vendor/k8s.io/apimachinery/pkg/util/version/version.go - cloudstack-kubernetes-provider - Git at Google

 /*
 Copyright 2016 The Kubernetes Authors.

 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */

 package version

 import (
 	"bytes"
 	"fmt"
 	"regexp"
 	"strconv"
 	"strings"
 )

 // Version is an opqaue representation of a version number
 type Version struct {
 	components    []uint
 	semver        bool
 	preRelease    string
 	buildMetadata string
 }

 var (
 	// versionMatchRE splits a version string into numeric and "extra" parts
 	versionMatchRE = regexp.MustCompile(`^\s*v?([0-9]+(?:\.[0-9]+)*)(.*)*$`)
 	// extraMatchRE splits the "extra" part of versionMatchRE into semver pre-release and build metadata; it does not validate the "no leading zeroes" constraint for pre-release
 	extraMatchRE = regexp.MustCompile(`^(?:-([0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*))?(?:\+([0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*))?\s*$`)
 )

 func parse(str string, semver bool) (*Version, error) {
 	parts := versionMatchRE.FindStringSubmatch(str)
 	if parts == nil {
 		return nil, fmt.Errorf("could not parse %q as version", str)
 	}
 	numbers, extra := parts[1], parts[2]

 	components := strings.Split(numbers, ".")
 	if (semver && len(components) != 3) || (!semver && len(components) < 2) {
 		return nil, fmt.Errorf("illegal version string %q", str)
 	}

 	v := &Version{
 		components: make([]uint, len(components)),
 		semver:     semver,
 	}
 	for i, comp := range components {
 		if (i == 0 || semver) && strings.HasPrefix(comp, "0") && comp != "0" {
 			return nil, fmt.Errorf("illegal zero-prefixed version component %q in %q", comp, str)
 		}
 		num, err := strconv.ParseUint(comp, 10, 0)
 		if err != nil {
 			return nil, fmt.Errorf("illegal non-numeric version component %q in %q: %v", comp, str, err)
 		}
 		v.components[i] = uint(num)
 	}

 	if semver && extra != "" {
 		extraParts := extraMatchRE.FindStringSubmatch(extra)
 		if extraParts == nil {
 			return nil, fmt.Errorf("could not parse pre-release/metadata (%s) in version %q", extra, str)
 		}
 		v.preRelease, v.buildMetadata = extraParts[1], extraParts[2]

 		for _, comp := range strings.Split(v.preRelease, ".") {
 			if _, err := strconv.ParseUint(comp, 10, 0); err == nil {
 				if strings.HasPrefix(comp, "0") && comp != "0" {
 					return nil, fmt.Errorf("illegal zero-prefixed version component %q in %q", comp, str)
 				}
 			}
 		}
 	}

 	return v, nil
 }

 // ParseGeneric parses a "generic" version string. The version string must consist of two
 // or more dot-separated numeric fields (the first of which can't have leading zeroes),
 // followed by arbitrary uninterpreted data (which need not be separated from the final
 // numeric field by punctuation). For convenience, leading and trailing whitespace is
 // ignored, and the version can be preceded by the letter "v". See also ParseSemantic.
 func ParseGeneric(str string) (*Version, error) {
 	return parse(str, false)
 }

 // MustParseGeneric is like ParseGeneric except that it panics on error
 func MustParseGeneric(str string) *Version {
 	v, err := ParseGeneric(str)
 	if err != nil {
 		panic(err)
 	}
 	return v
 }

 // ParseSemantic parses a version string that exactly obeys the syntax and semantics of
 // the "Semantic Versioning" specification (http://semver.org/) (although it ignores
 // leading and trailing whitespace, and allows the version to be preceded by "v"). For
 // version strings that are not guaranteed to obey the Semantic Versioning syntax, use
 // ParseGeneric.
 func ParseSemantic(str string) (*Version, error) {
 	return parse(str, true)
 }

 // MustParseSemantic is like ParseSemantic except that it panics on error
 func MustParseSemantic(str string) *Version {
 	v, err := ParseSemantic(str)
 	if err != nil {
 		panic(err)
 	}
 	return v
 }

 // Major returns the major release number
 func (v *Version) Major() uint {
 	return v.components[0]
 }

 // Minor returns the minor release number
 func (v *Version) Minor() uint {
 	return v.components[1]
 }

 // Patch returns the patch release number if v is a Semantic Version, or 0
 func (v *Version) Patch() uint {
 	if len(v.components) < 3 {
 		return 0
 	}
 	return v.components[2]
 }

 // BuildMetadata returns the build metadata, if v is a Semantic Version, or ""
 func (v *Version) BuildMetadata() string {
 	return v.buildMetadata
 }

 // PreRelease returns the prerelease metadata, if v is a Semantic Version, or ""
 func (v *Version) PreRelease() string {
 	return v.preRelease
 }

 // Components returns the version number components
 func (v *Version) Components() []uint {
 	return v.components
 }

 // WithMajor returns copy of the version object with requested major number
 func (v *Version) WithMajor(major uint) *Version {
 	result := *v
 	result.components = []uint{major, v.Minor(), v.Patch()}
 	return &result
 }

 // WithMinor returns copy of the version object with requested minor number
 func (v *Version) WithMinor(minor uint) *Version {
 	result := *v
 	result.components = []uint{v.Major(), minor, v.Patch()}
 	return &result
 }

 // WithPatch returns copy of the version object with requested patch number
 func (v *Version) WithPatch(patch uint) *Version {
 	result := *v
 	result.components = []uint{v.Major(), v.Minor(), patch}
 	return &result
 }

 // WithPreRelease returns copy of the version object with requested prerelease
 func (v *Version) WithPreRelease(preRelease string) *Version {
 	result := *v
 	result.components = []uint{v.Major(), v.Minor(), v.Patch()}
 	result.preRelease = preRelease
 	return &result
 }

 // String converts a Version back to a string; note that for versions parsed with
 // ParseGeneric, this will not include the trailing uninterpreted portion of the version
 // number.
 func (v *Version) String() string {
 	var buffer bytes.Buffer

 	for i, comp := range v.components {
 		if i > 0 {
 			buffer.WriteString(".")
 		}
 		buffer.WriteString(fmt.Sprintf("%d", comp))
 	}
 	if v.preRelease != "" {
 		buffer.WriteString("-")
 		buffer.WriteString(v.preRelease)
 	}
 	if v.buildMetadata != "" {
 		buffer.WriteString("+")
 		buffer.WriteString(v.buildMetadata)
 	}

 	return buffer.String()
 }

 // compareInternal returns -1 if v is less than other, 1 if it is greater than other, or 0
 // if they are equal
 func (v *Version) compareInternal(other *Version) int {

 	vLen := len(v.components)
 	oLen := len(other.components)
 	for i := 0; i < vLen && i < oLen; i++ {
 		switch {
 		case other.components[i] < v.components[i]:
 			return 1
 		case other.components[i] > v.components[i]:
 			return -1
 		}
 	}

 	// If components are common but one has more items and they are not zeros, it is bigger
 	switch {
 	case oLen < vLen && !onlyZeros(v.components[oLen:]):
 		return 1
 	case oLen > vLen && !onlyZeros(other.components[vLen:]):
 		return -1
 	}

 	if !v.semver || !other.semver {
 		return 0
 	}

 	switch {
 	case v.preRelease == "" && other.preRelease != "":
 		return 1
 	case v.preRelease != "" && other.preRelease == "":
 		return -1
 	case v.preRelease == other.preRelease: // includes case where both are ""
 		return 0
 	}

 	vPR := strings.Split(v.preRelease, ".")
 	oPR := strings.Split(other.preRelease, ".")
 	for i := 0; i < len(vPR) && i < len(oPR); i++ {
 		vNum, err := strconv.ParseUint(vPR[i], 10, 0)
 		if err == nil {
 			oNum, err := strconv.ParseUint(oPR[i], 10, 0)
 			if err == nil {
 				switch {
 				case oNum < vNum:
 					return 1
 				case oNum > vNum:
 					return -1
 				default:
 					continue
 				}
 			}
 		}
 		if oPR[i] < vPR[i] {
 			return 1
 		} else if oPR[i] > vPR[i] {
 			return -1
 		}
 	}

 	switch {
 	case len(oPR) < len(vPR):
 		return 1
 	case len(oPR) > len(vPR):
 		return -1
 	}

 	return 0
 }

 // returns false if array contain any non-zero element
 func onlyZeros(array []uint) bool {
 	for _, num := range array {
 		if num != 0 {
 			return false
 		}
 	}
 	return true
 }

 // AtLeast tests if a version is at least equal to a given minimum version. If both
 // Versions are Semantic Versions, this will use the Semantic Version comparison
 // algorithm. Otherwise, it will compare only the numeric components, with non-present
 // components being considered "0" (ie, "1.4" is equal to "1.4.0").
 func (v *Version) AtLeast(min *Version) bool {
 	return v.compareInternal(min) != -1
 }

 // LessThan tests if a version is less than a given version. (It is exactly the opposite
 // of AtLeast, for situations where asking "is v too old?" makes more sense than asking
 // "is v new enough?".)
 func (v *Version) LessThan(other *Version) bool {
 	return v.compareInternal(other) == -1
 }

 // Compare compares v against a version string (which will be parsed as either Semantic
 // or non-Semantic depending on v). On success it returns -1 if v is less than other, 1 if
 // it is greater than other, or 0 if they are equal.
 func (v *Version) Compare(other string) (int, error) {
 	ov, err := parse(other, v.semver)
 	if err != nil {
 		return 0, err
 	}
 	return v.compareInternal(ov), nil
 }
	/*
	Copyright 2016 The Kubernetes Authors.

	Licensed under the Apache License, Version 2.0 (the "License");
	you may not use this file except in compliance with the License.
	You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software
	distributed under the License is distributed on an "AS IS" BASIS,
	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	See the License for the specific language governing permissions and
	limitations under the License.
	*/

	package version

	import (
	"bytes"
	"fmt"
	"regexp"
	"strconv"
	"strings"
	)

	// Version is an opqaue representation of a version number
	type Version struct {
	components []uint
	semver bool
	preRelease string
	buildMetadata string
	}

	var (
	// versionMatchRE splits a version string into numeric and "extra" parts
	versionMatchRE = regexp.MustCompile(`^\sv?([0-9]+(?:\.[0-9]+))(.)$`)
	// extraMatchRE splits the "extra" part of versionMatchRE into semver pre-release and build metadata; it does not validate the "no leading zeroes" constraint for pre-release
	extraMatchRE = regexp.MustCompile(`^(?:-([0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)))?(?:\+([0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)))?\s*$`)
	)

	func parse(str string, semver bool) (*Version, error) {
	parts := versionMatchRE.FindStringSubmatch(str)
	if parts == nil {
	return nil, fmt.Errorf("could not parse %q as version", str)
	}
	numbers, extra := parts[1], parts[2]

	components := strings.Split(numbers, ".")
	if (semver && len(components) != 3) \|\| (!semver && len(components) < 2) {
	return nil, fmt.Errorf("illegal version string %q", str)
	}

	v := &Version{
	components: make([]uint, len(components)),
	semver: semver,
	}
	for i, comp := range components {
	if (i == 0 \|\| semver) && strings.HasPrefix(comp, "0") && comp != "0" {
	return nil, fmt.Errorf("illegal zero-prefixed version component %q in %q", comp, str)
	}
	num, err := strconv.ParseUint(comp, 10, 0)
	if err != nil {
	return nil, fmt.Errorf("illegal non-numeric version component %q in %q: %v", comp, str, err)
	}
	v.components[i] = uint(num)
	}

	if semver && extra != "" {
	extraParts := extraMatchRE.FindStringSubmatch(extra)
	if extraParts == nil {
	return nil, fmt.Errorf("could not parse pre-release/metadata (%s) in version %q", extra, str)
	}
	v.preRelease, v.buildMetadata = extraParts[1], extraParts[2]

	for _, comp := range strings.Split(v.preRelease, ".") {
	if _, err := strconv.ParseUint(comp, 10, 0); err == nil {
	if strings.HasPrefix(comp, "0") && comp != "0" {
	return nil, fmt.Errorf("illegal zero-prefixed version component %q in %q", comp, str)
	}
	}
	}
	}

	return v, nil
	}

	// ParseGeneric parses a "generic" version string. The version string must consist of two
	// or more dot-separated numeric fields (the first of which can't have leading zeroes),
	// followed by arbitrary uninterpreted data (which need not be separated from the final
	// numeric field by punctuation). For convenience, leading and trailing whitespace is
	// ignored, and the version can be preceded by the letter "v". See also ParseSemantic.
	func ParseGeneric(str string) (*Version, error) {
	return parse(str, false)
	}

	// MustParseGeneric is like ParseGeneric except that it panics on error
	func MustParseGeneric(str string) *Version {
	v, err := ParseGeneric(str)
	if err != nil {
	panic(err)
	}
	return v
	}

	// ParseSemantic parses a version string that exactly obeys the syntax and semantics of
	// the "Semantic Versioning" specification (http://semver.org/) (although it ignores
	// leading and trailing whitespace, and allows the version to be preceded by "v"). For
	// version strings that are not guaranteed to obey the Semantic Versioning syntax, use
	// ParseGeneric.
	func ParseSemantic(str string) (*Version, error) {
	return parse(str, true)
	}

	// MustParseSemantic is like ParseSemantic except that it panics on error
	func MustParseSemantic(str string) *Version {
	v, err := ParseSemantic(str)
	if err != nil {
	panic(err)
	}
	return v
	}

	// Major returns the major release number
	func (v *Version) Major() uint {
	return v.components[0]
	}

	// Minor returns the minor release number
	func (v *Version) Minor() uint {
	return v.components[1]
	}

	// Patch returns the patch release number if v is a Semantic Version, or 0
	func (v *Version) Patch() uint {
	if len(v.components) < 3 {
	return 0
	}
	return v.components[2]
	}

	// BuildMetadata returns the build metadata, if v is a Semantic Version, or ""
	func (v *Version) BuildMetadata() string {
	return v.buildMetadata
	}

	// PreRelease returns the prerelease metadata, if v is a Semantic Version, or ""
	func (v *Version) PreRelease() string {
	return v.preRelease
	}

	// Components returns the version number components
	func (v *Version) Components() []uint {
	return v.components
	}

	// WithMajor returns copy of the version object with requested major number
	func (v Version) WithMajor(major uint) Version {
	result := *v
	result.components = []uint{major, v.Minor(), v.Patch()}
	return &result
	}

	// WithMinor returns copy of the version object with requested minor number
	func (v Version) WithMinor(minor uint) Version {
	result := *v
	result.components = []uint{v.Major(), minor, v.Patch()}
	return &result
	}

	// WithPatch returns copy of the version object with requested patch number
	func (v Version) WithPatch(patch uint) Version {
	result := *v
	result.components = []uint{v.Major(), v.Minor(), patch}
	return &result
	}

	// WithPreRelease returns copy of the version object with requested prerelease
	func (v Version) WithPreRelease(preRelease string) Version {
	result := *v
	result.components = []uint{v.Major(), v.Minor(), v.Patch()}
	result.preRelease = preRelease
	return &result
	}

	// String converts a Version back to a string; note that for versions parsed with
	// ParseGeneric, this will not include the trailing uninterpreted portion of the version
	// number.
	func (v *Version) String() string {
	var buffer bytes.Buffer

	for i, comp := range v.components {
	if i > 0 {
	buffer.WriteString(".")
	}
	buffer.WriteString(fmt.Sprintf("%d", comp))
	}
	if v.preRelease != "" {
	buffer.WriteString("-")
	buffer.WriteString(v.preRelease)
	}
	if v.buildMetadata != "" {
	buffer.WriteString("+")
	buffer.WriteString(v.buildMetadata)
	}

	return buffer.String()
	}

	// compareInternal returns -1 if v is less than other, 1 if it is greater than other, or 0
	// if they are equal
	func (v Version) compareInternal(other Version) int {

	vLen := len(v.components)
	oLen := len(other.components)
	for i := 0; i < vLen && i < oLen; i++ {
	switch {
	case other.components[i] < v.components[i]:
	return 1
	case other.components[i] > v.components[i]:
	return -1
	}
	}

	// If components are common but one has more items and they are not zeros, it is bigger
	switch {
	case oLen < vLen && !onlyZeros(v.components[oLen:]):
	return 1
	case oLen > vLen && !onlyZeros(other.components[vLen:]):
	return -1
	}

	if !v.semver \|\| !other.semver {
	return 0
	}

	switch {
	case v.preRelease == "" && other.preRelease != "":
	return 1
	case v.preRelease != "" && other.preRelease == "":
	return -1
	case v.preRelease == other.preRelease: // includes case where both are ""
	return 0
	}

	vPR := strings.Split(v.preRelease, ".")
	oPR := strings.Split(other.preRelease, ".")
	for i := 0; i < len(vPR) && i < len(oPR); i++ {
	vNum, err := strconv.ParseUint(vPR[i], 10, 0)
	if err == nil {
	oNum, err := strconv.ParseUint(oPR[i], 10, 0)
	if err == nil {
	switch {
	case oNum < vNum:
	return 1
	case oNum > vNum:
	return -1
	default:
	continue
	}
	}
	}
	if oPR[i] < vPR[i] {
	return 1
	} else if oPR[i] > vPR[i] {
	return -1
	}
	}

	switch {
	case len(oPR) < len(vPR):
	return 1
	case len(oPR) > len(vPR):
	return -1
	}

	return 0
	}

	// returns false if array contain any non-zero element
	func onlyZeros(array []uint) bool {
	for _, num := range array {
	if num != 0 {
	return false
	}
	}
	return true
	}

	// AtLeast tests if a version is at least equal to a given minimum version. If both
	// Versions are Semantic Versions, this will use the Semantic Version comparison
	// algorithm. Otherwise, it will compare only the numeric components, with non-present
	// components being considered "0" (ie, "1.4" is equal to "1.4.0").
	func (v Version) AtLeast(min Version) bool {
	return v.compareInternal(min) != -1
	}

	// LessThan tests if a version is less than a given version. (It is exactly the opposite
	// of AtLeast, for situations where asking "is v too old?" makes more sense than asking
	// "is v new enough?".)
	func (v Version) LessThan(other Version) bool {
	return v.compareInternal(other) == -1
	}

	// Compare compares v against a version string (which will be parsed as either Semantic
	// or non-Semantic depending on v). On success it returns -1 if v is less than other, 1 if
	// it is greater than other, or 0 if they are equal.
	func (v *Version) Compare(other string) (int, error) {
	ov, err := parse(other, v.semver)
	if err != nil {
	return 0, err
	}
	return v.compareInternal(ov), nil
	}