diff --git a/.gitattributes b/.gitattributes
deleted file mode 100644
index 26a99ee..0000000
--- a/.gitattributes
+++ /dev/null
@@ -1,15 +0,0 @@
-# Set the default behavior, in case people don't have core.autocrlf set.
-* text=auto
-
-# convert to lf on checkout.
-*.go text eol=lf
-*.mod text eol=lf
-*.sum text eol=lf
-*.md text eol=lf
-*.svg text eol=lf
-*.conf text eol=lf
-
-# Denote all files that are truly binary and should not be modified.
-*.png binary
-*.jpg binary
-*.jpeg binary
\ No newline at end of file
diff --git a/FUTURE.md b/FUTURE.md
index 6bbb58e..1f6a120 100644
--- a/FUTURE.md
+++ b/FUTURE.md
@@ -1,9 +1,12 @@
 ## ✒ 未来版本的新特性 (Features in future versions)
 
+### v1.0.0
+
+* [x] 稳定的 API
+
 ### v0.6.x
 
-* [ ] 梳理代码，优化代码风格，精简部分代码和注释
-* [ ] 完善监控上报器，提供更多缓存信息查询的方法
+* [x] 梳理代码，优化代码风格，精简部分代码和注释
 
 ### v0.5.x
 
diff --git a/HISTORY.md b/HISTORY.md
index 6a701f0..176c1d9 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -1,5 +1,12 @@
 ## ✒ 历史版本的特性介绍 (Features in old versions)
 
+### v1.0.0
+
+> 此版本发布于 2025-03-15
+
+* 稳定的 API 版本
+* 调整快速时钟的代码，更改包名为 fastclock
+
 ### v0.6.1
 
 > 此版本发布于 2024-01-18
diff --git a/README.en.md b/README.en.md
index a835b6b..11faeed 100644
--- a/README.en.md
+++ b/README.en.md
@@ -23,7 +23,8 @@
 * Sentinel cleanup supports, cleaning up at fixed duration
 * Singleflight supports, which can decrease the times of cache penetration
 * Timer task supports, which is convenient to load data to cache
-* Report supports, providing several reporting points.
+* Report supports, providing several reporting points
+* Fast clock supports, fetching current time in nanoseconds
 
 _Check [HISTORY.md](./HISTORY.md) and [FUTURE.md](./FUTURE.md) to get more information._
 
@@ -143,11 +144,7 @@ BenchmarkGoCacheSet-12                   4921483               249.0 ns/op
 
 > Notice: Ecache only has lru mode, including v1 and v2; Freecache has 256 shardings, and we can't reset to 1.
 
-> Benchmarks: [_examples/performance_test.go](./_examples/performance_test.go)
-
-As you can see, cachego has a higher performance with sharding, but sharding has one-more-time positioning
-operation, so if the locking cost is less than the cost of positioning, this sharding is dragging. However, it has
-better performance in most time.
+> Benchmarks: [_examples/performance_test.go](./_examples/performance_test.go).
 
 ### 👥 Contributors
 
diff --git a/README.md b/README.md
index 8a07100..62585ed 100644
--- a/README.md
+++ b/README.md
@@ -23,6 +23,7 @@
 * 自带 singleflight 机制，减少缓存穿透的伤害
 * 自带定时任务封装，方便热数据定时加载到缓存
 * 支持上报缓存状况，可自定义多个缓存上报点
+* 自带快速时钟，支持纳秒级获取时间
 
 _历史版本的特性请查看 [HISTORY.md](./HISTORY.md)。未来版本的新特性和计划请查看 [FUTURE.md](./FUTURE.md)。_
 
@@ -142,10 +143,7 @@ BenchmarkGoCacheSet-12                   4921483               249.0 ns/op
 
 > 注：Ecache 只有 LRU 模式，v1 和 v2 两个版本；Freecache 默认是 256 分片，无法调节为 1 个分片进行对比测试。
 
-> 测试文件：[_examples/performance_test.go](./_examples/performance_test.go)
-
-可以看出，使用分片机制后的读写性能非常高，但是分片会多一次哈希定位的操作，如果加锁的消耗小于定位的消耗，那分片就不占优势。
-不过在绝大多数的情况下，分片机制带来的性能提升都是巨大的，尤其是对写操作较多的 lru 和 lfu 实现。
+> 测试文件：[_examples/performance_test.go](./_examples/performance_test.go)。
 
 ### 👥 贡献者
 
diff --git a/_examples/basic.go b/_examples/basic.go
index 47b9f67..ec3f756 100644
--- a/_examples/basic.go
+++ b/_examples/basic.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/_examples/clock.go b/_examples/fast_clock.go
similarity index 78%
rename from _examples/clock.go
rename to _examples/fast_clock.go
index fb228c6..5bb219b 100644
--- a/_examples/clock.go
+++ b/_examples/fast_clock.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -20,21 +20,17 @@ import (
 	"time"
 
 	"github.com/FishGoddess/cachego"
-	"github.com/FishGoddess/cachego/pkg/clock"
+	"github.com/FishGoddess/cachego/pkg/fastclock"
 )
 
 func main() {
-	// Create a fast clock and get current time in nanosecond by Now.
-	c := clock.New()
-	c.Now()
-
 	// Fast clock may return an "incorrect" time compared with time.Now.
 	// The gap will be smaller than about 100 ms.
 	for i := 0; i < 10; i++ {
 		time.Sleep(time.Duration(rand.Int63n(int64(time.Second))))
 
 		timeNow := time.Now().UnixNano()
-		clockNow := c.Now()
+		clockNow := fastclock.NowNanos()
 
 		fmt.Println(timeNow)
 		fmt.Println(clockNow)
@@ -43,8 +39,8 @@ func main() {
 	}
 
 	// You can specify the fast clock to cache by WithNow.
-	// All getting current time operations in this cache will use fast clock.
-	cache := cachego.NewCache(cachego.WithNow(clock.New().Now))
+	// All time used in this cache will be got from fast clock.
+	cache := cachego.NewCache(cachego.WithNow(fastclock.NowNanos))
 	cache.Set("key", 666, 100*time.Millisecond)
 
 	value, ok := cache.Get("key")
diff --git a/_examples/gc.go b/_examples/gc.go
index d30816f..80e51eb 100644
--- a/_examples/gc.go
+++ b/_examples/gc.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/_examples/lfu.go b/_examples/lfu.go
index 964f4e9..547d737 100644
--- a/_examples/lfu.go
+++ b/_examples/lfu.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/_examples/load.go b/_examples/load.go
index da22868..66ab77b 100644
--- a/_examples/load.go
+++ b/_examples/load.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/_examples/lru.go b/_examples/lru.go
index d983bef..31cfe44 100644
--- a/_examples/lru.go
+++ b/_examples/lru.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/_examples/performance_test.go b/_examples/performance_test.go
index 9a9be38..5d29f29 100644
--- a/_examples/performance_test.go
+++ b/_examples/performance_test.go
@@ -1,4 +1,4 @@
-// Copyright 2020 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/_examples/report.go b/_examples/report.go
index c7c69bc..3d29a85 100644
--- a/_examples/report.go
+++ b/_examples/report.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/_examples/sharding.go b/_examples/sharding.go
index b310200..fb6ce91 100644
--- a/_examples/sharding.go
+++ b/_examples/sharding.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/_examples/task.go b/_examples/task.go
index db814ad..b920917 100644
--- a/_examples/task.go
+++ b/_examples/task.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/_examples/ttl.go b/_examples/ttl.go
index 936ec4f..59dc4a0 100644
--- a/_examples/ttl.go
+++ b/_examples/ttl.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/cache.go b/cache.go
index e838fa4..383e3f0 100644
--- a/cache.go
+++ b/cache.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/cache_test.go b/cache_test.go
index 72413e7..33c903c 100644
--- a/cache_test.go
+++ b/cache_test.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/cache_type.go b/cache_type.go
index 95a65ea..26a3dbc 100644
--- a/cache_type.go
+++ b/cache_type.go
@@ -1,4 +1,4 @@
-// Copyright 2024 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/cache_type_test.go b/cache_type_test.go
index fba7442..17201d1 100644
--- a/cache_type_test.go
+++ b/cache_type_test.go
@@ -1,4 +1,4 @@
-// Copyright 2024 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/config.go b/config.go
index 2069c69..85d612d 100644
--- a/config.go
+++ b/config.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/config_test.go b/config_test.go
index 6491aa5..fa05dbb 100644
--- a/config_test.go
+++ b/config_test.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/doc.go b/doc.go
deleted file mode 100644
index 40a5e7d..0000000
--- a/doc.go
+++ /dev/null
@@ -1,478 +0,0 @@
-// Copyright 2020 FishGoddess. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-/*
-Package cachego provides an easy way to use foundation for your caching operations.
-
-1. basic:
-
-	// Use NewCache function to create a cache.
-	// By default, it creates a standard cache which evicts entries randomly.
-	// Use WithShardings to shard cache to several parts for higher performance.
-	// Use WithGC to clean expired entries every 10 minutes.
-	cache := cachego.NewCache(cachego.WithGC(10*time.Minute), cachego.WithShardings(64))
-
-	// Set an entry to cache with ttl.
-	cache.Set("key", 123, time.Second)
-
-	// Get an entry from cache.
-	value, ok := cache.Get("key")
-	fmt.Println(value, ok) // 123 true
-
-	// Check how many entries stores in cache.
-	size := cache.Size()
-	fmt.Println(size) // 1
-
-	// Clean expired entries.
-	cleans := cache.GC()
-	fmt.Println(cleans) // 1
-
-	// Set an entry which doesn't have ttl.
-	cache.Set("key", 123, cachego.NoTTL)
-
-	// Remove an entry.
-	removedValue := cache.Remove("key")
-	fmt.Println(removedValue) // 123
-
-	// Reset resets cache to initial status.
-	cache.Reset()
-
-	// Get value from cache and load it to cache if not found.
-	value, ok = cache.Get("key")
-	if !ok {
-		// Loaded entry will be set to cache and returned.
-		// By default, it will use singleflight.
-		value, _ = cache.Load("key", time.Second, func() (value interface{}, err error) {
-			return 666, nil
-		})
-	}
-
-	fmt.Println(value) // 666
-
-	// You can use WithLRU to specify the type of cache to lru.
-	// Also, try WithLFU if you want to use lfu to evict data.
-	cache = cachego.NewCache(cachego.WithLRU(100))
-	cache = cachego.NewCache(cachego.WithLFU(100))
-
-	// Use NewCacheWithReport to create a cache with report.
-	cache, reporter := cachego.NewCacheWithReport(cachego.WithCacheName("test"))
-	fmt.Println(reporter.CacheName())
-	fmt.Println(reporter.CacheType())
-
-2. ttl:
-
-	cache := cachego.NewCache()
-
-	// We think most of the entries in cache should have its ttl.
-	// So set an entry to cache should specify a ttl.
-	cache.Set("key", 666, time.Second)
-
-	value, ok := cache.Get("key")
-	fmt.Println(value, ok) // 666 true
-
-	time.Sleep(2 * time.Second)
-
-	// The entry is expired after ttl.
-	value, ok = cache.Get("key")
-	fmt.Println(value, ok) // <nil> false
-
-	// Notice that the entry still stores in cache even if it's expired.
-	// This is because we think you will reset entry to cache after cache missing in most situations.
-	// So we can reuse this entry and just reset its value and ttl.
-	size := cache.Size()
-	fmt.Println(size) // 1
-
-	// What should I do if I want an expired entry never storing in cache? Try GC:
-	cleans := cache.GC()
-	fmt.Println(cleans) // 1
-
-	size = cache.Size()
-	fmt.Println(size) // 0
-
-	// However, not all entries have ttl, and you can specify a NoTTL constant to do so.
-	// In fact, the entry won't expire as long as its ttl is <= 0.
-	// So you may have known NoTTL is a "readable" value of "<= 0".
-	cache.Set("key", 666, cachego.NoTTL)
-
-3. lru:
-
-	// By default, NewCache() returns a standard cache which evicts entries randomly.
-	cache := cachego.NewCache(cachego.WithMaxEntries(10))
-
-	for i := 0; i < 20; i++ {
-		key := strconv.Itoa(i)
-		cache.Set(key, i, cachego.NoTTL)
-	}
-
-	// Since we set 20 entries to cache, the size won't be 20 because we limit the max entries to 10.
-	size := cache.Size()
-	fmt.Println(size) // 10
-
-	// We don't know which entries will be evicted and stayed.
-	for i := 0; i < 20; i++ {
-		key := strconv.Itoa(i)
-		value, ok := cache.Get(key)
-		fmt.Println(key, value, ok)
-	}
-
-	fmt.Println()
-
-	// Sometimes we want it evicts entries by lru, try WithLRU.
-	// You need to specify the max entries storing in lru cache.
-	// More details see https://en.wikipedia.org/wiki/Cache_replacement_policies#Least_recently_used_(LRU).
-	cache = cachego.NewCache(cachego.WithLRU(10))
-
-	for i := 0; i < 20; i++ {
-		key := strconv.Itoa(i)
-		cache.Set(key, i, cachego.NoTTL)
-	}
-
-	// Only the least recently used entries can be got in a lru cache.
-	for i := 0; i < 20; i++ {
-		key := strconv.Itoa(i)
-		value, ok := cache.Get(key)
-		fmt.Println(key, value, ok)
-	}
-
-	// By default, lru will share one lock to do all operations.
-	// You can sharding cache to several parts for higher performance.
-	// Notice that max entries only effect to one part in sharding mode.
-	// For example, the total max entries will be 2*10 if shardings is 2 and max entries is 10 in WithLRU or WithMaxEntries.
-	// In some cache libraries, they will calculate max entries in each parts of shardings, like 10/2.
-	// However, the result divided by max entries and shardings may be not an integer which will make the total max entries incorrect.
-	// So we let users decide the exact max entries in each parts of shardings.
-	cache = cachego.NewCache(cachego.WithShardings(2), cachego.WithLRU(10))
-
-4. lfu:
-
-	// By default, NewCache() returns a standard cache which evicts entries randomly.
-	cache := cachego.NewCache(cachego.WithMaxEntries(10))
-
-	for i := 0; i < 20; i++ {
-		key := strconv.Itoa(i)
-		cache.Set(key, i, cachego.NoTTL)
-	}
-
-	// Since we set 20 entries to cache, the size won't be 20 because we limit the max entries to 10.
-	size := cache.Size()
-	fmt.Println(size) // 10
-
-	// We don't know which entries will be evicted and stayed.
-	for i := 0; i < 20; i++ {
-		key := strconv.Itoa(i)
-		value, ok := cache.Get(key)
-		fmt.Println(key, value, ok)
-	}
-
-	fmt.Println()
-
-	// Sometimes we want it evicts entries by lfu, try WithLFU.
-	// You need to specify the max entries storing in lfu cache.
-	// More details see https://en.wikipedia.org/wiki/Cache_replacement_policies#Least-frequently_used_(LFU).
-	cache = cachego.NewCache(cachego.WithLFU(10))
-
-	for i := 0; i < 20; i++ {
-		key := strconv.Itoa(i)
-
-		// Let entries have some frequently used operations.
-		for j := 0; j < i; j++ {
-			cache.Set(key, i, cachego.NoTTL)
-		}
-	}
-
-	for i := 0; i < 20; i++ {
-		key := strconv.Itoa(i)
-		value, ok := cache.Get(key)
-		fmt.Println(key, value, ok)
-	}
-
-	// By default, lfu will share one lock to do all operations.
-	// You can sharding cache to several parts for higher performance.
-	// Notice that max entries only effect to one part in sharding mode.
-	// For example, the total max entries will be 2*10 if shardings is 2 and max entries is 10 in WithLFU or WithMaxEntries.
-	// In some cache libraries, they will calculate max entries in each parts of shardings, like 10/2.
-	// However, the result divided by max entries and shardings may be not an integer which will make the total max entries incorrect.
-	// So we let users decide the exact max entries in each parts of shardings.
-	cache = cachego.NewCache(cachego.WithShardings(2), cachego.WithLFU(10))
-
-5. sharding:
-
-	// All operations in cache share one lock for concurrency.
-	// Use read lock or write lock is depends on cache implements.
-	// Get will use read lock in standard cache, but lru and lfu don't.
-	// This may be a serious performance problem in high qps.
-	cache := cachego.NewCache()
-
-	// We provide a sharding cache wrapper to shard one cache to several parts with hash.
-	// Every parts store its entries and all operations of one entry work on one part.
-	// This means there are more than one lock when you operate entries.
-	// The performance will be better in high qps.
-	cache = cachego.NewCache(cachego.WithShardings(64))
-	cache.Set("key", 666, cachego.NoTTL)
-
-	value, ok := cache.Get("key")
-	fmt.Println(value, ok) // 666 true
-
-	// Notice that max entries will be the sum of shards.
-	// For example, we set WithShardings(4) and WithMaxEntries(100), and the max entries in whole cache will be 4 * 100.
-	cache = cachego.NewCache(cachego.WithShardings(4), cachego.WithMaxEntries(100))
-
-	for i := 0; i < 1000; i++ {
-		key := strconv.Itoa(i)
-		cache.Set(key, i, cachego.NoTTL)
-	}
-
-	size := cache.Size()
-	fmt.Println(size) // 400
-
-6. gc:
-
-	cache := cachego.NewCache()
-	cache.Set("key", 666, time.Second)
-
-	time.Sleep(2 * time.Second)
-
-	// The entry is expired after ttl.
-	value, ok := cache.Get("key")
-	fmt.Println(value, ok) // <nil> false
-
-	// As you know the entry still stores in cache even if it's expired.
-	// This is because we think you will reset entry to cache after cache missing in most situations.
-	// So we can reuse this entry and just reset its value and ttl.
-	size := cache.Size()
-	fmt.Println(size) // 1
-
-	// What should I do if I want an expired entry never storing in cache? Try GC:
-	cleans := cache.GC()
-	fmt.Println(cleans) // 1
-
-	// Is there a smart way to do that? Try WithGC:
-	// For testing, we set a small duration of gc.
-	// You should set at least 3 minutes in production for performance.
-	cache = cachego.NewCache(cachego.WithGC(2 * time.Second))
-	cache.Set("key", 666, time.Second)
-
-	size = cache.Size()
-	fmt.Println(size) // 1
-
-	time.Sleep(3 * time.Second)
-
-	size = cache.Size()
-	fmt.Println(size) // 0
-
-	// Or you want a cancalable gc task? Try RunGCTask:
-	cache = cachego.NewCache()
-	cancel := cachego.RunGCTask(cache, 2*time.Second)
-
-	cache.Set("key", 666, time.Second)
-
-	size = cache.Size()
-	fmt.Println(size) // 1
-
-	time.Sleep(3 * time.Second)
-
-	size = cache.Size()
-	fmt.Println(size) // 0
-
-	cancel()
-
-	cache.Set("key", 666, time.Second)
-
-	size = cache.Size()
-	fmt.Println(size) // 1
-
-	time.Sleep(3 * time.Second)
-
-	size = cache.Size()
-	fmt.Println(size) // 1
-
-	// By default, gc only scans at most maxScans entries one time to remove expired entries.
-	// This is because scans all entries may cost much time if there is so many entries in cache, and a "stw" will happen.
-	// This can be a serious problem in some situations.
-	// Use WithMaxScans to set this value, remember, a value <= 0 means no scan limit.
-	cache = cachego.NewCache(cachego.WithGC(10*time.Minute), cachego.WithMaxScans(0))
-
-7. load:
-
-	// By default, singleflight is enabled in cache.
-	// Use WithDisableSingleflight to disable if you want.
-	cache := cachego.NewCache(cachego.WithDisableSingleflight())
-
-	// We recommend you to use singleflight.
-	cache = cachego.NewCache()
-
-	value, ok := cache.Get("key")
-	fmt.Println(value, ok) // <nil> false
-
-	if !ok {
-		// Load loads a value of key to cache with ttl.
-		// Use cachego.NoTTL if you want this value is no ttl.
-		// After loading value to cache, it returns the loaded value and error if failed.
-		value, _ = cache.Load("key", time.Second, func() (value interface{}, err error) {
-			return 666, nil
-		})
-	}
-
-	fmt.Println(value) // 666
-
-	value, ok = cache.Get("key")
-	fmt.Println(value, ok) // 666, true
-
-	time.Sleep(2 * time.Second)
-
-	value, ok = cache.Get("key")
-	fmt.Println(value, ok) // <nil>, false
-
-8. report:
-
-	func reportMissed(reporter *cachego.Reporter, key string) {
-		fmt.Printf("report: missed key %s, missed rate %.3f\n", key, reporter.MissedRate())
-	}
-
-	func reportHit(reporter *cachego.Reporter, key string, value interface{}) {
-		fmt.Printf("report: hit key %s value %+v, hit rate %.3f\n", key, value, reporter.HitRate())
-	}
-
-	func reportGC(reporter *cachego.Reporter, cost time.Duration, cleans int) {
-		fmt.Printf("report: gc cost %s cleans %d, gc count %d, cache size %d\n", cost, cleans, reporter.CountGC(), reporter.CacheSize())
-	}
-
-	func reportLoad(reporter *cachego.Reporter, key string, value interface{}, ttl time.Duration, err error) {
-		fmt.Printf("report: load key %s value %+v ttl %s, err %+v, load count %d\n", key, value, ttl, err, reporter.CountLoad())
-	}
-
-	// We provide some ways to report the status of cache.
-	// Use NewCacheWithReport to create a cache with reporting features.
-	cache, reporter := cachego.NewCacheWithReport(
-		// Sometimes you may have several caches in one service.
-		// You can set each name by WithCacheName and get the name from reporter.
-		cachego.WithCacheName("test"),
-
-		// For testing...
-		cachego.WithMaxEntries(3),
-		cachego.WithGC(100*time.Millisecond),
-
-		// ReportMissed reports the missed key getting from cache.
-		// ReportHit reports the hit entry getting from cache.
-		// ReportGC reports the status of cache gc.
-		// ReportLoad reports the result of loading.
-		cachego.WithReportMissed(reportMissed),
-		cachego.WithReportHit(reportHit),
-		cachego.WithReportGC(reportGC),
-		cachego.WithReportLoad(reportLoad),
-	)
-
-	for i := 0; i < 5; i++ {
-		key := strconv.Itoa(i)
-		evictedValue := cache.Set(key, key, 10*time.Millisecond)
-		fmt.Println(evictedValue)
-	}
-
-	for i := 0; i < 5; i++ {
-		key := strconv.Itoa(i)
-		value, ok := cache.Get(key)
-		fmt.Println(value, ok)
-	}
-
-	time.Sleep(200 * time.Millisecond)
-
-	value, err := cache.Load("key", time.Second, func() (value interface{}, err error) {
-		return 666, io.EOF
-	})
-
-	fmt.Println(value, err)
-
-	// These are some useful methods of reporter.
-	fmt.Println("CacheName:", reporter.CacheName())
-	fmt.Println("CacheType:", reporter.CacheType())
-	fmt.Println("CountMissed:", reporter.CountMissed())
-	fmt.Println("CountHit:", reporter.CountHit())
-	fmt.Println("CountGC:", reporter.CountGC())
-	fmt.Println("CountLoad:", reporter.CountLoad())
-	fmt.Println("CacheSize:", reporter.CacheSize())
-	fmt.Println("MissedRate:", reporter.MissedRate())
-	fmt.Println("HitRate:", reporter.HitRate())
-
-9. task:
-
-	var (
-		contextKey = struct{}{}
-	)
-
-	func beforePrint(ctx context.Context) {
-		fmt.Println("before:", ctx.Value(contextKey))
-	}
-
-	func afterPrint(ctx context.Context) {
-		fmt.Println("after:", ctx.Value(contextKey))
-	}
-
-	func printContextValue(ctx context.Context) {
-		fmt.Println("context value:", ctx.Value(contextKey))
-	}
-
-	// Create a context to stop the task.
-	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
-	defer cancel()
-
-	// Wrap context with key and value
-	ctx = context.WithValue(ctx, contextKey, "hello")
-
-	// Use New to create a task and run it.
-	// You can use it to load some hot data to cache at fixed duration.
-	// Before is called before the task loop, optional.
-	// After is called after the task loop, optional.
-	// Context is passed to fn include fn/before/after which can stop the task by Done(), optional.
-	// Duration is the duration between two loop of fn, optional.
-	// Run will start a new goroutine and run the task loop.
-	// The task will stop if context is done.
-	task.New(printContextValue).Before(beforePrint).After(afterPrint).Context(ctx).Duration(time.Second).Run()
-
-10. clock:
-
-	// Create a fast clock and get current time in nanosecond by Now.
-	c := clock.New()
-	c.Now()
-
-	// Fast clock may return an "incorrect" time compared with time.Now.
-	// The gap will be smaller than about 100 ms.
-	for i := 0; i < 10; i++ {
-		time.Sleep(time.Duration(rand.Int63n(int64(time.Second))))
-
-		timeNow := time.Now().UnixNano()
-		clockNow := c.Now()
-
-		fmt.Println(timeNow)
-		fmt.Println(clockNow)
-		fmt.Println("gap:", time.Duration(timeNow-clockNow))
-		fmt.Println()
-	}
-
-	// You can specify the fast clock to cache by WithNow.
-	// All getting current time operations in this cache will use fast clock.
-	cache := cachego.NewCache(cachego.WithNow(clock.New().Now))
-	cache.Set("key", 666, 100*time.Millisecond)
-
-	value, ok := cache.Get("key")
-	fmt.Println(value, ok) // 666, true
-
-	time.Sleep(200 * time.Millisecond)
-
-	value, ok = cache.Get("key")
-	fmt.Println(value, ok) // <nil>, false
-*/
-package cachego // import "github.com/FishGoddess/cachego"
-
-// Version is the version string representation of cachego.
-const Version = "v0.6.1"
diff --git a/entry.go b/entry.go
index 6316f61..884980c 100644
--- a/entry.go
+++ b/entry.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -17,9 +17,11 @@ package cachego
 import "time"
 
 type entry struct {
-	key        string
-	value      interface{}
-	expiration int64 // Time in nanosecond, valid util 2262 year (enough, uh?)
+	key   string
+	value interface{}
+
+	// Time in nanosecond, valid util 2262 year (enough, right?)
+	expiration int64
 	now        func() int64
 }
 
diff --git a/entry_test.go b/entry_test.go
index ed3e08d..32f0177 100644
--- a/entry_test.go
+++ b/entry_test.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/global.go b/global.go
index 890d914..0cd391c 100644
--- a/global.go
+++ b/global.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/global_test.go b/global_test.go
index 9a113b3..3e38107 100644
--- a/global_test.go
+++ b/global_test.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/go.mod b/go.mod
index a1f8805..f620f40 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,3 @@
 module github.com/FishGoddess/cachego
 
-go 1.20
+go 1.21
diff --git a/lfu.go b/lfu.go
index 1705f4b..f6816dd 100644
--- a/lfu.go
+++ b/lfu.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/lfu_test.go b/lfu_test.go
index edaaf51..c9333d8 100644
--- a/lfu_test.go
+++ b/lfu_test.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/load.go b/load.go
index b5e3f76..20cd4f0 100644
--- a/load.go
+++ b/load.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/load_test.go b/load_test.go
index 0b473f9..abbf86b 100644
--- a/load_test.go
+++ b/load_test.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/lru.go b/lru.go
index f023c77..34c1ee7 100644
--- a/lru.go
+++ b/lru.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/lru_test.go b/lru_test.go
index 0060ddf..755fbbf 100644
--- a/lru_test.go
+++ b/lru_test.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/option.go b/option.go
index 192dda2..2e90766 100644
--- a/option.go
+++ b/option.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/option_test.go b/option_test.go
index 5a64b8e..0d5681a 100644
--- a/option_test.go
+++ b/option_test.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/pkg/clock/clock.go b/pkg/clock/clock.go
deleted file mode 100644
index 6a3345e..0000000
--- a/pkg/clock/clock.go
+++ /dev/null
@@ -1,98 +0,0 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package clock
-
-import (
-	"sync"
-	"sync/atomic"
-	"time"
-)
-
-const (
-	duration = 100 * time.Millisecond
-)
-
-var (
-	clock     *Clock
-	clockOnce sync.Once
-)
-
-// Clock is a fast clock for getting current time.
-// It caches time and updates it in fixed duration which may return an "incorrect" time compared with time.Now().UnixNano().
-// In fact, we don't recommend you to use it unless you have to...
-// According to our benchmarks, it does run faster than time.Now:
-//
-// In my win10 pc:
-// goos: windows
-// goarch: amd64
-// cpu: AMD Ryzen 7 5800X 8-Core Processor
-// BenchmarkTimeNow-16             338466458                3.523 ns/op           0 B/op          0 allocs/op
-// BenchmarkClockNow-16            1000000000               0.2165 ns/op          0 B/op          0 allocs/op
-//
-// In my macbook with charging:
-// goos: darwin
-// goarch: amd64
-// pkg: github.com/FishGoddess/cachego/pkg/clock
-// cpu: Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
-// BenchmarkTimeNow-12             17841402                67.05 ns/op            0 B/op          0 allocs/op
-// BenchmarkClockNow-12            1000000000               0.2528 ns/op          0 B/op          0 allocs/op
-//
-// In my cloud server using 2 cores and running benchmarks in docker container:
-// goos: linux
-// goarch: amd64
-// pkg: github.com/FishGoddess/cachego/pkg/clock
-// cpu: AMD EPYC 7K62 48-Core Processor
-// BenchmarkTimeNow-2      17946441                65.62 ns/op            0 B/op          0 allocs/op
-// BenchmarkClockNow-2     1000000000               0.3162 ns/op          0 B/op          0 allocs/op
-//
-// PS: All benchmarks are ran with "go test -bench=. -benchtime=1s".
-//
-// However, the performance of time.Now is faster enough in many os and is enough for 99.9% situations.
-// The another reason choosing to use it is .
-// So, better performance should not be the first reason to use it.
-// The first reason to use it is reducing gc objects, but we hope you never use it :)
-type Clock struct {
-	now int64
-}
-
-// New creates a new clock which caches time and updates it in fixed duration.
-func New() *Clock {
-	clockOnce.Do(func() {
-		clock = &Clock{
-			now: time.Now().UnixNano(),
-		}
-
-		go clock.start()
-	})
-
-	return clock
-}
-
-func (c *Clock) start() {
-	for {
-		for i := 0; i < 9; i++ {
-			time.Sleep(duration)
-			atomic.AddInt64(&c.now, int64(duration))
-		}
-
-		time.Sleep(duration)
-		atomic.StoreInt64(&c.now, time.Now().UnixNano())
-	}
-}
-
-// Now returns the current time in nanoseconds.
-func (c *Clock) Now() int64 {
-	return atomic.LoadInt64(&c.now)
-}
diff --git a/pkg/clock/clock_test.go b/pkg/clock/clock_test.go
deleted file mode 100644
index aa70164..0000000
--- a/pkg/clock/clock_test.go
+++ /dev/null
@@ -1,76 +0,0 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package clock
-
-import (
-	"math"
-	"math/rand"
-	"testing"
-	"time"
-)
-
-// go test -bench=^BenchmarkTimeNow$ -benchtime=1s ./clock.go ./clock_test.go
-func BenchmarkTimeNow(b *testing.B) {
-	b.ReportAllocs()
-	b.ResetTimer()
-
-	for i := 0; i < b.N; i++ {
-		time.Now().Nanosecond()
-	}
-}
-
-// go test -bench=^BenchmarkClockNow$ -benchtime=1s ./clock.go ./clock_test.go
-func BenchmarkClockNow(b *testing.B) {
-	clock := New()
-
-	b.ReportAllocs()
-	b.ResetTimer()
-
-	for i := 0; i < b.N; i++ {
-		clock.Now()
-	}
-}
-
-// go test -v -cover -count=1 -test.cpu=1 -run=^TestNew$
-func TestNew(t *testing.T) {
-	var clocks []*Clock
-
-	for i := 0; i < 100; i++ {
-		clocks = append(clocks, New())
-	}
-
-	for i := 0; i < 100; i++ {
-		if clocks[i] != clock {
-			t.Fatalf("clocks[i] %p != clock %p", clocks[i], clock)
-		}
-	}
-}
-
-// go test -v -cover -count=1 -test.cpu=1 -run=^TestClock$
-func TestClock(t *testing.T) {
-	testClock := New()
-
-	for i := 0; i < 100; i++ {
-		now := testClock.Now()
-		t.Log(now)
-
-		expect := time.Now().UnixNano()
-		if math.Abs(float64(expect-now)) > float64(duration)*1.5 {
-			t.Fatalf("now %d is wrong with expect %d", now, expect)
-		}
-
-		time.Sleep(time.Duration(rand.Int63n(int64(duration))))
-	}
-}
diff --git a/pkg/fastclock/fast_clock.go b/pkg/fastclock/fast_clock.go
new file mode 100644
index 0000000..69ba68a
--- /dev/null
+++ b/pkg/fastclock/fast_clock.go
@@ -0,0 +1,83 @@
+// Copyright 2025 FishGoddess. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fastclock
+
+import (
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+// fastClock is a clock for getting current time faster.
+// It caches current time in nanos and updates it in fixed duration, so it's not a precise way to get current time.
+// In fact, we don't recommend you to use it unless you do need a fast way to get current time even the time is "incorrect".
+// According to our benchmarks, it does run faster than time.Now:
+//
+// In my linux server with 2 cores:
+// BenchmarkTimeNow-2               19150246                62.26 ns/op           0 B/op          0 allocs/op
+// BenchmarkFastClockNow-2         357209233                 3.46 ns/op           0 B/op          0 allocs/op
+// BenchmarkFastClockNowNanos-2    467461363                 2.55 ns/op           0 B/op          0 allocs/op
+//
+// However, the performance of time.Now is faster enough for 99.9% situations, so we hope you never use it :)
+type fastClock struct {
+	nanos int64
+}
+
+func newClock() *fastClock {
+	clock := &fastClock{
+		nanos: time.Now().UnixNano(),
+	}
+
+	go clock.start()
+	return clock
+}
+
+func (fc *fastClock) start() {
+	const duration = 100 * time.Millisecond
+
+	for {
+		for i := 0; i < 9; i++ {
+			time.Sleep(duration)
+			atomic.AddInt64(&fc.nanos, int64(duration))
+		}
+
+		time.Sleep(duration)
+		atomic.StoreInt64(&fc.nanos, time.Now().UnixNano())
+	}
+}
+
+func (fc *fastClock) currentNanos() int64 {
+	return atomic.LoadInt64(&fc.nanos)
+}
+
+var (
+	clock     *fastClock
+	clockOnce sync.Once
+)
+
+// Now returns the current time from fast clock.
+func Now() time.Time {
+	nanos := NowNanos()
+	return time.Unix(0, nanos)
+}
+
+// NowNanos returns the current time in nanos from fast clock.
+func NowNanos() int64 {
+	clockOnce.Do(func() {
+		clock = newClock()
+	})
+
+	return clock.currentNanos()
+}
diff --git a/pkg/fastclock/fast_clock_test.go b/pkg/fastclock/fast_clock_test.go
new file mode 100644
index 0000000..27a09ab
--- /dev/null
+++ b/pkg/fastclock/fast_clock_test.go
@@ -0,0 +1,87 @@
+// Copyright 2025 FishGoddess. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fastclock
+
+import (
+	"math"
+	"math/rand"
+	"testing"
+	"time"
+)
+
+// go test -v -run=^$ -bench=^BenchmarkTimeNow$ -benchtime=1s
+func BenchmarkTimeNow(b *testing.B) {
+	b.ReportAllocs()
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		time.Now()
+	}
+}
+
+// go test -v -run=^$ -bench=^BenchmarkFastClockNow$ -benchtime=1s
+func BenchmarkFastClockNow(b *testing.B) {
+	b.ReportAllocs()
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		Now()
+	}
+}
+
+// go test -v -run=^$ -bench=^BenchmarkFastClockNowNanos$ -benchtime=1s
+func BenchmarkFastClockNowNanos(b *testing.B) {
+	b.ReportAllocs()
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		NowNanos()
+	}
+}
+
+// go test -v -cover -count=1 -test.cpu=1 -run=^TestNow$
+func TestNow(t *testing.T) {
+	duration := 100 * time.Millisecond
+
+	for i := 0; i < 100; i++ {
+		got := Now()
+		gap := time.Since(got)
+		t.Logf("got: %v, gap: %v", got, gap)
+
+		if math.Abs(float64(gap.Nanoseconds())) > float64(duration)*1.1 {
+			t.Errorf("now %v is wrong", got)
+		}
+
+		time.Sleep(time.Duration(rand.Int63n(int64(duration))))
+	}
+}
+
+// go test -v -cover -count=1 -test.cpu=1 -run=^TestNowNanos$
+func TestNowNanos(t *testing.T) {
+	duration := 100 * time.Millisecond
+
+	for i := 0; i < 100; i++ {
+		gotNanos := NowNanos()
+		got := time.Unix(0, gotNanos)
+		gap := time.Since(got)
+		t.Logf("got: %v, gap: %v", got, gap)
+
+		if math.Abs(float64(gap.Nanoseconds())) > float64(duration)*1.1 {
+			t.Errorf("now %v is wrong", got)
+		}
+
+		time.Sleep(time.Duration(rand.Int63n(int64(duration))))
+	}
+}
diff --git a/pkg/heap/heap.go b/pkg/heap/heap.go
index 8bf74cc..4d8730d 100644
--- a/pkg/heap/heap.go
+++ b/pkg/heap/heap.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/pkg/heap/heap_test.go b/pkg/heap/heap_test.go
index b74556b..e0362bb 100644
--- a/pkg/heap/heap_test.go
+++ b/pkg/heap/heap_test.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/pkg/singleflight/singleflight.go b/pkg/singleflight/singleflight.go
index 306834e..2b857dc 100644
--- a/pkg/singleflight/singleflight.go
+++ b/pkg/singleflight/singleflight.go
@@ -1,4 +1,4 @@
-// Copyright 2021 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -18,7 +18,6 @@ import (
 	"sync"
 )
 
-// call wraps function with some information and stores result and error after calling.
 type call struct {
 	fn     func() (result interface{}, err error)
 	result interface{}
@@ -37,11 +36,10 @@ func newCall(fn func() (result interface{}, err error)) *call {
 	}
 }
 
-// do will call fn and fill result and error to call.
-// Notice: Any panics or runtime.Goexit() happening in fn() will be ignored.
 func (c *call) do() {
 	defer c.wg.Done()
 
+	// Notice: Any panics or runtime.Goexit() happening in fn() will be ignored.
 	c.result, c.err = c.fn()
 }
 
@@ -65,7 +63,6 @@ func (g *Group) Call(key string, fn func() (interface{}, error)) (interface{}, e
 	if c, ok := g.calls[key]; ok {
 		g.lock.Unlock()
 
-		// Waiting...
 		c.wg.Wait()
 		return c.result, c.err
 	}
diff --git a/pkg/singleflight/singleflight_test.go b/pkg/singleflight/singleflight_test.go
index 7daa777..928826d 100644
--- a/pkg/singleflight/singleflight_test.go
+++ b/pkg/singleflight/singleflight_test.go
@@ -1,4 +1,4 @@
-// Copyright 2021 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/pkg/task/task.go b/pkg/task/task.go
index b0c11cd..57d955e 100644
--- a/pkg/task/task.go
+++ b/pkg/task/task.go
@@ -1,4 +1,4 @@
-// Copyright 2022 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/pkg/task/task_test.go b/pkg/task/task_test.go
index 3b5fc3d..c0137b4 100644
--- a/pkg/task/task_test.go
+++ b/pkg/task/task_test.go
@@ -1,4 +1,4 @@
-// Copyright 2022 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/report.go b/report.go
index 31915c3..7faa842 100644
--- a/report.go
+++ b/report.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/report_test.go b/report_test.go
index 9619ed0..c434a72 100644
--- a/report_test.go
+++ b/report_test.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/sharding.go b/sharding.go
index 096e5c3..2b012fd 100644
--- a/sharding.go
+++ b/sharding.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/sharding_test.go b/sharding_test.go
index 71c7d22..e70dee1 100644
--- a/sharding_test.go
+++ b/sharding_test.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/standard.go b/standard.go
index 83dd0ad..722e8ba 100644
--- a/standard.go
+++ b/standard.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/standard_test.go b/standard_test.go
index 3af3b85..cf42b0c 100644
--- a/standard_test.go
+++ b/standard_test.go
@@ -1,4 +1,4 @@
-// Copyright 2023 FishGoddess. All Rights Reserved.
+// Copyright 2025 FishGoddess. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.