Clean generics in Tendermint with a monolith with associated types

Cargo.lock

@@ -7536,6 +7536,7 @@ dependencies = [
  "pallet-session",
  "sc-basic-authorship",
  "sc-client-api",
+ "sc-client-db",
  "sc-consensus",
  "sc-executor",
  "sc-network",

substrate/tendermint/client/Cargo.toml

@@ -38,6 +38,7 @@ sc-executor = { git = "https://github.com/serai-dex/substrate" }
 sc-network = { git = "https://github.com/serai-dex/substrate" }
 sc-network-gossip = { git = "https://github.com/serai-dex/substrate" }
 sc-service = { git = "https://github.com/serai-dex/substrate" }
+sc-client-db = { git = "https://github.com/serai-dex/substrate" }
 sc-client-api = { git = "https://github.com/serai-dex/substrate" }
 sc-consensus = { git = "https://github.com/serai-dex/substrate" }
 

substrate/tendermint/client/src/block_import.rs

@@ -2,45 +2,25 @@ use std::{sync::Arc, collections::HashMap};
 
 use async_trait::async_trait;
 
-use sp_inherents::CreateInherentDataProviders;
-use sp_runtime::traits::Block;
-use sp_api::TransactionFor;
-
-use sp_consensus::{Error, CacheKeyId, Environment};
+use sp_consensus::{Error, CacheKeyId};
 use sc_consensus::{BlockCheckParams, BlockImportParams, ImportResult, BlockImport};
 
-use sc_client_api::Backend;
-
-use sp_tendermint::TendermintApi;
-
-use crate::{
-  tendermint::{TendermintClient, TendermintImport},
-  Announce,
-};
+use crate::{types::TendermintAuthor, tendermint::TendermintImport};
 
 #[async_trait]
-impl<
-    B: Block,
-    Be: Backend<B> + 'static,
-    C: TendermintClient<B, Be>,
-    CIDP: CreateInherentDataProviders<B, ()> + 'static,
-    E: Send + Sync + Environment<B> + 'static,
-    A: Announce<B>,
-  > BlockImport<B> for TendermintImport<B, Be, C, CIDP, E, A>
+impl<T: TendermintAuthor> BlockImport<T::Block> for TendermintImport<T>
 where
-  TransactionFor<C, B>: Send + Sync + 'static,
-  Arc<C>: BlockImport<B, Transaction = TransactionFor<C, B>>,
-  <Arc<C> as BlockImport<B>>::Error: Into<Error>,
-  C::Api: TendermintApi<B>,
+  Arc<T::Client>: BlockImport<T::Block, Transaction = T::BackendTransaction>,
+  <Arc<T::Client> as BlockImport<T::Block>>::Error: Into<Error>,
 {
   type Error = Error;
-  type Transaction = TransactionFor<C, B>;
+  type Transaction = T::BackendTransaction;
 
   // TODO: Is there a DoS where you send a block without justifications, causing it to error,
   // yet adding it to the blacklist in the process preventing further syncing?
   async fn check_block(
     &mut self,
-    mut block: BlockCheckParams<B>,
+    mut block: BlockCheckParams<T::Block>,
   ) -> Result<ImportResult, Self::Error> {
     self.verify_order(block.parent_hash, block.number)?;
 
@@ -55,7 +35,7 @@ where
 
   async fn import_block(
     &mut self,
-    mut block: BlockImportParams<B, TransactionFor<C, B>>,
+    mut block: BlockImportParams<T::Block, Self::Transaction>,
     new_cache: HashMap<CacheKeyId, Vec<u8>>,
   ) -> Result<ImportResult, Self::Error> {
     self.check(&mut block).await?;

substrate/tendermint/client/src/import_queue.rs

@@ -8,15 +8,14 @@ use std::{
 };
 
 use sp_core::Decode;
-use sp_inherents::CreateInherentDataProviders;
 use sp_runtime::traits::{Header, Block};
-use sp_api::{BlockId, TransactionFor};
+use sp_api::BlockId;
 
-use sp_consensus::{Error, Environment};
+use sp_consensus::Error;
 use sc_consensus::{BlockImportStatus, BlockImportError, BlockImport, Link, BasicQueue};
 
 use sc_service::ImportQueue;
-use sc_client_api::Backend;
+use sc_client_api::{HeaderBackend, BlockBackend};
 
 use substrate_prometheus_endpoint::Registry;
 
@@ -25,13 +24,9 @@ use tendermint_machine::{
   TendermintMachine,
 };
 
-use sp_tendermint::TendermintApi;
-
 use crate::{
-  CONSENSUS_ID,
-  validators::TendermintValidators,
-  tendermint::{TendermintClient, TendermintImport},
-  Announce,
+  CONSENSUS_ID, types::TendermintAuthor, validators::TendermintValidators,
+  tendermint::TendermintImport,
 };
 
 pub type TendermintImportQueue<Block, Transaction> = BasicQueue<Block, Transaction>;
@@ -82,28 +77,19 @@ impl<'a, B: Block, T: Send> Future for ImportFuture<'a, B, T> {
   }
 }
 
-pub fn import_queue<
-  B: Block,
-  Be: Backend<B> + 'static,
-  C: TendermintClient<B, Be>,
-  CIDP: CreateInherentDataProviders<B, ()> + 'static,
-  E: Send + Sync + Environment<B> + 'static,
-  A: Announce<B>,
->(
-  client: Arc<C>,
-  announce: A,
-  providers: Arc<CIDP>,
-  env: E,
+pub fn import_queue<T: TendermintAuthor>(
+  client: Arc<T::Client>,
+  announce: T::Announce,
+  providers: Arc<T::CIDP>,
+  env: T::Environment,
   spawner: &impl sp_core::traits::SpawnEssentialNamed,
   registry: Option<&Registry>,
-) -> (impl Future<Output = ()>, TendermintImportQueue<B, TransactionFor<C, B>>)
+) -> (impl Future<Output = ()>, TendermintImportQueue<T::Block, T::BackendTransaction>)
 where
-  TransactionFor<C, B>: Send + Sync + 'static,
-  Arc<C>: BlockImport<B, Transaction = TransactionFor<C, B>>,
-  <Arc<C> as BlockImport<B>>::Error: Into<Error>,
-  C::Api: TendermintApi<B>,
+  Arc<T::Client>: BlockImport<T::Block, Transaction = T::BackendTransaction>,
+  <Arc<T::Client> as BlockImport<T::Block>>::Error: Into<Error>,
 {
-  let import = TendermintImport::new(client, announce, providers, env);
+  let import = TendermintImport::<T>::new(client, announce, providers, env);
 
   let authority = {
     let machine_clone = import.machine.clone();
@@ -120,7 +106,7 @@ where
             Ok(best) => BlockNumber(best + 1),
             Err(_) => panic!("BlockNumber exceeded u64"),
           },
-          Commit::<TendermintValidators<B, Be, C>>::decode(
+          Commit::<TendermintValidators<T>>::decode(
             &mut import_clone
               .client
               .justifications(&BlockId::Number(best))

substrate/tendermint/client/src/lib.rs

@@ -1,7 +1,9 @@
-use std::{sync::Arc, future::Future};
+use std::{marker::PhantomData, boxed::Box, sync::Arc, future::Future, error::Error};
 
 use sp_runtime::traits::Block as BlockTrait;
-use sp_api::TransactionFor;
+use sp_inherents::CreateInherentDataProviders;
+use sp_consensus::DisableProofRecording;
+use sp_api::{TransactionFor, ProvideRuntimeApi};
 
 use sc_executor::{NativeVersion, NativeExecutionDispatch, NativeElseWasmExecutor};
 use sc_transaction_pool::FullPool;
@@ -11,6 +13,9 @@ use substrate_prometheus_endpoint::Registry;
 
 use serai_runtime::{self, opaque::Block, RuntimeApi};
 
+mod types;
+use types::{TendermintClientMinimal, TendermintAuthor};
+
 mod validators;
 
 mod tendermint;
@@ -49,6 +54,39 @@ pub trait Announce<B: BlockTrait>: Send + Sync + Clone + 'static {
   fn announce(&self, hash: B::Hash);
 }
 
+struct Cidp;
+#[async_trait::async_trait]
+impl CreateInherentDataProviders<Block, ()> for Cidp {
+  type InherentDataProviders = (sp_timestamp::InherentDataProvider,);
+  async fn create_inherent_data_providers(
+    &self,
+    _: <Block as BlockTrait>::Hash,
+    _: (),
+  ) -> Result<Self::InherentDataProviders, Box<dyn Send + Sync + Error>> {
+    Ok((sp_timestamp::InherentDataProvider::from_system_time(),))
+  }
+}
+
+struct TendermintAuthorFirm<A: Announce<Block>>(PhantomData<A>);
+impl<A: Announce<Block>> TendermintClientMinimal for TendermintAuthorFirm<A> {
+  type Block = Block;
+  type Backend = sc_client_db::Backend<Block>;
+  type Api = <FullClient as ProvideRuntimeApi<Block>>::Api;
+  type Client = FullClient;
+}
+
+impl<A: Announce<Block>> TendermintAuthor for TendermintAuthorFirm<A> {
+  type CIDP = Cidp;
+  type Environment = sc_basic_authorship::ProposerFactory<
+    FullPool<Block, FullClient>,
+    Self::Backend,
+    Self::Client,
+    DisableProofRecording,
+  >;
+
+  type Announce = A;
+}
+
 pub fn import_queue<A: Announce<Block>>(
   task_manager: &TaskManager,
   client: Arc<FullClient>,
@@ -56,10 +94,10 @@ pub fn import_queue<A: Announce<Block>>(
   pool: Arc<FullPool<Block, FullClient>>,
   registry: Option<&Registry>,
 ) -> (impl Future<Output = ()>, TendermintImportQueue<Block, TransactionFor<FullClient, Block>>) {
-  import_queue::import_queue(
+  import_queue::import_queue::<TendermintAuthorFirm<A>>(
     client.clone(),
     announce,
-    Arc::new(|_, _| async { Ok(sp_timestamp::InherentDataProvider::from_system_time()) }),
+    Arc::new(Cidp),
     sc_basic_authorship::ProposerFactory::new(
       task_manager.spawn_handle(),
       client,

substrate/tendermint/client/src/tendermint.rs

@@ -17,103 +17,48 @@ use sp_runtime::{
   Digest, Justification,
 };
 use sp_blockchain::HeaderBackend;
-use sp_api::{BlockId, TransactionFor, ProvideRuntimeApi};
+use sp_api::BlockId;
 
 use sp_consensus::{Error, BlockOrigin, Proposer, Environment};
-use sc_consensus::{ForkChoiceStrategy, BlockImportParams, BlockImport, import_queue::IncomingBlock};
+use sc_consensus::{ForkChoiceStrategy, BlockImportParams, import_queue::IncomingBlock};
 
 use sc_service::ImportQueue;
-use sc_client_api::{BlockBackend, Backend, Finalizer};
+use sc_client_api::Finalizer;
 
 use tendermint_machine::{
   ext::{BlockError, Commit, Network},
   SignedMessage, TendermintHandle,
 };
 
-use sp_tendermint::TendermintApi;
-
 use crate::{
   CONSENSUS_ID,
+  types::TendermintAuthor,
   validators::TendermintValidators,
   import_queue::{ImportFuture, TendermintImportQueue},
   Announce,
 };
 
-pub trait TendermintClient<B: Block, Be: Backend<B> + 'static>:
-  Send
-  + Sync
-  + HeaderBackend<B>
-  + BlockBackend<B>
-  + BlockImport<B, Transaction = TransactionFor<Self, B>>
-  + Finalizer<B, Be>
-  + ProvideRuntimeApi<B>
-  + 'static
-where
-  TransactionFor<Self, B>: Send + Sync + 'static,
-  Self::Api: TendermintApi<B>,
-{
-}
-impl<
-    B: Send + Sync + Block + 'static,
-    Be: Send + Sync + Backend<B> + 'static,
-    C: Send
-      + Sync
-      + HeaderBackend<B>
-      + BlockBackend<B>
-      + BlockImport<B, Transaction = TransactionFor<C, B>>
-      + Finalizer<B, Be>
-      + ProvideRuntimeApi<B>
-      + 'static,
-  > TendermintClient<B, Be> for C
-where
-  TransactionFor<C, B>: Send + Sync + 'static,
-  C::Api: TendermintApi<B>,
-{
-}
+pub(crate) struct TendermintImport<T: TendermintAuthor> {
+  _ta: PhantomData<T>,
 
-pub(crate) struct TendermintImport<
-  B: Block,
-  Be: Backend<B> + 'static,
-  C: TendermintClient<B, Be>,
-  CIDP: CreateInherentDataProviders<B, ()> + 'static,
-  E: Send + Sync + Environment<B> + 'static,
-  A: Announce<B>,
-> where
-  TransactionFor<C, B>: Send + Sync + 'static,
-  C::Api: TendermintApi<B>,
-{
-  _block: PhantomData<B>,
-  _backend: PhantomData<Be>,
+  validators: Arc<TendermintValidators<T>>,
 
-  validators: Arc<TendermintValidators<B, Be, C>>,
-
-  importing_block: Arc<RwLock<Option<B::Hash>>>,
+  importing_block: Arc<RwLock<Option<<T::Block as Block>::Hash>>>,
   pub(crate) machine: Arc<RwLock<Option<TendermintHandle<Self>>>>,
 
-  pub(crate) client: Arc<C>,
-  announce: A,
-  providers: Arc<CIDP>,
+  pub(crate) client: Arc<T::Client>,
+  announce: T::Announce,
+  providers: Arc<T::CIDP>,
 
-  env: Arc<AsyncRwLock<E>>,
-  pub(crate) queue: Arc<AsyncRwLock<Option<TendermintImportQueue<B, TransactionFor<C, B>>>>>,
+  env: Arc<AsyncRwLock<T::Environment>>,
+  pub(crate) queue:
+    Arc<AsyncRwLock<Option<TendermintImportQueue<T::Block, T::BackendTransaction>>>>,
 }
 
-impl<
-    B: Block,
-    Be: Backend<B> + 'static,
-    C: TendermintClient<B, Be>,
-    CIDP: CreateInherentDataProviders<B, ()> + 'static,
-    E: Send + Sync + Environment<B> + 'static,
-    A: Announce<B>,
-  > Clone for TendermintImport<B, Be, C, CIDP, E, A>
-where
-  TransactionFor<C, B>: Send + Sync + 'static,
-  C::Api: TendermintApi<B>,
-{
+impl<T: TendermintAuthor> Clone for TendermintImport<T> {
   fn clone(&self) -> Self {
     TendermintImport {
-      _block: PhantomData,
-      _backend: PhantomData,
+      _ta: PhantomData,
 
       validators: self.validators.clone(),
 
@@ -130,27 +75,15 @@ where
   }
 }
 
-impl<
-    B: Block,
-    Be: Backend<B> + 'static,
-    C: TendermintClient<B, Be>,
-    CIDP: CreateInherentDataProviders<B, ()> + 'static,
-    E: Send + Sync + Environment<B> + 'static,
-    A: Announce<B>,
-  > TendermintImport<B, Be, C, CIDP, E, A>
-where
-  TransactionFor<C, B>: Send + Sync + 'static,
-  C::Api: TendermintApi<B>,
-{
+impl<T: TendermintAuthor> TendermintImport<T> {
   pub(crate) fn new(
-    client: Arc<C>,
-    announce: A,
-    providers: Arc<CIDP>,
-    env: E,
-  ) -> TendermintImport<B, Be, C, CIDP, E, A> {
+    client: Arc<T::Client>,
+    announce: T::Announce,
+    providers: Arc<T::CIDP>,
+    env: T::Environment,
+  ) -> TendermintImport<T> {
     TendermintImport {
-      _block: PhantomData,
-      _backend: PhantomData,
+      _ta: PhantomData,
 
       validators: Arc::new(TendermintValidators::new(client.clone())),
 
@@ -168,8 +101,8 @@ where
 
   async fn check_inherents(
     &self,
-    block: B,
-    providers: CIDP::InherentDataProviders,
+    block: T::Block,
+    providers: <T::CIDP as CreateInherentDataProviders<T::Block, ()>>::InherentDataProviders,
   ) -> Result<(), Error> {
     // TODO
     Ok(())
@@ -178,8 +111,8 @@ where
   // Ensure this is part of a sequential import
   pub(crate) fn verify_order(
     &self,
-    parent: B::Hash,
-    number: <B::Header as Header>::Number,
+    parent: <T::Block as Block>::Hash,
+    number: <<T::Block as Block>::Header as Header>::Number,
   ) -> Result<(), Error> {
     let info = self.client.info();
     if (info.best_hash != parent) || ((info.best_number + 1u16.into()) != number) {
@@ -193,7 +126,7 @@ where
   // Tendermint's propose message could be rewritten as a seal OR Tendermint could produce blocks
   // which this checks the proposer slot for, and then tells the Tendermint machine
   // While those would be more seamless with Substrate, there's no actual benefit to doing so
-  fn verify_origin(&self, hash: B::Hash) -> Result<(), Error> {
+  fn verify_origin(&self, hash: <T::Block as Block>::Hash) -> Result<(), Error> {
     if let Some(tm_hash) = *self.importing_block.read().unwrap() {
       if hash == tm_hash {
         return Ok(());
@@ -205,14 +138,14 @@ where
   // Errors if the justification isn't valid
   pub(crate) fn verify_justification(
     &self,
-    hash: B::Hash,
+    hash: <T::Block as Block>::Hash,
     justification: &Justification,
   ) -> Result<(), Error> {
     if justification.0 != CONSENSUS_ID {
       Err(Error::InvalidJustification)?;
     }
 
-    let commit: Commit<TendermintValidators<B, Be, C>> =
+    let commit: Commit<TendermintValidators<T>> =
       Commit::decode(&mut justification.1.as_ref()).map_err(|_| Error::InvalidJustification)?;
     if !self.verify_commit(hash, &commit) {
       Err(Error::InvalidJustification)?;
@@ -223,7 +156,10 @@ where
   // Verifies the justifications aren't malformed, not that the block is justified
   // Errors if justifications is neither empty nor a sinlge Tendermint justification
   // If the block does have a justification, finalized will be set to true
-  fn verify_justifications<T>(&self, block: &mut BlockImportParams<B, T>) -> Result<(), Error> {
+  fn verify_justifications<BT>(
+    &self,
+    block: &mut BlockImportParams<T::Block, BT>,
+  ) -> Result<(), Error> {
     if !block.finalized {
       if let Some(justifications) = &block.justifications {
         let mut iter = justifications.iter();
@@ -238,7 +174,10 @@ where
     Ok(())
   }
 
-  pub(crate) async fn check<T>(&self, block: &mut BlockImportParams<B, T>) -> Result<(), Error> {
+  pub(crate) async fn check<BT>(
+    &self,
+    block: &mut BlockImportParams<T::Block, BT>,
+  ) -> Result<(), Error> {
     if block.finalized {
       if block.fork_choice.is_none() {
         // Since we alw1ays set the fork choice, this means something else marked the block as
@@ -261,7 +200,7 @@ where
       if let Some(body) = block.body.clone() {
         self
           .check_inherents(
-            B::new(block.header.clone(), body),
+            T::Block::new(block.header.clone(), body),
             self.providers.create_inherent_data_providers(*block.header.parent_hash(), ()).await?,
           )
           .await?;
@@ -281,7 +220,7 @@ where
     Ok(())
   }
 
-  pub(crate) async fn get_proposal(&mut self, header: &B::Header) -> B {
+  pub(crate) async fn get_proposal(&mut self, header: &<T::Block as Block>::Header) -> T::Block {
     let inherent_data =
       match self.providers.create_inherent_data_providers(header.hash(), ()).await {
         Ok(providers) => match providers.create_inherent_data() {
@@ -315,30 +254,19 @@ where
 }
 
 #[async_trait]
-impl<
-    B: Block,
-    Be: Backend<B> + 'static,
-    C: TendermintClient<B, Be>,
-    CIDP: CreateInherentDataProviders<B, ()> + 'static,
-    E: Send + Sync + Environment<B> + 'static,
-    A: Announce<B>,
-  > Network for TendermintImport<B, Be, C, CIDP, E, A>
-where
-  TransactionFor<C, B>: Send + Sync + 'static,
-  C::Api: TendermintApi<B>,
-{
+impl<T: TendermintAuthor> Network for TendermintImport<T> {
   type ValidatorId = u16;
-  type SignatureScheme = TendermintValidators<B, Be, C>;
-  type Weights = TendermintValidators<B, Be, C>;
-  type Block = B;
+  type SignatureScheme = TendermintValidators<T>;
+  type Weights = TendermintValidators<T>;
+  type Block = T::Block;
 
   const BLOCK_TIME: u32 = { (serai_runtime::MILLISECS_PER_BLOCK / 1000) as u32 };
 
-  fn signature_scheme(&self) -> Arc<TendermintValidators<B, Be, C>> {
+  fn signature_scheme(&self) -> Arc<TendermintValidators<T>> {
     self.validators.clone()
   }
 
-  fn weights(&self) -> Arc<TendermintValidators<B, Be, C>> {
+  fn weights(&self) -> Arc<TendermintValidators<T>> {
     self.validators.clone()
   }
 
@@ -362,7 +290,7 @@ where
   // the node.
   //
   // When Tendermint completes, the block is finalized, setting it as the tip regardless of work.
-  async fn validate(&mut self, block: &B) -> Result<(), BlockError> {
+  async fn validate(&mut self, block: &T::Block) -> Result<(), BlockError> {
     let hash = block.hash();
     let (header, body) = block.clone().deconstruct();
     let parent = *header.parent_hash();
@@ -407,7 +335,11 @@ where
     Ok(())
   }
 
-  async fn add_block(&mut self, block: B, commit: Commit<TendermintValidators<B, Be, C>>) -> B {
+  async fn add_block(
+    &mut self,
+    block: T::Block,
+    commit: Commit<TendermintValidators<T>>,
+  ) -> T::Block {
     let hash = block.hash();
     let justification = (CONSENSUS_ID, commit.encode());
     debug_assert!(self.verify_justification(hash, &justification).is_ok());

substrate/tendermint/client/src/types.rs

@@ -0,0 +1,75 @@
+use sp_inherents::CreateInherentDataProviders;
+use sp_runtime::traits::{Header, Block};
+
+use sp_blockchain::HeaderBackend;
+use sp_api::{StateBackend, StateBackendFor, TransactionFor, ApiExt, ProvideRuntimeApi};
+
+use sp_consensus::Environment;
+use sc_consensus::BlockImport;
+
+use sc_client_api::{BlockBackend, Backend, Finalizer};
+
+use sp_tendermint::TendermintApi;
+
+use crate::Announce;
+
+/// Trait consolidating all generics required by sc_tendermint for processing.
+pub trait TendermintClient: Send + Sync + 'static {
+  type Block: Block;
+  type Backend: Backend<Self::Block> + 'static;
+
+  /// TransactionFor<Client, Block>
+  type BackendTransaction: Send + Sync + 'static;
+  /// StateBackendFor<Client, Block>
+  type StateBackend: StateBackend<
+    <<Self::Block as Block>::Header as Header>::Hashing,
+    Transaction = Self::BackendTransaction,
+  >;
+  // Client::Api
+  type Api: ApiExt<Self::Block, StateBackend = Self::StateBackend> + TendermintApi<Self::Block>;
+  type Client: Send
+    + Sync
+    + HeaderBackend<Self::Block>
+    + BlockBackend<Self::Block>
+    + BlockImport<Self::Block, Transaction = Self::BackendTransaction>
+    + Finalizer<Self::Block, Self::Backend>
+    + ProvideRuntimeApi<Self::Block, Api = Self::Api>
+    + 'static;
+}
+
+/// Trait implementable on firm types to automatically provide a full TendermintClient impl.
+pub trait TendermintClientMinimal: Send + Sync + 'static {
+  type Block: Block;
+  type Backend: Backend<Self::Block> + 'static;
+  type Api: ApiExt<Self::Block> + TendermintApi<Self::Block>;
+  type Client: Send
+    + Sync
+    + HeaderBackend<Self::Block>
+    + BlockBackend<Self::Block>
+    + BlockImport<Self::Block, Transaction = TransactionFor<Self::Client, Self::Block>>
+    + Finalizer<Self::Block, Self::Backend>
+    + ProvideRuntimeApi<Self::Block, Api = Self::Api>
+    + 'static;
+}
+
+impl<T: TendermintClientMinimal> TendermintClient for T
+where
+  <T::Client as ProvideRuntimeApi<T::Block>>::Api: TendermintApi<T::Block>,
+  TransactionFor<T::Client, T::Block>: Send + Sync + 'static,
+{
+  type Block = T::Block;
+  type Backend = T::Backend;
+
+  type BackendTransaction = TransactionFor<T::Client, T::Block>;
+  type StateBackend = StateBackendFor<T::Client, T::Block>;
+  type Api = <T::Client as ProvideRuntimeApi<T::Block>>::Api;
+  type Client = T::Client;
+}
+
+/// Trait consolidating additional generics required by sc_tendermint for authoring.
+pub trait TendermintAuthor: TendermintClient {
+  type CIDP: CreateInherentDataProviders<Self::Block, ()> + 'static;
+  type Environment: Send + Sync + Environment<Self::Block> + 'static;
+
+  type Announce: Announce<Self::Block>;
+}

substrate/tendermint/client/src/validators.rs

@@ -6,17 +6,16 @@ use sp_application_crypto::{
   sr25519::{Public, Pair, Signature},
 };
 
-use sp_runtime::traits::Block;
 use sp_staking::SessionIndex;
-use sp_api::{BlockId, TransactionFor};
+use sp_api::{BlockId, ProvideRuntimeApi};
 
-use sc_client_api::Backend;
+use sc_client_api::HeaderBackend;
 
 use tendermint_machine::ext::{BlockNumber, Round, Weights, SignatureScheme};
 
 use sp_tendermint::TendermintApi;
 
-use crate::tendermint::TendermintClient;
+use crate::types::TendermintClient;
 
 struct TendermintValidatorsStruct {
   session: SessionIndex,
@@ -29,13 +28,7 @@ struct TendermintValidatorsStruct {
 }
 
 impl TendermintValidatorsStruct {
-  fn from_module<B: Block, Be: Backend<B> + 'static, C: TendermintClient<B, Be>>(
-    client: &Arc<C>,
-  ) -> TendermintValidatorsStruct
-  where
-    TransactionFor<C, B>: Send + Sync + 'static,
-    C::Api: TendermintApi<B>,
-  {
+  fn from_module<T: TendermintClient>(client: &Arc<T::Client>) -> TendermintValidatorsStruct {
     let last = client.info().best_hash;
     let api = client.runtime_api();
     let session = api.current_session(&BlockId::Hash(last)).unwrap();
@@ -56,23 +49,13 @@ impl TendermintValidatorsStruct {
 }
 
 // Wrap every access of the validators struct in something which forces calling refresh
-struct Refresh<B: Block, Be: Backend<B> + 'static, C: TendermintClient<B, Be>>
-where
-  TransactionFor<C, B>: Send + Sync + 'static,
-  C::Api: TendermintApi<B>,
-{
-  _block: PhantomData<B>,
-  _backend: PhantomData<Be>,
-
-  client: Arc<C>,
+struct Refresh<T: TendermintClient> {
+  _tc: PhantomData<T>,
+  client: Arc<T::Client>,
   _refresh: Arc<RwLock<TendermintValidatorsStruct>>,
 }
 
-impl<B: Block, Be: Backend<B> + 'static, C: TendermintClient<B, Be>> Refresh<B, Be, C>
-where
-  TransactionFor<C, B>: Send + Sync + 'static,
-  C::Api: TendermintApi<B>,
-{
+impl<T: TendermintClient> Refresh<T> {
   // If the session has changed, re-create the struct with the data on it
   fn refresh(&self) {
     let session = self._refresh.read().unwrap().session;
@@ -83,16 +66,12 @@ where
         .current_session(&BlockId::Hash(self.client.info().best_hash))
         .unwrap()
     {
-      *self._refresh.write().unwrap() = TendermintValidatorsStruct::from_module(&self.client);
+      *self._refresh.write().unwrap() = TendermintValidatorsStruct::from_module::<T>(&self.client);
     }
   }
 }
 
-impl<B: Block, Be: Backend<B> + 'static, C: TendermintClient<B, Be>> Deref for Refresh<B, Be, C>
-where
-  TransactionFor<C, B>: Send + Sync + 'static,
-  C::Api: TendermintApi<B>,
-{
+impl<T: TendermintClient> Deref for Refresh<T> {
   type Target = RwLock<TendermintValidatorsStruct>;
   fn deref(&self) -> &RwLock<TendermintValidatorsStruct> {
     self.refresh();
@@ -100,37 +79,19 @@ where
   }
 }
 
-pub(crate) struct TendermintValidators<
-  B: Block,
-  Be: Backend<B> + 'static,
-  C: TendermintClient<B, Be>,
->(Refresh<B, Be, C>)
-where
-  TransactionFor<C, B>: Send + Sync + 'static,
-  C::Api: TendermintApi<B>;
+pub(crate) struct TendermintValidators<T: TendermintClient>(Refresh<T>);
 
-impl<B: Block, Be: Backend<B> + 'static, C: TendermintClient<B, Be>> TendermintValidators<B, Be, C>
-where
-  TransactionFor<C, B>: Send + Sync + 'static,
-  C::Api: TendermintApi<B>,
-{
-  pub(crate) fn new(client: Arc<C>) -> TendermintValidators<B, Be, C> {
+impl<T: TendermintClient> TendermintValidators<T> {
+  pub(crate) fn new(client: Arc<T::Client>) -> TendermintValidators<T> {
     TendermintValidators(Refresh {
-      _block: PhantomData,
-      _backend: PhantomData,
-
-      _refresh: Arc::new(RwLock::new(TendermintValidatorsStruct::from_module(&client))),
+      _tc: PhantomData,
+      _refresh: Arc::new(RwLock::new(TendermintValidatorsStruct::from_module::<T>(&client))),
       client,
     })
   }
 }
 
-impl<B: Block, Be: Backend<B> + 'static, C: TendermintClient<B, Be>> SignatureScheme
-  for TendermintValidators<B, Be, C>
-where
-  TransactionFor<C, B>: Send + Sync + 'static,
-  C::Api: TendermintApi<B>,
-{
+impl<T: TendermintClient> SignatureScheme for TendermintValidators<T> {
   type ValidatorId = u16;
   type Signature = Signature;
   type AggregateSignature = Vec<Signature>;
@@ -160,12 +121,7 @@ where
   }
 }
 
-impl<B: Block, Be: Backend<B> + 'static, C: TendermintClient<B, Be>> Weights
-  for TendermintValidators<B, Be, C>
-where
-  TransactionFor<C, B>: Send + Sync + 'static,
-  C::Api: TendermintApi<B>,
-{
+impl<T: TendermintClient> Weights for TendermintValidators<T> {
   type ValidatorId = u16;
 
   fn total_weight(&self) -> u64 {

substrate/tendermint/client/src/verifier.rs

@@ -2,41 +2,21 @@ use std::sync::Arc;
 
 use async_trait::async_trait;
 
-use sp_inherents::CreateInherentDataProviders;
-use sp_runtime::traits::Block;
-use sp_api::TransactionFor;
-
-use sp_consensus::{Error, CacheKeyId, Environment};
+use sp_consensus::{Error, CacheKeyId};
 use sc_consensus::{BlockImportParams, BlockImport, Verifier};
 
-use sc_client_api::Backend;
-
-use sp_tendermint::TendermintApi;
-
-use crate::{
-  tendermint::{TendermintClient, TendermintImport},
-  Announce,
-};
+use crate::{types::TendermintAuthor, tendermint::TendermintImport};
 
 #[async_trait]
-impl<
-    B: Block,
-    Be: Backend<B> + 'static,
-    C: TendermintClient<B, Be>,
-    CIDP: CreateInherentDataProviders<B, ()> + 'static,
-    E: Send + Sync + Environment<B> + 'static,
-    A: Announce<B>,
-  > Verifier<B> for TendermintImport<B, Be, C, CIDP, E, A>
+impl<T: TendermintAuthor> Verifier<T::Block> for TendermintImport<T>
 where
-  TransactionFor<C, B>: Send + Sync + 'static,
-  Arc<C>: BlockImport<B, Transaction = TransactionFor<C, B>>,
-  <Arc<C> as BlockImport<B>>::Error: Into<Error>,
-  C::Api: TendermintApi<B>,
+  Arc<T::Client>: BlockImport<T::Block, Transaction = T::BackendTransaction>,
+  <Arc<T::Client> as BlockImport<T::Block>>::Error: Into<Error>,
 {
   async fn verify(
     &mut self,
-    mut block: BlockImportParams<B, ()>,
-  ) -> Result<(BlockImportParams<B, ()>, Option<Vec<(CacheKeyId, Vec<u8>)>>), String> {
+    mut block: BlockImportParams<T::Block, ()>,
+  ) -> Result<(BlockImportParams<T::Block, ()>, Option<Vec<(CacheKeyId, Vec<u8>)>>), String> {
     self.check(&mut block).await.map_err(|e| format!("{}", e))?;
     Ok((block, None))
   }