all: clean up and proerly abstract database access

core/rawdb/database.go

@@ -0,0 +1,52 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package rawdb
+
+import (
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/ethdb/leveldb"
+	"github.com/ethereum/go-ethereum/ethdb/memorydb"
+)
+
+// NewDatabase creates a high level database on top of a given key-value data
+// store without a freezer moving immutable chain segments into cold storage.
+func NewDatabase(db ethdb.KeyValueStore) ethdb.Database {
+	return db
+}
+
+// NewMemoryDatabase creates an ephemeral in-memory key-value database without a
+// freezer moving immutable chain segments into cold storage.
+func NewMemoryDatabase() ethdb.Database {
+	return NewDatabase(memorydb.New())
+}
+
+// NewMemoryDatabaseWithCap creates an ephemeral in-memory key-value database with
+// an initial starting capacity, but without a freezer moving immutable chain
+// segments into cold storage.
+func NewMemoryDatabaseWithCap(size int) ethdb.Database {
+	return NewDatabase(memorydb.NewWithCap(size))
+}
+
+// NewLevelDBDatabase creates a persistent key-value database without a freezer
+// moving immutable chain segments into cold storage.
+func NewLevelDBDatabase(file string, cache int, handles int, namespace string) (ethdb.Database, error) {
+	db, err := leveldb.New(file, cache, handles, namespace)
+	if err != nil {
+		return nil, err
+	}
+	return NewDatabase(db), nil
+}