diff --git a/substrate/core/client/src/client.rs b/substrate/core/client/src/client.rs
index 7f8c81d5abea514d69ba7781597836f60a1160af..b0dfb939d07c1ef6d61c65774d5c88f2e1546d5a 100644
--- a/substrate/core/client/src/client.rs
+++ b/substrate/core/client/src/client.rs
@@ -25,7 +25,7 @@ use runtime_primitives::{
Justification,
generic::{BlockId, SignedBlock},
};
-use consensus::{Error as ConsensusError, ErrorKind as ConsensusErrorKind, ImportBlock, ImportResult, BlockOrigin};
+use consensus::{Error as ConsensusError, ErrorKind as ConsensusErrorKind, ImportBlock, ImportResult, BlockOrigin, ForkChoiceStrategy};
use runtime_primitives::traits::{
Block as BlockT, Header as HeaderT, Zero, As, NumberFor, CurrentHeight, BlockNumberToHash,
ApiRef, ProvideRuntimeApi, Digest, DigestItem,
@@ -544,6 +544,7 @@ impl<B, E, Block, RA> Client<B, E, Block, RA> where
authorities: Option<Vec<AuthorityId>>,
finalized: bool,
aux: Vec<(Vec<u8>, Option<Vec<u8>>)>,
+ fork_choice: ForkChoiceStrategy,
) -> error::Result<ImportResult> where
E: CallExecutor<Block, Blake2Hasher> + Send + Sync + Clone,
{
@@ -608,7 +609,10 @@ impl<B, E, Block, RA> Client<B, E, Block, RA> where
};
// TODO: non longest-chain rule.
- let is_new_best = finalized || import_headers.post().number() > &last_best_number;
+ let is_new_best = finalized || match fork_choice {
+ ForkChoiceStrategy::LongestChain => import_headers.post().number() > &last_best_number,
+ ForkChoiceStrategy::Custom(v) => v,
+ };
let leaf_state = if finalized {
::backend::NewBlockState::Final
} else if is_new_best {
@@ -1038,6 +1042,7 @@ impl<B, E, Block, RA> consensus::BlockImport<Block> for Client<B, E, Block, RA>
body,
finalized,
auxiliary,
+ fork_choice,
} = import_block;
assert!(justification.is_some() && finalized || justification.is_none());
@@ -1074,6 +1079,7 @@ impl<B, E, Block, RA> consensus::BlockImport<Block> for Client<B, E, Block, RA>
new_authorities,
finalized,
auxiliary,
+ fork_choice,
);
*self.importing_block.write() = None;
diff --git a/substrate/core/consensus/aura/src/lib.rs b/substrate/core/consensus/aura/src/lib.rs
index 911ae6304a320fae10a9ebfd084913fa32ff36b6..b57dab030c76fa401f4c046a770e71459a1acde4 100644
--- a/substrate/core/consensus/aura/src/lib.rs
+++ b/substrate/core/consensus/aura/src/lib.rs
@@ -61,7 +61,7 @@ use std::sync::Arc;
use std::time::Duration;
use codec::Encode;
-use consensus_common::{Authorities, BlockImport, Environment, Error as ConsensusError, Proposer};
+use consensus_common::{Authorities, BlockImport, Environment, Error as ConsensusError, Proposer, ForkChoiceStrategy};
use consensus_common::import_queue::{Verifier, BasicQueue};
use client::ChainHead;
use client::block_builder::api::BlockBuilder as BlockBuilderApi;
@@ -324,6 +324,7 @@ pub fn start_aura<B, C, E, I, SO, Error>(
body: Some(body),
finalized: false,
auxiliary: Vec::new(),
+ fork_choice: ForkChoiceStrategy::LongestChain,
};
if let Err(e) = block_import.import_block(import_block, None) {
@@ -524,6 +525,7 @@ impl<B: Block, C, E, MakeInherent, Inherent> Verifier<B> for AuraVerifier<C, E,
finalized: false,
justification,
auxiliary: Vec::new(),
+ fork_choice: ForkChoiceStrategy::LongestChain,
};
// FIXME: extract authorities - https://github.com/paritytech/substrate/issues/1019
diff --git a/substrate/core/consensus/common/src/block_import.rs b/substrate/core/consensus/common/src/block_import.rs
index 1f7f814a8ea43b3ff64295081c2e242a482b1ce6..488112f0ebe024c99fc1208f1053829eceec94bd 100644
--- a/substrate/core/consensus/common/src/block_import.rs
+++ b/substrate/core/consensus/common/src/block_import.rs
@@ -53,6 +53,15 @@ pub enum BlockOrigin {
File,
}
+/// Fork choice strategy.
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum ForkChoiceStrategy {
+ /// Longest chain fork choice.
+ LongestChain,
+ /// Custom fork choice rule, where true indicates the new block should be the best block.
+ Custom(bool),
+}
+
/// Data required to import a Block
pub struct ImportBlock<Block: BlockT> {
/// Origin of the Block
@@ -83,6 +92,8 @@ pub struct ImportBlock<Block: BlockT> {
/// Contains a list of key-value pairs. If values are `None`, the keys
/// will be deleted.
pub auxiliary: Vec<(Vec<u8>, Option<Vec<u8>>)>,
+ /// Fork choice strategy of this import.
+ pub fork_choice: ForkChoiceStrategy,
}
impl<Block: BlockT> ImportBlock<Block> {
diff --git a/substrate/core/consensus/common/src/lib.rs b/substrate/core/consensus/common/src/lib.rs
index 875f4c216aec44c03a6ab64ba5237e5fb5422f96..e9b5d82951f624f81cd5b7b01e3dcb73fc078fe1 100644
--- a/substrate/core/consensus/common/src/lib.rs
+++ b/substrate/core/consensus/common/src/lib.rs
@@ -55,7 +55,7 @@ pub mod evaluation;
const MAX_TRANSACTIONS_SIZE: usize = 4 * 1024 * 1024;
pub use self::error::{Error, ErrorKind};
-pub use block_import::{BlockImport, ImportBlock, BlockOrigin, ImportResult};
+pub use block_import::{BlockImport, ImportBlock, BlockOrigin, ImportResult, ForkChoiceStrategy};
/// Trait for getting the authorities at a given block.
pub trait Authorities<B: Block> {
diff --git a/substrate/core/network/src/test/mod.rs b/substrate/core/network/src/test/mod.rs
index b2beba05db732fb2f2639de327b4e62ece10990b..94518978bc0915d11b05f0269f9c318ef6749129 100644
--- a/substrate/core/network/src/test/mod.rs
+++ b/substrate/core/network/src/test/mod.rs
@@ -38,7 +38,7 @@ use service::{NetworkLink, TransactionPool};
use network_libp2p::{NodeIndex, PeerId, Severity};
use keyring::Keyring;
use codec::Encode;
-use consensus::{BlockImport, BlockOrigin, ImportBlock};
+use consensus::{BlockImport, BlockOrigin, ImportBlock, ForkChoiceStrategy};
use consensus::Error as ConsensusError;
use consensus::import_queue::{import_many_blocks, ImportQueue, ImportQueueStatus, IncomingBlock};
use consensus::import_queue::{Link, SharedBlockImport, Verifier};
@@ -101,6 +101,7 @@ impl<B: BlockT> Verifier<B> for PassThroughVerifier {
justification,
post_digests: vec![],
auxiliary: Vec::new(),
+ fork_choice: ForkChoiceStrategy::LongestChain,
}, None))
}
}
diff --git a/substrate/core/test-client/src/client_ext.rs b/substrate/core/test-client/src/client_ext.rs
index a833472e445d8421eac20954321b58b82e5f2eb2..f766f427cd724494f7c34484977ce56af7bc4ddc 100644
--- a/substrate/core/test-client/src/client_ext.rs
+++ b/substrate/core/test-client/src/client_ext.rs
@@ -17,7 +17,7 @@
//! Client extension for tests.
use client::{self, Client};
-use consensus::{ImportBlock, BlockImport, BlockOrigin, Error as ConsensusError};
+use consensus::{ImportBlock, BlockImport, BlockOrigin, Error as ConsensusError, ForkChoiceStrategy};
use runtime_primitives::Justification;
use runtime_primitives::generic::BlockId;
use primitives::Blake2Hasher;
@@ -57,6 +57,7 @@ impl<B, E, RA> TestClient for Client<B, E, runtime::Block, RA>
body: Some(block.extrinsics),
finalized: false,
auxiliary: Vec::new(),
+ fork_choice: ForkChoiceStrategy::LongestChain,
};
self.import_block(import, None).map(|_| ())
@@ -73,6 +74,7 @@ impl<B, E, RA> TestClient for Client<B, E, runtime::Block, RA>
body: Some(block.extrinsics),
finalized: true,
auxiliary: Vec::new(),
+ fork_choice: ForkChoiceStrategy::LongestChain,
};
self.import_block(import, None).map(|_| ())