cloudfoundry/cf-k8s-controllers

package authorization

import (
    "context"
    "fmt"
    "time"

    "k8s.io/apimachinery/pkg/util/cache"
)

const (
    cacheTTL = 120 * time.Second
)

type CachingIdentityProvider struct {
    identityProvider IdentityProvider
    identityCache    *cache.Expiring
}

func NewCachingIdentityProvider(identityProvider IdentityProvider, identityCache *cache.Expiring) *CachingIdentityProvider {
    return &CachingIdentityProvider{
        identityProvider: identityProvider,
        identityCache:    identityCache,
    }
}

func (p *CachingIdentityProvider) GetIdentity(ctx context.Context, info Info) (Identity, error) {
    idInterface, ok := p.identityCache.Get(info.Hash())
    if ok {
        id, castOK := idInterface.(Identity)
        if castOK {
            return id, nil
        }
        return Identity{}, fmt.Errorf("identity-provider cache: expected authorization.Identity{}, got %T", idInterface)
    }

    identity, err := p.identityProvider.GetIdentity(ctx, info)
    if err == nil {
        p.identityCache.Set(info.Hash(), identity, cacheTTL)
    }

    return identity, err
}