Forge block timestamps in manual seal mode (paritytech#76)

* sketch the idea

* re-enable some tests

* re-enable genesis-block test

* re-work timestamp test

* prettier

* fix test

node/standalone/src/main.rs

@@ -23,6 +23,7 @@ mod service;
 mod cli;
 mod command;
 mod rpc;
+mod mock_timestamp;
 
 fn main() -> sc_cli::Result<()> {
 	command::run()

node/standalone/src/mock_timestamp.rs

@@ -0,0 +1,62 @@
+/// Provide a mock duration starting at 0 in millisecond for timestamp inherent.
+/// Each call will increment timestamp by slot_duration making Aura think time has passed.
+// Copyright 2019-2020 PureStake Inc.
+// This file is part of Moonbeam.
+
+// Moonbeam is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Moonbeam is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Moonbeam.  If not, see <http://www.gnu.org/licenses/>.
+
+// This module introduces a FAKE timestamp inherent data provider which will
+// always include timestamps that are one aura-slot-duration apart from one another.
+// This allows us to use manual seal to author blocks quickly without violating
+// timestamp assumptions made by either the Aura pallet or the Timestamp pallet.
+//
+// This code was taken from https://github.com/paritytech/frontier/pull/170
+// When moonbeam updates to a Frontier version that includes that PR, we should re-evaluate
+// whether it makes sense to keep this here.
+
+use sp_inherents::{InherentData, InherentIdentifier, ProvideInherentData};
+use sp_timestamp::InherentError;
+use std::cell::RefCell;
+
+use moonbeam_runtime::MINIMUM_PERIOD;
+
+const SLOT_DURATION : u64 = MINIMUM_PERIOD * 2;
+
+/// Provide a mock duration starting at 0 in millisecond for timestamp inherent.
+/// Each call will increment timestamp by slot_duration making Aura think time has passed.
+pub struct MockTimestampInherentDataProvider;
+
+pub const INHERENT_IDENTIFIER: InherentIdentifier = *b"timstap0";
+
+thread_local!(static TIMESTAMP: RefCell<u64> = RefCell::new(0));
+
+impl ProvideInherentData for MockTimestampInherentDataProvider {
+	fn inherent_identifier(&self) -> &'static InherentIdentifier {
+		&INHERENT_IDENTIFIER
+	}
+
+	fn provide_inherent_data(
+		&self,
+		inherent_data: &mut InherentData,
+	) -> Result<(), sp_inherents::Error> {
+		TIMESTAMP.with(|x| {
+			*x.borrow_mut() += SLOT_DURATION;
+			inherent_data.put_data(INHERENT_IDENTIFIER, &*x.borrow())
+		})
+	}
+
+	fn error_to_string(&self, error: &[u8]) -> Option<String> {
+		InherentError::try_from(&INHERENT_IDENTIFIER, error).map(|e| format!("{:?}", e))
+	}
+}

node/standalone/src/service.rs

@@ -30,6 +30,7 @@ use sp_consensus_aura::sr25519::{AuthorityPair as AuraPair};
 use sc_finality_grandpa::{
 	GrandpaBlockImport, FinalityProofProvider as GrandpaFinalityProofProvider, SharedVoterState,
 };
+use crate::mock_timestamp::MockTimestampInherentDataProvider;
 
 // Our native executor instance.
 native_executor_instance!(
@@ -84,7 +85,7 @@ pub fn new_partial(config: &Configuration, manual_seal: bool) -> Result<
 
 	if manual_seal {
 		inherent_data_providers
-			.register_provider(sp_timestamp::InherentDataProvider)
+			.register_provider(MockTimestampInherentDataProvider)
 			.map_err(Into::into)
 			.map_err(sp_consensus::error::Error::InherentData)?;
 

runtime/src/lib.rs

@@ -100,6 +100,9 @@ pub type Hash = sp_core::H256;
 /// Digest item type.
 pub type DigestItem = generic::DigestItem<Hash>;
 
+/// Minimum time between blocks.
+pub const MINIMUM_PERIOD: u64 = 3000;
+
 /// Opaque types. These are used by the CLI to instantiate machinery that don't need to know
 /// the specifics of the runtime. They can then be made to be agnostic over specific formats
 /// of data like extrinsics, allowing for them to continue syncing the network through upgrades
@@ -193,7 +196,7 @@ parameter_types! {
 	// When running in standalone mode, this controls the block time.
 	// Block time is double the minimum period.
 	// https://github.com/paritytech/substrate/blob/e4803bd/frame/aura/src/lib.rs#L197-L199
-	pub const MinimumPeriod: u64 = 3_000;
+	pub const MinimumPeriod: u64 = MINIMUM_PERIOD;
 }
 
 impl pallet_timestamp::Trait for Runtime {

tests/tests/test-block.ts

@@ -57,10 +57,11 @@ describeWithMoonbeam("Moonbeam RPC (Block)", `simple-specs.json`, (context) => {
   });
 
   it("should have valid timestamp after block production", async function () {
+    // Originally ,this test required the timestamp be in the last finve minutes.
+    // This requirement doesn't make sense when we forge timestamps in manual seal.
     const block = await context.web3.eth.getBlock("latest");
-    const last5Minutes = Date.now() / 1000 - 300;
     const next5Minutes = Date.now() / 1000 + 300;
-    expect(block.timestamp).to.be.least(last5Minutes);
+    expect(block.timestamp).to.be.least(0);
     expect(block.timestamp).to.be.below(next5Minutes);
   });
 
@@ -81,7 +82,7 @@ describeWithMoonbeam("Moonbeam RPC (Block)", `simple-specs.json`, (context) => {
       //parentHash: "0x04540257811b46d103d9896e7807040e7de5080e285841c5430d1a81588a0ce4",
       receiptsRoot: "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
       sha3Uncles: "0x0000000000000000000000000000000000000000000000000000000000000000",
-      size: 539,
+      size: 535,
       stateRoot: "0x0000000000000000000000000000000000000000000000000000000000000000",
       //timestamp: 1595012243836,
       totalDifficulty: null,