ethdb

Documentation

Index

• Constants
• Variables
• type Batch
  • func NewTableBatch(db Database, prefix string) Batch
• type Database
  • func NewTable(db Database, prefix string) Database
• type LDBDatabase
  • func NewLDBDatabase(file string, cache int, handles int) (*LDBDatabase, error)
  • func (db *LDBDatabase) Close()
  • func (db *LDBDatabase) Delete(key []byte) error
  • func (db *LDBDatabase) Get(key []byte) ([]byte, error)
  • func (db *LDBDatabase) Has(key []byte) (bool, error)
  • func (db *LDBDatabase) LDB() *leveldb.DB
  • func (db *LDBDatabase) Meter(prefix string)
  • func (db *LDBDatabase) NewBatch() Batch
  • func (db *LDBDatabase) NewIterator() iterator.Iterator
  • func (db *LDBDatabase) Path() string
  • func (db *LDBDatabase) Put(key []byte, value []byte) error
• type MemDatabase
  • func NewMemDatabase() (*MemDatabase, error)
  • func (db *MemDatabase) Close()
  • func (db *MemDatabase) Delete(key []byte) error
  • func (db *MemDatabase) Get(key []byte) ([]byte, error)
  • func (db *MemDatabase) Has(key []byte) (bool, error)
  • func (db *MemDatabase) Keys() [][]byte
  • func (db *MemDatabase) NewBatch() Batch
  • func (db *MemDatabase) Put(key []byte, value []byte) error
• type Putter

Constants

const IdealBatchSize = 100 * 1024

Code using batches should try to add this much data to the batch. The value was determined empirically. 批处理数据的最大值

Variables

var OpenFileLimit = 64

Types

type Batch

type Batch interface {
	Putter
	ValueSize() int // amount of data in the batch
	Write() error
}

Batch is a write-only database that commits changes to its host database when Write is called. Batch cannot be used concurrently. 批量操作，不能并发操作，当 Write 方法被调用的时候，数据库会提交写入的更改

func NewTableBatch

func NewTableBatch(db Database, prefix string) Batch

NewTableBatch returns a Batch object which prefixes all keys with a given string.

type Database

type Database interface {
	Putter
	Get(key []byte) ([]byte, error)
	Has(key []byte) (bool, error)
	Delete(key []byte) error
	Close()
	NewBatch() Batch
}

Database wraps all database operations. All methods are safe for concurrent use. 数据库接口定义了所有的数据库操作， 所有的方法都是多线程安全的。

func NewTable

func NewTable(db Database, prefix string) Database

NewTable returns a Database object that prefixes all keys with a given string.

type LDBDatabase

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

ldb 数据对象

func NewLDBDatabase

func NewLDBDatabase(file string, cache int, handles int) (*LDBDatabase, error)

NewLDBDatabase returns a LevelDB wrapped object. 新建 level DB 对象

func (*LDBDatabase) Close

func (db *LDBDatabase) Close()

func (*LDBDatabase) Delete

func (db *LDBDatabase) Delete(key []byte) error

Delete deletes the key from the queue and database

func (*LDBDatabase) Get

func (db *LDBDatabase) Get(key []byte) ([]byte, error)

Get returns the given key if it's present.

func (*LDBDatabase) Has

func (db *LDBDatabase) Has(key []byte) (bool, error)

func (*LDBDatabase) LDB

func (db *LDBDatabase) LDB() *leveldb.DB

func (*LDBDatabase) Meter

func (db *LDBDatabase) Meter(prefix string)

Meter configures the database metrics collectors and 初始化 meter 参数 geth --metrics: 可以启动性能指标收集和报告

func (*LDBDatabase) NewBatch

func (db *LDBDatabase) NewBatch() Batch

func (*LDBDatabase) NewIterator

func (db *LDBDatabase) NewIterator() iterator.Iterator

func (*LDBDatabase) Path

func (db *LDBDatabase) Path() string

Path returns the path to the database directory.

func (*LDBDatabase) Put

func (db *LDBDatabase) Put(key []byte, value []byte) error

Put puts the given key / value to the queue

type MemDatabase

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

* This is a test memory database. Do not use for any production it does not get persisted

func NewMemDatabase

func NewMemDatabase() (*MemDatabase, error)

初始化 memdb 对象

func (*MemDatabase) Close

func (db *MemDatabase) Close()

func (*MemDatabase) Delete

func (db *MemDatabase) Delete(key []byte) error

func (*MemDatabase) Get

func (db *MemDatabase) Get(key []byte) ([]byte, error)

func (*MemDatabase) Has

func (db *MemDatabase) Has(key []byte) (bool, error)

func (*MemDatabase) Keys

func (db *MemDatabase) Keys() [][]byte

func (*MemDatabase) NewBatch

func (db *MemDatabase) NewBatch() Batch

func (*MemDatabase) Put

func (db *MemDatabase) Put(key []byte, value []byte) error

写入

type Putter

type Putter interface {
	Put(key []byte, value []byte) error
}

Putter wraps the database write operation supported by both batches and regular databases. 同时支持单挑数据写入和批量写入的操作