// Diff two objects, and produce an RFC 6902 JSON Patch.
func NewJSONPatch(a interface{}, b interface{}) (jsonpatch.JSONPatch, locale.Error) {
// convert a to json
aBytes, uerr := json.Marshal(a)
if uerr != nil {
return nil, locale.UntranslatedError(uerr)
}
// convert b to json
bBytes, uerr := json.Marshal(b)
if uerr != nil {
return nil, locale.UntranslatedError(uerr)
}
// diff them
p, uerr := matt.CreatePatch(aBytes, bBytes)
if uerr != nil {
return nil, locale.UntranslatedError(uerr)
}
pBytes, uerr := json.Marshal(p)
if uerr != nil {
return nil, locale.UntranslatedError(uerr)
}
// return
var ret jsonpatch.JSONPatch
uerr = json.Unmarshal(pBytes, &ret)
return ret, locale.UntranslatedError(uerr)
}
// Patch is a method on an application which will modify an existing Application.
func (a *Application) Patch(patchedApplication *Application) (*Application, *http.Response, []error) {
o, err := json.Marshal(a)
if err != nil {
return nil, nil, []error{err}
}
p, err := json.Marshal(patchedApplication)
if err != nil {
return nil, nil, []error{err}
}
patch, err := jsonpatch.CreatePatch([]byte(o), []byte(p))
if err != nil {
fmt.Printf("Error creating JSON patch:%v", err)
return nil, nil, []error{err}
}
patchBytes, err := json.Marshal(patch)
if err != nil {
return nil, nil, []error{err}
}
k := kumoru.New()
k.Logger.Debugf("Patch string: %s", patchBytes)
k.Patch(fmt.Sprintf("%s/v1/applications/%s", k.EndPoint.Application, a.UUID))
k.TargetType = "json-patch+json"
k.RawString = string(string(patchBytes))
k.SignRequest(true)
resp, body, errs := k.End()
if len(errs) > 0 {
return a, resp, errs
}
if resp.StatusCode >= 400 {
errs = append(errs, fmt.Errorf("%s", resp.Status))
}
pApp := Application{}
err = json.Unmarshal([]byte(body), &pApp)
if err != nil {
errs = append(errs, err)
return a, resp, errs
}
return &pApp, resp, nil
}
//called by realtime.flusher ONLY!
func (o *Object) computeUpdate() bool {
//ensure only 1 update computation at a time
o.mut.Lock()
defer o.mut.Unlock()
if o.checked {
return false
}
//mark
o.checked = true
newBytes, err := json.Marshal(o.value)
if err != nil {
log.Printf("go-realtime: %s: marshal failed: %s", o.key, err)
return false
}
//calculate change set
ops, _ := jsonpatch.CreatePatch(o.bytes, newBytes)
if len(o.bytes) > 0 && len(ops) == 0 {
return false
}
delta, _ := json.Marshal(ops)
prev := o.version
o.version++
//send this new change to each subscriber
for _, u := range o.subscribers {
update := &update{
Key: o.key,
Version: o.version,
}
u.mut.Lock()
//choose optimal update (send the smallest)
if u.versions[o.key] == prev && len(o.bytes) > 0 && len(delta) < len(o.bytes) {
update.Delta = true
update.Data = delta
} else {
update.Delta = false
update.Data = newBytes
}
//insert pending update
u.pending = append(u.pending, update)
//user now has this version
u.versions[o.key] = o.version
u.mut.Unlock()
}
o.bytes = newBytes
return true
}
