[Util] add nWorker to verify execution result

cmd/util/cmd/verify_execution_result/cmd.go

@@ -18,6 +18,7 @@ var (
 	flagChunkDataPackDir string
 	flagChain            string
 	flagFromTo           string
+	flagWorkerCount      uint // number of workers to verify the blocks concurrently
 )
 
 // # verify the last 100 sealed blocks
@@ -47,12 +48,20 @@ func init() {
 
 	Cmd.Flags().StringVar(&flagFromTo, "from_to", "",
 		"the height range to verify blocks (inclusive), i.e, 1-1000, 1000-2000, 2000-3000, etc.")
+
+	Cmd.Flags().UintVar(&flagWorkerCount, "worker_count", 1,
+		"number of workers to use for verification, default is 1")
+
 }
 
 func run(*cobra.Command, []string) {
 	chainID := flow.ChainID(flagChain)
 	_ = chainID.Chain()
 
+	if flagWorkerCount < 1 {
+		log.Fatal().Msgf("worker count must be at least 1, but got %v", flagWorkerCount)
+	}
+
 	lg := log.With().
 		Str("chain", string(chainID)).
 		Str("datadir", flagDatadir).
@@ -66,15 +75,15 @@ func run(*cobra.Command, []string) {
 		}
 
 		lg.Info().Msgf("verifying range from %d to %d", from, to)
-		err = verifier.VerifyRange(from, to, chainID, flagDatadir, flagChunkDataPackDir)
+		err = verifier.VerifyRange(from, to, chainID, flagDatadir, flagChunkDataPackDir, flagWorkerCount)
 		if err != nil {
 			lg.Fatal().Err(err).Msgf("could not verify range from %d to %d", from, to)
 		}
 		lg.Info().Msgf("successfully verified range from %d to %d", from, to)
 
 	} else {
 		lg.Info().Msgf("verifying last %d sealed blocks", flagLastK)
-		err := verifier.VerifyLastKHeight(flagLastK, chainID, flagDatadir, flagChunkDataPackDir)
+		err := verifier.VerifyLastKHeight(flagLastK, chainID, flagDatadir, flagChunkDataPackDir, flagWorkerCount)
 		if err != nil {
 			lg.Fatal().Err(err).Msg("could not verify last k height")
 		}

engine/verification/verifier/verifiers.go

@@ -1,8 +1,10 @@
 package verifier
 
 import (
+	"context"
 	"errors"
 	"fmt"
+	"sync"
 
 	"github.com/rs/zerolog"
 	"github.com/rs/zerolog/log"
@@ -25,7 +27,7 @@ import (
 // It assumes the latest sealed block has been executed, and the chunk data packs have not been
 // pruned.
 // Note, it returns nil if certain block is not executed, in this case warning will be logged
-func VerifyLastKHeight(k uint64, chainID flow.ChainID, protocolDataDir string, chunkDataPackDir string) (err error) {
+func VerifyLastKHeight(k uint64, chainID flow.ChainID, protocolDataDir string, chunkDataPackDir string, nWorker uint) (err error) {
 	closer, storages, chunkDataPacks, state, verifier, err := initStorages(chainID, protocolDataDir, chunkDataPackDir)
 	if err != nil {
 		return fmt.Errorf("could not init storages: %w", err)
@@ -62,12 +64,9 @@ func VerifyLastKHeight(k uint64, chainID flow.ChainID, protocolDataDir string, c
 
 	log.Info().Msgf("verifying blocks from %d to %d", from, to)
 
-	for height := from; height <= to; height++ {
-		log.Info().Uint64("height", height).Msg("verifying height")
-		err := verifyHeight(height, storages.Headers, chunkDataPacks, storages.Results, state, verifier)
-		if err != nil {
-			return fmt.Errorf("could not verify height %d: %w", height, err)
-		}
+	err = verifyConcurrently(from, to, nWorker, storages.Headers, chunkDataPacks, storages.Results, state, verifier, verifyHeight)
+	if err != nil {
+		return err
 	}
 
 	return nil
@@ -79,6 +78,7 @@ func VerifyRange(
 	from, to uint64,
 	chainID flow.ChainID,
 	protocolDataDir string, chunkDataPackDir string,
+	nWorker uint,
 ) (err error) {
 	closer, storages, chunkDataPacks, state, verifier, err := initStorages(chainID, protocolDataDir, chunkDataPackDir)
 	if err != nil {
@@ -99,12 +99,94 @@ func VerifyRange(
 		return fmt.Errorf("cannot verify blocks before the root block, from: %d, root: %d", from, root)
 	}
 
-	for height := from; height <= to; height++ {
-		log.Info().Uint64("height", height).Msg("verifying height")
-		err := verifyHeight(height, storages.Headers, chunkDataPacks, storages.Results, state, verifier)
-		if err != nil {
-			return fmt.Errorf("could not verify height %d: %w", height, err)
+	err = verifyConcurrently(from, to, nWorker, storages.Headers, chunkDataPacks, storages.Results, state, verifier, verifyHeight)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func verifyConcurrently(
+	from, to uint64,
+	nWorker uint,
+	headers storage.Headers,
+	chunkDataPacks storage.ChunkDataPacks,
+	results storage.ExecutionResults,
+	state protocol.State,
+	verifier module.ChunkVerifier,
+	verifyHeight func(uint64, storage.Headers, storage.ChunkDataPacks, storage.ExecutionResults, protocol.State, module.ChunkVerifier) error,
+) error {
+	tasks := make(chan uint64, int(nWorker))
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel() // Ensure cancel is called to release resources
+
+	var lowestErr error
+	var lowestErrHeight uint64 = ^uint64(0) // Initialize to max value of uint64
+	var mu sync.Mutex                       // To protect access to lowestErr and lowestErrHeight
+
+	// Worker function
+	worker := func() {
+		for {
+			select {
+			case <-ctx.Done():
+				return // Stop processing tasks if context is canceled
+			case height, ok := <-tasks:
+				if !ok {
+					return // Exit if the tasks channel is closed
+				}
+				log.Info().Uint64("height", height).Msg("verifying height")
+				err := verifyHeight(height, headers, chunkDataPacks, results, state, verifier)
+				if err != nil {
+					log.Error().Uint64("height", height).Err(err).Msg("error encountered while verifying height")
+
+					// when encountered an error, the error might not be from the lowest height that had
+					// error, so we need to first cancel the context to stop worker from processing further tasks
+					// and wait until all workers are done, which will ensure all the heights before this height
+					// that had error are processed. Then we can safely update the lowestErr and lowestErrHeight
+					mu.Lock()
+					if height < lowestErrHeight {
+						lowestErr = err
+						lowestErrHeight = height
+						cancel() // Cancel context to stop further task dispatch
+					}
+					mu.Unlock()
+				} else {
+					log.Info().Uint64("height", height).Msg("verified height successfully")
+				}
+			}
+		}
+	}
+
+	// Start nWorker workers
+	var wg sync.WaitGroup
+	for i := 0; i < int(nWorker); i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			worker()
+		}()
+	}
+
+	// Send tasks to workers
+	go func() {
+		defer close(tasks) // Close tasks channel once all tasks are pushed
+		for height := from; height <= to; height++ {
+			select {
+			case <-ctx.Done():
+				return // Stop pushing tasks if context is canceled
+			case tasks <- height:
+			}
 		}
+	}()
+
+	// Wait for all workers to complete
+	wg.Wait()
+
+	// Check if there was an error
+	if lowestErr != nil {
+		log.Error().Uint64("height", lowestErrHeight).Err(lowestErr).Msg("error encountered while verifying height")
+		return fmt.Errorf("could not verify height %d: %w", lowestErrHeight, lowestErr)
 	}
 
 	return nil

engine/verification/verifier/verifiers_test.go

@@ -0,0 +1,85 @@
+package verifier
+
+import (
+	"errors"
+	"fmt"
+	"testing"
+
+	"github.com/onflow/flow-go/module"
+	mockmodule "github.com/onflow/flow-go/module/mock"
+	"github.com/onflow/flow-go/state/protocol"
+	"github.com/onflow/flow-go/storage"
+	"github.com/onflow/flow-go/storage/mock"
+	unittestMocks "github.com/onflow/flow-go/utils/unittest/mocks"
+)
+
+func TestVerifyConcurrently(t *testing.T) {
+
+	tests := []struct {
+		name        string
+		from        uint64
+		to          uint64
+		nWorker     uint
+		errors      map[uint64]error // Map of heights to errors
+		expectedErr error
+	}{
+		{
+			name:        "All heights verified successfully",
+			from:        1,
+			to:          5,
+			nWorker:     3,
+			errors:      nil,
+			expectedErr: nil,
+		},
+		{
+			name:        "Single error at a height",
+			from:        1,
+			to:          5,
+			nWorker:     3,
+			errors:      map[uint64]error{3: errors.New("mock error")},
+			expectedErr: fmt.Errorf("mock error"),
+		},
+		{
+			name:        "Multiple errors, lowest height returned",
+			from:        1,
+			to:          5,
+			nWorker:     3,
+			errors:      map[uint64]error{2: errors.New("error 2"), 4: errors.New("error 4")},
+			expectedErr: fmt.Errorf("error 2"),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Reset mockVerifyHeight for each test
+			mockVerifyHeight := func(
+				height uint64,
+				headers storage.Headers,
+				chunkDataPacks storage.ChunkDataPacks,
+				results storage.ExecutionResults,
+				state protocol.State,
+				verifier module.ChunkVerifier,
+			) error {
+				if err, ok := tt.errors[height]; ok {
+					return err
+				}
+				return nil
+			}
+
+			mockHeaders := mock.NewHeaders(t)
+			mockChunkDataPacks := mock.NewChunkDataPacks(t)
+			mockResults := mock.NewExecutionResults(t)
+			mockState := unittestMocks.NewProtocolState()
+			mockVerifier := mockmodule.NewChunkVerifier(t)
+
+			err := verifyConcurrently(tt.from, tt.to, tt.nWorker, mockHeaders, mockChunkDataPacks, mockResults, mockState, mockVerifier, mockVerifyHeight)
+			if tt.expectedErr != nil {
+				if err == nil || errors.Is(err, tt.expectedErr) {
+					t.Fatalf("expected error: %v, got: %v", tt.expectedErr, err)
+				}
+			} else if err != nil {
+				t.Fatalf("expected no error, got: %v", err)
+			}
+		})
+	}
+}