storage

type Batch struct {
	// SaveKeys save opts
	SaveKeys []string
	// SaveValues save opts
	SaveValues []string
	// RemoveKeys remove keys
	RemoveKeys []string
}

type KV interface {
	// Batch do batch
	Batch(batch *Batch) error
	// Save save key-value paire to storage
	Save(key, value string) error
	// Load load data of key
	Load(key string) (string, error)
	// Remove delete key from storage
	Remove(key string) error
	// LoadRange iterates all key-value pairs in the storage
	LoadRange(key, endKey string, limit int64) ([]string, []string, error)
	// CountRange count all key-value pairs in the storage
	CountRange(key, endKey string) (uint64, error)
	// AllocID allocate a id from kv
	AllocID() (uint64, error)
	// SaveIfNotExists put the value at path
	// returns true, nil, nil if created
	// returns false, exists, nil if not created
	SaveIfNotExists(key string, value string, batch *Batch) (bool, string, error)
	// RemoveIfValueMatched returns true if the expect value is and the exists value are matched
	RemoveIfValueMatched(key string, expect string) (bool, error)
}

type Storage interface {
	// KV return KV
	KV() KV

	// SaveConfig stores marshallable cfg to the configPath.
	SaveConfig(cfg interface{}) error
	// LoadConfig loads config from configPath then unmarshal it to cfg.
	LoadConfig(cfg interface{}) (bool, error)

	// SaveScheduleConfig saves the config of scheduler.
	SaveScheduleConfig(scheduleName string, data []byte) error
	// RemoveScheduleConfig removes the config of scheduler.
	RemoveScheduleConfig(scheduleName string) error
	// LoadScheduleConfig loads the config of scheduler.
	LoadScheduleConfig(scheduleName string) (string, error)
	// LoadAllScheduleConfig loads all schedulers' config.
	LoadAllScheduleConfig() ([]string, []string, error)

	// PutRule puts the meta to the storage
	PutRule(key string, rule interface{}) error
	// LoadRules load all rules
	LoadRules(limit int64, f func(k, v string) error) error
	// RemoveRule remove rule
	RemoveRule(key string) error

	// PutResource puts the meta to the storage
	PutRuleGroup(groupID string, group interface{}) error
	// RemoveRule remove rule group
	RemoveRuleGroup(groupID string) error
	// LoadResources load all rule groups
	LoadRuleGroups(limit int64, f func(k, v string) error) error

	// PutResource puts the meta to the storage
	PutResource(meta metadata.Resource) error
	// RemoveResource remove resource from storage
	RemoveResource(meta metadata.Resource) error
	// GetResource returns the spec resource
	GetResource(id uint64) (metadata.Resource, error)
	// LoadResources load all resources
	LoadResources(limit int64, do func(metadata.Resource)) error

	// PutContainer returns nil if container is add or update succ
	PutContainer(meta metadata.Container) error
	// RemoveContainer remove container from storage
	RemoveContainer(meta metadata.Container) error
	// GetContainer returns the spec container
	GetContainer(id uint64) (metadata.Container, error)
	// LoadContainers load all containers
	LoadContainers(limit int64, do func(meta metadata.Container, leaderWeight float64, resourceWeight float64)) error

	//PutContainerWeight saves a container's leader and resource weight to storage.
	PutContainerWeight(id uint64, leaderWeight, resourceWeight float64) error

	// PutTimestamp puts the timestamp to storage
	PutTimestamp(time.Time) error
	// GetTimestamp returns tso timestamp
	GetTimestamp() (time.Time, error)

	// AlreadyBootstrapped returns the cluster was already bootstrapped
	AlreadyBootstrapped() (bool, error)
	// PutBootstrapped put cluster is bootstrapped
	PutBootstrapped(container metadata.Container, resources ...metadata.Resource) (bool, error)
}