forked from ethereum/go-ethereum
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Splits generic db from enodes packages (ethereum#1162)
* Renames
* NewGenericDB -> New
* Splits generic db from enodes packages
This enables other packages to create leveldbs outside of the enode package.- Loading branch information
Joshua Gutow
authored
Oct 27, 2020
1 parent
2e17f0d
commit c8dcba7
Showing
6 changed files
with
216 additions
and
215 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,183 @@ | ||
| // Copyright 2017 The Celo Authors | ||
| // This file is part of the celo library. | ||
| // | ||
| // The celo 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 celo 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 celo library. If not, see <http://www.gnu.org/licenses/>. | ||
|
|
||
| package db | ||
|
|
||
| import ( | ||
| "bytes" | ||
| "encoding/binary" | ||
| "os" | ||
|
|
||
| "github.com/syndtr/goleveldb/leveldb" | ||
| lvlerrors "github.com/syndtr/goleveldb/leveldb/errors" | ||
| "github.com/syndtr/goleveldb/leveldb/opt" | ||
| "github.com/syndtr/goleveldb/leveldb/storage" | ||
| "github.com/syndtr/goleveldb/leveldb/util" | ||
|
|
||
| "github.com/ethereum/go-ethereum/log" | ||
| ) | ||
|
|
||
| const ( | ||
| dbVersionKey = "version" // Version of the database to flush if changes | ||
| ) | ||
|
|
||
| // GenericDB manages a levelDB database | ||
| type GenericDB struct { | ||
| db *leveldb.DB | ||
| writeOptions *opt.WriteOptions | ||
| } | ||
|
|
||
| type GenericEntry interface{} | ||
|
|
||
| // New will open a new db at the given file path with the given version. | ||
| // If the path is empty, the db will be created in memory. | ||
| // If there is a version mismatch in the existing db, the contents are flushed. | ||
| func New(dbVersion int64, path string, logger log.Logger, writeOptions *opt.WriteOptions) (*GenericDB, error) { | ||
| db, err := NewDB(dbVersion, path, logger) | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
| return &GenericDB{ | ||
| db: db, | ||
| writeOptions: writeOptions, | ||
| }, nil | ||
| } | ||
|
|
||
| // Close flushes and closes the database files. | ||
| func (gdb *GenericDB) Close() error { | ||
| return gdb.db.Close() | ||
| } | ||
|
|
||
| // Upsert iterates through each provided entry and determines if the entry is | ||
| // new. If there is an existing entry in the db, `onUpdatedEntry` is called. | ||
| // If there is no existing entry, `onNewEntry` is called. Db content modifications are left to those functions | ||
| // by providing a leveldb Batch that is written after all entries are processed. | ||
| func (gdb *GenericDB) Upsert( | ||
| entries []GenericEntry, | ||
| getExistingEntry func(entry GenericEntry) (GenericEntry, error), | ||
| onUpdatedEntry func(batch *leveldb.Batch, existingEntry GenericEntry, newEntry GenericEntry) error, | ||
| onNewEntry func(batch *leveldb.Batch, entry GenericEntry) error, | ||
| ) error { | ||
| batch := new(leveldb.Batch) | ||
| for _, entry := range entries { | ||
| existingEntry, err := getExistingEntry(entry) | ||
| isNew := err == leveldb.ErrNotFound | ||
| if !isNew && err != nil { | ||
| return err | ||
| } | ||
| if isNew { | ||
| if err := onNewEntry(batch, entry); err != nil { | ||
| return err | ||
| } | ||
| } else { | ||
| if err := onUpdatedEntry(batch, existingEntry, entry); err != nil { | ||
| return err | ||
| } | ||
| } | ||
| } | ||
|
|
||
| if batch.Len() > 0 { | ||
| err := gdb.Write(batch) | ||
| if err != nil { | ||
| return err | ||
| } | ||
| } | ||
| return nil | ||
| } | ||
|
|
||
| // Get gets the bytes at a given key in the db | ||
| func (gdb *GenericDB) Get(key []byte) ([]byte, error) { | ||
| return gdb.db.Get(key, nil) | ||
| } | ||
|
|
||
| // Write writes a Batch to modify the db | ||
| func (gdb *GenericDB) Write(batch *leveldb.Batch) error { | ||
| return gdb.db.Write(batch, gdb.writeOptions) | ||
| } | ||
|
|
||
| // Iterate will iterate through each entry in the db whose key has the prefix | ||
| // keyPrefix, and call `onEntry` with the bytes of the key (without the prefix) | ||
| // and the bytes of the value | ||
| func (gdb *GenericDB) Iterate(keyPrefix []byte, onEntry func([]byte, []byte) error) error { | ||
| iter := gdb.db.NewIterator(util.BytesPrefix(keyPrefix), nil) | ||
| defer iter.Release() | ||
|
|
||
| for iter.Next() { | ||
| key := iter.Key()[len(keyPrefix):] | ||
| err := onEntry(key, iter.Value()) | ||
| if err != nil { | ||
| return err | ||
| } | ||
| } | ||
| return iter.Error() | ||
| } | ||
|
|
||
| // newDB creates/opens a leveldb persistent database at the given path. | ||
| // If no path is given, an in-memory, temporary database is constructed. | ||
| func NewDB(dbVersion int64, path string, logger log.Logger) (*leveldb.DB, error) { | ||
| if path == "" { | ||
| return NewMemoryDB() | ||
| } | ||
| return NewPersistentDB(dbVersion, path, logger) | ||
| } | ||
|
|
||
| // newMemoryDB creates a new in-memory node database without a persistent backend. | ||
| func NewMemoryDB() (*leveldb.DB, error) { | ||
| db, err := leveldb.Open(storage.NewMemStorage(), nil) | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
| return db, nil | ||
| } | ||
|
|
||
| // newPersistentNodeDB creates/opens a leveldb backed persistent database, | ||
| // also flushing its contents in case of a version mismatch. | ||
| func NewPersistentDB(dbVersion int64, path string, logger log.Logger) (*leveldb.DB, error) { | ||
| opts := &opt.Options{OpenFilesCacheCapacity: 5} | ||
| db, err := leveldb.OpenFile(path, opts) | ||
| if _, iscorrupted := err.(*lvlerrors.ErrCorrupted); iscorrupted { | ||
| db, err = leveldb.RecoverFile(path, nil) | ||
| } | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
| currentVer := make([]byte, binary.MaxVarintLen64) | ||
| currentVer = currentVer[:binary.PutVarint(currentVer, dbVersion)] | ||
|
|
||
| blob, err := db.Get([]byte(dbVersionKey), nil) | ||
| switch err { | ||
| case leveldb.ErrNotFound: | ||
| // Version not found (i.e. empty cache), insert it | ||
| if err := db.Put([]byte(dbVersionKey), currentVer, nil); err != nil { | ||
| db.Close() | ||
| return nil, err | ||
| } | ||
|
|
||
| case nil: | ||
| // Version present, flush if different | ||
| if !bytes.Equal(blob, currentVer) { | ||
| oldVersion, _ := binary.Varint(blob) | ||
| newVersion, _ := binary.Varint(currentVer) | ||
| logger.Info("DB version has changed. Creating a new leveldb.", "old version", oldVersion, "new version", newVersion) | ||
| db.Close() | ||
| if err = os.RemoveAll(path); err != nil { | ||
| return nil, err | ||
| } | ||
| return NewPersistentDB(dbVersion, path, logger) | ||
| } | ||
| } | ||
| return db, nil | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.