datastor

type Client interface {
	// Creates an object, using the given data.
	// The key of the object is generated by the server, and returned.
	CreateObject(data []byte) (key []byte, err error)

	// Get an existing object, linked to a given key.
	//
	// ErrKeyNotFound is returned in case the requested key couldn't be found.
	// ErrObjectCorrupted is returned in case the stored object is corrupted.
	GetObject(key []byte) (*Object, error)

	// DeleteObject deletes an object, using a given key.
	// Deleting an non-existing object is considered valid.
	DeleteObject(key []byte) error

	// GetObjectStatus returns the status of an object,
	// indicating whether it's OK, missing or corrupt.
	GetObjectStatus(key []byte) (ObjectStatus, error)

	// ExistObject returns whether or not an object exists.
	//
	// ErrObjectCorrupted is returned in case the object key exists,
	// but the object is corrupted.
	ExistObject(key []byte) (bool, error)

	// ListObjectKeyIterator returns an iterator,
	// from which the keys of all stored objects within the namespace
	// (identified by the given label), an be retrieved.
	//
	// In case an error while the iterator is active,
	// it will be returned as part of the last returned result,
	// which is then considered to be invalid.
	// When an error is returned, as part of a result,
	// the iterator channel will be automatically closed as soon
	// as that item is received.
	ListObjectKeyIterator(ctx context.Context) (<-chan ObjectKeyResult, error)

	// GetNamespace returns the available information of a namespace.
	//
	// ErrKeyNotFound is returned in case no
	// stored namespace exist for the used label.
	GetNamespace() (*Namespace, error)

	// Utilization return the amount of bytes stored in
	// the namespace the client is connected to
	Utilization() int64

	// Close any open resources.
	Close() error
}

type Cluster interface {
	// GetClient returns a client for the zstordb server
	// at the given (shard) address.
	// The given shard does not have to be part of
	// the predefined shard list, which makes up this cluster,
	// it can be any address, as long as it points to
	// a valid and supported zstordb server.
	GetShard(id string) (Shard, error)

	// GetRandomClient gets any shard available in this cluster:
	// it only ever returns a client created from a shard
	// which comes from the pre-defined shard-list
	// (given at creation time of this cluster):
	GetRandomShard() (Shard, error)

	// GetShardIterator can be used to get an iterator (channel),
	// which will give you a shard, until either all shards have been exhausted,
	// or the given context has been cancelled. It is guaranteed by the implementation,
	// that each returned shard, from the same shard iterator,
	// hasn't been returned before by that iterator (channel).
	//
	// exceptShards is an optional input parameter,
	// when given, the iterator won't return the listed shards
	// which are part of that exceptShards slice.
	GetShardIterator(exceptShards []string) ShardIterator

	// ListedShardCount returns the amount of listed shards available in this cluster.
	ListedShardCount() int

	// Close any open resources.
	Close() error
}

type Health struct {
	DataIOErrors  int64
	IndexIOErrors int64
	DataFaults    int64
	IndexFaults   int64

	DataIOErrorLast  int64
	IndexIOErrorLast int64
}

type LazyShardIterator struct {
	// contains filtered or unexported fields
}

type LeastUsedShardIterator struct {
	// contains filtered or unexported fields
}

type Namespace struct {
	Label               string
	ReadRequestPerHour  int64
	WriteRequestPerHour int64
	NrObjects           int64
	Used                int64 //the number of bytes present in the namespace
	Free                int64
	Health              *Health
}

type Object struct {
	Key  []byte
	Data []byte
}

type ObjectKeyResult struct {
	Key   []byte
	Error error
}

type ObjectStatus uint8

type RandomShardIterator struct {
	// contains filtered or unexported fields
}

type Shard interface {
	Client

	// Identifier returns the (unique) identifier of this shard.
	Identifier() string
	Address() string
	Namespace() string
	Password() string
}

type ShardConfig struct {
	Address   string `json:"address"`
	Namespace string `json:"namespace"`
	Password  string `json:"password"`
}

type ShardIterator interface {
	// Next moves the iterator to the next available shard
	// if this is not possible it will return false
	// This function has to be called prior to the first Shard call.
	Next() bool

	// Shard returns the current shard, you can call this function as much as you want.
	// The function will return another Shard or become invalid,
	// after you call Next again.
	Shard() Shard
}

type SpreadingConstructor func() (ShardIterator, error)

type SpreadingType uint8