ledisdb/store/goleveldb/db.go

142 lines
2.5 KiB
Go

package goleveldb
import (
"github.com/siddontang/goleveldb/leveldb"
"github.com/siddontang/goleveldb/leveldb/cache"
"github.com/siddontang/goleveldb/leveldb/filter"
"github.com/siddontang/goleveldb/leveldb/opt"
"github.com/siddontang/ledisdb/store/driver"
"os"
)
const defaultFilterBits int = 10
type Config struct {
Path string `json:"path"`
Compression bool `json:"compression"`
BlockSize int `json:"block_size"`
WriteBufferSize int `json:"write_buffer_size"`
CacheSize int `json:"cache_size"`
MaxOpenFiles int `json:"max_open_files"`
}
type DB struct {
cfg *Config
db *leveldb.DB
opts *opt.Options
iteratorOpts *opt.ReadOptions
cache cache.Cache
filter filter.Filter
}
func Open(cfg *Config) (*DB, error) {
if err := os.MkdirAll(cfg.Path, os.ModePerm); err != nil {
return nil, err
}
db := new(DB)
db.cfg = cfg
if err := db.open(); err != nil {
return nil, err
}
return db, nil
}
func Repair(cfg *Config) error {
db, err := leveldb.RecoverFile(cfg.Path, newOptions(cfg))
if err != nil {
return err
}
db.Close()
return nil
}
func (db *DB) open() error {
db.opts = newOptions(db.cfg)
db.iteratorOpts = &opt.ReadOptions{}
db.iteratorOpts.DontFillCache = true
var err error
db.db, err = leveldb.OpenFile(db.cfg.Path, db.opts)
return err
}
func newOptions(cfg *Config) *opt.Options {
opts := &opt.Options{}
opts.ErrorIfMissing = false
if cfg.CacheSize > 0 {
opts.BlockCache = cache.NewLRUCache(cfg.CacheSize)
}
//we must use bloomfilter
opts.Filter = filter.NewBloomFilter(defaultFilterBits)
if !cfg.Compression {
opts.Compression = opt.NoCompression
} else {
opts.Compression = opt.SnappyCompression
}
if cfg.BlockSize > 0 {
opts.BlockSize = cfg.BlockSize
}
if cfg.WriteBufferSize > 0 {
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
}