Dynamic Benchmarking DB Whitelist (#6815)

* Add `get_whitelist` api

* add whitelisted caller

* Whitelist caller

* remove caller 0

* initial piping of origin (not actual value yet)

* remove attempt to pass origin around

* Add whitelist for `DidUpdate` storage on `pallet_timestamp`

* fix traits

* only add to whitelist if !contains

* PassBy not implemented error

* Whitelist read/writes explicitly per key

* update docs

* reduce trait constraint

* copy pasta

* Apply suggestions from code review

Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>
Co-authored-by: Alexander Popiak <alexander.popiak@parity.io>

* rename functions @apopiak

* missed some renaming

* enable doc tests

* Update docs

Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>
Co-authored-by: Alexander Popiak <alexander.popiak@parity.io>

Author: 3 people

src/benchmarking.rs

@@ -23,7 +23,7 @@ use super::*;
 use sp_std::prelude::*;
 use frame_system::RawOrigin;
 use frame_support::{ensure, traits::OnFinalize};
-use frame_benchmarking::benchmarks;
+use frame_benchmarking::{benchmarks, TrackedStorageKey};
 
 use crate::Module as Timestamp;
 
@@ -34,8 +34,14 @@ benchmarks! {
 
 	set {
 		let t in 1 .. MAX_TIME;
+		// Ignore write to `DidUpdate` since it transient.
+		let did_update_key = crate::DidUpdate::hashed_key().to_vec();
+		frame_benchmarking::benchmarking::add_to_whitelist(TrackedStorageKey {
+			key: did_update_key,
+			has_been_read: false,
+			has_been_written: true,
+		});
 	}: _(RawOrigin::None, t.into())
-
 	verify {
 		ensure!(Timestamp::<T>::now() == t.into(), "Time was not set.");
 	}
@@ -44,8 +50,10 @@ benchmarks! {
 		let t in 1 .. MAX_TIME;
 		Timestamp::<T>::set(RawOrigin::None.into(), t.into())?;
 		ensure!(DidUpdate::exists(), "Time was not set.");
+		// Ignore read/write to `DidUpdate` since it is transient.
+		let did_update_key = crate::DidUpdate::hashed_key().to_vec();
+		frame_benchmarking::benchmarking::add_to_whitelist(did_update_key.into());
 	}: { Timestamp::<T>::on_finalize(t.into()); }
-
 	verify {
 		ensure!(!DidUpdate::exists(), "Time was not removed.");
 	}