GoFrame Session-Storage接口开发

大部分场景下，通过gsession组件内置提供的常见Storage实现已经能够满足需求。如果有特殊的场景需要制定不易开发Storage当然也是支持的，因为gsession的功能都采用了接口化设计。

Storage定义

https://github.com/gogf/gf/v2/blob/master/os/gsession/gsession_storage.go

// Storage is the interface definition for session storage.
type Storage interface {
 // New creates a custom session id.
 // This function can be used for custom session creation.
 New(ctx context.Context, ttl time.Duration) (id string, err error)

 // Get retrieves and returns session value with given key.
 // It returns nil if the key does not exist in the session.
 Get(ctx context.Context, id string, key string) (value interface{}, err error)

 // GetMap retrieves all key-value pairs as map from storage.
 GetMap(ctx context.Context, id string) (data map[string]interface{}, err error)

 // GetSize retrieves and returns the size of key-value pairs from storage.
 GetSize(ctx context.Context, id string) (size int, err error)

 // Set sets one key-value session pair to the storage.
 // The parameter `ttl` specifies the TTL for the session id.
 Set(ctx context.Context, id string, key string, value interface{}, ttl time.Duration) error

 // SetMap batch sets key-value session pairs as map to the storage.
 // The parameter `ttl` specifies the TTL for the session id.
 SetMap(ctx context.Context, id string, data map[string]interface{}, ttl time.Duration) error

 // Remove deletes key with its value from storage.
 Remove(ctx context.Context, id string, key string) error

 // RemoveAll deletes all key-value pairs from storage.
 RemoveAll(ctx context.Context, id string) error

 // GetSession returns the session data as `*gmap.StrAnyMap` for given session id from storage.
 //
 // The parameter `ttl` specifies the TTL for this session.
 // The parameter `data` is the current old session data stored in memory,
 // and for some storage it might be nil if memory storage is disabled.
 //
 // This function is called ever when session starts. It returns nil if the TTL is exceeded.
 GetSession(ctx context.Context, id string, ttl time.Duration, data *gmap.StrAnyMap) (*gmap.StrAnyMap, error)

 // SetSession updates the data for specified session id.
 // This function is called ever after session, which is changed dirty, is closed.
 // This copy all session data map from memory to storage.
 SetSession(ctx context.Context, id string, data *gmap.StrAnyMap, ttl time.Duration) error

 // UpdateTTL updates the TTL for specified session id.
 // This function is called ever after session, which is not dirty, is closed.
 UpdateTTL(ctx context.Context, id string, ttl time.Duration) error
}

每一个方法的调用时机都在注释中详细介绍了，开发者在实现自定义的Storage时，可以充分参考内置的几种Storage实现。