111 lines
2.4 KiB
Go
111 lines
2.4 KiB
Go
//go:generate stringer -type=FeatureFlag
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package features
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import (
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"expvar"
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"fmt"
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"sync"
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)
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type FeatureFlag int
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const (
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unused FeatureFlag = iota // unused is used for testing
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IDNASupport
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AllowAccountDeactivation
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AllowKeyRollover
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ResubmitMissingSCTsOnly
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GoogleSafeBrowsingV4
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UseAIAIssuerURL
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AllowTLS02Challenges
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GenerateOCSPEarly
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CountCertificatesExact
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RandomDirectoryEntry
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IPv6First
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DirectoryMeta
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)
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// List of features and their default value, protected by fMu
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var features = map[FeatureFlag]bool{
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unused: false,
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IDNASupport: false,
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AllowAccountDeactivation: false,
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AllowKeyRollover: false,
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ResubmitMissingSCTsOnly: false,
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GoogleSafeBrowsingV4: false,
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UseAIAIssuerURL: false,
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AllowTLS02Challenges: false,
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GenerateOCSPEarly: false,
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CountCertificatesExact: false,
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RandomDirectoryEntry: false,
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IPv6First: false,
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DirectoryMeta: false,
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}
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var fMu = new(sync.RWMutex)
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var initial = map[FeatureFlag]bool{}
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var nameToFeature = make(map[string]FeatureFlag, len(features))
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func init() {
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for f, v := range features {
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nameToFeature[f.String()] = f
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initial[f] = v
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}
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}
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// expvar.Set requires a type that satisfies the expvar.Var interface,
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// since neither string nor bool implement this interface we require
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// a basic shim.
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type boolVar bool
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func (b boolVar) String() string { return fmt.Sprintf("%t", b) }
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// Set accepts a list of features and whether they should
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// be enabled or disabled, it will return a error if passed
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// a feature name that it doesn't know
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func Set(featureSet map[string]bool) error {
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fMu.Lock()
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defer fMu.Unlock()
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for n, v := range featureSet {
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f, present := nameToFeature[n]
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if !present {
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return fmt.Errorf("feature '%s' doesn't exist", n)
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}
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features[f] = v
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}
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return nil
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}
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// Export populates a expvar.Map with the state of all
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// of the features.
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func Export(m *expvar.Map) {
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fMu.RLock()
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defer fMu.RUnlock()
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for f, v := range features {
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m.Set(f.String(), boolVar(v))
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}
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}
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// Enabled returns true if the feature is enabled or false
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// if it isn't, it will panic if passed a feature that it
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// doesn't know.
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func Enabled(n FeatureFlag) bool {
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fMu.RLock()
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defer fMu.RUnlock()
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v, present := features[n]
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if !present {
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panic(fmt.Sprintf("feature '%s' doesn't exist", n.String()))
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}
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return v
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}
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// Reset resets the features to their initial state
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func Reset() {
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fMu.Lock()
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defer fMu.Unlock()
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features = initial
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}
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