Import of https://github.com/ciena/voltctl at commit 40d61fbf3f910ed4017cf67c9c79e8e1f82a33a5
Change-Id: I8464c59e60d76cb8612891db3303878975b5416c
diff --git a/vendor/k8s.io/apimachinery/pkg/labels/selector.go b/vendor/k8s.io/apimachinery/pkg/labels/selector.go
new file mode 100644
index 0000000..374d2ef
--- /dev/null
+++ b/vendor/k8s.io/apimachinery/pkg/labels/selector.go
@@ -0,0 +1,891 @@
+/*
+Copyright 2014 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 labels
+
+import (
+ "bytes"
+ "fmt"
+ "sort"
+ "strconv"
+ "strings"
+
+ "github.com/golang/glog"
+ "k8s.io/apimachinery/pkg/selection"
+ "k8s.io/apimachinery/pkg/util/sets"
+ "k8s.io/apimachinery/pkg/util/validation"
+)
+
+// Requirements is AND of all requirements.
+type Requirements []Requirement
+
+// Selector represents a label selector.
+type Selector interface {
+ // Matches returns true if this selector matches the given set of labels.
+ Matches(Labels) bool
+
+ // Empty returns true if this selector does not restrict the selection space.
+ Empty() bool
+
+ // String returns a human readable string that represents this selector.
+ String() string
+
+ // Add adds requirements to the Selector
+ Add(r ...Requirement) Selector
+
+ // Requirements converts this interface into Requirements to expose
+ // more detailed selection information.
+ // If there are querying parameters, it will return converted requirements and selectable=true.
+ // If this selector doesn't want to select anything, it will return selectable=false.
+ Requirements() (requirements Requirements, selectable bool)
+
+ // Make a deep copy of the selector.
+ DeepCopySelector() Selector
+}
+
+// Everything returns a selector that matches all labels.
+func Everything() Selector {
+ return internalSelector{}
+}
+
+type nothingSelector struct{}
+
+func (n nothingSelector) Matches(_ Labels) bool { return false }
+func (n nothingSelector) Empty() bool { return false }
+func (n nothingSelector) String() string { return "" }
+func (n nothingSelector) Add(_ ...Requirement) Selector { return n }
+func (n nothingSelector) Requirements() (Requirements, bool) { return nil, false }
+func (n nothingSelector) DeepCopySelector() Selector { return n }
+
+// Nothing returns a selector that matches no labels
+func Nothing() Selector {
+ return nothingSelector{}
+}
+
+// NewSelector returns a nil selector
+func NewSelector() Selector {
+ return internalSelector(nil)
+}
+
+type internalSelector []Requirement
+
+func (s internalSelector) DeepCopy() internalSelector {
+ if s == nil {
+ return nil
+ }
+ result := make([]Requirement, len(s))
+ for i := range s {
+ s[i].DeepCopyInto(&result[i])
+ }
+ return result
+}
+
+func (s internalSelector) DeepCopySelector() Selector {
+ return s.DeepCopy()
+}
+
+// ByKey sorts requirements by key to obtain deterministic parser
+type ByKey []Requirement
+
+func (a ByKey) Len() int { return len(a) }
+
+func (a ByKey) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
+
+func (a ByKey) Less(i, j int) bool { return a[i].key < a[j].key }
+
+// Requirement contains values, a key, and an operator that relates the key and values.
+// The zero value of Requirement is invalid.
+// Requirement implements both set based match and exact match
+// Requirement should be initialized via NewRequirement constructor for creating a valid Requirement.
+// +k8s:deepcopy-gen=true
+type Requirement struct {
+ key string
+ operator selection.Operator
+ // In huge majority of cases we have at most one value here.
+ // It is generally faster to operate on a single-element slice
+ // than on a single-element map, so we have a slice here.
+ strValues []string
+}
+
+// NewRequirement is the constructor for a Requirement.
+// If any of these rules is violated, an error is returned:
+// (1) The operator can only be In, NotIn, Equals, DoubleEquals, NotEquals, Exists, or DoesNotExist.
+// (2) If the operator is In or NotIn, the values set must be non-empty.
+// (3) If the operator is Equals, DoubleEquals, or NotEquals, the values set must contain one value.
+// (4) If the operator is Exists or DoesNotExist, the value set must be empty.
+// (5) If the operator is Gt or Lt, the values set must contain only one value, which will be interpreted as an integer.
+// (6) The key is invalid due to its length, or sequence
+// of characters. See validateLabelKey for more details.
+//
+// The empty string is a valid value in the input values set.
+func NewRequirement(key string, op selection.Operator, vals []string) (*Requirement, error) {
+ if err := validateLabelKey(key); err != nil {
+ return nil, err
+ }
+ switch op {
+ case selection.In, selection.NotIn:
+ if len(vals) == 0 {
+ return nil, fmt.Errorf("for 'in', 'notin' operators, values set can't be empty")
+ }
+ case selection.Equals, selection.DoubleEquals, selection.NotEquals:
+ if len(vals) != 1 {
+ return nil, fmt.Errorf("exact-match compatibility requires one single value")
+ }
+ case selection.Exists, selection.DoesNotExist:
+ if len(vals) != 0 {
+ return nil, fmt.Errorf("values set must be empty for exists and does not exist")
+ }
+ case selection.GreaterThan, selection.LessThan:
+ if len(vals) != 1 {
+ return nil, fmt.Errorf("for 'Gt', 'Lt' operators, exactly one value is required")
+ }
+ for i := range vals {
+ if _, err := strconv.ParseInt(vals[i], 10, 64); err != nil {
+ return nil, fmt.Errorf("for 'Gt', 'Lt' operators, the value must be an integer")
+ }
+ }
+ default:
+ return nil, fmt.Errorf("operator '%v' is not recognized", op)
+ }
+
+ for i := range vals {
+ if err := validateLabelValue(vals[i]); err != nil {
+ return nil, err
+ }
+ }
+ return &Requirement{key: key, operator: op, strValues: vals}, nil
+}
+
+func (r *Requirement) hasValue(value string) bool {
+ for i := range r.strValues {
+ if r.strValues[i] == value {
+ return true
+ }
+ }
+ return false
+}
+
+// Matches returns true if the Requirement matches the input Labels.
+// There is a match in the following cases:
+// (1) The operator is Exists and Labels has the Requirement's key.
+// (2) The operator is In, Labels has the Requirement's key and Labels'
+// value for that key is in Requirement's value set.
+// (3) The operator is NotIn, Labels has the Requirement's key and
+// Labels' value for that key is not in Requirement's value set.
+// (4) The operator is DoesNotExist or NotIn and Labels does not have the
+// Requirement's key.
+// (5) The operator is GreaterThanOperator or LessThanOperator, and Labels has
+// the Requirement's key and the corresponding value satisfies mathematical inequality.
+func (r *Requirement) Matches(ls Labels) bool {
+ switch r.operator {
+ case selection.In, selection.Equals, selection.DoubleEquals:
+ if !ls.Has(r.key) {
+ return false
+ }
+ return r.hasValue(ls.Get(r.key))
+ case selection.NotIn, selection.NotEquals:
+ if !ls.Has(r.key) {
+ return true
+ }
+ return !r.hasValue(ls.Get(r.key))
+ case selection.Exists:
+ return ls.Has(r.key)
+ case selection.DoesNotExist:
+ return !ls.Has(r.key)
+ case selection.GreaterThan, selection.LessThan:
+ if !ls.Has(r.key) {
+ return false
+ }
+ lsValue, err := strconv.ParseInt(ls.Get(r.key), 10, 64)
+ if err != nil {
+ glog.V(10).Infof("ParseInt failed for value %+v in label %+v, %+v", ls.Get(r.key), ls, err)
+ return false
+ }
+
+ // There should be only one strValue in r.strValues, and can be converted to a integer.
+ if len(r.strValues) != 1 {
+ glog.V(10).Infof("Invalid values count %+v of requirement %#v, for 'Gt', 'Lt' operators, exactly one value is required", len(r.strValues), r)
+ return false
+ }
+
+ var rValue int64
+ for i := range r.strValues {
+ rValue, err = strconv.ParseInt(r.strValues[i], 10, 64)
+ if err != nil {
+ glog.V(10).Infof("ParseInt failed for value %+v in requirement %#v, for 'Gt', 'Lt' operators, the value must be an integer", r.strValues[i], r)
+ return false
+ }
+ }
+ return (r.operator == selection.GreaterThan && lsValue > rValue) || (r.operator == selection.LessThan && lsValue < rValue)
+ default:
+ return false
+ }
+}
+
+// Key returns requirement key
+func (r *Requirement) Key() string {
+ return r.key
+}
+
+// Operator returns requirement operator
+func (r *Requirement) Operator() selection.Operator {
+ return r.operator
+}
+
+// Values returns requirement values
+func (r *Requirement) Values() sets.String {
+ ret := sets.String{}
+ for i := range r.strValues {
+ ret.Insert(r.strValues[i])
+ }
+ return ret
+}
+
+// Empty returns true if the internalSelector doesn't restrict selection space
+func (lsel internalSelector) Empty() bool {
+ if lsel == nil {
+ return true
+ }
+ return len(lsel) == 0
+}
+
+// String returns a human-readable string that represents this
+// Requirement. If called on an invalid Requirement, an error is
+// returned. See NewRequirement for creating a valid Requirement.
+func (r *Requirement) String() string {
+ var buffer bytes.Buffer
+ if r.operator == selection.DoesNotExist {
+ buffer.WriteString("!")
+ }
+ buffer.WriteString(r.key)
+
+ switch r.operator {
+ case selection.Equals:
+ buffer.WriteString("=")
+ case selection.DoubleEquals:
+ buffer.WriteString("==")
+ case selection.NotEquals:
+ buffer.WriteString("!=")
+ case selection.In:
+ buffer.WriteString(" in ")
+ case selection.NotIn:
+ buffer.WriteString(" notin ")
+ case selection.GreaterThan:
+ buffer.WriteString(">")
+ case selection.LessThan:
+ buffer.WriteString("<")
+ case selection.Exists, selection.DoesNotExist:
+ return buffer.String()
+ }
+
+ switch r.operator {
+ case selection.In, selection.NotIn:
+ buffer.WriteString("(")
+ }
+ if len(r.strValues) == 1 {
+ buffer.WriteString(r.strValues[0])
+ } else { // only > 1 since == 0 prohibited by NewRequirement
+ // normalizes value order on output, without mutating the in-memory selector representation
+ // also avoids normalization when it is not required, and ensures we do not mutate shared data
+ buffer.WriteString(strings.Join(safeSort(r.strValues), ","))
+ }
+
+ switch r.operator {
+ case selection.In, selection.NotIn:
+ buffer.WriteString(")")
+ }
+ return buffer.String()
+}
+
+// safeSort sort input strings without modification
+func safeSort(in []string) []string {
+ if sort.StringsAreSorted(in) {
+ return in
+ }
+ out := make([]string, len(in))
+ copy(out, in)
+ sort.Strings(out)
+ return out
+}
+
+// Add adds requirements to the selector. It copies the current selector returning a new one
+func (lsel internalSelector) Add(reqs ...Requirement) Selector {
+ var sel internalSelector
+ for ix := range lsel {
+ sel = append(sel, lsel[ix])
+ }
+ for _, r := range reqs {
+ sel = append(sel, r)
+ }
+ sort.Sort(ByKey(sel))
+ return sel
+}
+
+// Matches for a internalSelector returns true if all
+// its Requirements match the input Labels. If any
+// Requirement does not match, false is returned.
+func (lsel internalSelector) Matches(l Labels) bool {
+ for ix := range lsel {
+ if matches := lsel[ix].Matches(l); !matches {
+ return false
+ }
+ }
+ return true
+}
+
+func (lsel internalSelector) Requirements() (Requirements, bool) { return Requirements(lsel), true }
+
+// String returns a comma-separated string of all
+// the internalSelector Requirements' human-readable strings.
+func (lsel internalSelector) String() string {
+ var reqs []string
+ for ix := range lsel {
+ reqs = append(reqs, lsel[ix].String())
+ }
+ return strings.Join(reqs, ",")
+}
+
+// Token represents constant definition for lexer token
+type Token int
+
+const (
+ // ErrorToken represents scan error
+ ErrorToken Token = iota
+ // EndOfStringToken represents end of string
+ EndOfStringToken
+ // ClosedParToken represents close parenthesis
+ ClosedParToken
+ // CommaToken represents the comma
+ CommaToken
+ // DoesNotExistToken represents logic not
+ DoesNotExistToken
+ // DoubleEqualsToken represents double equals
+ DoubleEqualsToken
+ // EqualsToken represents equal
+ EqualsToken
+ // GreaterThanToken represents greater than
+ GreaterThanToken
+ // IdentifierToken represents identifier, e.g. keys and values
+ IdentifierToken
+ // InToken represents in
+ InToken
+ // LessThanToken represents less than
+ LessThanToken
+ // NotEqualsToken represents not equal
+ NotEqualsToken
+ // NotInToken represents not in
+ NotInToken
+ // OpenParToken represents open parenthesis
+ OpenParToken
+)
+
+// string2token contains the mapping between lexer Token and token literal
+// (except IdentifierToken, EndOfStringToken and ErrorToken since it makes no sense)
+var string2token = map[string]Token{
+ ")": ClosedParToken,
+ ",": CommaToken,
+ "!": DoesNotExistToken,
+ "==": DoubleEqualsToken,
+ "=": EqualsToken,
+ ">": GreaterThanToken,
+ "in": InToken,
+ "<": LessThanToken,
+ "!=": NotEqualsToken,
+ "notin": NotInToken,
+ "(": OpenParToken,
+}
+
+// ScannedItem contains the Token and the literal produced by the lexer.
+type ScannedItem struct {
+ tok Token
+ literal string
+}
+
+// isWhitespace returns true if the rune is a space, tab, or newline.
+func isWhitespace(ch byte) bool {
+ return ch == ' ' || ch == '\t' || ch == '\r' || ch == '\n'
+}
+
+// isSpecialSymbol detect if the character ch can be an operator
+func isSpecialSymbol(ch byte) bool {
+ switch ch {
+ case '=', '!', '(', ')', ',', '>', '<':
+ return true
+ }
+ return false
+}
+
+// Lexer represents the Lexer struct for label selector.
+// It contains necessary informationt to tokenize the input string
+type Lexer struct {
+ // s stores the string to be tokenized
+ s string
+ // pos is the position currently tokenized
+ pos int
+}
+
+// read return the character currently lexed
+// increment the position and check the buffer overflow
+func (l *Lexer) read() (b byte) {
+ b = 0
+ if l.pos < len(l.s) {
+ b = l.s[l.pos]
+ l.pos++
+ }
+ return b
+}
+
+// unread 'undoes' the last read character
+func (l *Lexer) unread() {
+ l.pos--
+}
+
+// scanIDOrKeyword scans string to recognize literal token (for example 'in') or an identifier.
+func (l *Lexer) scanIDOrKeyword() (tok Token, lit string) {
+ var buffer []byte
+IdentifierLoop:
+ for {
+ switch ch := l.read(); {
+ case ch == 0:
+ break IdentifierLoop
+ case isSpecialSymbol(ch) || isWhitespace(ch):
+ l.unread()
+ break IdentifierLoop
+ default:
+ buffer = append(buffer, ch)
+ }
+ }
+ s := string(buffer)
+ if val, ok := string2token[s]; ok { // is a literal token?
+ return val, s
+ }
+ return IdentifierToken, s // otherwise is an identifier
+}
+
+// scanSpecialSymbol scans string starting with special symbol.
+// special symbol identify non literal operators. "!=", "==", "="
+func (l *Lexer) scanSpecialSymbol() (Token, string) {
+ lastScannedItem := ScannedItem{}
+ var buffer []byte
+SpecialSymbolLoop:
+ for {
+ switch ch := l.read(); {
+ case ch == 0:
+ break SpecialSymbolLoop
+ case isSpecialSymbol(ch):
+ buffer = append(buffer, ch)
+ if token, ok := string2token[string(buffer)]; ok {
+ lastScannedItem = ScannedItem{tok: token, literal: string(buffer)}
+ } else if lastScannedItem.tok != 0 {
+ l.unread()
+ break SpecialSymbolLoop
+ }
+ default:
+ l.unread()
+ break SpecialSymbolLoop
+ }
+ }
+ if lastScannedItem.tok == 0 {
+ return ErrorToken, fmt.Sprintf("error expected: keyword found '%s'", buffer)
+ }
+ return lastScannedItem.tok, lastScannedItem.literal
+}
+
+// skipWhiteSpaces consumes all blank characters
+// returning the first non blank character
+func (l *Lexer) skipWhiteSpaces(ch byte) byte {
+ for {
+ if !isWhitespace(ch) {
+ return ch
+ }
+ ch = l.read()
+ }
+}
+
+// Lex returns a pair of Token and the literal
+// literal is meaningfull only for IdentifierToken token
+func (l *Lexer) Lex() (tok Token, lit string) {
+ switch ch := l.skipWhiteSpaces(l.read()); {
+ case ch == 0:
+ return EndOfStringToken, ""
+ case isSpecialSymbol(ch):
+ l.unread()
+ return l.scanSpecialSymbol()
+ default:
+ l.unread()
+ return l.scanIDOrKeyword()
+ }
+}
+
+// Parser data structure contains the label selector parser data structure
+type Parser struct {
+ l *Lexer
+ scannedItems []ScannedItem
+ position int
+}
+
+// ParserContext represents context during parsing:
+// some literal for example 'in' and 'notin' can be
+// recognized as operator for example 'x in (a)' but
+// it can be recognized as value for example 'value in (in)'
+type ParserContext int
+
+const (
+ // KeyAndOperator represents key and operator
+ KeyAndOperator ParserContext = iota
+ // Values represents values
+ Values
+)
+
+// lookahead func returns the current token and string. No increment of current position
+func (p *Parser) lookahead(context ParserContext) (Token, string) {
+ tok, lit := p.scannedItems[p.position].tok, p.scannedItems[p.position].literal
+ if context == Values {
+ switch tok {
+ case InToken, NotInToken:
+ tok = IdentifierToken
+ }
+ }
+ return tok, lit
+}
+
+// consume returns current token and string. Increments the position
+func (p *Parser) consume(context ParserContext) (Token, string) {
+ p.position++
+ tok, lit := p.scannedItems[p.position-1].tok, p.scannedItems[p.position-1].literal
+ if context == Values {
+ switch tok {
+ case InToken, NotInToken:
+ tok = IdentifierToken
+ }
+ }
+ return tok, lit
+}
+
+// scan runs through the input string and stores the ScannedItem in an array
+// Parser can now lookahead and consume the tokens
+func (p *Parser) scan() {
+ for {
+ token, literal := p.l.Lex()
+ p.scannedItems = append(p.scannedItems, ScannedItem{token, literal})
+ if token == EndOfStringToken {
+ break
+ }
+ }
+}
+
+// parse runs the left recursive descending algorithm
+// on input string. It returns a list of Requirement objects.
+func (p *Parser) parse() (internalSelector, error) {
+ p.scan() // init scannedItems
+
+ var requirements internalSelector
+ for {
+ tok, lit := p.lookahead(Values)
+ switch tok {
+ case IdentifierToken, DoesNotExistToken:
+ r, err := p.parseRequirement()
+ if err != nil {
+ return nil, fmt.Errorf("unable to parse requirement: %v", err)
+ }
+ requirements = append(requirements, *r)
+ t, l := p.consume(Values)
+ switch t {
+ case EndOfStringToken:
+ return requirements, nil
+ case CommaToken:
+ t2, l2 := p.lookahead(Values)
+ if t2 != IdentifierToken && t2 != DoesNotExistToken {
+ return nil, fmt.Errorf("found '%s', expected: identifier after ','", l2)
+ }
+ default:
+ return nil, fmt.Errorf("found '%s', expected: ',' or 'end of string'", l)
+ }
+ case EndOfStringToken:
+ return requirements, nil
+ default:
+ return nil, fmt.Errorf("found '%s', expected: !, identifier, or 'end of string'", lit)
+ }
+ }
+}
+
+func (p *Parser) parseRequirement() (*Requirement, error) {
+ key, operator, err := p.parseKeyAndInferOperator()
+ if err != nil {
+ return nil, err
+ }
+ if operator == selection.Exists || operator == selection.DoesNotExist { // operator found lookahead set checked
+ return NewRequirement(key, operator, []string{})
+ }
+ operator, err = p.parseOperator()
+ if err != nil {
+ return nil, err
+ }
+ var values sets.String
+ switch operator {
+ case selection.In, selection.NotIn:
+ values, err = p.parseValues()
+ case selection.Equals, selection.DoubleEquals, selection.NotEquals, selection.GreaterThan, selection.LessThan:
+ values, err = p.parseExactValue()
+ }
+ if err != nil {
+ return nil, err
+ }
+ return NewRequirement(key, operator, values.List())
+
+}
+
+// parseKeyAndInferOperator parse literals.
+// in case of no operator '!, in, notin, ==, =, !=' are found
+// the 'exists' operator is inferred
+func (p *Parser) parseKeyAndInferOperator() (string, selection.Operator, error) {
+ var operator selection.Operator
+ tok, literal := p.consume(Values)
+ if tok == DoesNotExistToken {
+ operator = selection.DoesNotExist
+ tok, literal = p.consume(Values)
+ }
+ if tok != IdentifierToken {
+ err := fmt.Errorf("found '%s', expected: identifier", literal)
+ return "", "", err
+ }
+ if err := validateLabelKey(literal); err != nil {
+ return "", "", err
+ }
+ if t, _ := p.lookahead(Values); t == EndOfStringToken || t == CommaToken {
+ if operator != selection.DoesNotExist {
+ operator = selection.Exists
+ }
+ }
+ return literal, operator, nil
+}
+
+// parseOperator return operator and eventually matchType
+// matchType can be exact
+func (p *Parser) parseOperator() (op selection.Operator, err error) {
+ tok, lit := p.consume(KeyAndOperator)
+ switch tok {
+ // DoesNotExistToken shouldn't be here because it's a unary operator, not a binary operator
+ case InToken:
+ op = selection.In
+ case EqualsToken:
+ op = selection.Equals
+ case DoubleEqualsToken:
+ op = selection.DoubleEquals
+ case GreaterThanToken:
+ op = selection.GreaterThan
+ case LessThanToken:
+ op = selection.LessThan
+ case NotInToken:
+ op = selection.NotIn
+ case NotEqualsToken:
+ op = selection.NotEquals
+ default:
+ return "", fmt.Errorf("found '%s', expected: '=', '!=', '==', 'in', notin'", lit)
+ }
+ return op, nil
+}
+
+// parseValues parses the values for set based matching (x,y,z)
+func (p *Parser) parseValues() (sets.String, error) {
+ tok, lit := p.consume(Values)
+ if tok != OpenParToken {
+ return nil, fmt.Errorf("found '%s' expected: '('", lit)
+ }
+ tok, lit = p.lookahead(Values)
+ switch tok {
+ case IdentifierToken, CommaToken:
+ s, err := p.parseIdentifiersList() // handles general cases
+ if err != nil {
+ return s, err
+ }
+ if tok, _ = p.consume(Values); tok != ClosedParToken {
+ return nil, fmt.Errorf("found '%s', expected: ')'", lit)
+ }
+ return s, nil
+ case ClosedParToken: // handles "()"
+ p.consume(Values)
+ return sets.NewString(""), nil
+ default:
+ return nil, fmt.Errorf("found '%s', expected: ',', ')' or identifier", lit)
+ }
+}
+
+// parseIdentifiersList parses a (possibly empty) list of
+// of comma separated (possibly empty) identifiers
+func (p *Parser) parseIdentifiersList() (sets.String, error) {
+ s := sets.NewString()
+ for {
+ tok, lit := p.consume(Values)
+ switch tok {
+ case IdentifierToken:
+ s.Insert(lit)
+ tok2, lit2 := p.lookahead(Values)
+ switch tok2 {
+ case CommaToken:
+ continue
+ case ClosedParToken:
+ return s, nil
+ default:
+ return nil, fmt.Errorf("found '%s', expected: ',' or ')'", lit2)
+ }
+ case CommaToken: // handled here since we can have "(,"
+ if s.Len() == 0 {
+ s.Insert("") // to handle (,
+ }
+ tok2, _ := p.lookahead(Values)
+ if tok2 == ClosedParToken {
+ s.Insert("") // to handle ,) Double "" removed by StringSet
+ return s, nil
+ }
+ if tok2 == CommaToken {
+ p.consume(Values)
+ s.Insert("") // to handle ,, Double "" removed by StringSet
+ }
+ default: // it can be operator
+ return s, fmt.Errorf("found '%s', expected: ',', or identifier", lit)
+ }
+ }
+}
+
+// parseExactValue parses the only value for exact match style
+func (p *Parser) parseExactValue() (sets.String, error) {
+ s := sets.NewString()
+ tok, lit := p.lookahead(Values)
+ if tok == EndOfStringToken || tok == CommaToken {
+ s.Insert("")
+ return s, nil
+ }
+ tok, lit = p.consume(Values)
+ if tok == IdentifierToken {
+ s.Insert(lit)
+ return s, nil
+ }
+ return nil, fmt.Errorf("found '%s', expected: identifier", lit)
+}
+
+// Parse takes a string representing a selector and returns a selector
+// object, or an error. This parsing function differs from ParseSelector
+// as they parse different selectors with different syntaxes.
+// The input will cause an error if it does not follow this form:
+//
+// <selector-syntax> ::= <requirement> | <requirement> "," <selector-syntax>
+// <requirement> ::= [!] KEY [ <set-based-restriction> | <exact-match-restriction> ]
+// <set-based-restriction> ::= "" | <inclusion-exclusion> <value-set>
+// <inclusion-exclusion> ::= <inclusion> | <exclusion>
+// <exclusion> ::= "notin"
+// <inclusion> ::= "in"
+// <value-set> ::= "(" <values> ")"
+// <values> ::= VALUE | VALUE "," <values>
+// <exact-match-restriction> ::= ["="|"=="|"!="] VALUE
+//
+// KEY is a sequence of one or more characters following [ DNS_SUBDOMAIN "/" ] DNS_LABEL. Max length is 63 characters.
+// VALUE is a sequence of zero or more characters "([A-Za-z0-9_-\.])". Max length is 63 characters.
+// Delimiter is white space: (' ', '\t')
+// Example of valid syntax:
+// "x in (foo,,baz),y,z notin ()"
+//
+// Note:
+// (1) Inclusion - " in " - denotes that the KEY exists and is equal to any of the
+// VALUEs in its requirement
+// (2) Exclusion - " notin " - denotes that the KEY is not equal to any
+// of the VALUEs in its requirement or does not exist
+// (3) The empty string is a valid VALUE
+// (4) A requirement with just a KEY - as in "y" above - denotes that
+// the KEY exists and can be any VALUE.
+// (5) A requirement with just !KEY requires that the KEY not exist.
+//
+func Parse(selector string) (Selector, error) {
+ parsedSelector, err := parse(selector)
+ if err == nil {
+ return parsedSelector, nil
+ }
+ return nil, err
+}
+
+// parse parses the string representation of the selector and returns the internalSelector struct.
+// The callers of this method can then decide how to return the internalSelector struct to their
+// callers. This function has two callers now, one returns a Selector interface and the other
+// returns a list of requirements.
+func parse(selector string) (internalSelector, error) {
+ p := &Parser{l: &Lexer{s: selector, pos: 0}}
+ items, err := p.parse()
+ if err != nil {
+ return nil, err
+ }
+ sort.Sort(ByKey(items)) // sort to grant determistic parsing
+ return internalSelector(items), err
+}
+
+func validateLabelKey(k string) error {
+ if errs := validation.IsQualifiedName(k); len(errs) != 0 {
+ return fmt.Errorf("invalid label key %q: %s", k, strings.Join(errs, "; "))
+ }
+ return nil
+}
+
+func validateLabelValue(v string) error {
+ if errs := validation.IsValidLabelValue(v); len(errs) != 0 {
+ return fmt.Errorf("invalid label value: %q: %s", v, strings.Join(errs, "; "))
+ }
+ return nil
+}
+
+// SelectorFromSet returns a Selector which will match exactly the given Set. A
+// nil and empty Sets are considered equivalent to Everything().
+func SelectorFromSet(ls Set) Selector {
+ if ls == nil || len(ls) == 0 {
+ return internalSelector{}
+ }
+ var requirements internalSelector
+ for label, value := range ls {
+ r, err := NewRequirement(label, selection.Equals, []string{value})
+ if err == nil {
+ requirements = append(requirements, *r)
+ } else {
+ //TODO: double check errors when input comes from serialization?
+ return internalSelector{}
+ }
+ }
+ // sort to have deterministic string representation
+ sort.Sort(ByKey(requirements))
+ return requirements
+}
+
+// SelectorFromValidatedSet returns a Selector which will match exactly the given Set.
+// A nil and empty Sets are considered equivalent to Everything().
+// It assumes that Set is already validated and doesn't do any validation.
+func SelectorFromValidatedSet(ls Set) Selector {
+ if ls == nil || len(ls) == 0 {
+ return internalSelector{}
+ }
+ var requirements internalSelector
+ for label, value := range ls {
+ requirements = append(requirements, Requirement{key: label, operator: selection.Equals, strValues: []string{value}})
+ }
+ // sort to have deterministic string representation
+ sort.Sort(ByKey(requirements))
+ return requirements
+}
+
+// ParseToRequirements takes a string representing a selector and returns a list of
+// requirements. This function is suitable for those callers that perform additional
+// processing on selector requirements.
+// See the documentation for Parse() function for more details.
+// TODO: Consider exporting the internalSelector type instead.
+func ParseToRequirements(selector string) ([]Requirement, error) {
+ return parse(selector)
+}