README
¶
配置
type ConfigOpt func(*bigcache.Config)
- Shards int
分片数量，必须是2的幂次方， 例如21,22....；
// 即shards切片长度
shards []*cacheShard
-
LifeWindow time.Duration
- 整体缓存过期时间；
- 若CleanWindow大于0，每隔CleanWindow时间间隔，过期的缓存会被自动清理；
- 否则，bigcache在每次设置缓存时，会判断最早的缓存是否过期，若过期，则清理；
-
CleanWindow time.Duration
若大于0，则会定期自动删除缓存时间超过LifeWindow
if config.CleanWindow > 0 {
go func() {
ticker := time.NewTicker(config.CleanWindow)
defer ticker.Stop()
for {
select {
case <-ctx.Done():
fmt.Println("ctx done, shutting down bigcache cleanup routine")
return
case t := <-ticker.C:
cache.cleanUp(uint64(t.Unix()))
case <-cache.close:
return
}
}
}()
}
- MaxEntriesInWindow int
必须大于0，用于计算每个shard的初始大小
// initialShardSize computes initial shard size
max(MaxEntriesInWindow/Shards, 10)
- MaxEntrySize int
每个实体最大的内存大小，单位byte，必须大于0
// queue.ByteQueue.capacity大小，若此值大于HardMaxCacheSize，则取HardMaxCacheSize
max(MaxEntriesInWindow/Shards, 10) * MaxEntrySize
- StatsEnabled bool
若开启，各个cacheShard分片会统计每个key的命中次数
- Verbose bool
若开启，会打印新内存分配的信息
- Hasher bigchache.Hasher
为key生成无符号的64位整数哈希值
// bigchache
type Hasher interface {
Sum64(key string) uint64
}
- HardMaxCacheSize int
每个分片，缓存（queue.ByteQueue）最大内存大小，单位MB，若为0，则表示没有限制
使用
func main() {
cacheName := "cacheDemo"
err := memcache.NewBigCache(context.Background(), cacheName, memcache.WithCleanWindow(time.Minute), memcache.WithLifeWindow(50*time.Second))
if err != nil {
fmt.Printf("new memory cache error %v\n", err)
}
memcache.Set(cacheName, "key9999999", []byte("key9999999"))
startTime := time.Now()
data, err := memcache.Get(cacheName, "key9999999")
fmt.Printf("spend time %v\n", time.Now().UnixMicro()-startTime.UnixMicro())
if err != nil {
fmt.Printf("memory cache Get error %v\n", err)
return
}
fmt.Printf("data is %v\n", string(data))
}
由于bigcache有一个整体的过期时间和清理策略，通过CleanWindow来控制清理时间间隔，以及LifeWindow来控制整体缓存的有效时间；
在使用时，注意LifeWindow与这里设置的过期时间，建议把LifeWindow设置比TTL大一些，避免被bigcache自动清理，例如1分钟
需要调用c.Close()或者通过取消上下文，让bigcache定时器goroutine退出
Benchmarks
1: 50秒有效期，1分钟清理窗口配置下，1000万数据下，100并发写，100并发读，平均延时1微秒延时，最高延时30微妙。
bench test
goos: darwin
goarch: arm64
pkg: github.com/gowins/dionysus/memcache
BenchmarkBigCacheSet-8 17409649 382.0 ns/op 152 B/op 2 allocs/op
BenchmarkBigCacheGet-8 16806682 278.9 ns/op 85 B/op 2 allocs/op
BenchmarkBigCacheSetParallel-8 41394356 134.9 ns/op 117 B/op 3 allocs/op
BenchmarkBigCacheGetParallel-8 44905400 92.14 ns/op 23 B/op 1 allocs/op
PASS
ok github.com/gowins/dionysus/memcache 49.881s
2: GC pause time
go version
go version go1.19 linux/amd64
go run caches_gc_overhead_comparison.go
Number of entries: 10000000
GC pause for bigcache: 0.306077ms
Number of entries: 20000000
GC pause for bigcache: 0.506077ms
Documentation
¶
Index ¶
- func Close(name string) error
- func Delete(name string, key string) error
- func Get(name string, key string) ([]byte, error)
- func GetCache(name string) (*bigcache.BigCache, bool)
- func InitBigCache(name string, opts ...ConfigOpt) *bigcache.BigCache
- func NewBigCache(ctx context.Context, name string, opts ...ConfigOpt) error
- func Set(name string, key string, value []byte) error
- type ConfigOpt
- func WithCleanWindow(cleanWindow time.Duration) ConfigOpt
- func WithHardMaxCacheSize(size int) ConfigOpt
- func WithHasher(hasher bigcache.Hasher) ConfigOpt
- func WithLifeWindow(lifeWindow time.Duration) ConfigOpt
- func WithLogger(l bigcache.Logger) ConfigOpt
- func WithMaxEntriesInWindow(max int) ConfigOpt
- func WithMaxEntrySize(max int) ConfigOpt
- func WithOnRemove(f func(string, []byte)) ConfigOpt
- func WithOnRemoveWithMetadata(f func(string, []byte, bigcache.Metadata)) ConfigOpt
- func WithOnRemoveWithReason(f func(string, []byte, bigcache.RemoveReason)) ConfigOpt
- func WithShards(shards int) ConfigOpt
- func WithStatsEnabled(enable bool) ConfigOpt
- func WithVerbose(v bool) ConfigOpt
- type Hasher
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func InitBigCache ¶
func NewBigCache ¶
NewBigCache return Cacher implementation
Types ¶
type ConfigOpt ¶
type ConfigOpt func(*bigcache.Config)
ConfigOpt set bigcache.Config fileds
func WithCleanWindow ¶
WithLifeWindow set bigcache.Config.CleanWindow field
func WithHardMaxCacheSize ¶
WithHardMaxCacheSize set bigcache.Config.HardMaxCacheSize field
func WithHasher ¶
func WithHasher(hasher bigcache.Hasher) ConfigOpt
WithHasher set bigcache.Config.Hasher field
func WithLifeWindow ¶
WithLifeWindow set bigcache.Config.LifeWindow field
func WithLogger ¶
func WithLogger(l bigcache.Logger) ConfigOpt
WithLogger set bigcache.Config.Logger field
func WithMaxEntriesInWindow ¶
WithMaxEntriesInWindow set bigcache.Config.MaxEntriesInWindow field
func WithMaxEntrySize ¶
WithMaxEntrySize set bigcache.Config.MaxEntrySize
func WithOnRemove ¶
WithOnRemove set bigcache.Config.OnRemove
func WithOnRemoveWithMetadata ¶
WithOnRemoveWithMetadata set bigcache.Config.OnRemoveWithMetadata field
func WithOnRemoveWithReason ¶
WithOnRemoveWithReason set bigcache.Config.OnRemoveWithReason field
func WithStatsEnabled ¶
WithStatsEnabled set bigcache.Config.StatsEnabled field
Source Files