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。

注意事项

​Storage​接口中，并不是所有的接口方法都需要实现，开发者仅需要根据业务需要，实现特定调用时机的一些接口即可。

为了提高​Session​的执行性能，接口有​gmap.StrAnyMap​容器类型的使用。