/usr/share/gocode/src/github.com/lunny/nodb/multi.go is in golang-github-lunny-nodb-dev 0.0~git20160621.0.fc1ef06-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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import (
"errors"
"fmt"
)
var (
ErrNestMulti = errors.New("nest multi not supported")
ErrMultiDone = errors.New("multi has been closed")
)
type Multi struct {
*DB
}
func (db *DB) IsInMulti() bool {
return db.status == DBInMulti
}
// begin a mutli to execute commands,
// it will block any other write operations before you close the multi, unlike transaction, mutli can not rollback
func (db *DB) Multi() (*Multi, error) {
if db.IsInMulti() {
return nil, ErrNestMulti
}
m := new(Multi)
m.DB = new(DB)
m.DB.status = DBInMulti
m.DB.l = db.l
m.l.wLock.Lock()
m.DB.sdb = db.sdb
m.DB.bucket = db.sdb
m.DB.index = db.index
m.DB.kvBatch = m.newBatch()
m.DB.listBatch = m.newBatch()
m.DB.hashBatch = m.newBatch()
m.DB.zsetBatch = m.newBatch()
m.DB.binBatch = m.newBatch()
m.DB.setBatch = m.newBatch()
return m, nil
}
func (m *Multi) newBatch() *batch {
return m.l.newBatch(m.bucket.NewWriteBatch(), &multiBatchLocker{}, nil)
}
func (m *Multi) Close() error {
if m.bucket == nil {
return ErrMultiDone
}
m.l.wLock.Unlock()
m.bucket = nil
return nil
}
func (m *Multi) Select(index int) error {
if index < 0 || index >= int(MaxDBNumber) {
return fmt.Errorf("invalid db index %d", index)
}
m.DB.index = uint8(index)
return nil
}
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