DynamoDB event

eventdb.go

package main

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"log"
	"math/big"
	"net/http"
	"strconv"
	"strings"

	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
	"github.com/aws/aws-sdk-go/service/dynamodb"
	"github.com/aws/aws-sdk-go/service/dynamodb/dynamodbattribute"
)

type itemStruct struct {
	Wallet       string
	Uncle        []int64
	TxBlock      int64 // Блок на котором мы остановили наблюдения
	Txs          []string
	Mined        []int64
	Erc20TxBlock int64
	Erc20Txs     []string
	Blockchain   string
}


func unmarshalStreamImage(attribute map[string]events.DynamoDBAttributeValue, out interface{}) error {

	dbAttrMap := make(map[string]*dynamodb.AttributeValue)

	for k, v := range attribute {

		var dbAttr dynamodb.AttributeValue

		bytes, marshalErr := v.MarshalJSON()
		if marshalErr != nil {
			return marshalErr
		}

		json.Unmarshal(bytes, &dbAttr)
		dbAttrMap[k] = &dbAttr
	}

	return dynamodbattribute.UnmarshalMap(dbAttrMap, out)

}


func handler(e events.DynamoDBEvent) error {

	for _, v := range e.Records {
		switch v.EventName {
		case "INSERT":
			fallthrough
		case "MODIFY":
			tableName := strings.Split(v.EventSourceArn, "/")[1]
			if tableName != "cryptosiren_wallets" {
				return nil
			}

			updatedData := v.Change.NewImage // Old data
			oldData := v.Change.OldImage // Update data

			var parsedData *itemStruct
			err := unmarshalStreamImage(updatedData, &parsedData)

			if err != nil {
				fmt.Println("Got error unmarshalling parsedData:")
				fmt.Println(err.Error())
			}

			var oldParsedData *itemStruct
			err = unmarshalStreamImage(oldData, &oldParsedData)
			if err != nil {
				fmt.Println("Got error unmarshalling oldParsedData:")
				fmt.Println(err.Error())
			}

		default:
		}
	}
	return nil
}

func main() {
	lambda.Start(handler)
}