scoria

Documentation

Overview

Package scoria provides the public API for ScoriaDB, a high-performance embedded LSM-based key-value store with MVCC, Column Families, and transaction support.

Index

• type Batch
• type CFDB
  • func EmbeddedCFDB(dataDir string) (CFDB, error)
• type CompactionLevelOpts
• type DB
  • func Open(opts Options) (DB, error)
• type Iterator
• type Options
  • func DefaultOptions(workDir string) Options
• type ScoriaDB
  • func NewScoriaDB(dataDir string) (*ScoriaDB, error)
  • func NewScoriaDBWithOptions(dataDir string, walOpts engine.WALOptions) (*ScoriaDB, error)
  • func (db *ScoriaDB) Close() error
  • func (db *ScoriaDB) CreateCF(name string) error
  • func (db *ScoriaDB) Delete(key []byte) error
  • func (db *ScoriaDB) DeleteCF(cfName string, key []byte) error
  • func (db *ScoriaDB) DropCF(name string) error
  • func (db *ScoriaDB) Get(key []byte) ([]byte, error)
  • func (db *ScoriaDB) GetCF(cfName string, key []byte) ([]byte, error)
  • func (db *ScoriaDB) ListCFs() []string
  • func (db *ScoriaDB) NewBatch() Batch
  • func (db *ScoriaDB) NewBatchForCF(cfName string) Batch
  • func (db *ScoriaDB) NewTransaction() Transaction
  • func (db *ScoriaDB) Put(key, value []byte) error
  • func (db *ScoriaDB) PutCF(cfName string, key, value []byte) error
  • func (db *ScoriaDB) Scan(prefix []byte) Iterator
  • func (db *ScoriaDB) ScanCF(cfName string, prefix []byte) Iterator
• type Transaction

Types

type Batch

type Batch interface {
	AddPut(key, value []byte)
	AddDelete(key []byte)
	Commit() error
	Clear()
	Size() int
}

Batch represents an atomic batch of operations.

type CFDB

type CFDB interface {
	// Basic operations (default CF)
	Get(key []byte) ([]byte, error)
	Put(key, value []byte) error
	Delete(key []byte) error
	Scan(prefix []byte) Iterator

	// Column Family operations
	GetCF(cf string, key []byte) ([]byte, error)
	PutCF(cf string, key, value []byte) error
	DeleteCF(cf string, key []byte) error
	ScanCF(cf string, prefix []byte) Iterator

	// Transactions and batches
	NewTransaction() Transaction
	NewBatch() Batch
	NewBatchForCF(cfName string) Batch

	// Column Family administration
	CreateCF(name string) error
	DropCF(name string) error
	ListCFs() []string

	// Close
	Close() error
}

CFDB represents the public interface of ScoriaDB with support for Column Families, transactions, batches, and iterators.

func EmbeddedCFDB

func EmbeddedCFDB(dataDir string) (CFDB, error)

EmbeddedCFDB returns a CFDB interface for embedding.

type CompactionLevelOpts

type CompactionLevelOpts struct {
	// Level номер уровня (0, 1, …).
	Level int
	// MaxFiles максимальное количество SSTable на этом уровне.
	// Если 0, используется значение по умолчанию.
	MaxFiles int
	// TargetSize целевой размер уровня в байтах.
	// Если 0, используется значение по умолчанию.
	TargetSize int64
}

CompactionLevelOpts содержит настройки для одного уровня LSM-дерева.

type DB

type DB interface {
	Get(key []byte) ([]byte, error)
	Put(key, value []byte) error
	Delete(key []byte) error
	Close() error
}

DB is the base interface for operations without Column Families (default CF only).

func Open

func Open(opts Options) (DB, error)

Open opens (or creates) a ScoriaDB database with the given options.

type Iterator

type Iterator interface {
	Next() bool
	Key() []byte
	Value() []byte
	Err() error
	Close()
}

Iterator iterates over keys and values.

type Options

type Options struct {
	// WorkDir — рабочая директория, где будут храниться данные.
	WorkDir string
	// MemTableSize — максимальный размер MemTable в байтах перед flush.
	// Если 0, используется значение по умолчанию (64 MiB).
	MemTableSize int64
	// Levels — настройки уровней компакшена.
	// Если nil, используются настройки по умолчанию.
	Levels []CompactionLevelOpts
	// VFS — абстракция файловой системы.
	// Если nil, используется vfs.DefaultVFS.
	VFS vfs.VFS
	// WALOptions — настройки Write-Ahead Log.
	// Если nil, используются DefaultWALOptions() с групповым коммитом.
	// Для отключения группового коммита передайте WALOptions{GroupCommitEnabled: false}.
	WALOptions *engine.WALOptions
}

Options содержит настройки для открытия/создания базы данных.

func DefaultOptions

func DefaultOptions(workDir string) Options

DefaultOptions возвращает Options с настройками по умолчанию.

type ScoriaDB

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

ScoriaDB implements CFDB using the Column Family registry.

func NewScoriaDB

func NewScoriaDB(dataDir string) (*ScoriaDB, error)

NewScoriaDB creates a new ScoriaDB database with Column Family support.

func NewScoriaDBWithOptions

func NewScoriaDBWithOptions(dataDir string, walOpts engine.WALOptions) (*ScoriaDB, error)

NewScoriaDBWithOptions creates a new ScoriaDB with the specified WAL options.

func (*ScoriaDB) Close

func (db *ScoriaDB) Close() error

Close closes all Column Families and releases resources.

func (*ScoriaDB) CreateCF

func (db *ScoriaDB) CreateCF(name string) error

CreateCF creates a new Column Family.

func (*ScoriaDB) Delete

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

Delete removes a key from the default CF.

func (*ScoriaDB) DeleteCF

func (db *ScoriaDB) DeleteCF(cfName string, key []byte) error

DeleteCF removes a key from the specified Column Family.

func (*ScoriaDB) DropCF

func (db *ScoriaDB) DropCF(name string) error

DropCF drops a Column Family. System CFs cannot be dropped.

func (*ScoriaDB) Get

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

Get returns the value for a key from the default CF.

func (*ScoriaDB) GetCF

func (db *ScoriaDB) GetCF(cfName string, key []byte) ([]byte, error)

func (*ScoriaDB) ListCFs

func (db *ScoriaDB) ListCFs() []string

ListCFs returns a list of all Column Family names.

func (*ScoriaDB) NewBatch

func (db *ScoriaDB) NewBatch() Batch

NewBatch creates a new batch of operations bound to the default CF.

func (*ScoriaDB) NewBatchForCF

func (db *ScoriaDB) NewBatchForCF(cfName string) Batch

NewBatchForCF creates a new batch bound to the specified CF.

func (*ScoriaDB) NewTransaction

func (db *ScoriaDB) NewTransaction() Transaction

NewTransaction creates a new transaction on the default CF.

func (*ScoriaDB) Put

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

Put writes a key-value pair to the default CF.

func (*ScoriaDB) PutCF

func (db *ScoriaDB) PutCF(cfName string, key, value []byte) error

PutCF writes a key-value pair to the specified Column Family.

func (*ScoriaDB) Scan

func (db *ScoriaDB) Scan(prefix []byte) Iterator

Scan returns an iterator over keys with the given prefix in the default CF.

func (*ScoriaDB) ScanCF

func (db *ScoriaDB) ScanCF(cfName string, prefix []byte) Iterator

ScanCF returns an iterator over keys with the given prefix in the specified CF.

type Transaction

type Transaction interface {
	Get(key []byte) ([]byte, error)
	Put(key, value []byte) error
	Delete(key []byte) error
	Commit() error
	Rollback() error
}

Transaction represents an interactive transaction.