Make AggregateHeapProfileInfo public

Summary: So a user can collect `AggregateHeapProfileInfo` from different invocations and merge them.

Reviewed By: bobyangyf

Differential Revision: D38518063

fbshipit-source-id: 4d8e77bafccd1651492c0b9030fd93e3188a07ee

Author: stepancheg

starlark/src/environment/modules.rs

@@ -218,7 +218,7 @@ impl FrozenModule {
     }
 
     /// Retained memory info, or error if not enabled.
-    fn aggregated_heap_profile_info(&self) -> anyhow::Result<&AggregateHeapProfileInfo> {
+    pub fn aggregated_heap_profile_info(&self) -> anyhow::Result<&AggregateHeapProfileInfo> {
         self.module
             .0
             .heap_profile

starlark/src/values/layout/heap/profile/aggregated.rs

@@ -286,8 +286,13 @@ impl<'c> StackFrameWithContext<'c> {
     }
 }
 
+/// Aggregated heap profiling data when heap profiling is enabled.
+///
+/// Can be:
+/// * written as CSV or flamegraph
+/// * merged with another data
 #[derive(Clone)]
-pub(crate) struct AggregateHeapProfileInfo {
+pub struct AggregateHeapProfileInfo {
     pub(crate) strings: StringIndex,
     pub(crate) root: StackFrame,
     /// String `"TOTALS"`. It is needed in heap summary output.
@@ -335,8 +340,8 @@ impl AggregateHeapProfileInfo {
         }
     }
 
-    #[allow(dead_code)] // TODO: used later.
-    fn merge<'a>(
+    /// Merge aggregated heap profile from multiple sources (e.g. from several runs).
+    pub fn merge<'a>(
         profiles: impl IntoIterator<Item = &'a AggregateHeapProfileInfo>,
     ) -> AggregateHeapProfileInfo {
         let mut strings = StringIndex::default();
@@ -355,13 +360,14 @@ impl AggregateHeapProfileInfo {
     }
 
     /// Write this out recursively to a file.
-    pub(crate) fn gen_flame_graph(&self) -> String {
+    pub fn gen_flame_graph(&self) -> String {
         let mut writer = FlameGraphWriter::new();
         self.root().write_flame_graph(&mut writer, &mut vec![]);
         writer.finish()
     }
 
-    pub(crate) fn gen_summary_csv(&self) -> String {
+    /// Write per-function summary in CSV format.
+    pub fn gen_summary_csv(&self) -> String {
         HeapSummaryByFunction::init(self).gen_csv(self)
     }
 }

starlark/src/values/mod.rs

@@ -49,6 +49,7 @@ pub use crate::values::layout::heap::heap_type::FrozenHeap;
 pub use crate::values::layout::heap::heap_type::FrozenHeapRef;
 pub use crate::values::layout::heap::heap_type::Heap;
 pub use crate::values::layout::heap::heap_type::Tracer;
+pub use crate::values::layout::heap::profile::aggregated::AggregateHeapProfileInfo;
 pub use crate::values::layout::identity::ValueIdentity;
 pub use crate::values::layout::static_string::constant_string;
 pub use crate::values::layout::static_string::StarlarkStrNRepr;