blockdb: allow to dump blocks to json-encoded file

- Allow to dump blockdb to a json file
  - Compared to leveldb, a json file is easier to trace.
- Add interfaces block database:
  - Close would be required by database that needs cleanup.
  - BlockIterator is required when we need to access 'all' blocks,
     adding a new method 'GetAll' as the constructor for iterators.
- Remove GetByValidatorAndHeight from blockdb.Reader
  - This function is not used anywhere, to make interface
     minimum, remove it.
- Fix typo: backend -> backed

2 files changed, 9 insertions, 10 deletions

diff --git a/simulation/simulation.go b/simulation/simulation.go
index 2ea768e..8542051 100644
--- a/simulation/simulation.go
+++ b/simulation/simulation.go
@@ -51,14 +51,14 @@ func Run(configPath string) {
 
 			for i := 0; i < cfg.Validator.Num; i++ {
 				id := types.ValidatorID{Hash: common.NewRandomHash()}
-				vs = append(vs, NewValidator(id, cfg.Validator, network, nil))
+				vs = append(vs, NewValidator(id, cfg.Validator, network))
 			}
 		} else if networkType == config.NetworkTypeTCPLocal {
 			for i := 0; i < cfg.Validator.Num; i++ {
 				id := types.ValidatorID{Hash: common.NewRandomHash()}
 				network := NewTCPNetwork(true, cfg.Networking.PeerServer)
 				go network.Start()
-				vs = append(vs, NewValidator(id, cfg.Validator, network, nil))
+				vs = append(vs, NewValidator(id, cfg.Validator, network))
 			}
 		}
 
@@ -70,7 +70,7 @@ func Run(configPath string) {
 		id := types.ValidatorID{Hash: common.NewRandomHash()}
 		network := NewTCPNetwork(false, cfg.Networking.PeerServer)
 		go network.Start()
-		v := NewValidator(id, cfg.Validator, network, nil)
+		v := NewValidator(id, cfg.Validator, network)
 		go v.Run()
 		vs = append(vs, v)
 	}
diff --git a/simulation/validator.go b/simulation/validator.go
index 27e02fb..fb8afed 100644
--- a/simulation/validator.go
+++ b/simulation/validator.go
@@ -20,8 +20,6 @@ package simulation
 import (
 	"time"
 
-	"github.com/syndtr/goleveldb/leveldb"
-
 	"github.com/dexon-foundation/dexon-consensus-core/blockdb"
 	"github.com/dexon-foundation/dexon-consensus-core/common"
 	"github.com/dexon-foundation/dexon-consensus-core/core"
@@ -35,7 +33,6 @@ type Validator struct {
 	app     *SimApp
 
 	config     config.Validator
-	db         *leveldb.DB
 	msgChannel chan interface{}
 	isFinished chan struct{}
 
@@ -51,16 +48,18 @@ type Validator struct {
 func NewValidator(
 	id types.ValidatorID,
 	config config.Validator,
-	network Network,
-	db *leveldb.DB) *Validator {
+	network Network) *Validator {
 	app := NewSimApp(id, network)
-	lattice := core.NewBlockLattice(blockdb.NewMemBackedBlockDB(), app)
+	db, err := blockdb.NewMemBackedBlockDB()
+	if err != nil {
+		panic(err)
+	}
+	lattice := core.NewBlockLattice(db, app)
 	return &Validator{
 		ID:         id,
 		config:     config,
 		network:    network,
 		app:        app,
-		db:         db,
 		lattice:    lattice,
 		isFinished: make(chan struct{}),
 	}