raftio

type ChunkHandler func(pb.Chunk) bool

type ConnectionInfo struct {
	Address            string
	SnapshotConnection bool
}

type EntryInfo struct {
	ClusterID uint64
	NodeID    uint64
	Index     uint64
}

type IConnection interface {
	// Close closes the IConnection instance.
	Close()
	// SendMessageBatch sends the specified message batch to the target. It is
	// recommended to deliver the message batch to the target in order to enjoy
	// best possible performance, but out of order delivery is allowed at the
	// cost of reduced performance.
	SendMessageBatch(batch pb.MessageBatch) error
}

type ILogDB interface {
	// Name returns the type name of the ILogDB instance.
	Name() string
	// Close closes the ILogDB instance.
	Close() error
	// BinaryFormat returns an constant uint32 value representing the binary
	// format version compatible with the ILogDB instance.
	BinaryFormat() uint32
	// ListNodeInfo lists all available NodeInfo found in the log DB.
	ListNodeInfo() ([]NodeInfo, error)
	// SaveBootstrapInfo saves the specified bootstrap info to the log DB.
	SaveBootstrapInfo(clusterID uint64,
		nodeID uint64, bootstrap pb.Bootstrap) error
	// GetBootstrapInfo returns saved bootstrap info from log DB. It returns
	// ErrNoBootstrapInfo when there is no previously saved bootstrap info for
	// the specified node.
	GetBootstrapInfo(clusterID uint64, nodeID uint64) (pb.Bootstrap, error)
	// SaveRaftState atomically saves the Raft states, log entries and snapshots
	// metadata found in the pb.Update list to the log DB.
	SaveRaftState(updates []pb.Update, shardID uint64) error
	// IterateEntries returns the continuous Raft log entries of the specified
	// Raft node between the index value range of [low, high) up to a max size
	// limit of maxSize bytes. It returns the located log entries, their total
	// size in bytes and the occurred error.
	IterateEntries(ents []pb.Entry,
		size uint64, clusterID uint64, nodeID uint64, low uint64,
		high uint64, maxSize uint64) ([]pb.Entry, uint64, error)
	// ReadRaftState returns the persistented raft state found in Log DB.
	ReadRaftState(clusterID uint64,
		nodeID uint64, lastIndex uint64) (RaftState, error)
	// RemoveEntriesTo removes entries associated with the specified Raft node up
	// to the specified index.
	RemoveEntriesTo(clusterID uint64, nodeID uint64, index uint64) error
	// CompactEntriesTo reclaims underlying storage space used for storing
	// entries up to the specified index.
	CompactEntriesTo(clusterID uint64,
		nodeID uint64, index uint64) (<-chan struct{}, error)
	// SaveSnapshots saves all snapshot metadata found in the pb.Update list.
	SaveSnapshots([]pb.Update) error
	// DeleteSnapshot removes the specified snapshot metadata from the log DB.
	DeleteSnapshot(clusterID uint64, nodeID uint64, index uint64) error
	// ListSnapshots lists available snapshots associated with the specified
	// Raft node for index range (0, index].
	ListSnapshots(clusterID uint64,
		nodeID uint64, index uint64) ([]pb.Snapshot, error)
	// RemoveNodeData removes all data associated with the specified node.
	RemoveNodeData(clusterID uint64, nodeID uint64) error
	// ImportSnapshot imports the specified snapshot by creating all required
	// metadata in the logdb.
	ImportSnapshot(snapshot pb.Snapshot, nodeID uint64) error
}

type IRaftEventListener interface {
	LeaderUpdated(info LeaderInfo)
}

type ISnapshotConnection interface {
	// Close closes the ISnapshotConnection instance.
	Close()
	// SendChunk sends the snapshot chunk to the target. It is
	// recommended to have the snapshot chunk delivered in order for the best
	// performance, but out of order delivery is allowed at the cost of reduced
	// performance.
	SendChunk(chunk pb.Chunk) error
}

type ISystemEventListener interface {
	NodeHostShuttingDown()
	NodeUnloaded(info NodeInfo)
	NodeReady(info NodeInfo)
	MembershipChanged(info NodeInfo)
	ConnectionEstablished(info ConnectionInfo)
	ConnectionFailed(info ConnectionInfo)
	SendSnapshotStarted(info SnapshotInfo)
	SendSnapshotCompleted(info SnapshotInfo)
	SendSnapshotAborted(info SnapshotInfo)
	SnapshotReceived(info SnapshotInfo)
	SnapshotRecovered(info SnapshotInfo)
	SnapshotCreated(info SnapshotInfo)
	SnapshotCompacted(info SnapshotInfo)
	LogCompacted(info EntryInfo)
	LogDBCompacted(info EntryInfo)
}

type ITransport interface {
	// Name returns the type name of the ITransport instance.
	Name() string
	// Start launches the transport module and make it ready to start sending and
	// receiving Raft messages. If necessary, ITransport may take this opportunity
	// to start listening for incoming data.
	Start() error
	// Stop stops the transport module.
	Stop()
	// GetConnection returns an IConnection instance used for sending messages
	// to the specified target NodeHost instance.
	GetConnection(ctx context.Context, target string) (IConnection, error)
	// GetSnapshotConnection returns an ISnapshotConnection instance used for
	// sending snapshot chunks to the specified target NodeHost instance.
	GetSnapshotConnection(ctx context.Context,
		target string) (ISnapshotConnection, error)
}

type LeaderInfo struct {
	ClusterID uint64
	NodeID    uint64
	Term      uint64
	LeaderID  uint64
}

type MessageHandler func(pb.MessageBatch)

type Metrics struct {
	// Busy indicates whether the LogDB is busy and not suitable for saving new
	// data into the store.
	Busy bool
}

type NodeInfo struct {
	ClusterID uint64
	NodeID    uint64
}

type RaftState struct {
	// State is the Raft state persistent to the disk
	State pb.State
	// FirstIndex is the index of the first entry to iterate
	FirstIndex uint64
	// EntryCount is the number of entries to iterate
	EntryCount uint64
}

type SnapshotInfo struct {
	ClusterID uint64
	NodeID    uint64
	From      uint64
	Index     uint64
}