raftmdb

README

raft-mdb

This repository provides the raftmdb package. The package exports the MDBStore which is an implementation of both a LogStore and StableStore.

It is meant to be used as a backend for the raft package here.

This implementation uses LMDB. LMDB has a number of advantages to other embedded databases includes transactions, MVCC, and lack of compaction.

The one disadvantage is because it is a C library, it requires the use of cgo which complicates cross compilation. For that reason, this is in a seperate package from raft, so that clients can avoid cgo if they so choose.

Documentation

The documentation for this package can be found on Godoc here.

Documentation

Index

• type MDBStore
  • func NewMDBStore(base string) (*MDBStore, error)
  • func NewMDBStoreWithSize(base string, maxSize int64) (*MDBStore, error)
  • func (m *MDBStore) Close() error
  • func (m *MDBStore) DeleteRange(minIdx, maxIdx uint64) error
  • func (m *MDBStore) FirstIndex() (uint64, error)
  • func (m *MDBStore) Get(key []byte) ([]byte, error)
  • func (m *MDBStore) GetLog(index uint64, logOut *raft.Log) error
  • func (m *MDBStore) GetUint64(key []byte) (v64 uint64, err error)
  • func (m *MDBStore) LastIndex() (uint64, error)
  • func (m *MDBStore) Set(key, val []byte) error
  • func (m *MDBStore) SetUint64(key []byte, val uint64) error
  • func (m *MDBStore) StoreLog(log *raft.Log) error
  • func (m *MDBStore) StoreLogs(logs []*raft.Log) error

Types

type MDBStore

type MDBStore struct {
	// Determines how frequently the MDBStore will check for stale readers.
	// ReaderCheck is guaranteed to be called between any two updates more than
	// ReaderCheckPeriod apart.  If ReaderCheckPeriod is the MDBStore will only
	// check for stale readers while initializing.  ReaderCheckPeriod only
	// needs to be non-zero if other applications read from the backing
	// database concurrently.
	ReaderCheckPeriod time.Duration
	// contains filtered or unexported fields
}

MDBStore provides an implementation of LogStore and StableStore, all backed by a single MDB database.

func NewMDBStore

func NewMDBStore(base string) (*MDBStore, error)

NewMDBStore returns a new MDBStore and potential error. Requres a base directory from which to operate. Uses the default maximum size.

func NewMDBStoreWithSize

func NewMDBStoreWithSize(base string, maxSize int64) (*MDBStore, error)

NewMDBStoreWithSize returns a new MDBStore and potential error. Requres a base directory from which to operate, and a maximum size. If maxSize is not 0, a default value is used.

func (*MDBStore) Close

func (m *MDBStore) Close() error

Close is used to gracefully shutdown the MDB store

func (*MDBStore) DeleteRange

func (m *MDBStore) DeleteRange(minIdx, maxIdx uint64) error

DeleteRange deletes a range of log entries. The range is inclusive.

func (*MDBStore) FirstIndex

func (m *MDBStore) FirstIndex() (uint64, error)

FirstIndex returns the first index in the MDBStore

func (*MDBStore) Get

func (m *MDBStore) Get(key []byte) ([]byte, error)

Get returns the value for a given key.

func (*MDBStore) GetLog

func (m *MDBStore) GetLog(index uint64, logOut *raft.Log) error

GetLog gets a log entry at a given index

func (*MDBStore) GetUint64

func (m *MDBStore) GetUint64(key []byte) (v64 uint64, err error)

GetUint64 returns the value of a key interpreted as a uint64 value.

func (*MDBStore) LastIndex

func (m *MDBStore) LastIndex() (uint64, error)

LastIndex returns the last index in the MDBStore

func (*MDBStore) Set

func (m *MDBStore) Set(key, val []byte) error

Set associates a key with a value.

func (*MDBStore) SetUint64

func (m *MDBStore) SetUint64(key []byte, val uint64) error

SetUint64 sets a key to a uint64 value.

func (*MDBStore) StoreLog

func (m *MDBStore) StoreLog(log *raft.Log) error

StoreLog stores a log entry

func (*MDBStore) StoreLogs

func (m *MDBStore) StoreLogs(logs []*raft.Log) error

StoreLogs stores multiple log entries