Extract storage from blockchain construction (#1318)

This change separates storage instance construction from blockchain
construction. This is necessary for having ability to use custom storage
implementation as a backing storage for the blockchain.

blockchain/blockchain.go

@@ -4,13 +4,10 @@ import (
 	"errors"
 	"fmt"
 	"math/big"
-	"path/filepath"
 	"sync"
 	"sync/atomic"
 
 	"github.com/0xPolygon/polygon-edge/blockchain/storage"
-	"github.com/0xPolygon/polygon-edge/blockchain/storage/leveldb"
-	"github.com/0xPolygon/polygon-edge/blockchain/storage/memory"
 	"github.com/0xPolygon/polygon-edge/chain"
 	"github.com/0xPolygon/polygon-edge/helper/common"
 	"github.com/0xPolygon/polygon-edge/state"
@@ -187,7 +184,7 @@ func (b *Blockchain) GetAvgGasPrice() *big.Int {
 // NewBlockchain creates a new blockchain object
 func NewBlockchain(
 	logger hclog.Logger,
-	dataDir string,
+	db storage.Storage,
 	config *chain.Chain,
 	consensus Verifier,
 	executor Executor,
@@ -197,6 +194,7 @@ func NewBlockchain(
 		logger:    logger.Named("blockchain"),
 		config:    config,
 		consensus: consensus,
+		db:        db,
 		executor:  executor,
 		txSigner:  txSigner,
 		stream:    &eventStream{},
@@ -206,26 +204,6 @@ func NewBlockchain(
 		},
 	}
 
-	var (
-		db  storage.Storage
-		err error
-	)
-
-	if dataDir == "" {
-		if db, err = memory.NewMemoryStorage(nil); err != nil {
-			return nil, err
-		}
-	} else {
-		if db, err = leveldb.NewLevelDBStorage(
-			filepath.Join(dataDir, "blockchain"),
-			logger,
-		); err != nil {
-			return nil, err
-		}
-	}
-
-	b.db = db
-
 	if err := b.initCaches(defaultCacheSize); err != nil {
 		return nil, err
 	}

blockchain/testing.go

@@ -7,6 +7,7 @@ import (
 	"testing"
 
 	"github.com/0xPolygon/polygon-edge/blockchain/storage"
+	"github.com/0xPolygon/polygon-edge/blockchain/storage/memory"
 
 	"github.com/0xPolygon/polygon-edge/chain"
 	"github.com/0xPolygon/polygon-edge/state"
@@ -343,7 +344,12 @@ func newBlockChain(config *chain.Chain, executor Executor) (*Blockchain, error)
 		executor = &mockExecutor{}
 	}
 
-	b, err := NewBlockchain(hclog.NewNullLogger(), "", config, &MockVerifier{}, executor, &mockSigner{})
+	db, err := memory.NewMemoryStorage(nil)
+	if err != nil {
+		return nil, err
+	}
+
+	b, err := NewBlockchain(hclog.NewNullLogger(), db, config, &MockVerifier{}, executor, &mockSigner{})
 	if err != nil {
 		return nil, err
 	}

server/server.go

@@ -11,6 +11,9 @@ import (
 	"path/filepath"
 	"time"
 
+	"github.com/0xPolygon/polygon-edge/blockchain/storage"
+	"github.com/0xPolygon/polygon-edge/blockchain/storage/leveldb"
+	"github.com/0xPolygon/polygon-edge/blockchain/storage/memory"
 	consensusPolyBFT "github.com/0xPolygon/polygon-edge/consensus/polybft"
 
 	"github.com/0xPolygon/polygon-edge/archive"
@@ -245,8 +248,27 @@ func NewServer(config *Config) (*Server, error) {
 	// use the eip155 signer
 	signer := crypto.NewEIP155Signer(chain.AllForksEnabled.At(0), uint64(m.config.Chain.Params.ChainID))
 
+	// create storage instance for blockchain
+	var db storage.Storage
+	{
+		if m.config.DataDir == "" {
+			db, err = memory.NewMemoryStorage(nil)
+			if err != nil {
+				return nil, err
+			}
+		} else {
+			db, err = leveldb.NewLevelDBStorage(
+				filepath.Join(m.config.DataDir, "blockchain"),
+				m.logger,
+			)
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+
 	// blockchain object
-	m.blockchain, err = blockchain.NewBlockchain(logger, m.config.DataDir, config.Chain, nil, m.executor, signer)
+	m.blockchain, err = blockchain.NewBlockchain(logger, db, config.Chain, nil, m.executor, signer)
 	if err != nil {
 		return nil, err
 	}