storage

type CloseableStorage interface {
	// Close close the storage
	Close() error
}

type DataStorage interface {
	StatisticalStorage
	CloseableStorage

	// Sync sync data data to persistent device
	Sync() error
	// RemoveShardData remove shard data
	RemoveShardData(shard bhmetapb.Shard, encodedStartKey, encodedEndKey []byte) error
	// SplitCheck Find a key from [start, end), so that the sum of bytes of the value of [start, key) <=size,
	// returns the current bytes in [start,end), and the founded key
	SplitCheck(start []byte, end []byte, size uint64) (currentSize uint64, currentKeys uint64, splitKeys [][]byte, err error)
	// CreateSnapshot create a snapshot file under the giving path
	CreateSnapshot(path string, start, end []byte) error
	// ApplySnapshot apply a snapshort file from giving path
	ApplySnapshot(path string) error
}

type KVStorage interface {
	CloseableStorage
	// Write write the data in batch
	Write(wb *util.WriteBatch, sync bool) error

	// Set put the key, value pair to the storage
	Set(key []byte, value []byte) error
	// SetWithTTL put the key, value pair to the storage with a ttl in seconds
	SetWithTTL(key []byte, value []byte, ttl int32) error
	// Get returns the value of the key
	Get(key []byte) ([]byte, error)
	// MGet get multi values
	MGet(keys ...[]byte) ([][]byte, error)
	// Delete remove the key from the storage
	Delete(key []byte) error

	// Scan scans the key-value paire in [start, end), and perform with a handler function, if the function
	// returns false, the scan will be terminated, if the `pooledKey` is true, raftstore will call `Free` when
	// scan completed.
	Scan(start, end []byte, handler func(key, value []byte) (bool, error), pooledKey bool) error
	// PrefixScan scans the key-value pairs starts from prefix but only keys for the same prefix,
	// while perform with a handler function, if the function returns false, the scan will be terminated.
	// if the `pooledKey` is true, raftstore will call `Free` when
	// scan completed.
	PrefixScan(prefix []byte, handler func(key, value []byte) (bool, error), pooledKey bool) error
	// Free free the pooled bytes
	Free(pooled []byte)

	// RangeDelete delete data in [start,end).
	RangeDelete(start, end []byte) error
	// Seek returns the first key-value that >= key
	Seek(key []byte) ([]byte, []byte, error)
}

type MetadataStorage interface {
	StatisticalStorage
	KVStorage
	CloseableStorage
}

type StatisticalStorage interface {
	// Stats storage status
	Stats() stats.Stats
}