backend

Documentation

Overview

Package backend defines a standard interface for etcd's backend MVCC storage.

Index

• Constants
• Variables
• func NewDefaultTmpBackend() (*backend, string)
• func NewTmpBackend(batchInterval time.Duration, batchLimit int) (*backend, string)
• type Backend
  • func New(path string, d time.Duration, limit int) Backend
  • func NewDefaultBackend(path string) Backend
• type BatchTx
• type IgnoreKey
• type Snapshot

Constants

const (
	// DefaultQuotaBytes is the number of bytes the backend Size may
	// consume before exceeding the space quota.
	DefaultQuotaBytes = int64(2 * 1024 * 1024 * 1024) // 2GB
	// MaxQuotaBytes is the maximum number of bytes suggested for a backend
	// quota. A larger quota may lead to degraded performance.
	MaxQuotaBytes = int64(8 * 1024 * 1024 * 1024) // 8GB
)

Variables

var (

	// InitialMmapSize is the initial size of the mmapped region. Setting this larger than
	// the potential max db size can prevent writer from blocking reader.
	// This only works for linux.
	InitialMmapSize = int64(10 * 1024 * 1024 * 1024)
)

Functions

func NewDefaultTmpBackend

func NewDefaultTmpBackend() (*backend, string)

func NewTmpBackend

func NewTmpBackend(batchInterval time.Duration, batchLimit int) (*backend, string)

NewTmpBackend creates a backend implementation for testing.

Types

type Backend

type Backend interface {
	BatchTx() BatchTx
	Snapshot() Snapshot
	Hash(ignores map[IgnoreKey]struct{}) (uint32, error)
	// Size returns the current size of the backend.
	Size() int64
	Defrag() error
	ForceCommit()
	Close() error
}

func New

func New(path string, d time.Duration, limit int) Backend

func NewDefaultBackend

func NewDefaultBackend(path string) Backend

type BatchTx

type BatchTx interface {
	Lock()
	Unlock()
	// 创建bucket
	UnsafeCreateBucket(name []byte)
	// 向指定bucket中添加键值对数据
	UnsafePut(bucketName []byte, key []byte, value []byte)
	//
	UnsafeSeqPut(bucketName []byte, key []byte, value []byte)
	UnsafeRange(bucketName []byte, key, endKey []byte, limit int64) (keys [][]byte, vals [][]byte)
	UnsafeDelete(bucketName []byte, key []byte)
	UnsafeForEach(bucketName []byte, visitor func(k, v []byte) error) error
	// 提交事务，然后打开一个新的读写事务
	Commit()
	// 提交但是不打开新的读写事务
	CommitAndStop()
}

type IgnoreKey

type IgnoreKey struct {
	Bucket string
	Key    string
}

type Snapshot

type Snapshot interface {
	// Size gets the size of the snapshot.
	Size() int64
	// WriteTo writes the snapshot into the given writer.
	WriteTo(w io.Writer) (n int64, err error)
	// Close closes the snapshot.
	Close() error
}