partition

Documentation

Overview

Package partition implements a location system to find a shard or index rule. This system reflects the entity identity which is a intermediate result in calculating the target shard.

Index

• Variables
• func GetTagByOffset(value []*modelv1.TagFamilyForWrite, fIndex, tIndex int) (*modelv1.TagValue, error)
• func ParseIndexRuleLocators(entity *databasev1.Entity, families []*databasev1.TagFamilySpec, ...) (locators IndexRuleLocator, fil FieldIndexLocation)
• func ShardID(key []byte, shardNum uint32) (uint, error)
• type FieldIndexLocation
• type FieldWithType
• type IndexRuleLocator
• type Locator
  • func NewEntityLocator(families []*databasev1.TagFamilySpec, entity *databasev1.Entity, ...) Locator
  • func NewShardingKeyLocator(families []*databasev1.TagFamilySpec, shardingKey *databasev1.ShardingKey) Locator
  • func (l Locator) Find(subject string, value []*modelv1.TagFamilyForWrite) (pbv1.Entity, pbv1.EntityValues, error)
  • func (l Locator) Locate(subject string, value []*modelv1.TagFamilyForWrite, shardNum uint32) (pbv1.EntityValues, common.ShardID, error)
• type TagLocator

Variables

var ErrMalformedElement = errors.New("element is malformed")

ErrMalformedElement indicates the element is malformed.

Functions

func GetTagByOffset

func GetTagByOffset(value []*modelv1.TagFamilyForWrite, fIndex, tIndex int) (*modelv1.TagValue, error)

GetTagByOffset gets a tag value based of a tag family offset and a tag offset in this family.

func ParseIndexRuleLocators

func ParseIndexRuleLocators(entity *databasev1.Entity, families []*databasev1.TagFamilySpec,
	indexRules []*databasev1.IndexRule, indexMode bool,
) (locators IndexRuleLocator, fil FieldIndexLocation)

ParseIndexRuleLocators returns a IndexRuleLocator based on the tag family spec and index rules.

func ShardID

func ShardID(key []byte, shardNum uint32) (uint, error)

ShardID calculates a shard id.

Types

type FieldIndexLocation

type FieldIndexLocation map[string]map[string]FieldWithType

FieldIndexLocation is a helper struct to store the field index location.

type FieldWithType

type FieldWithType struct {
	Key  index.FieldKey
	Type pbv1.ValueType
}

FieldWithType is a helper struct to store the field type.

type IndexRuleLocator

type IndexRuleLocator struct {
	EntitySet      map[string]int
	TagFamilyTRule []map[string]*databasev1.IndexRule
}

IndexRuleLocator is a helper struct to locate the index rule by tag name.

type Locator

type Locator struct {
	TagLocators []TagLocator
	ModRevision int64
}

Locator combines several TagLocators that help find the entity or sharding key value.

func NewEntityLocator

func NewEntityLocator(families []*databasev1.TagFamilySpec, entity *databasev1.Entity, modRevision int64) Locator

NewEntityLocator return a Locator based on tag family spec and entity spec.

func NewShardingKeyLocator

func NewShardingKeyLocator(families []*databasev1.TagFamilySpec, shardingKey *databasev1.ShardingKey) Locator

NewShardingKeyLocator returns a Locator based on tag family spec and sharding key spec.

func (Locator) Find

func (l Locator) Find(subject string, value []*modelv1.TagFamilyForWrite) (pbv1.Entity, pbv1.EntityValues, error)

Find the entity from a tag family, prepend a subject to the entity.

func (Locator) Locate

func (l Locator) Locate(subject string, value []*modelv1.TagFamilyForWrite, shardNum uint32) (pbv1.EntityValues, common.ShardID, error)

Locate a shard and find the entity or sharding key from a tag family, prepend a subject to the entity or sharding key.

type TagLocator

type TagLocator struct {
	FamilyOffset int
	TagOffset    int
}

TagLocator contains offsets to retrieve a tag swiftly.