feat: get_offset for SharedPtr

src/allocator.rs

@@ -110,6 +110,11 @@ impl Allocator {
 
         // TODO: Consolidate chunks
     }
+
+    pub(crate) unsafe fn get_offset(&self, ptr: *const u8) -> usize {
+        let allocator = BUMP_ALLOCATOR.lock().unwrap();
+        allocator.get_offset(ptr)
+    }
 }
 
 #[cfg(test)]

src/bump_allocator.rs

@@ -55,7 +55,7 @@ impl BumpAllocator {
         }
     }
 
-    pub unsafe fn alloc(&mut self, size: usize) -> Option<*mut u8> {
+    pub(crate) unsafe fn alloc(&mut self, size: usize) -> Option<*mut u8> {
         let new_head = self.head.byte_add(size);
 
         if new_head > self.end_of_mem {
@@ -75,13 +75,22 @@ impl BumpAllocator {
         ret
     }
 
-    pub fn dealloc(&mut self) {
+    pub(crate) fn dealloc(&mut self) {
         self.number_of_allocated_chunks -= 1;
 
         if self.number_of_allocated_chunks == 0 {
             self.head = self.start_of_mem;
         }
     }
+
+    pub(crate) unsafe fn get_offset(&self, ptr: *const u8) -> usize {
+        let offset = ptr.byte_offset_from(self.start_of_mem);
+
+        debug_assert!(offset >= 0);
+        debug_assert!(offset < self.end_of_mem.byte_offset_from(self.start_of_mem));
+
+        offset as usize
+    }
 }
 
 #[cfg(test)]

src/sharedptr.rs

@@ -19,6 +19,14 @@ impl SharedPtr<'_> {
 
         Some(SharedPtr(buf))
     }
+
+    pub fn get_offset(&self) -> usize {
+        let allocator = ALLOCATOR.lock().unwrap();
+
+        unsafe {
+            allocator.get_offset(self.as_ptr())
+        }
+    }
 }
 
 impl<'a> Deref for SharedPtr<'a> {