DockerCLI/vendor/github.com/Microsoft/hcsshim/internal/mergemaps/merge.go

53 lines
1.4 KiB
Go

package mergemaps
import "encoding/json"
// Merge recursively merges map `fromMap` into map `ToMap`. Any pre-existing values
// in ToMap are overwritten. Values in fromMap are added to ToMap.
// From http://stackoverflow.com/questions/40491438/merging-two-json-strings-in-golang
func Merge(fromMap, ToMap interface{}) interface{} {
switch fromMap := fromMap.(type) {
case map[string]interface{}:
ToMap, ok := ToMap.(map[string]interface{})
if !ok {
return fromMap
}
for keyToMap, valueToMap := range ToMap {
if valueFromMap, ok := fromMap[keyToMap]; ok {
fromMap[keyToMap] = Merge(valueFromMap, valueToMap)
} else {
fromMap[keyToMap] = valueToMap
}
}
case nil:
// merge(nil, map[string]interface{...}) -> map[string]interface{...}
ToMap, ok := ToMap.(map[string]interface{})
if ok {
return ToMap
}
}
return fromMap
}
// MergeJSON merges the contents of a JSON string into an object representation,
// returning a new object suitable for translating to JSON.
func MergeJSON(object interface{}, additionalJSON []byte) (interface{}, error) {
if len(additionalJSON) == 0 {
return object, nil
}
objectJSON, err := json.Marshal(object)
if err != nil {
return nil, err
}
var objectMap, newMap map[string]interface{}
err = json.Unmarshal(objectJSON, &objectMap)
if err != nil {
return nil, err
}
err = json.Unmarshal(additionalJSON, &newMap)
if err != nil {
return nil, err
}
return Merge(newMap, objectMap), nil
}