atomic_bitmap: keep the byte_size in the AtomicBitmap

Keeping the byte_size in the struct gives freedom
to the caller to use it for any processing at
their end.This field can be used by the caller
in case of enlarging the bitmap.

Signed-off-by: Muminul Islam <[email protected]>

Author: russell-islam

src/bitmap/backend/atomic_bitmap.rs

@@ -18,6 +18,7 @@ use crate::mmap::NewBitmap;
 pub struct AtomicBitmap {
     map: Vec<AtomicU64>,
     size: usize,
+    byte_size: usize,
     page_size: NonZeroUsize,
 }
 
@@ -33,6 +34,7 @@ impl AtomicBitmap {
         AtomicBitmap {
             map,
             size: num_pages,
+            byte_size,
             page_size,
         }
     }
@@ -117,6 +119,11 @@ impl AtomicBitmap {
         self.size
     }
 
+    /// Get the size in bytes i.e how many bytes the bitmap can represent, one bit per page.
+    pub fn byte_size(&self) -> usize {
+        self.byte_size
+    }
+
     /// Atomically get and reset the dirty page bitmap.
     pub fn get_and_reset(&self) -> Vec<u64> {
         self.map
@@ -144,6 +151,7 @@ impl Clone for AtomicBitmap {
         AtomicBitmap {
             map,
             size: self.size,
+            byte_size: self.byte_size,
             page_size: self.page_size,
         }
     }