fix(os/gcache): a little memory leak for removed timestamp key (#3779)

errors/gcode/gcode.go

@@ -46,7 +46,7 @@ var (
 	CodeNotFound                  = localCode{65, "Not Found", nil}                    // Resource does not exist.
 	CodeInvalidRequest            = localCode{66, "Invalid Request", nil}              // Invalid request.
 	CodeNecessaryPackageNotImport = localCode{67, "Necessary Package Not Import", nil} // It needs necessary package import.
-	CodeInternalPanic             = localCode{68, "Internal Panic", nil}               // An panic occurred internally.
+	CodeInternalPanic             = localCode{68, "Internal Panic", nil}               // A panic occurred internally.
 	CodeBusinessValidationFailed  = localCode{300, "Business Validation Failed", nil}  // Business validation failed.
 )
 

os/gcache/gcache_adapter_memory.go

@@ -290,7 +290,7 @@ func (c *AdapterMemory) Remove(ctx context.Context, keys ...interface{}) (*gvar.
 	for _, key := range removedKeys {
 		c.eventList.PushBack(&adapterMemoryEvent{
 			k: key,
-			e: gtime.TimestampMilli() - 1000000,
+			e: gtime.TimestampMilli() - 1000,
 		})
 	}
 	return gvar.New(value), nil
@@ -416,12 +416,13 @@ func (c *AdapterMemory) syncEventAndClearExpired(ctx context.Context) {
 		oldExpireTime = c.expireTimes.Get(event.k)
 		// Calculating the new expiration time set.
 		newExpireTime = c.makeExpireKey(event.e)
+		// Expiration changed for this key.
 		if newExpireTime != oldExpireTime {
 			c.expireSets.GetOrNew(newExpireTime).Add(event.k)
 			if oldExpireTime != 0 {
 				c.expireSets.GetOrNew(oldExpireTime).Remove(event.k)
 			}
-			// Updating the expired time for <event.k>.
+			// Updating the expired time for `event.k`.
 			c.expireTimes.Set(event.k, newExpireTime)
 		}
 		// Adding the key the LRU history by writing operations.

os/gcache/gcache_adapter_memory_expire_sets.go

@@ -13,8 +13,10 @@ import (
 )
 
 type adapterMemoryExpireSets struct {
-	mu         sync.RWMutex        // expireSetMu ensures the concurrent safety of expireSets map.
-	expireSets map[int64]*gset.Set // expireSets is the expiring timestamp to its key set mapping, which is used for quick indexing and deleting.
+	// expireSetMu ensures the concurrent safety of expireSets map.
+	mu sync.RWMutex
+	// expireSets is the expiring timestamp in seconds to its key set mapping, which is used for quick indexing and deleting.
+	expireSets map[int64]*gset.Set
 }
 
 func newAdapterMemoryExpireSets() *adapterMemoryExpireSets {