bolt_storage.go

package storage

//bolt存储引擎实现  

import (

    "github.com/boltdb/bolt"

    "time"

)

var wukong_documents = []byte("wukong_documents")

//bolt结构体 实现  同时实现storage接口

type boltStorage struct {

    db *bolt.DB

}

//实现存储引擎map集合  实现value  对应的函数  

func openBoltStorage(path string) (Storage, error) {

    db, err := bolt.Open(path, 0600, &bolt.Options{Timeout: 3600 * time.Second})

    if err != nil {

        return nil, err

    }

    err = db.Update(func(tx *bolt.Tx) error {

        _, err := tx.CreateBucketIfNotExists(wukong_documents)

        return err

    })

    if err != nil {

        db.Close()

        return nil, err

    }

    return &boltStorage{db}, nil

}

func (s *boltStorage) WALName() string {

    return s.db.Path()

}

func (s *boltStorage) Set(k []byte, v []byte) error {

    return s.db.Update(func(tx *bolt.Tx) error {

        return tx.Bucket(wukong_documents).Put(k, v)

    })

}

func (s *boltStorage) Get(k []byte) (b []byte, err error) {

    err = s.db.View(func(tx *bolt.Tx) error {

        b = tx.Bucket(wukong_documents).Get(k)

        return nil

    })

    return

}

func (s *boltStorage) Delete(k []byte) error {

    return s.db.Update(func(tx *bolt.Tx) error {

        return tx.Bucket(wukong_documents).Delete(k)

    })

}

func (s *boltStorage) ForEach(fn func(k, v []byte) error) error {

    return s.db.View(func(tx *bolt.Tx) error {

        b := tx.Bucket(wukong_documents)

        c := b.Cursor()

        for k, v := c.First(); k != nil; k, v = c.Next() {

            if err := fn(k, v); err != nil {

                return err

            }

        }

        return nil

    })

}

func (s *boltStorage) Close() error {

    return s.db.Close()

}