segment

README

DO NOT USE

this repository exists as part of a proposal that has not yet been accepted

Documentation

Index

• Variables
• type DictionaryIterator
• type DocVisitState
• type DocumentFieldTermVisitable
• type DocumentFieldValueVisitor
• type Location
• type OptimizablePostingsIterator
• type PersistedSegment
• type Plugin
• type Posting
• type PostingsIterator
• type PostingsList
• type Segment
• type StatsReporter
• type TermDictionary
• type UnpersistedSegment

Variables

var ErrClosed = fmt.Errorf("index closed")

Types

type DictionaryIterator

type DictionaryIterator interface {
	Next() (*index.DictEntry, error)
}

type DocVisitState

type DocVisitState interface {
}

type DocumentFieldTermVisitable

type DocumentFieldTermVisitable interface {
	VisitDocumentFieldTerms(localDocNum uint64, fields []string,
		visitor index.DocumentFieldTermVisitor, optional DocVisitState) (DocVisitState, error)

	// VisitableDocValueFields implementation should return
	// the list of fields which are document value persisted and
	// therefore visitable by the above VisitDocumentFieldTerms method.
	VisitableDocValueFields() ([]string, error)
}

DocumentFieldTermVisitable is implemented by various scorch segment implementations with persistence for the un inverting of the postings or other indexed values.

type DocumentFieldValueVisitor

type DocumentFieldValueVisitor func(field string, typ byte, value []byte, pos []uint64) bool

DocumentFieldValueVisitor defines a callback to be visited for each stored field value. The return value determines if the visitor should keep going. Returning true continues visiting, false stops.

type Location

type Location interface {
	Field() string
	Start() uint64
	End() uint64
	Pos() uint64
	ArrayPositions() []uint64
	Size() int
}

type OptimizablePostingsIterator

type OptimizablePostingsIterator interface {
	ActualBitmap() *roaring.Bitmap
	DocNum1Hit() (uint64, bool)
	ReplaceActual(*roaring.Bitmap)
}

type PersistedSegment

type PersistedSegment interface {
	Segment
	Path() string
}

type Plugin

type Plugin interface {

	// Type is the name for this segment plugin
	Type() string

	// Version is a numeric value identifying a specific version of this type.
	// When incompatible changes are made to a particular type of plugin, the
	// version must be incremented.
	Version() uint32

	// New takes a set of AnalysisResults and turns them into a new Segment
	New(results []*index.AnalysisResult) (Segment, uint64, error)

	// Open attempts to open the file at the specified path and
	// return the corresponding Segment
	Open(path string) (Segment, error)

	// Merge takes a set of Segments, and creates a new segment on disk at
	// the specified path.
	// Drops is a set of bitmaps (one for each segment) indicating which
	// documents can be dropped from the segments during the merge.
	// If the closeCh channel is closed, Merge will cease doing work at
	// the next opportunity, and return an error (closed).
	// StatsReporter can optionally be provided, in which case progress
	// made during the merge is reported while operation continues.
	// Returns:
	// A slice of new document numbers (one for each input segment),
	// this allows the caller to know a particular document's new
	// document number in the newly merged segment.
	// The number of bytes written to the new segment file.
	// An error, if any occurred.
	Merge(segments []Segment, drops []*roaring.Bitmap, path string,
		closeCh chan struct{}, s StatsReporter) (
		[][]uint64, uint64, error)
}

Plugin represents the essential functions required by a package to plug in it's segment implementation

type Posting

type Posting interface {
	Number() uint64

	Frequency() uint64
	Norm() float64

	Locations() []Location

	Size() int
}

type PostingsIterator

type PostingsIterator interface {
	// The caller is responsible for copying whatever it needs from
	// the returned Posting instance before calling Next(), as some
	// implementations may return a shared instance to reduce memory
	// allocations.
	Next() (Posting, error)

	// Advance will return the posting with the specified doc number
	// or if there is no such posting, the next posting.
	// Callers MUST NOT attempt to pass a docNum that is less than or
	// equal to the currently visited posting doc Num.
	Advance(docNum uint64) (Posting, error)

	Size() int
}

type PostingsList

type PostingsList interface {
	Iterator(includeFreq, includeNorm, includeLocations bool, prealloc PostingsIterator) PostingsIterator

	Size() int

	Count() uint64
}

type Segment

type Segment interface {
	Dictionary(field string) (TermDictionary, error)

	VisitDocument(num uint64, visitor DocumentFieldValueVisitor) error

	DocID(num uint64) ([]byte, error)

	Count() uint64

	DocNumbers([]string) (*roaring.Bitmap, error)

	Fields() []string

	Close() error

	Size() int

	AddRef()
	DecRef() error
}

type StatsReporter

type StatsReporter interface {
	ReportBytesWritten(bytesWritten uint64)
}

type TermDictionary

type TermDictionary interface {
	PostingsList(term []byte, except *roaring.Bitmap, prealloc PostingsList) (PostingsList, error)

	AutomatonIterator(a vellum.Automaton,
		startKeyInclusive, endKeyExclusive []byte) DictionaryIterator

	Contains(key []byte) (bool, error)
}

type UnpersistedSegment

type UnpersistedSegment interface {
	Segment
	Persist(path string) error
}