Expose allocated_bytes on Heap/FrozenHeap

Summary: Useful to cheaply see how big heaps are

Reviewed By: krallin

Differential Revision: D30933010

fbshipit-source-id: 05c81261c844ce57d113c6b9ad98d3147e0d9606

Author: ndmitchell

starlark/src/values/layout/heap.rs

@@ -127,6 +127,12 @@ impl PartialEq<FrozenHeapRef> for FrozenHeapRef {
 impl Eq for FrozenHeapRef {}
 
 impl FrozenHeapRef {
+    /// Number of bytes allocated on this heap, not including any memory
+    /// represented by [`extra_memory`](crate::values::StarlarkValue::extra_memory).
+    pub fn allocated_bytes(&self) -> usize {
+        self.0.arena.allocated_bytes()
+    }
+
     /// Obtain a summary of how much memory is currently allocated by this heap.
     /// Doesn't include the heaps it keeps alive by reference.
     pub fn allocated_summary(&self) -> HeapSummary {
@@ -192,6 +198,12 @@ impl FrozenHeap {
         self.alloc_raw(simple(val))
     }
 
+    /// Number of bytes allocated on this heap, not including any memory
+    /// represented by [`extra_memory`](crate::values::StarlarkValue::extra_memory).
+    pub fn allocated_bytes(&self) -> usize {
+        self.arena.allocated_bytes()
+    }
+
     /// Obtain a summary of how much memory is currently allocated by this heap.
     pub fn allocated_summary(&self) -> HeapSummary {
         self.arena.allocated_summary()
@@ -271,10 +283,13 @@ impl Heap {
         Self::default()
     }
 
-    pub(crate) fn allocated_bytes(&self) -> usize {
+    /// Number of bytes allocated on this heap, not including any memory
+    /// represented by [`extra_memory`](crate::values::StarlarkValue::extra_memory).
+    pub fn allocated_bytes(&self) -> usize {
         self.arena.borrow().allocated_bytes()
     }
 
+    /// Only those allocated on the inline heap (mostly strings)
     pub(crate) fn allocated_bytes_inline(&self) -> usize {
         self.arena.borrow().allocated_bytes_inline()
     }