pebbledb

Documentation

Index

• Constants
• Variables
• func MVCCEncode(key []byte, version int64) (dst []byte)
• func MVCCKeyCompare(a, b []byte) int
• func SplitMVCCKey(mvccKey []byte) (key, version []byte, ok bool)
• type Batch
  • func NewBatch(storage *pebble.DB, version int64) (*Batch, error)
  • func (b *Batch) Delete(storeKey string, key []byte) error
  • func (b *Batch) Reset()
  • func (b *Batch) Set(storeKey string, key, value []byte) error
  • func (b *Batch) Size() int
  • func (b *Batch) Write() (err error)
• type Database
  • func New(dataDir string) (*Database, error)
  • func NewWithDB(storage *pebble.DB) *Database
  • func (db *Database) ApplyChangeset(version int64, cs *proto.NamedChangeSet) error
  • func (db *Database) Close() error
  • func (db *Database) Get(storeKey string, targetVersion int64, key []byte) ([]byte, error)
  • func (db *Database) GetLatestVersion() (int64, error)
  • func (db *Database) Has(storeKey string, version int64, key []byte) (bool, error)
  • func (db *Database) Import(version int64, ch <-chan sstypes.ImportEntry) error
  • func (db *Database) Iterator(storeKey string, version int64, start, end []byte) (types.Iterator, error)
  • func (db *Database) Prune(version int64) error
  • func (db *Database) ReverseIterator(storeKey string, version int64, start, end []byte) (types.Iterator, error)
  • func (db *Database) SetLatestVersion(version int64) error

Constants

const (
	VersionSize = 8

	StorePrefixTpl = "s/k:%s/" // s/k:<storeKey>

)

Variables

var MVCCComparer = &pebble.Comparer{
	Name: "ss_pebbledb_comparator",

	Compare: MVCCKeyCompare,

	AbbreviatedKey: func(k []byte) uint64 {
		key, _, ok := SplitMVCCKey(k)
		if !ok {
			return 0
		}

		return pebble.DefaultComparer.AbbreviatedKey(key)
	},

	Equal: func(a, b []byte) bool {
		return MVCCKeyCompare(a, b) == 0
	},

	Separator: func(dst, a, b []byte) []byte {
		aKey, _, ok := SplitMVCCKey(a)
		if !ok {
			return append(dst, a...)
		}

		bKey, _, ok := SplitMVCCKey(b)
		if !ok {
			return append(dst, a...)
		}

		if bytes.Equal(aKey, bKey) {
			return append(dst, a...)
		}

		n := len(dst)

		dst = pebble.DefaultComparer.Separator(dst, aKey, bKey)

		buf := dst[n:]
		if bytes.Equal(aKey, buf) {
			return append(dst[:n], a...)
		}

		return append(dst, 0)
	},

	ImmediateSuccessor: func(dst, a []byte) []byte {

		return append(append(dst, a...), 0)
	},

	Successor: func(dst, a []byte) []byte {
		aKey, _, ok := SplitMVCCKey(a)
		if !ok {
			return append(dst, a...)
		}

		n := len(dst)

		dst = pebble.DefaultComparer.Successor(dst, aKey)

		buf := dst[n:]
		if bytes.Equal(aKey, buf) {
			return append(dst[:n], a...)
		}

		return append(dst, 0)
	},

	FormatKey: func(k []byte) fmt.Formatter {
		return mvccKeyFormatter{key: k}
	},

	Split: func(k []byte) int {
		key, _, ok := SplitMVCCKey(k)
		if !ok {
			return len(k)
		}

		return len(key) + 1
	},
}

MVCCComparer returns a PebbleDB Comparer with encoding and decoding routines for MVCC control, used to compare and store versioned keys.

Note: This Comparer implementation is largely based on PebbleDB's internal MVCC example, which can be found here: https://github.com/cockroachdb/pebble/blob/master/cmd/pebble/mvcc.go

Functions

func MVCCEncode

func MVCCEncode(key []byte, version int64) (dst []byte)

<key>\x00[<version>]<#version-bytes>

func MVCCKeyCompare

func MVCCKeyCompare(a, b []byte) int

MVCCKeyCompare compares two MVCC keys.

func SplitMVCCKey

func SplitMVCCKey(mvccKey []byte) (key, version []byte, ok bool)

SplitMVCCKey accepts an MVCC key and returns the "user" key, the MVCC version, and a boolean indicating if the provided key is an MVCC key.

Types

type Batch

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

func NewBatch

func NewBatch(storage *pebble.DB, version int64) (*Batch, error)

func (*Batch) Delete

func (b *Batch) Delete(storeKey string, key []byte) error

func (*Batch) Reset

func (b *Batch) Reset()

func (*Batch) Set

func (b *Batch) Set(storeKey string, key, value []byte) error

func (*Batch) Size

func (b *Batch) Size() int

func (*Batch) Write

func (b *Batch) Write() (err error)

type Database

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

func New

func New(dataDir string) (*Database, error)

func NewWithDB

func NewWithDB(storage *pebble.DB) *Database

func (*Database) ApplyChangeset

func (db *Database) ApplyChangeset(version int64, cs *proto.NamedChangeSet) error

func (*Database) Close

func (db *Database) Close() error

func (*Database) Get

func (db *Database) Get(storeKey string, targetVersion int64, key []byte) ([]byte, error)

func (*Database) GetLatestVersion

func (db *Database) GetLatestVersion() (int64, error)

func (*Database) Has

func (db *Database) Has(storeKey string, version int64, key []byte) (bool, error)

func (*Database) Import

func (db *Database) Import(version int64, ch <-chan sstypes.ImportEntry) error

func (*Database) Iterator

func (db *Database) Iterator(storeKey string, version int64, start, end []byte) (types.Iterator, error)

func (*Database) Prune

func (db *Database) Prune(version int64) error

Prune for the PebbleDB SS backend is currently not supported. It seems the only reliable way to prune is to iterate over the desired domain and either manually tombstone or delete. Either way, the operation would be timely.

See: https://github.com/cockroachdb/cockroach/blob/33623e3ee420174a4fd3226d1284b03f0e3caaac/pkg/storage/mvcc.go#L3182

func (*Database) ReverseIterator

func (db *Database) ReverseIterator(storeKey string, version int64, start, end []byte) (types.Iterator, error)

func (*Database) SetLatestVersion

func (db *Database) SetLatestVersion(version int64) error