no network parition

3b.go

package main

import (
	"encoding/json"
	"log"
	"os"
	"sync"

	maelstrom "github.com/jepsen-io/maelstrom/demo/go"
)

type State struct {
	messages []int
	nodeId   string
	nodeIds  []string
	*sync.Mutex
}

func NewState() *State {
	return &State{
		messages: make([]int, 0),
		Mutex:    &sync.Mutex{},
	}
}

func (s *State) addMsg(msg int) {
	s.Lock()
	defer s.Unlock()
	s.messages = append(s.messages, msg)
}

func (s *State) addTopo(nodes []string) {
	s.Lock()
	defer s.Unlock()
	s.nodeIds = nodes
}

func main() {
	l := log.New(os.Stderr, "", 0)
	l.Prefix()
	n := maelstrom.NewNode()
	state := NewState()

	n.Handle("broadcast", func(msg maelstrom.Message) error {
		type broadcastMsg struct {
			Type    string `json:"type"`
			Message int    `json:"message,omitempty"`
		}
		var body broadcastMsg
		if err := json.Unmarshal(msg.Body, &body); err != nil {
			return err
		}
		state.addMsg(body.Message)

		for _, id := range state.nodeIds {
			if id == state.nodeId {
				continue
			}
			if id == msg.Src {
				continue
			}
			if err := n.Send(id, msg.Body); err != nil {
				panic(err)
			}
		}
		body.Message = 0
		body.Type = "broadcast_ok"
		return n.Reply(msg, body)
	})

	n.Handle("read", func(msg maelstrom.Message) error {
		var body map[string]any
		if err := json.Unmarshal(msg.Body, &body); err != nil {
			return err
		}
		body["type"] = "read_ok"
		body["messages"] = state.messages
		return n.Reply(msg, body)
	})

	n.Handle("topology", func(msg maelstrom.Message) error {
		type topologyMSG struct {
			Type     string              `json:"type"`
			Topology map[string][]string `json:"topology,omitempty"`
		}
		var body topologyMSG
		if err := json.Unmarshal(msg.Body, &body); err != nil {
			return err
		}
		// state.addTopo(getAllUniqueNodesFromTopology(state.nodeId, state.nodeIds, body.Topology))
		state.addTopo(state.nodeIds)
		body.Type = "topology_ok"
		body.Topology = nil
		return n.Reply(msg, body)
	})

	n.Handle("init", func(msg maelstrom.Message) error {
		type initBody struct {
			Type    string   `json:"type"`
			MsgId   int      `json:"msg_id"`
			NodeId  string   `json:"node_id"`
			NodeIds []string `json:"node_ids"`
		}

		var body initBody
		if err := json.Unmarshal(msg.Body, &body); err != nil {
			return err
		}
		body.Type = "init_ok"
		state.nodeId = body.NodeId
		state.nodeIds = body.NodeIds
		return n.Reply(msg, body)
	})

	if err := n.Run(); err != nil {
		log.Printf("ERROR: %s", err)
		os.Exit(1)
	}
}