podman

1
// Copyright 2013 Dario Castañé. All rights reserved.
2
// Copyright 2009 The Go Authors. All rights reserved.
3
// Use of this source code is governed by a BSD-style
4
// license that can be found in the LICENSE file.
5

6
// Based on src/pkg/reflect/deepequal.go from official
7
// golang's stdlib.
8

9
package mergo
10

11
import (
12
	"errors"
13
	"reflect"
14
)
15

16
// Errors reported by Mergo when it finds invalid arguments.
17
var (
18
	ErrNilArguments                = errors.New("src and dst must not be nil")
19
	ErrDifferentArgumentsTypes     = errors.New("src and dst must be of same type")
20
	ErrNotSupported                = errors.New("only structs, maps, and slices are supported")
21
	ErrExpectedMapAsDestination    = errors.New("dst was expected to be a map")
22
	ErrExpectedStructAsDestination = errors.New("dst was expected to be a struct")
23
	ErrNonPointerArgument          = errors.New("dst must be a pointer")
24
)
25

26
// During deepMerge, must keep track of checks that are
27
// in progress.  The comparison algorithm assumes that all
28
// checks in progress are true when it reencounters them.
29
// Visited are stored in a map indexed by 17 * a1 + a2;
30
type visit struct {
31
	typ  reflect.Type
32
	next *visit
33
	ptr  uintptr
34
}
35

36
// From src/pkg/encoding/json/encode.go.
37
func isEmptyValue(v reflect.Value, shouldDereference bool) bool {
38
	switch v.Kind() {
39
	case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
40
		return v.Len() == 0
41
	case reflect.Bool:
42
		return !v.Bool()
43
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
44
		return v.Int() == 0
45
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
46
		return v.Uint() == 0
47
	case reflect.Float32, reflect.Float64:
48
		return v.Float() == 0
49
	case reflect.Interface, reflect.Ptr:
50
		if v.IsNil() {
51
			return true
52
		}
53
		if shouldDereference {
54
			return isEmptyValue(v.Elem(), shouldDereference)
55
		}
56
		return false
57
	case reflect.Func:
58
		return v.IsNil()
59
	case reflect.Invalid:
60
		return true
61
	}
62
	return false
63
}
64

65
func resolveValues(dst, src interface{}) (vDst, vSrc reflect.Value, err error) {
66
	if dst == nil || src == nil {
67
		err = ErrNilArguments
68
		return
69
	}
70
	vDst = reflect.ValueOf(dst).Elem()
71
	if vDst.Kind() != reflect.Struct && vDst.Kind() != reflect.Map && vDst.Kind() != reflect.Slice {
72
		err = ErrNotSupported
73
		return
74
	}
75
	vSrc = reflect.ValueOf(src)
76
	// We check if vSrc is a pointer to dereference it.
77
	if vSrc.Kind() == reflect.Ptr {
78
		vSrc = vSrc.Elem()
79
	}
80
	return
81
}
82