl<const N: usize> Send for SharedPtr<N> {}
-unsafe impl<const N: usize> Sync for SharedPtr<N> {}
+unsafe impl Send for SharedPtr {}
+unsafe impl Sync for SharedPtr {}
 
-impl<const N: usize> SharedPtr<N> {
-    pub fn new() -> Option<Self> {
+impl SharedPtr {
+    pub fn new(size: usize) -> Option<Self> {
         let mut allocator = ALLOCATOR.lock().unwrap();
 
-        let buf = allocator.allocate(N)?;
+        let buf = allocator.allocate(size)?;
 
-        Some(SharedPtr(buf))
+        Some(SharedPtr{ptr: buf, size})
     }
 
     pub fn get_offset(&self) -> usize {
         let allocator = ALLOCATOR.lock().unwrap();
 
-        unsafe { allocator.get_offset(self.as_ptr()) }
+        unsafe { allocator.get_offset(self.ptr) }
+    }
+
+    pub fn get_size(&self) -> usize {
+        self.size
     }
 }
 
-impl<const N: usize> Deref for SharedPtr<N> {
-    type Target = [u8; N];
+impl Deref for SharedPtr {
+    type Target = [u8];
 
     fn deref(&self) -> &Self::Target {
         unsafe {
-            slice::from_raw_parts(self.0, N)
+            slice::from_raw_parts(self.ptr, self.size)
                 .try_into()
                 .expect("This should never fail")
         }
     }
 }
 
-impl<const N: usize> DerefMut for SharedPtr<N> {
+impl DerefMut for SharedPtr {
     fn deref_mut(&mut self) -> &mut Self::Target {
         unsafe {
-            slice::from_raw_parts_mut(self.0, N)
+            slice::from_raw_parts_mut(self.ptr, self.size)
                 .try_into()
                 .expect("This should never fail")
         }
     }
 }
 
-impl<const N: usize> Drop for SharedPtr<N> {
+impl Drop for SharedPtr {
     fn drop(&mut self) {
         let mut allocator = ALLOCATOR.lock().unwrap();
 
-        allocator.deallocate(self.0);
+        allocator.deallocate(self.ptr);
     }
 }
 
@@ -61,7 +68,7 @@ mod tests {
 
     #[test]
     fn test() {
-        let mut x = SharedPtr::<10>::new().unwrap();
+        let mut x = SharedPtr::new(10).unwrap();
         x[0] = 1;
         assert_eq!(x[0], 1);
         drop(x);
@@ -69,7 +76,7 @@ mod tests {
 
     #[test]
     fn slice() {
-        let mut x = SharedPtr::<10>::new().unwrap();
+        let mut x = SharedPtr::new(10).unwrap();
         x[0] = 1;
         x[1] = 2;
         assert_eq!(x[0..=1], [1, 2]);