go-ethereum/core/rawdb/database.go
2019-05-16 10:39:31 +03:00

120 lines
3.8 KiB
Go

// 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 (
"fmt"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/ethdb/leveldb"
"github.com/ethereum/go-ethereum/ethdb/memorydb"
)
// freezerdb is a databse wrapper that enabled freezer data retrievals.
type freezerdb struct {
ethdb.KeyValueStore
ethdb.AncientStore
}
// Close implements io.Closer, closing both the fast key-value store as well as
// the slow ancient tables.
func (frdb *freezerdb) Close() error {
var errs []error
if err := frdb.KeyValueStore.Close(); err != nil {
errs = append(errs, err)
}
if err := frdb.AncientStore.Close(); err != nil {
errs = append(errs, err)
}
if len(errs) != 0 {
return fmt.Errorf("%v", errs)
}
return nil
}
// nofreezedb is a database wrapper that disables freezer data retrievals.
type nofreezedb struct {
ethdb.KeyValueStore
}
// Frozen returns nil as we don't have a backing chain freezer.
func (db *nofreezedb) Ancient(kind string, number uint64) ([]byte, error) {
return nil, errOutOfBounds
}
// 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 &nofreezedb{
KeyValueStore: db,
}
}
// NewDatabaseWithFreezer creates a high level database on top of a given key-
// value data store with a freezer moving immutable chain segments into cold
// storage.
func NewDatabaseWithFreezer(db ethdb.KeyValueStore, freezer string, namespace string) (ethdb.Database, error) {
frdb, err := newFreezer(freezer, namespace)
if err != nil {
return nil, err
}
go frdb.freeze(db)
return &freezerdb{
KeyValueStore: db,
AncientStore: frdb,
}, nil
}
// 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
}
// NewLevelDBDatabaseWithFreezer creates a persistent key-value database with a
// freezer moving immutable chain segments into cold storage.
func NewLevelDBDatabaseWithFreezer(file string, cache int, handles int, freezer string, namespace string) (ethdb.Database, error) {
kvdb, err := leveldb.New(file, cache, handles, namespace)
if err != nil {
return nil, err
}
frdb, err := NewDatabaseWithFreezer(kvdb, freezer, namespace)
if err != nil {
kvdb.Close()
return nil, err
}
return frdb, nil
}