perf(internal/blocksync): do not ValidateBlock twice (#2026)

blocksync/reactor.go

@@ -419,7 +419,7 @@ FOR_LOOP:
 
 			// TODO: same thing for app - but we would need a way to
 			// get the hash without persisting the state
-			state, _, err = bcR.blockExec.ApplyBlock(state, firstID, first)
+			state, err = bcR.blockExec.ApplyVerifiedBlock(state, firstID, first)
 			if err != nil {
 				// TODO This is bad, are we zombie?
 				panic(fmt.Sprintf("Failed to process committed block (%d:%X): %v", first.Height, first.Hash(), err))

state/execution.go

@@ -179,6 +179,14 @@ func (blockExec *BlockExecutor) ValidateBlock(state State, block *types.Block) e
 	return blockExec.evpool.CheckEvidence(block.Evidence.Evidence)
 }
 
+// ApplyVerifiedBlock does the same as `ApplyBlock`, but skips verification.
+func (blockExec *BlockExecutor) ApplyVerifiedBlock(
+	state State, blockID types.BlockID, block *types.Block,
+) (State, error) {
+	newState, _, err := blockExec.applyBlock(state, blockID, block)
+	return newState, err
+}
+
 // ApplyBlock validates the block against the state, executes it against the app,
 // fires the relevant events, commits the app, and saves the new state and responses.
 // It returns the new state and the block height to retain (pruning older blocks).
@@ -193,6 +201,10 @@ func (blockExec *BlockExecutor) ApplyBlock(
 		return state, 0, ErrInvalidBlock(err)
 	}
 
+	return blockExec.applyBlock(state, blockID, block)
+}
+
+func (blockExec *BlockExecutor) applyBlock(state State, blockID types.BlockID, block *types.Block) (State, int64, error) {
 	startTime := time.Now().UnixNano()
 	abciResponses, err := execBlockOnProxyApp(
 		blockExec.logger, blockExec.proxyApp, block, blockExec.store, state.InitialHeight,