table

Documentation

Overview

Package table allows read and write sorted key/value.

Index

• Variables
• type Reader
  • func NewReader(f io.ReaderAt, size int64, cache cache.Namespace, bpool *util.BufferPool, ...) *Reader
  • func (r *Reader) Find(key []byte, ro *opt.ReadOptions) (rkey, value []byte, err error)
  • func (r *Reader) Get(key []byte, ro *opt.ReadOptions) (value []byte, err error)
  • func (r *Reader) NewIterator(slice *util.Range, ro *opt.ReadOptions) iterator.Iterator
  • func (r *Reader) OffsetOf(key []byte) (offset int64, err error)
  • func (r *Reader) Release()
• type Writer
  • func NewWriter(f io.Writer, o *opt.Options) *Writer
  • func (w *Writer) Append(key, value []byte) error
  • func (w *Writer) BlocksLen() int
  • func (w *Writer) BytesLen() int
  • func (w *Writer) Close() error
  • func (w *Writer) EntriesLen() int

Variables

var (
	ErrNotFound       = util.ErrNotFound
	ErrReaderReleased = errors.New("leveldb/table: reader released")
	ErrIterReleased   = errors.New("leveldb/table: iterator released")
)

Types

type Reader

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

Reader is a table reader.

func NewReader

func NewReader(f io.ReaderAt, size int64, cache cache.Namespace, bpool *util.BufferPool, o *opt.Options) *Reader

NewReader creates a new initialized table reader for the file. The cache and bpool is optional and can be nil.

The returned table reader instance is goroutine-safe.

func (*Reader) Find

func (r *Reader) Find(key []byte, ro *opt.ReadOptions) (rkey, value []byte, err error)

Find finds key/value pair whose key is greater than or equal to the given key. It returns ErrNotFound if the table doesn't contain such pair.

The caller should not modify the contents of the returned slice, but it is safe to modify the contents of the argument after Find returns.

func (*Reader) Get

func (r *Reader) Get(key []byte, ro *opt.ReadOptions) (value []byte, err error)

Get gets the value for the given key. It returns errors.ErrNotFound if the table does not contain the key.

The caller should not modify the contents of the returned slice, but it is safe to modify the contents of the argument after Get returns.

func (*Reader) NewIterator

func (r *Reader) NewIterator(slice *util.Range, ro *opt.ReadOptions) iterator.Iterator

NewIterator creates an iterator from the table.

Slice allows slicing the iterator to only contains keys in the given range. A nil Range.Start is treated as a key before all keys in the table. And a nil Range.Limit is treated as a key after all keys in the table.

The returned iterator is not goroutine-safe and should be released when not used.

Also read Iterator documentation of the leveldb/iterator package.

func (*Reader) OffsetOf

func (r *Reader) OffsetOf(key []byte) (offset int64, err error)

OffsetOf returns approximate offset for the given key.

It is safe to modify the contents of the argument after Get returns.

func (*Reader) Release

func (r *Reader) Release()

Release implements util.Releaser. It also close the file if it is an io.Closer.

type Writer

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

Writer is a table writer.

func NewWriter

func NewWriter(f io.Writer, o *opt.Options) *Writer

NewWriter creates a new initialized table writer for the file.

Table writer is not goroutine-safe.

func (*Writer) Append

func (w *Writer) Append(key, value []byte) error

Append appends key/value pair to the table. The keys passed must be in increasing order.

It is safe to modify the contents of the arguments after Append returns.

func (*Writer) BlocksLen

func (w *Writer) BlocksLen() int

BlocksLen returns number of blocks written so far.

func (*Writer) BytesLen

func (w *Writer) BytesLen() int

BytesLen returns number of bytes written so far.

func (*Writer) Close

func (w *Writer) Close() error

Close will finalize the table. Calling Append is not possible after Close, but calling BlocksLen, EntriesLen and BytesLen is still possible.

func (*Writer) EntriesLen

func (w *Writer) EntriesLen() int

EntriesLen returns number of entries added so far.