[perf] fix double serialization for continueAsNew input (IWF-140)

[longquanzheng]

Right now the input is stored like this in the history:

[{"checksum":"\ufffd^\ufffd`\ufffd\ufffd\ufffd\ufffd\u0014_H\u0016\ufffd\ufffd\ufffd=","jsonData":"{\"StatesToStartFromBeginning\":[{\"stateId\":\"PersistRuleState\",\"stateInput\":{\"data\":\"{\\\"createdByUserId\\\":\\\"mwhitty\\\",\\\"shouldApplyToExistingJobs\\\":true,\\\"tagsToAdd\\\":[\\\"tag1\\\",\\\"tag2\\\"],\\\"statusToChange\\\":\\\"OPEN\\\",\\\"campaignToAdd\\\":\\\"CAMPAIGN-X\\\",\\\"ownerToChange\\\":\\\"qlong\\\",\\\"userIdsToNotify\\\":[\\\"user1\\\",\\\"user2\\\"],\\\"userIdsToGrantEditAccess\\\":[\\\"user3\\\",\\\"user4\\\"]}\",\"encoding\":\"springJackson\"}}],\"StateExecutionsToResume\":{},\"InterStateChannelReceived\":{},\"SignalsReceived\":{},\"StateExecutionCounterInfo\":{\"StateIdStartedCount\":{\"PersistRuleState\":50},\"StateIdCurrentlyExecutingCount\":{},\"TotalCurrentlyExecutingCount\":0},\"StateOutputs\":[],\"StaleSkipTimerSignals\":null,\"DataObjects\":[{\"key\":\"TotalPages\",\"value\":{\"data\":\"0\",\"encoding\":\"springJackson\"}}],\"SearchAttributes\":null}","totalPages":1}]

You can see a lot of \\ in it which is very wasteful and hard to read.

This is because this DumpWorkflowInternal activity has serialized the data that is already JSON serialized.

iwf/service/interpreter/activityImpl.go

Line 264 in ef706ab

func DumpWorkflowInternal(

We need to improve this.

---

Spent two days into this, and realized that JSON is not going to work for saving the double serialization. This is because the data that we are storing is not valid JSON because of pagination, hence we cannot use json.RawMessage.

The best way is to use proto based serialization like gRPC.

Defer this for now until we know it's necessary to do this

[longquanzheng]

Testing code when trying to override JSON mashal/unmashal, but didn't work:

package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"strings"
)

type MyResponse struct {
	JsonData1 string `json:"jsonData1"`
}

func (v MyResponse) MarshalJSON() ([]byte, error) {
	respCopy := v
	respCopy.JsonData1 = ""
	v0, err := json.Marshal(respCopy)
	if err != nil {
		return nil, err
	}
	return []byte(string(v0) + "&" + v.JsonData1), nil
}

func (v *MyResponse) UnmarshalJSON(src []byte) error {
	vs := strings.Split(string(src), "&")
	if len(vs) != 2 {
		panic("error in deserialization")
	}
	err := json.Unmarshal([]byte(vs[0]), &v)
	if err != nil {
		return err
	}
	v.JsonData1 = vs[1][1:]
	return nil
}

type SomeStruct struct {
	StringVal string `json:"stringVal"`
	IntVal    int    `json:"intVal"`
}

type EncodedObject struct {
	Encoding string `json:"encoding,omitempty"`
	Data     string `json:"data,omitempty"`
}

func main() {

	val0 := SomeStruct{
		StringVal: "aaaa|-$*&$",
		IntVal:    100,
	}

	encodedVal0, err := json.Marshal(val0)
	if err != nil {
		panic(err)
	}
	val00 := EncodedObject{
		Encoding: "json",
		Data:     string(encodedVal0),
	}
	encodedVal00, err := json.Marshal(val00)
	if err != nil {
		panic(err)
	}
	// {"data":"{\"stringVal\":\"aaaa\",\"intVal\":100}","encoding":"json"}
	fmt.Println(string(encodedVal00))

	val1 := MyResponse{
		JsonData1: string(encodedVal00[0:80]), // NOTE: for some reasons, I have to use part of it...(if you are interested, it is because of pagination)
	}

	b := new(bytes.Buffer)
	d := json.NewEncoder(b)
	d.SetEscapeHTML(false)
	err = d.Encode(val1)
	if err != nil {
		panic(err)
	}
	encodedVal1 := b.String()

	// {"jsonData1":"{\"encoding\":\"json\",\"data\":\"{\\\"stringVal\\\":\\\"aaaa\\\""}
	fmt.Println(encodedVal1)
}