diff options
Diffstat (limited to 'vendor/github.com/aws/aws-sdk-go/aws/awsutil/copy.go')
-rw-r--r-- | vendor/github.com/aws/aws-sdk-go/aws/awsutil/copy.go | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/vendor/github.com/aws/aws-sdk-go/aws/awsutil/copy.go b/vendor/github.com/aws/aws-sdk-go/aws/awsutil/copy.go new file mode 100644 index 0000000..8429470 --- /dev/null +++ b/vendor/github.com/aws/aws-sdk-go/aws/awsutil/copy.go @@ -0,0 +1,100 @@ +package awsutil + +import ( + "io" + "reflect" +) + +// Copy deeply copies a src structure to dst. Useful for copying request and +// response structures. +// +// Can copy between structs of different type, but will only copy fields which +// are assignable, and exist in both structs. Fields which are not assignable, +// or do not exist in both structs are ignored. +func Copy(dst, src interface{}) { + dstval := reflect.ValueOf(dst) + if !dstval.IsValid() { + panic("Copy dst cannot be nil") + } + + rcopy(dstval, reflect.ValueOf(src), true) +} + +// CopyOf returns a copy of src while also allocating the memory for dst. +// src must be a pointer type or this operation will fail. +func CopyOf(src interface{}) (dst interface{}) { + dsti := reflect.New(reflect.TypeOf(src).Elem()) + dst = dsti.Interface() + rcopy(dsti, reflect.ValueOf(src), true) + return +} + +// rcopy performs a recursive copy of values from the source to destination. +// +// root is used to skip certain aspects of the copy which are not valid +// for the root node of a object. +func rcopy(dst, src reflect.Value, root bool) { + if !src.IsValid() { + return + } + + switch src.Kind() { + case reflect.Ptr: + if _, ok := src.Interface().(io.Reader); ok { + if dst.Kind() == reflect.Ptr && dst.Elem().CanSet() { + dst.Elem().Set(src) + } else if dst.CanSet() { + dst.Set(src) + } + } else { + e := src.Type().Elem() + if dst.CanSet() && !src.IsNil() { + dst.Set(reflect.New(e)) + } + if src.Elem().IsValid() { + // Keep the current root state since the depth hasn't changed + rcopy(dst.Elem(), src.Elem(), root) + } + } + case reflect.Struct: + t := dst.Type() + for i := 0; i < t.NumField(); i++ { + name := t.Field(i).Name + srcVal := src.FieldByName(name) + dstVal := dst.FieldByName(name) + if srcVal.IsValid() && dstVal.CanSet() { + rcopy(dstVal, srcVal, false) + } + } + case reflect.Slice: + if src.IsNil() { + break + } + + s := reflect.MakeSlice(src.Type(), src.Len(), src.Cap()) + dst.Set(s) + for i := 0; i < src.Len(); i++ { + rcopy(dst.Index(i), src.Index(i), false) + } + case reflect.Map: + if src.IsNil() { + break + } + + s := reflect.MakeMap(src.Type()) + dst.Set(s) + for _, k := range src.MapKeys() { + v := src.MapIndex(k) + v2 := reflect.New(v.Type()).Elem() + rcopy(v2, v, false) + dst.SetMapIndex(k, v2) + } + default: + // Assign the value if possible. If its not assignable, the value would + // need to be converted and the impact of that may be unexpected, or is + // not compatible with the dst type. + if src.Type().AssignableTo(dst.Type()) { + dst.Set(src) + } + } +} |