kv

type BufferStore struct {
	MemBuffer
	// contains filtered or unexported fields
}

type Client interface {
	// Send sends request to KV layer, returns a Response.
	Send(ctx context.Context, req *Request) Response

	// IsRequestTypeSupported checks if reqType and subType is supported.
	IsRequestTypeSupported(reqType, subType int64) bool
}

type Driver interface {
	// Open returns a new Storage.
	// The path is the string for storage specific format.
	Open(path string) (Storage, error)
}

type EncodedKey []byte

type FnKeyCmp func(key Key) bool

type InjectedSnapshot struct {
	Snapshot
	// contains filtered or unexported fields
}

type InjectedStore struct {
	Storage
	// contains filtered or unexported fields
}

type InjectedTransaction struct {
	Transaction
	// contains filtered or unexported fields
}

type InjectionConfig struct {
	sync.RWMutex
	// contains filtered or unexported fields
}

type IsoLevel int

type Iterator interface {
	Valid() bool
	Key() Key
	Value() []byte
	Next() error
	Close()
}

type Key []byte

type KeyRange struct {
	StartKey Key
	EndKey   Key
}

type MemBuffer interface {
	RetrieverMutator
	// Size returns sum of keys and values length.
	Size() int
	// Len returns the number of entries in the DB.
	Len() int
	// Reset cleanup the MemBuffer
	Reset()
	// SetCap sets the MemBuffer capability, to reduce memory allocations.
	// Please call it before you use the MemBuffer, otherwise it will not works.
	SetCap(cap int)
}

type MockTxn interface {
	Transaction
	GetOption(opt Option) interface{}
}

type Mutator interface {
	// Set sets the value for key k as v into kv store.
	// v must NOT be nil or empty, otherwise it returns ErrCannotSetNilValue.
	Set(k Key, v []byte) error
	// Delete removes the entry for key k from kv store.
	Delete(k Key) error
}

type Option int

type Options interface {
	// Get gets an option value.
	Get(opt Option) (v interface{}, ok bool)
}

type Request struct {
	// Tp is the request type.
	Tp        int64
	StartTs   uint64
	Data      []byte
	KeyRanges []KeyRange
	// KeepOrder is true, if the response should be returned in order.
	KeepOrder bool
	// Desc is true, if the request is sent in descending order.
	Desc bool
	// Concurrency is 1, if it only sends the request to a single storage unit when
	// ResponseIterator.Next is called. If concurrency is greater than 1, the request will be
	// sent to multiple storage units concurrently.
	Concurrency int
	// IsolationLevel is the isolation level, default is SI.
	IsolationLevel IsoLevel
	// Priority is the priority of this KV request, its value may be PriorityNormal/PriorityLow/PriorityHigh.
	Priority int
	// NotFillCache makes this request do not touch the LRU cache of the underlying storage.
	NotFillCache bool
	// SyncLog decides whether the WAL(write-ahead log) of this request should be synchronized.
	SyncLog bool
	// Streaming indicates using streaming API for this request, result in that one Next()
	// call would not corresponds to a whole region result.
	Streaming bool
}

type Response interface {
	// Next returns a resultSubset from a single storage unit.
	// When full result set is returned, nil is returned.
	// TODO: Find a better interface for resultSubset that can avoid allocation and reuse bytes.
	Next(ctx context.Context) (resultSubset []byte, err error)
	// Close response.
	Close() error
}

type Retriever interface {
	// Get gets the value for key k from kv store.
	// If corresponding kv pair does not exist, it returns nil and ErrNotExist.
	Get(k Key) ([]byte, error)
	// Seek creates an Iterator positioned on the first entry that k <= entry's key.
	// If such entry is not found, it returns an invalid Iterator with no error.
	// The Iterator must be Closed after use.
	Seek(k Key) (Iterator, error)

	// SeekReverse creates a reversed Iterator positioned on the first entry which key is less than k.
	// The returned iterator will iterate from greater key to smaller key.
	// If k is nil, the returned iterator will be positioned at the last key.
	SeekReverse(k Key) (Iterator, error)
}

type RetrieverMutator interface {
	Retriever
	Mutator
}

type Snapshot interface {
	Retriever
	// BatchGet gets a batch of values from snapshot.
	BatchGet(keys []Key) (map[string][]byte, error)
}

type Storage interface {
	// Begin transaction
	Begin() (Transaction, error)
	// BeginWithStartTS begins transaction with startTS.
	BeginWithStartTS(startTS uint64) (Transaction, error)
	// GetSnapshot gets a snapshot that is able to read any data which data is <= ver.
	// if ver is MaxVersion or > current max committed version, we will use current version for this snapshot.
	GetSnapshot(ver Version) (Snapshot, error)
	// GetClient gets a client instance.
	GetClient() Client
	// Close store
	Close() error
	// UUID return a unique ID which represents a Storage.
	UUID() string
	// CurrentVersion returns current max committed version.
	CurrentVersion() (Version, error)
	// GetOracle gets a timestamp oracle client.
	GetOracle() oracle.Oracle
	// SupportDeleteRange gets the storage support delete range or not.
	SupportDeleteRange() (supported bool)
}

type Transaction interface {
	MemBuffer
	// Commit commits the transaction operations to KV store.
	Commit(context.Context) error
	// Rollback undoes the transaction operations to KV store.
	Rollback() error
	// String implements fmt.Stringer interface.
	String() string
	// LockKeys tries to lock the entries with the keys in KV store.
	LockKeys(keys ...Key) error
	// SetOption sets an option with a value, when val is nil, uses the default
	// value of this option.
	SetOption(opt Option, val interface{})
	// DelOption deletes an option.
	DelOption(opt Option)
	// IsReadOnly checks if the transaction has only performed read operations.
	IsReadOnly() bool
	// StartTS returns the transaction start timestamp.
	StartTS() uint64
	// Valid returns if the transaction is valid.
	// A transaction become invalid after commit or rollback.
	Valid() bool
	// GetMemBuffer return the MemBuffer binding to this transaction.
	GetMemBuffer() MemBuffer
	// GetSnapshot returns the snapshot of this transaction.
	GetSnapshot() Snapshot
}

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

type UnionStore interface {
	MemBuffer
	// CheckLazyConditionPairs loads all lazy values from store then checks if all values are matched.
	// Lazy condition pairs should be checked before transaction commit.
	CheckLazyConditionPairs() error
	// WalkBuffer iterates all buffered kv pairs.
	WalkBuffer(f func(k Key, v []byte) error) error
	// SetOption sets an option with a value, when val is nil, uses the default
	// value of this option.
	SetOption(opt Option, val interface{})
	// DelOption deletes an option.
	DelOption(opt Option)
	// GetOption gets an option.
	GetOption(opt Option) interface{}
	// GetMemBuffer return the MemBuffer binding to this UnionStore.
	GetMemBuffer() MemBuffer
}

type Version struct {
	Ver uint64
}

type VersionProvider interface {
	CurrentVersion() (Version, error)
}