matchbox/api/matchers.go

package api

import (
	"sort"
	"strings"
)

// RequirementSet is a map of key:value equality requirements which
// match against any Labels which are supersets.
type RequirementSet map[string]string

// Matches returns true if the given labels satisfy all the requirements,
// false otherwise.
func (r RequirementSet) Matches(labels Labels) bool {
	for k, v := range r {
		if labels == nil || labels.Get(k) != v {
			return false
		}
	}
	return true
}

func (r RequirementSet) String() string {
	requirements := make([]string, 0, len(r))
	for key, value := range r {
		requirements = append(requirements, key+"="+value)
	}
	// sort by "key=value" pairs for a deterministic ordering
	sort.StringSlice(requirements).Sort()
	return strings.Join(requirements, ",")
}

// Labels present key to value mappings, independent of their storage.
type Labels interface {
	// Get returns the value for the given label.
	Get(label string) string
}

// LabelSet is a map of key:value labels.
type LabelSet map[string]string

// Get returns the value for the given label.
func (ls LabelSet) Get(label string) string {
	return ls[label]
}