gitea/vendor/github.com/lunny/nodb/store/goleveldb/db.go

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2019-02-05 16:52:51 +00:00
package goleveldb
import (
"github.com/syndtr/goleveldb/leveldb"
"github.com/syndtr/goleveldb/leveldb/cache"
"github.com/syndtr/goleveldb/leveldb/filter"
"github.com/syndtr/goleveldb/leveldb/opt"
"github.com/syndtr/goleveldb/leveldb/storage"
"github.com/lunny/nodb/config"
"github.com/lunny/nodb/store/driver"
"os"
)
const defaultFilterBits int = 10
type Store struct {
}
func (s Store) String() string {
return DBName
}
type MemStore struct {
}
func (s MemStore) String() string {
return MemDBName
}
type DB struct {
path string
cfg *config.LevelDBConfig
db *leveldb.DB
opts *opt.Options
iteratorOpts *opt.ReadOptions
cache cache.Cache
filter filter.Filter
}
func (s Store) Open(path string, cfg *config.Config) (driver.IDB, error) {
if err := os.MkdirAll(path, os.ModePerm); err != nil {
return nil, err
}
db := new(DB)
db.path = path
db.cfg = &cfg.LevelDB
db.initOpts()
var err error
db.db, err = leveldb.OpenFile(db.path, db.opts)
if err != nil {
return nil, err
}
return db, nil
}
func (s Store) Repair(path string, cfg *config.Config) error {
db, err := leveldb.RecoverFile(path, newOptions(&cfg.LevelDB))
if err != nil {
return err
}
db.Close()
return nil
}
func (s MemStore) Open(path string, cfg *config.Config) (driver.IDB, error) {
db := new(DB)
db.path = path
db.cfg = &cfg.LevelDB
db.initOpts()
var err error
db.db, err = leveldb.Open(storage.NewMemStorage(), db.opts)
if err != nil {
return nil, err
}
return db, nil
}
func (s MemStore) Repair(path string, cfg *config.Config) error {
return nil
}
func (db *DB) initOpts() {
db.opts = newOptions(db.cfg)
db.iteratorOpts = &opt.ReadOptions{}
db.iteratorOpts.DontFillCache = true
}
func newOptions(cfg *config.LevelDBConfig) *opt.Options {
opts := &opt.Options{}
opts.ErrorIfMissing = false
cfg.Adjust()
//opts.BlockCacher = cache.NewLRU(cfg.CacheSize)
opts.BlockCacheCapacity = cfg.CacheSize
//we must use bloomfilter
opts.Filter = filter.NewBloomFilter(defaultFilterBits)
if !cfg.Compression {
opts.Compression = opt.NoCompression
} else {
opts.Compression = opt.SnappyCompression
}
opts.BlockSize = cfg.BlockSize
opts.WriteBuffer = cfg.WriteBufferSize
return opts
}
func (db *DB) Close() error {
return db.db.Close()
}
func (db *DB) Put(key, value []byte) error {
return db.db.Put(key, value, nil)
}
func (db *DB) Get(key []byte) ([]byte, error) {
v, err := db.db.Get(key, nil)
if err == leveldb.ErrNotFound {
return nil, nil
}
return v, nil
}
func (db *DB) Delete(key []byte) error {
return db.db.Delete(key, nil)
}
func (db *DB) NewWriteBatch() driver.IWriteBatch {
wb := &WriteBatch{
db: db,
wbatch: new(leveldb.Batch),
}
return wb
}
func (db *DB) NewIterator() driver.IIterator {
it := &Iterator{
db.db.NewIterator(nil, db.iteratorOpts),
}
return it
}
func (db *DB) Begin() (driver.Tx, error) {
return nil, driver.ErrTxSupport
}
func (db *DB) NewSnapshot() (driver.ISnapshot, error) {
snapshot, err := db.db.GetSnapshot()
if err != nil {
return nil, err
}
s := &Snapshot{
db: db,
snp: snapshot,
}
return s, nil
}
func init() {
driver.Register(Store{})
driver.Register(MemStore{})
}