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Storm

Storm is simple and powerful ORM for BoltDB. The goal of this project is to provide a simple way to save any object in BoltDB and to easily retrieve it.

Getting Started

go get -u github.com/asdine/storm

Import Storm

import "github.com/asdine/storm"

Open a database

Quick way of opening a database

db, err := storm.Open("my.db")

defer db.Close()

Open can receive multiple options to customize the way it behaves. See Options below

Simple ORM

Declare your structures

type User struct {
  ID int // primary key
  Group string `storm:"index"` // this field will be indexed
  Email string `storm:"unique"` // this field will be indexed with a unique constraint
  Name string // this field will not be indexed
  Age int `storm:"index"`
}

The primary key can be of any type as long as it is not a zero value. Storm will search for the tag id, if not present Storm will search for a field named ID.

type User struct {
  ThePrimaryKey string `storm:"id"`// primary key
  Group string `storm:"index"` // this field will be indexed
  Email string `storm:"unique"` // this field will be indexed with a unique constraint
  Name string // this field will not be indexed
}

Storm handles tags in nested structures with the inline tag

type Base struct {
  Ident bson.ObjectId `storm:"id"`
}

type User struct {
	Base      `storm:"inline"`
	Group     string `storm:"index"`
	Email     string `storm:"unique"`
	Name      string
	CreatedAt time.Time `storm:"index"`
}

Save your object

user := User{
  ID: 10,
  Group: "staff",
  Email: "john@provider.com",
  Name: "John",
  Age: 21,
  CreatedAt: time.Now(),
}

err := db.Save(&user)
// err == nil

user.ID++
err = db.Save(&user)
// err == "already exists"

That's it.

Save creates or updates all the required indexes and buckets, checks the unique constraints and saves the object to the store.

Fetch your object

Only indexed fields can be used to find a record

var user User
err := db.One("Email", "john@provider.com", &user)
// err == nil

err = db.One("Name", "John", &user)
// err == "not found"

Fetch multiple objects

var users []User
err := db.Find("Group", "staff", &users)

Fetch all objects

var users []User
err := db.All(&users)

Fetch all objects sorted by index

var users []User
err := db.AllByIndex("CreatedAt", &users)

Fetch a range of objects

var users []User
err := db.Range("Age", 10, 21, &users)

Skip and Limit

var users []User
err := db.Find("Group", "staff", &users, storm.Skip(10))
err = db.Find("Group", "staff", &users, storm.Limit(10))
err = db.Find("Group", "staff", &users, storm.Limit(10), storm.Skip(10))

err = db.All(&users, storm.Limit(10), storm.Skip(10))
err = db.AllByIndex("CreatedAt", &users, storm.Limit(10), storm.Skip(10))
err = db.Range("Age", 10, 21, &users, storm.Limit(10), storm.Skip(10))

Remove an object

err := db.Remove(&user)

Initialize buckets and indexes before saving an object

err := db.Init(&User{})

Useful when starting your application

Transactions

tx, err := db.Begin(true)

accountA.Amount -= 100
accountB.Amount += 100

err = tx.Save(accountA)
if err != nil {
  tx.Rollback()
  return err
}

err = tx.Save(accountB)
if err != nil {
  tx.Rollback()
  return err
}

tx.Commit()

Options

Storm options are functions that can be passed when constructing you Storm instance. You can pass it any number of options.

BoltOptions

By default, Storm opens a database with the mode 0600 and a timeout of one second. You can change this behavior by using BoltOptions

db, err := storm.Open("my.db", storm.BoltOptions(0600, &bolt.Options{Timeout: 1 * time.Second}))

EncodeDecoder

To store the data in BoltDB, Storm encodes it in GOB by default. If you wish to change this behavior you can pass a codec that implements codec.EncodeDecoder via the storm.Codec option:

db := storm.Open("my.db", storm.Codec(myCodec))

Provided Codecs

You can easily implement your own EncodeDecoder, but Storm comes with built-in support for GOB (default), JSON, Sereal and Protocol Buffers

These can be used by importing the relevant package and use that codec to configure Storm. The example below shows all three (without proper error handling):

import (
	"github.com/asdine/storm"
	"github.com/asdine/storm/codec/gob"
	"github.com/asdine/storm/codec/json"
	"github.com/asdine/storm/codec/sereal"
	"github.com/asdine/storm/codec/protobuf"
)

var gobDb, _ = storm.Open("gob.db", storm.Codec(gob.Codec))
var jsonDb, _ = storm.Open("json.db", storm.Codec(json.Codec))
var serealDb, _ = storm.Open("sereal.db", storm.Codec(sereal.Codec))
var protobufDb, _ = storm.Open("protobuf.db", storm.Codec(protobuf.Codec))

Auto Increment

Storm can auto increment integer IDs so you don't have to worry about that when saving your objects.

db := storm.Open("my.db", storm.AutoIncrement())

Nodes and nested buckets

Storm takes advantage of BoltDB nested buckets feature by using storm.Node. A storm.Node is the underlying object used by storm.DB to manipulate a bucket. To create a nested bucket and use the same API as storm.DB, you can use the DB.From method.

repo := db.From("repo")

err := repo.Save(&Issue{
  Title: "I want more features",
  Author: user.ID,
})

err = repo.Save(newRelease("0.10"))

var issues []Issue
err = repo.Find("Author", user.ID, &issues)

var release Release
err = repo.One("Tag", "0.10", &release)

You can also chain the nodes to create a hierarchy

chars := db.From("characters")
heroes := chars.From("heroes")
enemies := chars.From("enemies")

items := db.From("items")
potions := items.From("consumables").From("medicine").From("potions")

You can even pass the entire hierarchy as arguments to From:

privateNotes := db.From("notes", "private")
workNotes :=  db.From("notes", "work")

Simple Key/Value store

Storm can be used as a simple, robust, key/value store that can store anything. The key and the value can be of any type as long as the key is not a zero value.

Saving data :

db.Set("logs", time.Now(), "I'm eating my breakfast man")
db.Set("sessions", bson.NewObjectId(), &someUser)
db.Set("weird storage", "754-3010", map[string]interface{}{
  "hair": "blonde",
  "likes": []string{"cheese", "star wars"},
})

Fetching data :

user := User{}
db.Get("sessions", someObjectId, &user)

var details map[string]interface{}
db.Get("weird storage", "754-3010", &details)

db.Get("sessions", someObjectId, &details)

Deleting data :

db.Delete("sessions", someObjectId)
db.Delete("weird storage", "754-3010")

BoltDB

BoltDB is still easily accessible and can be used as usual

db.Bolt.View(func(tx *bolt.Tx) error {
  bucket := tx.Bucket([]byte("my bucket"))
  val := bucket.Get([]byte("any id"))
  fmt.Println(string(val))
  return nil
})

A transaction can be also be passed to Storm

db.Bolt.Update(func(tx *bolt.Tx) error {
  ...
  dbx := db.WithTransaction(tx)
  err = dbx.Save(&user)
  ...
  return nil
})

TODO

Search
Reverse order
More indexes

License

MIT

Author

Asdine El Hrychy

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