Append overlay optimization. (#1223)

This branch propose to avoid clones in append by storing offset and size
in previous overlay depth.
That way on rollback we can just truncate and change size of existing
value.
To avoid copy it also means that :

- append on new overlay layer if there is an existing value: create a
new Append entry with previous offsets, and take memory of previous
overlay value.
- rollback on append: restore value by applying offsets and put it back
in previous overlay value
- commit on append: appended value overwrite previous value (is an empty
vec as the memory was taken). offsets of commited layer are dropped, if
there is offset in previous overlay layer they are maintained.
- set value (or remove) when append offsets are present: current
appended value is moved back to previous overlay value with offset
applied and current empty entry is overwrite (no offsets kept).

The modify mechanism is not needed anymore.
This branch lacks testing and break some existing genericity (bit of
duplicated code), but good to have to check direction.

Generally I am not sure if it is worth or we just should favor
differents directions (transients blob storage for instance), as the
current append mechanism is a bit tricky (having a variable length in
first position means we sometime need to insert in front of a vector).

Fix #30.

---------

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
Co-authored-by: EgorPopelyaev <egor@parity.io>
Co-authored-by: Alexandru Vasile <60601340+lexnv@users.noreply.github.com>
Co-authored-by: Bastian Köcher <git@kchr.de>
Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>
Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>
Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>
Co-authored-by: Branislav Kontur <bkontur@gmail.com>
Co-authored-by: Bastian Köcher <info@kchr.de>
Co-authored-by: Sebastian Kunert <skunert49@gmail.com>

polkadot/node/core/pvf/common/src/executor_interface.rs

@@ -215,19 +215,19 @@ type HostFunctions = (
 struct ValidationExternalities(sp_externalities::Extensions);
 
 impl sp_externalities::Externalities for ValidationExternalities {
-	fn storage(&self, _: &[u8]) -> Option<Vec<u8>> {
+	fn storage(&mut self, _: &[u8]) -> Option<Vec<u8>> {
 		panic!("storage: unsupported feature for parachain validation")
 	}
 
-	fn storage_hash(&self, _: &[u8]) -> Option<Vec<u8>> {
+	fn storage_hash(&mut self, _: &[u8]) -> Option<Vec<u8>> {
 		panic!("storage_hash: unsupported feature for parachain validation")
 	}
 
-	fn child_storage_hash(&self, _: &ChildInfo, _: &[u8]) -> Option<Vec<u8>> {
+	fn child_storage_hash(&mut self, _: &ChildInfo, _: &[u8]) -> Option<Vec<u8>> {
 		panic!("child_storage_hash: unsupported feature for parachain validation")
 	}
 
-	fn child_storage(&self, _: &ChildInfo, _: &[u8]) -> Option<Vec<u8>> {
+	fn child_storage(&mut self, _: &ChildInfo, _: &[u8]) -> Option<Vec<u8>> {
 		panic!("child_storage: unsupported feature for parachain validation")
 	}
 
@@ -275,11 +275,11 @@ impl sp_externalities::Externalities for ValidationExternalities {
 		panic!("child_storage_root: unsupported feature for parachain validation")
 	}
 
-	fn next_child_storage_key(&self, _: &ChildInfo, _: &[u8]) -> Option<Vec<u8>> {
+	fn next_child_storage_key(&mut self, _: &ChildInfo, _: &[u8]) -> Option<Vec<u8>> {
 		panic!("next_child_storage_key: unsupported feature for parachain validation")
 	}
 
-	fn next_storage_key(&self, _: &[u8]) -> Option<Vec<u8>> {
+	fn next_storage_key(&mut self, _: &[u8]) -> Option<Vec<u8>> {
 		panic!("next_storage_key: unsupported feature for parachain validation")
 	}
 

prdoc/pr_1223.prdoc

@@ -0,0 +1,13 @@
+title: Optimize storage append operation
+
+doc:
+  - audience: [Node Dev, Runtime Dev]
+    description: |
+      This pull request optimizes the storage append operation in the `OverlayedChanges`.
+      Before the internal buffer was cloned every time a new transaction was created. Cloning
+      the internal buffer is now only done when there is no other possibility. This should
+      improve the performance in situations like when depositing events from batched calls.
+
+crates:
+  - name: sp-state-machine
+    bump: major

substrate/client/executor/src/integration_tests/mod.rs

@@ -178,15 +178,15 @@ fn storage_should_work(wasm_method: WasmExecutionMethod) {
 		assert_eq!(output, b"all ok!".to_vec().encode());
 	}
 
-	let expected = TestExternalities::new(sp_core::storage::Storage {
+	let mut expected = TestExternalities::new(sp_core::storage::Storage {
 		top: map![
 			b"input".to_vec() => value,
 			b"foo".to_vec() => b"bar".to_vec(),
 			b"baz".to_vec() => b"bar".to_vec()
 		],
 		children_default: map![],
 	});
-	assert_eq!(ext, expected);
+	assert!(ext.eq(&mut expected));
 }
 
 test_wasm_execution!(clear_prefix_should_work);
@@ -208,15 +208,15 @@ fn clear_prefix_should_work(wasm_method: WasmExecutionMethod) {
 		assert_eq!(output, b"all ok!".to_vec().encode());
 	}
 
-	let expected = TestExternalities::new(sp_core::storage::Storage {
+	let mut expected = TestExternalities::new(sp_core::storage::Storage {
 		top: map![
 			b"aaa".to_vec() => b"1".to_vec(),
 			b"aab".to_vec() => b"2".to_vec(),
 			b"bbb".to_vec() => b"5".to_vec()
 		],
 		children_default: map![],
 	});
-	assert_eq!(expected, ext);
+	assert!(expected.eq(&mut ext));
 }
 
 test_wasm_execution!(blake2_256_should_work);

substrate/primitives/externalities/src/lib.rs

@@ -83,24 +83,24 @@ pub trait Externalities: ExtensionStore {
 	fn set_offchain_storage(&mut self, key: &[u8], value: Option<&[u8]>);
 
 	/// Read runtime storage.
-	fn storage(&self, key: &[u8]) -> Option<Vec<u8>>;
+	fn storage(&mut self, key: &[u8]) -> Option<Vec<u8>>;
 
 	/// Get storage value hash.
 	///
 	/// This may be optimized for large values.
-	fn storage_hash(&self, key: &[u8]) -> Option<Vec<u8>>;
+	fn storage_hash(&mut self, key: &[u8]) -> Option<Vec<u8>>;
 
 	/// Get child storage value hash.
 	///
 	/// This may be optimized for large values.
 	///
 	/// Returns an `Option` that holds the SCALE encoded hash.
-	fn child_storage_hash(&self, child_info: &ChildInfo, key: &[u8]) -> Option<Vec<u8>>;
+	fn child_storage_hash(&mut self, child_info: &ChildInfo, key: &[u8]) -> Option<Vec<u8>>;
 
 	/// Read child runtime storage.
 	///
 	/// Returns an `Option` that holds the SCALE encoded hash.
-	fn child_storage(&self, child_info: &ChildInfo, key: &[u8]) -> Option<Vec<u8>>;
+	fn child_storage(&mut self, child_info: &ChildInfo, key: &[u8]) -> Option<Vec<u8>>;
 
 	/// Set storage entry `key` of current contract being called (effective immediately).
 	fn set_storage(&mut self, key: Vec<u8>, value: Vec<u8>) {
@@ -124,20 +124,20 @@ pub trait Externalities: ExtensionStore {
 	}
 
 	/// Whether a storage entry exists.
-	fn exists_storage(&self, key: &[u8]) -> bool {
+	fn exists_storage(&mut self, key: &[u8]) -> bool {
 		self.storage(key).is_some()
 	}
 
 	/// Whether a child storage entry exists.
-	fn exists_child_storage(&self, child_info: &ChildInfo, key: &[u8]) -> bool {
+	fn exists_child_storage(&mut self, child_info: &ChildInfo, key: &[u8]) -> bool {
 		self.child_storage(child_info, key).is_some()
 	}
 
 	/// Returns the key immediately following the given key, if it exists.
-	fn next_storage_key(&self, key: &[u8]) -> Option<Vec<u8>>;
+	fn next_storage_key(&mut self, key: &[u8]) -> Option<Vec<u8>>;
 
 	/// Returns the key immediately following the given key, if it exists, in child storage.
-	fn next_child_storage_key(&self, child_info: &ChildInfo, key: &[u8]) -> Option<Vec<u8>>;
+	fn next_child_storage_key(&mut self, child_info: &ChildInfo, key: &[u8]) -> Option<Vec<u8>>;
 
 	/// Clear an entire child storage.
 	///

substrate/primitives/io/src/lib.rs

@@ -181,7 +181,7 @@ impl From<MultiRemovalResults> for KillStorageResult {
 #[runtime_interface]
 pub trait Storage {
 	/// Returns the data for `key` in the storage or `None` if the key can not be found.
-	fn get(&self, key: &[u8]) -> Option<bytes::Bytes> {
+	fn get(&mut self, key: &[u8]) -> Option<bytes::Bytes> {
 		self.storage(key).map(bytes::Bytes::from)
 	}
 
@@ -190,7 +190,7 @@ pub trait Storage {
 	/// doesn't exist at all.
 	/// If `value_out` length is smaller than the returned length, only `value_out` length bytes
 	/// are copied into `value_out`.
-	fn read(&self, key: &[u8], value_out: &mut [u8], value_offset: u32) -> Option<u32> {
+	fn read(&mut self, key: &[u8], value_out: &mut [u8], value_offset: u32) -> Option<u32> {
 		self.storage(key).map(|value| {
 			let value_offset = value_offset as usize;
 			let data = &value[value_offset.min(value.len())..];
@@ -211,7 +211,7 @@ pub trait Storage {
 	}
 
 	/// Check whether the given `key` exists in storage.
-	fn exists(&self, key: &[u8]) -> bool {
+	fn exists(&mut self, key: &[u8]) -> bool {
 		self.exists_storage(key)
 	}
 
@@ -387,7 +387,7 @@ pub trait DefaultChildStorage {
 	///
 	/// Parameter `storage_key` is the unprefixed location of the root of the child trie in the
 	/// parent trie. Result is `None` if the value for `key` in the child storage can not be found.
-	fn get(&self, storage_key: &[u8], key: &[u8]) -> Option<Vec<u8>> {
+	fn get(&mut self, storage_key: &[u8], key: &[u8]) -> Option<Vec<u8>> {
 		let child_info = ChildInfo::new_default(storage_key);
 		self.child_storage(&child_info, key).map(|s| s.to_vec())
 	}
@@ -400,7 +400,7 @@ pub trait DefaultChildStorage {
 	/// If `value_out` length is smaller than the returned length, only `value_out` length bytes
 	/// are copied into `value_out`.
 	fn read(
-		&self,
+		&mut self,
 		storage_key: &[u8],
 		key: &[u8],
 		value_out: &mut [u8],
@@ -478,7 +478,7 @@ pub trait DefaultChildStorage {
 	/// Check a child storage key.
 	///
 	/// Check whether the given `key` exists in default child defined at `storage_key`.
-	fn exists(&self, storage_key: &[u8], key: &[u8]) -> bool {
+	fn exists(&mut self, storage_key: &[u8], key: &[u8]) -> bool {
 		let child_info = ChildInfo::new_default(storage_key);
 		self.exists_child_storage(&child_info, key)
 	}

substrate/primitives/state-machine/Cargo.toml

@@ -30,16 +30,19 @@ sp-externalities = { path = "../externalities", default-features = false }
 sp-panic-handler = { path = "../panic-handler", optional = true }
 sp-trie = { path = "../trie", default-features = false }
 trie-db = { version = "0.29.0", default-features = false }
+arbitrary = { version = "1", features = ["derive"], optional = true }
 
 [dev-dependencies]
 array-bytes = "6.2.2"
 pretty_assertions = "1.2.1"
 rand = "0.8.5"
 sp-runtime = { path = "../runtime" }
 assert_matches = "1.5"
+arbitrary = { version = "1", features = ["derive"] }
 
 [features]
 default = ["std"]
+fuzzing = ["arbitrary"]
 std = [
 	"codec/std",
 	"hash-db/std",

substrate/primitives/state-machine/fuzz/Cargo.toml

@@ -0,0 +1,30 @@
+[package]
+name = "sp-state-machine-fuzz"
+version = "0.0.0"
+publish = false
+license = "Apache-2.0"
+edition = "2021"
+
+[package.metadata]
+cargo-fuzz = true
+
+[dependencies]
+libfuzzer-sys = "0.4"
+sp-runtime = { path = "../../runtime" }
+
+[dependencies.sp-state-machine]
+path = ".."
+features = ["fuzzing"]
+
+# Prevent this from interfering with workspaces
+[workspace]
+members = ["."]
+
+[profile.release]
+debug = 1
+
+[[bin]]
+name = "fuzz_append"
+path = "fuzz_targets/fuzz_append.rs"
+test = false
+doc = false

substrate/primitives/state-machine/fuzz/fuzz_targets/fuzz_append.rs

@@ -0,0 +1,26 @@
+// This file is part of Substrate.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#![no_main]
+
+use libfuzzer_sys::fuzz_target;
+use sp_state_machine::fuzzing::{fuzz_append, FuzzAppendPayload};
+use sp_runtime::traits::BlakeTwo256;
+
+fuzz_target!(|data: FuzzAppendPayload| {
+	fuzz_append::<BlakeTwo256>(data);
+});