kvdb

Documentation

Overview

Package kvdb 迭代器实现

Index

• func ErrNotFound(err error) bool
• type Batch
• type Database
  • func NewTable(db Database, prefix string) Database
• type Iterator
• type QuickIterator
  • func NewQuickIterator(ldb Database, prefix []byte, middleKey []byte) *QuickIterator
  • func (qi *QuickIterator) Error() error
  • func (qi *QuickIterator) Key() []byte
  • func (qi *QuickIterator) Next() bool
  • func (qi *QuickIterator) Release()
  • func (qi *QuickIterator) Value() []byte

Functions

func ErrNotFound

func ErrNotFound(err error) bool

ErrNotFound return true or false when key not found

Types

type Batch

type Batch interface {
	ValueSize() int
	Write() error
	Reset()
	Put(key []byte, value []byte) error
	Delete(key []byte) error
	PutIfAbsent(key []byte, value []byte) error
	Exist(key []byte) bool
}

Batch Batch操作的接口

type Database

type Database interface {
	Open(path string, options map[string]interface{}) error
	Put(key []byte, value []byte) error
	Get(key []byte) ([]byte, error)
	Has(key []byte) (bool, error)
	Delete(key []byte) error
	Close()
	NewBatch() Batch
	NewIteratorWithRange(start []byte, limit []byte) Iterator
	NewIteratorWithPrefix(prefix []byte) Iterator
}

Database KV数据库的接口

func NewTable

func NewTable(db Database, prefix string) Database

NewTable 基于前缀编码方式实现多表

type Iterator

type Iterator interface {
	Key() []byte
	Value() []byte
	Next() bool
	Prev() bool
	Last() bool
	First() bool
	Error() error
	Release()
}

Iterator NewIteratorXX操作后得到的迭代器

type QuickIterator

type QuickIterator struct {
	// contains filtered or unexported fields
}

QuickIterator define the data structure of quick iterator

func NewQuickIterator

func NewQuickIterator(ldb Database, prefix []byte, middleKey []byte) *QuickIterator

NewQuickIterator new quick iterator instance

func (*QuickIterator) Error

func (qi *QuickIterator) Error() error

Error return err for quick iterator

func (*QuickIterator) Key

func (qi *QuickIterator) Key() []byte

Key get key by quick iterator

func (*QuickIterator) Next

func (qi *QuickIterator) Next() bool

Next if iterator finished

func (*QuickIterator) Release

func (qi *QuickIterator) Release()

Release release iterators of quick iterator

func (*QuickIterator) Value

func (qi *QuickIterator) Value() []byte

Value get value by quick iterator