.
├── LICENSE
├── README.md
├── assert_test.go
├── bigcache.go
├── bigcache_bench_test.go
├── bigcache_test.go
├── bytes.go
├── bytes_appengine.go
├── clock.go
├── config.go
├── encoding.go
├── encoding_test.go
├── entry_not_found_error.go
├── examples_test.go
├── fnv.go
├── fnv_bench_test.go
├── fnv_test.go
├── go.mod
├── go.sum
├── hash.go
├── hash_test.go
├── iterator.go
├── iterator_test.go
├── logger.go
├── queue
│?? ├── bytes_queue.go
│?? └── bytes_queue_test.go
├── server
│?? ├── README.md
│?? ├── cache_handlers.go
│?? ├── middleware.go
│?? ├── middleware_test.go
│?? ├── server.go
│?? ├── server_test.go
│?? └── stats_handler.go
├── shard.go
├── stats.go
└── utils.go
2 directories, 36 files

func TestSetGet(t *testing.T) {
    // new一個(gè)bigCache對(duì)象
    cache, _ := bigcache.New(context.Background(), bigcache.DefaultConfig(10*time.Minute))
    // get獲取一個(gè)無(wú)值的key
    vNil, err := cache.Get("key")
    t.Log(vNil, err) // [] Entry not found 值為空的[]字節(jié)slice
    // set 存儲(chǔ)數(shù)據(jù)
    cache.Set("key", []byte("value"))
    // get 獲取數(shù)據(jù)
    v, _ := cache.Get("key")
    t.Log(v)         // 輸出 [118 97 108 117 101]
    t.Log(string(v)) // 輸出 value
}

cache, _ := bigcache.New(context.Background(), bigcache.DefaultConfig(10*time.Minute))

// New initialize new instance of BigCache
// New用來(lái)初始化一個(gè)新的BigCache實(shí)例。
func New(ctx context.Context, config Config) (*BigCache, error) {
    return newBigCache(ctx, config, &systemClock{})
}

// DefaultConfig initializes config with default values.
// DefaultConfig 初始化Config，給定默認(rèn)值。
// When load for BigCache can be predicted in advance then it is better to use custom config.
// 當(dāng)load加載 BigCache 的時(shí)候，如果在使用之前就能預(yù)估到使用量，然后預(yù)設(shè)置config，它好于使用默認(rèn)config。
func DefaultConfig(eviction time.Duration) Config {
    return Config{
        Shards:             1024,
        LifeWindow:         eviction,
        CleanWindow:        1 * time.Second,
        MaxEntriesInWindow: 1000 * 10 * 60,
        MaxEntrySize:       500,
        StatsEnabled:       false,
        Verbose:            true,
        Hasher:             newDefaultHasher(),
        HardMaxCacheSize:   0,
        Logger:             DefaultLogger(),
    }
}

// Config for BigCache
type Config struct {
    // Number of cache shards, value must be a power of two
    Shards int
    // Time after which entry can be evicted
    // LifeWindow后,緩存對(duì)象被認(rèn)為不活躍,但并不會(huì)刪除對(duì)象
    LifeWindow time.Duration
    // Interval between removing expired entries (clean up).
    // If set to <= 0 then no action is performed. Setting to < 1 second is counterproductive — bigcache has a one second resolution.
    // CleanWindow后，會(huì)刪除被認(rèn)為不活躍的對(duì)象（超過(guò)LifeWindow時(shí)間的對(duì)象），0代表不操作；
    CleanWindow time.Duration
    // Max number of entries in life window. Used only to calculate initial size for cache shards.
    // When proper value is set then additional memory allocation does not occur.
    // 設(shè)置最大存儲(chǔ)對(duì)象數(shù)量，僅在初始化時(shí)可以設(shè)置
    MaxEntriesInWindow int
    // Max size of entry in bytes. Used only to calculate initial size for cache shards.
    // 緩存對(duì)象的最大字節(jié)數(shù)，僅在初始化時(shí)可以設(shè)置
    MaxEntrySize int
    // StatsEnabled if true calculate the number of times a cached resource was requested.
    StatsEnabled bool
    // Verbose mode prints information about new memory allocation
    // 是否打印內(nèi)存分配信息
    Verbose bool
    // Hasher used to map between string keys and unsigned 64bit integers, by default fnv64 hashing is used.
    Hasher Hasher
    // HardMaxCacheSize is a limit for BytesQueue size in MB.
    // It can protect application from consuming all available memory on machine, therefore from running OOM Killer.
    // Default value is 0 which means unlimited size. When the limit is higher than 0 and reached then
    // the oldest entries are overridden for the new ones. The max memory consumption will be bigger than
    // HardMaxCacheSize due to Shards' s additional memory. Every Shard consumes additional memory for map of keys
    // and statistics (map[uint64]uint32) the size of this map is equal to number of entries in
    // cache ~ 2×(64+32)×n bits + overhead or map itself.
    // 設(shè)置緩存最大值(單位為MB),0表示無(wú)限制
    HardMaxCacheSize int
    // OnRemove is a callback fired when the oldest entry is removed because of its expiration time or no space left
    // for the new entry, or because delete was called.
    // Default value is nil which means no callback and it prevents from unwrapping the oldest entry.
    // ignored if OnRemoveWithMetadata is specified.
    // 在緩存過(guò)期或者被刪除時(shí),可設(shè)置回調(diào)函數(shù)，參數(shù)是(key、val)，默認(rèn)是nil不設(shè)置
    OnRemove func(key string, entry []byte)
    // OnRemoveWithMetadata is a callback fired when the oldest entry is removed because of its expiration time or no space left
    // for the new entry, or because delete was called. A structure representing details about that specific entry.
    // Default value is nil which means no callback and it prevents from unwrapping the oldest entry.
    OnRemoveWithMetadata func(key string, entry []byte, keyMetadata Metadata)
    // OnRemoveWithReason is a callback fired when the oldest entry is removed because of its expiration time or no space left
    // for the new entry, or because delete was called. A constant representing the reason will be passed through.
    // Default value is nil which means no callback and it prevents from unwrapping the oldest entry.
    // Ignored if OnRemove is specified.
    // 在緩存過(guò)期或者被刪除時(shí),可設(shè)置回調(diào)函數(shù)，參數(shù)是(key、val,reason)默認(rèn)是nil不設(shè)置
    OnRemoveWithReason func(key string, entry []byte, reason RemoveReason)
    onRemoveFilter int
    // Logger is a logging interface and used in combination with `Verbose`
    // Defaults to `DefaultLogger()`
    Logger Logger
}