Merge pull request #1 from sei-protocol/tony-chen-add-option-for-bloo…

…m-filter

Add GoLevelDB with bloom filter backend

db.go

@@ -13,7 +13,8 @@ const (
 	// popular implementation)
 	//   - pure go
 	//   - stable
-	GoLevelDBBackend BackendType = "goleveldb"
+	GoLevelDBBackend                BackendType = "goleveldb"
+	GoLevelDBBackendWithBloomFilter BackendType = "goleveldb-bloom"
 	// CLevelDBBackend represents cleveldb (uses levigo wrapper)
 	//   - fast
 	//   - requires gcc

goleveldb.go

@@ -6,15 +6,22 @@ import (
 
 	"github.com/syndtr/goleveldb/leveldb"
 	"github.com/syndtr/goleveldb/leveldb/errors"
+	"github.com/syndtr/goleveldb/leveldb/filter"
 	"github.com/syndtr/goleveldb/leveldb/opt"
 	"github.com/syndtr/goleveldb/leveldb/util"
 )
 
+const BloomFilterBitSize = 256
+
 func init() {
 	dbCreator := func(name string, dir string) (DB, error) {
 		return NewGoLevelDB(name, dir)
 	}
 	registerDBCreator(GoLevelDBBackend, dbCreator, false)
+	dbCreatorWithBloomFilter := func(name string, dir string) (DB, error) {
+		return NewGoLevelDBWithBloomFilter(name, dir)
+	}
+	registerDBCreator(GoLevelDBBackendWithBloomFilter, dbCreatorWithBloomFilter, false)
 }
 
 type GoLevelDB struct {
@@ -27,6 +34,10 @@ func NewGoLevelDB(name string, dir string) (*GoLevelDB, error) {
 	return NewGoLevelDBWithOpts(name, dir, nil)
 }
 
+func NewGoLevelDBWithBloomFilter(name string, dir string) (*GoLevelDB, error) {
+	return NewGoLevelDBWithOpts(name, dir, &opt.Options{Filter: filter.NewBloomFilter(BloomFilterBitSize)})
+}
+
 func NewGoLevelDBWithOpts(name string, dir string, o *opt.Options) (*GoLevelDB, error) {
 	dbPath := filepath.Join(dir, name+".db")
 	db, err := leveldb.OpenFile(dbPath, o)