db

Documentation

Overview

Package db provides a generic interface around key/value databases.

Index

• Variables
• type Bucket
• type DB
• type Tx

Variables

var (
	ErrDataExist      = util.Error("数据已存在")
	ErrDataNotExist   = util.Error("数据不存在")
	ErrBucketExist    = util.Error("数据集已存在")
	ErrBucketNotExist = util.Error("数据集不存在")
	ErrStopEach       = errors.New("db: stop each")
)

Errors.

Types

type Bucket

type Bucket interface {
	// IsEmpty checks if the bucket is empty.
	IsEmpty() (bool, error)
	// Has checks if the bucket has the key.
	Has(key []byte) (bool, error)
	// Get retrieves the value for a key in the bucket.
	Get(key []byte, value interface{}) error
	// Put sets the value for a key in the bucket.
	Put(key []byte, value interface{}) error
	// Create creates a new value.
	Create(key []byte, value interface{}) error
	// Update updates the value.
	Update(key []byte, value interface{}) error
	// Delete removes the key from the bucket.
	Delete(key []byte) error
	// Each applies the function f to each values.
	Each(f interface{}, min, max []byte) error
	// Bucket retrieves a bucket by key.
	Bucket(key []byte) Bucket
	// CreateBucket creates a new bucket.
	CreateBucket(key []byte) (Bucket, error)
	// DeleteBucket deletes the bucket by key.
	DeleteBucket(key []byte) error
	// RequireBucket creates a new bucket if it doesn't already exist and returns a reference to it.
	RequireBucket(key []byte) (Bucket, error)
}

Bucket represents a collection of items inside the database.

type DB

type DB interface {
	// Close closes the database.
	Close() error
	// Begin starts a new transaction.
	Begin(writable bool) (Tx, error)
}

DB represents a database.

type Tx

type Tx interface {
	// Rollback closes the transaction and ignores all previous updates.
	Rollback() error
	// Commit writes all changes to database.
	Commit() error
	// Bucket retrieves a bucket by key.
	Bucket(key []byte) Bucket
	// CreateBucket creates a new bucket.
	CreateBucket(key []byte) (Bucket, error)
	// DeleteBucket deletes the bucket by key.
	DeleteBucket(key []byte) error
	// RequireBucket creates a new bucket if it doesn't already exist and returns a reference to it.
	RequireBucket(key []byte) (Bucket, error)
}

Tx represents a transaction on the database.