spool

type ActiveNode struct {
	// corresponding node model
	Model *model.Node

	// node status
	Status *Status

	// send check ping to the node and receive the node's information
	// It SHOULD be buffered channel for non-blocking at the socket pool
	Ping chan bool

	// save shards on the node
	Save chan []*model.ShardToSave

	// load shards from the node
	Load chan *LoadChan

	// delete shards on the node
	Delete chan []*model.ShardToDelete

	// flush the deleted shard list to the node
	Flush chan bool
	// contains filtered or unexported fields
}

type DataMsg struct {
	Type     string      `json:"type"`
	Contents interface{} `json:"contents"`
}

type LoadChan struct {
	Shards []*model.ShardToLoad
	WG     *sync.WaitGroup
}

type SocketPool struct {
	// mutex for all nodes' status
	NodesStatusLock sync.Mutex

	// registered nodes
	Nodes map[*ActiveNode]bool

	// register requests from the node
	Register chan *ActiveNode

	// unregister requests from the node
	Unregister chan *ActiveNode
	// contains filtered or unexported fields
}

type Status struct {
	// TODO: measure rtt when ping and pong
	// round trip time (ms)
	RTT uint `json:"rtt"`

	// network bandwidth (Mbps)
	Bandwidth uint `json:"bandwidth"`

	// available capacity of the node (Byte)
	Capacity uint64 `json:"capacity"`
	// contains filtered or unexported fields
}