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Version: 1.16.x

gcache 模块采用了适配器设计模式,提供了 Adapter 适配器接口,任何实现了 Adapter 接口的对象均可注册到缓存管理对象中,使得开发者可以对缓存管理对象进行灵活的扩展。

gcache.Cache 对象结构定义如下:

// Cache struct.
type Cache struct {
Adapter // Adapter for cache features.
}

Adapter 接口定义如下:

https://godoc.org/github.com/gogf/gf/os/gcache#Adapter

// Adapter is the adapter for cache features implements.
type Adapter interface {
// Set sets cache with <key>-<value> pair, which is expired after <duration>.
//
// It does not expire if <duration> == 0.
// It deletes the <key> if <duration> < 0.
Set(ctx context.Context, key interface{}, value interface{}, duration time.Duration) error

// Sets batch sets cache with key-value pairs by <data>, which is expired after <duration>.
//
// It does not expire if <duration> == 0.
// It deletes the keys of <data> if <duration> < 0 or given <value> is nil.
Sets(ctx context.Context, data map[interface{}]interface{}, duration time.Duration) error

// SetIfNotExist sets cache with <key>-<value> pair which is expired after <duration>
// if <key> does not exist in the cache. It returns true the <key> dose not exist in the
// cache and it sets <value> successfully to the cache, or else it returns false.
//
// The parameter <value> can be type of <func() interface{}>, but it dose nothing if its
// result is nil.
//
// It does not expire if <duration> == 0.
// It deletes the <key> if <duration> < 0 or given <value> is nil.
SetIfNotExist(ctx context.Context, key interface{}, value interface{}, duration time.Duration) (bool, error)

// Get retrieves and returns the associated value of given <key>.
// It returns nil if it does not exist, its value is nil or it's expired.
Get(ctx context.Context, key interface{}) (interface{}, error)

// GetOrSet retrieves and returns the value of <key>, or sets <key>-<value> pair and
// returns <value> if <key> does not exist in the cache. The key-value pair expires
// after <duration>.
//
// It does not expire if <duration> == 0.
// It deletes the <key> if <duration> < 0 or given <value> is nil, but it does nothing
// if <value> is a function and the function result is nil.
GetOrSet(ctx context.Context, key interface{}, value interface{}, duration time.Duration) (interface{}, error)

// GetOrSetFunc retrieves and returns the value of <key>, or sets <key> with result of
// function <f> and returns its result if <key> does not exist in the cache. The key-value
// pair expires after <duration>.
//
// It does not expire if <duration> == 0.
// It deletes the <key> if <duration> < 0 or given <value> is nil, but it does nothing
// if <value> is a function and the function result is nil.
GetOrSetFunc(ctx context.Context, key interface{}, f func() (interface{}, error), duration time.Duration) (interface{}, error)

// GetOrSetFuncLock retrieves and returns the value of <key>, or sets <key> with result of
// function <f> and returns its result if <key> does not exist in the cache. The key-value
// pair expires after <duration>.
//
// It does not expire if <duration> == 0.
// It does nothing if function <f> returns nil.
//
// Note that the function <f> should be executed within writing mutex lock for concurrent
// safety purpose.
GetOrSetFuncLock(ctx context.Context, key interface{}, f func() (interface{}, error), duration time.Duration) (interface{}, error)

// Contains returns true if <key> exists in the cache, or else returns false.
Contains(ctx context.Context, key interface{}) (bool, error)

// GetExpire retrieves and returns the expiration of <key> in the cache.
//
// It returns 0 if the <key> does not expire.
// It returns -1 if the <key> does not exist in the cache.
GetExpire(ctx context.Context, key interface{}) (time.Duration, error)

// Remove deletes one or more keys from cache, and returns its value.
// If multiple keys are given, it returns the value of the last deleted item.
Remove(ctx context.Context, keys ...interface{}) (value interface{}, err error)

// Update updates the value of <key> without changing its expiration and returns the old value.
// The returned value <exist> is false if the <key> does not exist in the cache.
//
// It deletes the <key> if given <value> is nil.
// It does nothing if <key> does not exist in the cache.
Update(ctx context.Context, key interface{}, value interface{}) (oldValue interface{}, exist bool, err error)

// UpdateExpire updates the expiration of <key> and returns the old expiration duration value.
//
// It returns -1 and does nothing if the <key> does not exist in the cache.
// It deletes the <key> if <duration> < 0.
UpdateExpire(ctx context.Context, key interface{}, duration time.Duration) (oldDuration time.Duration, err error)

// Size returns the number of items in the cache.
Size(ctx context.Context) (size int, err error)

// Data returns a copy of all key-value pairs in the cache as map type.
// Note that this function may leads lots of memory usage, you can implement this function
// if necessary.
Data(ctx context.Context) (map[interface{}]interface{}, error)

// Keys returns all keys in the cache as slice.
Keys(ctx context.Context) ([]interface{}, error)

// Values returns all values in the cache as slice.
Values(ctx context.Context) ([]interface{}, error)

// Clear clears all data of the cache.
// Note that this function is sensitive and should be carefully used.
Clear(ctx context.Context) error

// Close closes the cache if necessary.
Close(ctx context.Context) error
}

适配器的注册方法:

// SetAdapter changes the adapter for this cache.
// Be very note that, this setting function is not concurrent-safe, which means you should not call
// this setting function concurrently in multiple goroutines.
func (c *Cache) SetAdapter(adapter Adapter)

具体示例请参考 缓存管理-Redis缓存 章节。