writelog

Documentation

Index

• Variables
• func DrainIterator(it Iterator) error
• type Annotations
• type Iterator
  • func NewStaticIterator(writeLog WriteLog) Iterator
• type LogEntry
  • func (k *LogEntry) Equal(cmp *LogEntry) bool
  • func (k *LogEntry) MarshalJSON() ([]byte, error)
  • func (k *LogEntry) Type() LogEntryType
  • func (k *LogEntry) UnmarshalJSON(src []byte) error
• type LogEntryAnnotation
• type LogEntryType
• type PipeIterator
  • func NewPipeIterator(ctx context.Context) PipeIterator
  • func (i *PipeIterator) Close()
  • func (i *PipeIterator) Next() (bool, error)
  • func (i *PipeIterator) Put(logEntry *LogEntry) error
  • func (i *PipeIterator) PutError(err error) error
  • func (i *PipeIterator) Value() (LogEntry, error)
• type WriteLog
  • func (wl WriteLog) Equal(cmp WriteLog) bool

Variables

var (

	// ErrIteratorInvalid is raised when Value() is called on an iterator that finished already or hasn't started yet.
	ErrIteratorInvalid = errors.New("mkvs: write log iterator invalid")
)

Functions

func DrainIterator

func DrainIterator(it Iterator) error

DrainIterator drains the iterator, discarding all values.

Types

type Annotations

type Annotations []LogEntryAnnotation

Annotations are extra metadata about write log entries.

This should always be passed alongside a WriteLog.

type Iterator

type Iterator interface {
	// Next advances the iterator to the next element and returns false if there are no more elements.
	Next() (bool, error)
	// Value returns the log entry the iterator is currently pointing to.
	Value() (LogEntry, error)
}

Iterator iterates over MKVS write log entries between two different storage instances.

func NewStaticIterator

func NewStaticIterator(writeLog WriteLog) Iterator

NewStaticIterator returns a new writelog iterator that's backed by a static in-memory array.

type LogEntry

type LogEntry struct {
	Key   []byte
	Value []byte
	// contains filtered or unexported fields
}

LogEntry is a write log entry.

func (*LogEntry) Equal

func (k *LogEntry) Equal(cmp *LogEntry) bool

Equal compares vs another log entry for equality.

func (*LogEntry) MarshalJSON

func (k *LogEntry) MarshalJSON() ([]byte, error)

func (*LogEntry) Type

func (k *LogEntry) Type() LogEntryType

Type returns the type of the write log entry.

func (*LogEntry) UnmarshalJSON

func (k *LogEntry) UnmarshalJSON(src []byte) error

type LogEntryAnnotation

type LogEntryAnnotation struct {
	InsertedNode *node.Pointer
}

LogEntryAnnotation is an annotation for a single write log entry.

Entries in a WriteLogAnnotation correspond to WriteLog entries at their respective indexes.

type LogEntryType

type LogEntryType int

LogEntryType is a type of a write log entry.

const (
	LogInsert LogEntryType = iota
	LogDelete
)

type PipeIterator

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

PipeIterator is a queue-backed writelog iterator which can be asynchronously both pushed into and read from.

func NewPipeIterator

func NewPipeIterator(ctx context.Context) PipeIterator

NewPipeIterator returns a new PipeIterator.

func (*PipeIterator) Close

func (i *PipeIterator) Close()

Close signals an end of the log entry stream to the iterator's read side.

func (*PipeIterator) Next

func (i *PipeIterator) Next() (bool, error)

func (*PipeIterator) Put

func (i *PipeIterator) Put(logEntry *LogEntry) error

func (*PipeIterator) PutError

func (i *PipeIterator) PutError(err error) error

PutError pushed an error to the iterator's read side.

func (*PipeIterator) Value

func (i *PipeIterator) Value() (LogEntry, error)

type WriteLog

type WriteLog []LogEntry

WriteLog is a write log.

The keys in the write log must be unique.

func (WriteLog) Equal

func (wl WriteLog) Equal(cmp WriteLog) bool

Equal compares vs another write log for equality.