index

Documentation

Index

• Constants
• Variables
• func EncodeFieldToIndexValue(val document.Value) ([]byte, error)
• type Index
• type ListIndex
  • func NewListIndex(tx engine.Transaction, idxName string) *ListIndex
  • func (i *ListIndex) AscendGreaterOrEqual(pivot *Pivot, fn func(val document.Value, key []byte) error) error
  • func (i *ListIndex) Delete(val document.Value, key []byte) error
  • func (i *ListIndex) DescendLessOrEqual(pivot *Pivot, fn func(val document.Value, key []byte) error) error
  • func (i *ListIndex) Set(val document.Value, key []byte) error
  • func (i *ListIndex) Truncate() error
• type Pivot
  • func EmptyPivot(t document.ValueType) *Pivot
• type Type
  • func NewTypeFromValueType(t document.ValueType) Type
• type UniqueIndex
  • func NewUniqueIndex(tx engine.Transaction, idxName string) *UniqueIndex
  • func (i *UniqueIndex) AscendGreaterOrEqual(pivot *Pivot, fn func(val document.Value, key []byte) error) error
  • func (i *UniqueIndex) Delete(val document.Value, key []byte) error
  • func (i *UniqueIndex) DescendLessOrEqual(pivot *Pivot, fn func(val document.Value, key []byte) error) error
  • func (i *UniqueIndex) Set(val document.Value, key []byte) error
  • func (i *UniqueIndex) Truncate() error

Constants

const (
	// StorePrefix is the prefix used to name the index store.
	StorePrefix = "i" + string(separator)
)

Variables

var (
	// ErrDuplicate is returned when a value is already associated with a key
	ErrDuplicate = errors.New("duplicate")
)

Functions

func EncodeFieldToIndexValue

func EncodeFieldToIndexValue(val document.Value) ([]byte, error)

EncodeFieldToIndexValue returns a byte array that represents the value in such a way that can be compared for ordering and indexing

Types

type Index

type Index interface {
	// Set associates a value with a key.
	Set(val document.Value, key []byte) error

	// Delete all the references to the key from the index.
	Delete(val document.Value, key []byte) error

	// AscendGreaterOrEqual seeks for the pivot and then goes through all the subsequent key value pairs in increasing order and calls the given function for each pair.
	// If the given function returns an error, the iteration stops and returns that error.
	// If the pivot is nil, starts from the beginning.
	AscendGreaterOrEqual(pivot *Pivot, fn func(val document.Value, key []byte) error) error

	// DescendLessOrEqual seeks for the pivot and then goes through all the subsequent key value pairs in descreasing order and calls the given function for each pair.
	// If the given function returns an error, the iteration stops and returns that error.
	// If the pivot is nil, starts from the end.
	DescendLessOrEqual(pivot *Pivot, fn func(val document.Value, key []byte) error) error

	// Truncate deletes all the index data.
	Truncate() error
}

An Index associates encoded values with keys. It is sorted by value following the lexicographic order.

type ListIndex

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

ListIndex is an implementation that associates a value with a list of keys.

func NewListIndex

func NewListIndex(tx engine.Transaction, idxName string) *ListIndex

NewListIndex creates an index that associates a value with a list of keys.

func (*ListIndex) AscendGreaterOrEqual

func (i *ListIndex) AscendGreaterOrEqual(pivot *Pivot, fn func(val document.Value, key []byte) error) error

AscendGreaterOrEqual seeks for the pivot and then goes through all the subsequent key value pairs in increasing order and calls the given function for each pair. If the given function returns an error, the iteration stops and returns that error. If the pivot is nil, starts from the beginning.

func (*ListIndex) Delete

func (i *ListIndex) Delete(val document.Value, key []byte) error

Delete all the references to the key from the index.

func (*ListIndex) DescendLessOrEqual

func (i *ListIndex) DescendLessOrEqual(pivot *Pivot, fn func(val document.Value, key []byte) error) error

DescendLessOrEqual seeks for the pivot and then goes through all the subsequent key value pairs in descreasing order and calls the given function for each pair. If the given function returns an error, the iteration stops and returns that error. If the pivot is nil, starts from the end.

func (*ListIndex) Set

func (i *ListIndex) Set(val document.Value, key []byte) error

Set associates a value with a key. It is possible to associate multiple keys for the same value but a key can be associated to only one value.

func (*ListIndex) Truncate

func (i *ListIndex) Truncate() error

Truncate deletes all the index data.

type Pivot

type Pivot struct {
	Value document.Value
	// contains filtered or unexported fields
}

A Pivot is a value that is used to seek for a particular value in an index. A Pivot is typed and can only be used to seek for values of the same type.

func EmptyPivot

func EmptyPivot(t document.ValueType) *Pivot

EmptyPivot returns a pivot that starts at the beginning of any indexed values compatible with the given type.

type Type

type Type byte

Type of the index. Values are stored in different sub indexes depending on their types. They are automatically converted to one of the following types:

Text and Blob values are stored in Bytes indexes. Signed, unsigned integers, and floats are stored in Float indexes. Booleans are stores in Bool indexes.

const (
	Null Type = iota + 1
	Bool
	Float
	Bytes
)

index value types

func NewTypeFromValueType

func NewTypeFromValueType(t document.ValueType) Type

NewTypeFromValueType returns the right index type associated with t.

type UniqueIndex

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

UniqueIndex is an implementation that associates a value with a exactly one key.

func NewUniqueIndex

func NewUniqueIndex(tx engine.Transaction, idxName string) *UniqueIndex

NewUniqueIndex creates an index that associates a value with a exactly one key.

func (*UniqueIndex) AscendGreaterOrEqual

func (i *UniqueIndex) AscendGreaterOrEqual(pivot *Pivot, fn func(val document.Value, key []byte) error) error

AscendGreaterOrEqual seeks for the pivot and then goes through all the subsequent key value pairs in increasing order and calls the given function for each pair. If the given function returns an error, the iteration stops and returns that error. If the pivot is nil, starts from the beginning.

func (*UniqueIndex) Delete

func (i *UniqueIndex) Delete(val document.Value, key []byte) error

Delete all the references to the key from the index.

func (*UniqueIndex) DescendLessOrEqual

func (i *UniqueIndex) DescendLessOrEqual(pivot *Pivot, fn func(val document.Value, key []byte) error) error

DescendLessOrEqual seeks for the pivot and then goes through all the subsequent key value pairs in descreasing order and calls the given function for each pair. If the given function returns an error, the iteration stops and returns that error. If the pivot is nil, starts from the end.

func (*UniqueIndex) Set

func (i *UniqueIndex) Set(val document.Value, key []byte) error

Set associates a value with exactly one key. If the association already exists, it returns an error.

func (*UniqueIndex) Truncate

func (i *UniqueIndex) Truncate() error

Truncate deletes all the index data.