github.com/timstclair/heapster@v0.20.0-alpha1/Godeps/_workspace/src/k8s.io/kubernetes/pkg/util/port_range.go (about) 1 /* 2 Copyright 2015 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 "fmt" 21 "strconv" 22 "strings" 23 ) 24 25 // PortRange represents a range of TCP/UDP ports. To represent a single port, 26 // set Size to 1. 27 type PortRange struct { 28 Base int 29 Size int 30 } 31 32 // Contains tests whether a given port falls within the PortRange. 33 func (pr *PortRange) Contains(p int) bool { 34 return (p >= pr.Base) && ((p - pr.Base) < pr.Size) 35 } 36 37 // String converts the PortRange to a string representation, which can be 38 // parsed by PortRange.Set or ParsePortRange. 39 func (pr PortRange) String() string { 40 if pr.Size == 0 { 41 return "" 42 } 43 return fmt.Sprintf("%d-%d", pr.Base, pr.Base+pr.Size-1) 44 } 45 46 // Set parses a string of the form "min-max", inclusive at both ends, and 47 // sets the PortRange from it. This is part of the flag.Value and pflag.Value 48 // interfaces. 49 func (pr *PortRange) Set(value string) error { 50 value = strings.TrimSpace(value) 51 52 // TODO: Accept "80" syntax 53 // TODO: Accept "80+8" syntax 54 55 if value == "" { 56 pr.Base = 0 57 pr.Size = 0 58 return nil 59 } 60 61 hyphenIndex := strings.Index(value, "-") 62 if hyphenIndex == -1 { 63 return fmt.Errorf("expected hyphen in port range") 64 } 65 66 var err error 67 var low int 68 var high int 69 low, err = strconv.Atoi(value[:hyphenIndex]) 70 if err == nil { 71 high, err = strconv.Atoi(value[hyphenIndex+1:]) 72 } 73 if err != nil { 74 return fmt.Errorf("unable to parse port range: %s", value) 75 } 76 77 if high < low { 78 return fmt.Errorf("end port cannot be less than start port: %s", value) 79 } 80 pr.Base = low 81 pr.Size = 1 + high - low 82 return nil 83 } 84 85 // Type returns a descriptive string about this type. This is part of the 86 // pflag.Value interface. 87 func (*PortRange) Type() string { 88 return "portRange" 89 } 90 91 // ParsePortRange parses a string of the form "min-max", inclusive at both 92 // ends, and initializs a new PortRange from it. 93 func ParsePortRange(value string) (*PortRange, error) { 94 pr := &PortRange{} 95 err := pr.Set(value) 96 if err != nil { 97 return nil, err 98 } 99 return pr, nil 100 }