}

// lruCache is a least-recently-used cache
type lruCache struct {
	// factory to use to create new rate limiters
	rateLimiterFactory func() flowcontrol.RateLimiter
	// the actual LRU cache
	cache *lru.Cache
}

func (c *lruCache) get(key interface{}) flowcontrol.RateLimiter {
	value, found := c.cache.Get(key)
	if !found {
		rateLimter := c.rateLimiterFactory()
		c.cache.Add(key, rateLimter)
		return rateLimter
	}

		return nil, err
	}

	path := filepath.Join(cfg.GOMODCACHE, "cache", "lock")
	if err := os.MkdirAll(filepath.Dir(path), 0777); err != nil {
		return nil, fmt.Errorf("failed to create cache directory: %w", err)
	}

	return lockedfile.MutexAt(path).Lock()
}

// A cachingRepo is a cache around an underlying Repo,

	// unbounded growth on the cache - for a given info the transformer is always the same.
	// The key always corresponds to the exact same value, with the caveat that
	// since we use the value.Context.AuthenticatedData to overwrite old keys,
	// we always have to check that the info matches (to validate the transformer is correct).
	cache.AllowExpiredGet = true
	return &simpleCache{
		cache: cache,
		ttl:   ttl,
	}
}

}

func newSimpleCache(clock clock.Clock, ttl time.Duration, providerName string) *simpleCache {
	cache := utilcache.NewExpiringWithClock(clock)
	cache.AllowExpiredGet = true // for a given key, the value (the decryptTransformer) is always the same
	return &simpleCache{
		cache: cache,
		ttl:   ttl,
		hashPool: &sync.Pool{
			New: func() interface{} {
				return sha256.New()
			},
		},

# Test go build -pgo flag.
# Specifically, the build cache handles profile content correctly.

[short] skip 'compiles and links executables'

# Set up fresh GOCACHE.
env GOCACHE=$WORK/gocache
mkdir $GOCACHE

# build without PGO
go build triv.go

# build with PGO, should trigger rebuild
# starting with an empty profile (the compiler accepts it)
go build -x -pgo=prof -o triv.exe triv.go
stderr 'preprofile.*-i.*prof'

env GO111MODULE=off
[short] skip # rebuilds all of std

# Set up fresh GOCACHE.
env GOCACHE=$WORK/gocache
mkdir $GOCACHE

# Verify the standard library (specifically internal/runtime/atomic) can be
# built with -gcflags when -n is given. See golang.org/issue/29346.
go build -n -gcflags=all='-l' std

type boringPub struct {
	key  *boring.PublicKeyRSA
	orig PublicKey
}

var pubCache bcache.Cache[PublicKey, boringPub]
var privCache bcache.Cache[PrivateKey, boringPriv]

func init() {
	pubCache.Register()
	privCache.Register()
}

func boringPublicKey(pub *PublicKey) (*boring.PublicKeyRSA, error) {
	b := pubCache.Get(pub)
	if b != nil && publicKeyEqual(&b.orig, pub) {
		return b.key, nil
	}

	g := NewWithT(t)
	d := t.TempDir()
	t.Logf("Test Dir: %q", d)

	c := NewCache(d)

	f := c.GetFileFor(CacheKey{})
	g.Expect(f).To(BeEmpty())
}

func TestCache_Delete(t *testing.T) {
	g := NewWithT(t)
	d := t.TempDir()
	t.Logf("Test Dir: %q", d)

	c := NewCache(d)

	_, err := c.Apply(gateway)
	g.Expect(err).To(BeNil())

	keys1, err := c.Apply(virtualService)

env GO111MODULE=off
[short] skip # rebuilds std for mips

# Set up fresh GOCACHE.
env GOCACHE=$WORK/gocache
mkdir $GOCACHE

# Building for mipsle without setting GOMIPS will use floating point registers.
env GOARCH=mipsle
env GOOS=linux
go build -gcflags=-S f.go
stderr ADDD.F[0-9]+,.F[0-9]+,.F[0-9]+

# Clean cache
go clean -cache

# Building with GOMIPS=softfloat will not use floating point registers
env GOMIPS=softfloat

env GO111MODULE=off
[short] skip

# Set up fresh GOCACHE.
env GOCACHE=$WORK/gocache
mkdir $GOCACHE

# Building a main package should run the compiler and linker ...
go build -o $devnull -x main.go
stderr '(compile|gccgo)( |\.exe).*main\.go'
stderr '(link|gccgo)( |\.exe)'

# ... and then the linker again ...
go build -o $devnull -x main.go
! stderr '(compile|gccgo)( |\.exe).*main\.go'
stderr '(link|gccgo)( |\.exe)'