ethdb

Documentation

Index

• Constants
• Variables
• type Batch
  • func NewTableBatch(db Database, prefix string) Batch
• type Database
  • func NewTable(db Database, prefix string) Database
• type Deleter
• 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) NewIteratorWithPrefix(prefix []byte) iterator.Iterator
  • func (db *LDBDatabase) Path() string
  • func (db *LDBDatabase) Put(key []byte, value []byte) error
• type MemDatabase
  • func NewMemDatabase() *MemDatabase
  • func NewMemDatabaseWithCap(size int) *MemDatabase
  • 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) Len() int
  • func (db *MemDatabase) NewBatch() Batch
  • func (db *MemDatabase) Put(key []byte, value []byte) error
• type Putter

Constants

const IdealBatchSize = 100 * 1024 // 批处理数据的时候用的值，这个值是根据实际调试经验确定的

Code using batches should try to add this much data to the batch. The value was determined empirically.

Variables

var OpenFileLimit = 64 // 限制同时最多只能打开64个文件

Types

type Batch

type Batch interface {
	Putter
	Deleter
	ValueSize() int // amount of data in the batch
	Write() error
	// Reset resets the batch for reuse
	Reset()
}

Batch is a write-only database that commits changes to its host database when Write is called. Batch cannot be used concurrently.

批量操作接口，不能多线程同时使用，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
	Deleter
	Get(key []byte) ([]byte, error)
	Has(key []byte) (bool, error)
	Close()
	NewBatch() Batch
}

Database wraps all database operations. All methods are safe for concurrent use.

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. * NewTable 函数 返回一个Database对象，该对象为具有给定字符串的所有键添加前缀。

type Deleter

type Deleter interface {
	Delete(key []byte) error
}

Deleter wraps the database delete operation supported by both batches and regular databases.

用于普通操作和批量操作 删除数据

type LDBDatabase

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

定义了一套用于记录操作db的结构

func NewLDBDatabase

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

NewLDBDatabase returns a LevelDB wrapped object.

func (*LDBDatabase) Close

func (db *LDBDatabase) Close()

某次数据库操作结束后关闭该实例，停止metrics统计信息，防止多个因为启动的数据库实例过多造成内部资源竞争

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

func (*LDBDatabase) NewBatch

func (db *LDBDatabase) NewBatch() Batch

func (*LDBDatabase) NewIterator

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

func (*LDBDatabase) NewIteratorWithPrefix

func (db *LDBDatabase) NewIteratorWithPrefix(prefix []byte) iterator.Iterator

NewIteratorWithPrefix returns a iterator to iterate over subset of database content with a particular prefix.

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

func NewMemDatabaseWithCap

func NewMemDatabaseWithCap(size int) *MemDatabase

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) Len

func (db *MemDatabase) Len() int

func (*MemDatabase) NewBatch

func (db *MemDatabase) NewBatch() Batch

func (*MemDatabase) Put

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

type Putter

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

Putter wraps the database write operation supported by both batches and regular databases.

用于普通操作和批量操作 写入数据