github.com/timstclair/heapster@v0.20.0-alpha1/Godeps/_workspace/src/k8s.io/kubernetes/pkg/util/diff.go (about) 1 /* 2 Copyright 2014 The Kubernetes Authors All rights reserved. 3 4 Licensed under the Apache License, Version 2.0 (the "License"); 5 you may not use this file except in compliance with the License. 6 You may obtain a copy of the License at 7 8 http://www.apache.org/licenses/LICENSE-2.0 9 10 Unless required by applicable law or agreed to in writing, software 11 distributed under the License is distributed on an "AS IS" BASIS, 12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 See the License for the specific language governing permissions and 14 limitations under the License. 15 */ 16 17 package util 18 19 import ( 20 "bytes" 21 "encoding/json" 22 "fmt" 23 "strings" 24 "text/tabwriter" 25 26 "github.com/davecgh/go-spew/spew" 27 ) 28 29 // StringDiff diffs a and b and returns a human readable diff. 30 func StringDiff(a, b string) string { 31 ba := []byte(a) 32 bb := []byte(b) 33 out := []byte{} 34 i := 0 35 for ; i < len(ba) && i < len(bb); i++ { 36 if ba[i] != bb[i] { 37 break 38 } 39 out = append(out, ba[i]) 40 } 41 out = append(out, []byte("\n\nA: ")...) 42 out = append(out, ba[i:]...) 43 out = append(out, []byte("\n\nB: ")...) 44 out = append(out, bb[i:]...) 45 out = append(out, []byte("\n\n")...) 46 return string(out) 47 } 48 49 // ObjectDiff writes the two objects out as JSON and prints out the identical part of 50 // the objects followed by the remaining part of 'a' and finally the remaining part of 'b'. 51 // For debugging tests. 52 func ObjectDiff(a, b interface{}) string { 53 ab, err := json.Marshal(a) 54 if err != nil { 55 panic(fmt.Sprintf("a: %v", err)) 56 } 57 bb, err := json.Marshal(b) 58 if err != nil { 59 panic(fmt.Sprintf("b: %v", err)) 60 } 61 return StringDiff(string(ab), string(bb)) 62 } 63 64 // ObjectGoPrintDiff is like ObjectDiff, but uses go-spew to print the objects, 65 // which shows absolutely everything by recursing into every single pointer 66 // (go's %#v formatters OTOH stop at a certain point). This is needed when you 67 // can't figure out why reflect.DeepEqual is returning false and nothing is 68 // showing you differences. This will. 69 func ObjectGoPrintDiff(a, b interface{}) string { 70 s := spew.ConfigState{DisableMethods: true} 71 return StringDiff( 72 s.Sprintf("%#v", a), 73 s.Sprintf("%#v", b), 74 ) 75 } 76 77 // ObjectGoPrintSideBySide prints a and b as textual dumps side by side, 78 // enabling easy visual scanning for mismatches. 79 func ObjectGoPrintSideBySide(a, b interface{}) string { 80 s := spew.ConfigState{ 81 Indent: " ", 82 // Extra deep spew. 83 DisableMethods: true, 84 } 85 sA := s.Sdump(a) 86 sB := s.Sdump(b) 87 88 linesA := strings.Split(sA, "\n") 89 linesB := strings.Split(sB, "\n") 90 width := 0 91 for _, s := range linesA { 92 l := len(s) 93 if l > width { 94 width = l 95 } 96 } 97 for _, s := range linesB { 98 l := len(s) 99 if l > width { 100 width = l 101 } 102 } 103 buf := &bytes.Buffer{} 104 w := tabwriter.NewWriter(buf, width, 0, 1, ' ', 0) 105 max := len(linesA) 106 if len(linesB) > max { 107 max = len(linesB) 108 } 109 for i := 0; i < max; i++ { 110 var a, b string 111 if i < len(linesA) { 112 a = linesA[i] 113 } 114 if i < len(linesB) { 115 b = linesB[i] 116 } 117 fmt.Fprintf(w, "%s\t%s\n", a, b) 118 } 119 w.Flush() 120 return buf.String() 121 }