diff --git a/sharded.go b/sharded.go index bcc0538..a8f7d8b 100644 --- a/sharded.go +++ b/sharded.go @@ -8,6 +8,8 @@ import ( "os" "runtime" "time" + + "golang.org/x/exp/constraints" ) // This is an experimental and unexported (for now) attempt at making a cache @@ -19,15 +21,15 @@ import ( // // See cache_test.go for a few benchmarks. -type unexportedShardedCache struct { - *shardedCache +type unexportedShardedCache[V constraints.Ordered] struct { + *shardedCache[V] } -type shardedCache struct { +type shardedCache[V constraints.Ordered] struct { seed uint32 m uint32 - cs []*cache - janitor *shardedJanitor + cs []*orderedCache[string, V] + janitor *shardedJanitor[V] } // djb2 with better shuffling. 5x faster than FNV with the hash.Hash overhead. @@ -62,43 +64,36 @@ func djb33(seed uint32, k string) uint32 { return d ^ (d >> 16) } -func (sc *shardedCache) bucket(k string) *cache { +func (sc *shardedCache[V]) bucket(k string) *orderedCache[string, V] { return sc.cs[djb33(sc.seed, k)%sc.m] } -func (sc *shardedCache) Set(k string, x interface{}, d time.Duration) { +func (sc *shardedCache[V]) Set(k string, x V, d time.Duration) { sc.bucket(k).Set(k, x, d) } -func (sc *shardedCache) Add(k string, x interface{}, d time.Duration) error { +func (sc *shardedCache[V]) Add(k string, x V, d time.Duration) error { return sc.bucket(k).Add(k, x, d) } -func (sc *shardedCache) Replace(k string, x interface{}, d time.Duration) error { +func (sc *shardedCache[V]) Replace(k string, x V, d time.Duration) error { return sc.bucket(k).Replace(k, x, d) } -func (sc *shardedCache) Get(k string) (interface{}, bool) { +func (sc *shardedCache[V]) Get(k string) (*V, bool) { return sc.bucket(k).Get(k) } -func (sc *shardedCache) Increment(k string, n int64) error { - return sc.bucket(k).Increment(k, n) +func (sc *shardedCache[V]) Increment(k string, n V) error { + _, err := sc.bucket(k).Increment(k, n) + return err } -func (sc *shardedCache) IncrementFloat(k string, n float64) error { - return sc.bucket(k).IncrementFloat(k, n) -} - -func (sc *shardedCache) Decrement(k string, n int64) error { - return sc.bucket(k).Decrement(k, n) -} - -func (sc *shardedCache) Delete(k string) { +func (sc *shardedCache[V]) Delete(k string) { sc.bucket(k).Delete(k) } -func (sc *shardedCache) DeleteExpired() { +func (sc *shardedCache[V]) DeleteExpired() { for _, v := range sc.cs { v.DeleteExpired() } @@ -109,26 +104,26 @@ func (sc *shardedCache) DeleteExpired() { // fields of the items should be checked. Note that explicit synchronization // is needed to use a cache and its corresponding Items() return values at // the same time, as the maps are shared. -func (sc *shardedCache) Items() []map[string]Item { - res := make([]map[string]Item, len(sc.cs)) +func (sc *shardedCache[V]) Items() []map[string]Item[V] { + res := make([]map[string]Item[V], len(sc.cs)) for i, v := range sc.cs { res[i] = v.Items() } return res } -func (sc *shardedCache) Flush() { +func (sc *shardedCache[V]) Flush() { for _, v := range sc.cs { v.Flush() } } -type shardedJanitor struct { +type shardedJanitor[V constraints.Ordered] struct { Interval time.Duration stop chan bool } -func (j *shardedJanitor) Run(sc *shardedCache) { +func (j *shardedJanitor[V]) Run(sc *shardedCache[V]) { j.stop = make(chan bool) tick := time.Tick(j.Interval) for { @@ -141,19 +136,19 @@ func (j *shardedJanitor) Run(sc *shardedCache) { } } -func stopShardedJanitor(sc *unexportedShardedCache) { +func stopShardedJanitor[V constraints.Ordered](sc *unexportedShardedCache[V]) { sc.janitor.stop <- true } -func runShardedJanitor(sc *shardedCache, ci time.Duration) { - j := &shardedJanitor{ +func runShardedJanitor[V constraints.Ordered](sc *shardedCache[V], ci time.Duration) { + j := &shardedJanitor[V]{ Interval: ci, } sc.janitor = j go j.Run(sc) } -func newShardedCache(n int, de time.Duration) *shardedCache { +func newShardedCache[V constraints.Ordered](n int, de time.Duration) *shardedCache[V] { max := big.NewInt(0).SetUint64(uint64(math.MaxUint32)) rnd, err := rand.Int(rand.Reader, max) var seed uint32 @@ -163,30 +158,34 @@ func newShardedCache(n int, de time.Duration) *shardedCache { } else { seed = uint32(rnd.Uint64()) } - sc := &shardedCache{ + sc := &shardedCache[V]{ seed: seed, m: uint32(n), - cs: make([]*cache, n), + cs: make([]*orderedCache[string, V], n), } for i := 0; i < n; i++ { - c := &cache{ - defaultExpiration: de, - items: map[string]Item{}, + c := &orderedCache[string, V]{ + Cache: &Cache[string, V]{ + cache: &cache[string, V]{ + defaultExpiration: de, + items: map[string]Item[V]{}, + }, + }, } sc.cs[i] = c } return sc } -func unexportedNewSharded(defaultExpiration, cleanupInterval time.Duration, shards int) *unexportedShardedCache { +func unexportedNewSharded[V constraints.Ordered](defaultExpiration, cleanupInterval time.Duration, shards int) *unexportedShardedCache[V] { if defaultExpiration == 0 { defaultExpiration = -1 } - sc := newShardedCache(shards, defaultExpiration) - SC := &unexportedShardedCache{sc} + sc := newShardedCache[V](shards, defaultExpiration) + SC := &unexportedShardedCache[V]{sc} if cleanupInterval > 0 { runShardedJanitor(sc, cleanupInterval) - runtime.SetFinalizer(SC, stopShardedJanitor) + runtime.SetFinalizer(SC, stopShardedJanitor[V]) } return SC } diff --git a/sharded_test.go b/sharded_test.go index 84220ad..0216e2f 100644 --- a/sharded_test.go +++ b/sharded_test.go @@ -27,7 +27,7 @@ var shardedKeys = []string{ } func TestShardedCache(t *testing.T) { - tc := unexportedNewSharded(DefaultExpiration, 0, 13) + tc := unexportedNewSharded[string](DefaultExpiration, 0, 13) for _, v := range shardedKeys { tc.Set(v, "value", DefaultExpiration) } @@ -43,7 +43,7 @@ func BenchmarkShardedCacheGetNotExpiring(b *testing.B) { func benchmarkShardedCacheGet(b *testing.B, exp time.Duration) { b.StopTimer() - tc := unexportedNewSharded(exp, 0, 10) + tc := unexportedNewSharded[string](exp, 0, 10) tc.Set("foobarba", "zquux", DefaultExpiration) b.StartTimer() for i := 0; i < b.N; i++ { @@ -62,7 +62,7 @@ func BenchmarkShardedCacheGetManyConcurrentNotExpiring(b *testing.B) { func benchmarkShardedCacheGetManyConcurrent(b *testing.B, exp time.Duration) { b.StopTimer() n := 10000 - tsc := unexportedNewSharded(exp, 0, 20) + tsc := unexportedNewSharded[string](exp, 0, 20) keys := make([]string, n) for i := 0; i < n; i++ { k := "foo" + strconv.Itoa(i)