thalos/api/README.md

Thalos Golang API

Usage

The api is designed with callback functions that are called when messages arrive

Example

package main

import (
	"context"
	"fmt"
	"os"
	"os/signal"

	"github.com/eosswedenorg/thalos/api"
	"github.com/eosswedenorg/thalos/api/message"
	_ "github.com/eosswedenorg/thalos/api/message/json"
	api_redis "github.com/eosswedenorg/thalos/api/redis"
	"github.com/redis/go-redis/v9"
)

func main() {
	// Create redis client
	rdb := redis.NewClient(&redis.Options{})

	sub := api_redis.NewSubscriber(context.Background(), rdb, api_redis.Namespace{
		Prefix:  "ship",
		ChainID: "1064487b3cd1a897ce03ae5b6a865651747e2e152090f99c1d19d44e01aea5a4", // Wax mainnet.
	})

    // Create client
	codec, err := message.GetCodec("json")
	if err != nil {
		fmt.Println("Failed to get json codec")
		return
	}

	client := api.NewClient(sub, codec.Decoder)

    // Subscribe to some channels.
	err = client.Subscribe(
		api.TransactionChannel,
		api.ActionChannel{Contract: "eosio"}.Channel(),
		api.ActionChannel{Name: "mine"}.Channel(),
		api.HeartbeatChannel,
		api.TableDeltaChannel{}.Channel(),
	)

	if err != nil {
		fmt.Println(err)
		return
	}

    // Wait for interrupt in a go routine and close the client.
	go func() {
		sig := make(chan os.Signal)
		signal.Notify(sig, os.Interrupt)

		<-sig
		fmt.Println("Got interrupt")

		client.Close()
	}()

    // Read messages
	for t := range client.Channel() {
		switch msg := t.(type) {
		case error:
			fmt.Println("Error:", msg)
		case message.TransactionTrace:
			fmt.Println("Transaction", msg.BlockNum, msg.ID)
			fmt.Println(msg)
			fmt.Println("---")
		case message.HeartBeat :
			fmt.Println("Heartbeat")
			fmt.Println(msg)
			fmt.Println("---")
		}
	}
}

Message channels and types

There are several types of channels to subscribe to aswell with their respectivly message types.

NOTE: this is not the same as an go channel. all messages will be posted to the same go channel that can be accessed by client.Channel()

Channel type	Message type	Description
-	error	Posted if an error occured on the client. There is no channel to subscribe to. error messages will always be posted.
HeartbeatChannel	HeartBeat	Heartbeat message. Used to know if thalos is there or not if messages are not posted frequently on real channels.
RollbackChannel	RollbackMessage	This message is posted if the chain has experienced a microfork.
TransactionChannel	TransactionTrace	Information about an transaction
ActionChannel	ActionTrace	Information about an action
TableDeltaChannel	TableDelta	Information about an table change