common

Documentation

Index

• Variables
• func ShardKeyForTraceID(traceID []byte, shardCount int) int
• func SortRecords(records []Record)
• func ValidateShardCount(shardCount int) int
• type DataReader
• type DataWriter
• type DataWriterGeneric
• type ID
• type IndexReader
• type IndexWriter
• type ObjectCombiner
• type ObjectReaderWriter
• type Record
• type RecordReaderWriter
• type Records
  • func (r Records) At(_ context.Context, i int) (*Record, error)
  • func (r Records) Find(_ context.Context, id ID) (*Record, int, error)
• type ShardedBloomFilter
  • func NewBloom(fp float64, shardSize, estimatedObjects uint) *ShardedBloomFilter
  • func (b *ShardedBloomFilter) Add(traceID []byte)
  • func (b *ShardedBloomFilter) GetShardCount() int
  • func (b *ShardedBloomFilter) Marshal() ([][]byte, error)
  • func (b *ShardedBloomFilter) Test(traceID []byte) bool

Variables

var (
	ErrUnsupported = fmt.Errorf("unsupported")
)

This file contains types that need to be referenced by both the ./encoding and ./encoding/vX packages. It primarily exists here to break dependency loops.

Functions

func ShardKeyForTraceID

func ShardKeyForTraceID(traceID []byte, shardCount int) int

func SortRecords

func SortRecords(records []Record)

SortRecords sorts a slice of record pointers

func ValidateShardCount

func ValidateShardCount(shardCount int) int

For backward compatibility

Types

type DataReader

type DataReader interface {
	Read(context.Context, []Record, [][]byte, []byte) ([][]byte, []byte, error)
	Close()

	// NextPage can be used to iterate at a page at a time. May return ErrUnsupported for older formats
	//  NextPage takes a reusable buffer to read the page into and returns it in case it needs to resize
	//  NextPage returns the uncompressed page buffer ready for object iteration and the length of the
	//    original page from the page header. len(page) might not equal page len!
	NextPage([]byte) ([]byte, uint32, error)
}

DataReader returns a slice of pages in the encoding/v0 format referenced by the slice of *Records passed in. The length of the returned slice is guaranteed to be equal to the length of the provided records unless error is non nil. DataReader is the primary abstraction point for supporting multiple data formats.

type DataWriter

type DataWriter interface {
	// Write writes the passed ID/byte to the current page
	Write(ID, []byte) (int, error)
	// CutPage completes the current page and start a new one.  It
	//  returns the length in bytes of the cut page.
	CutPage() (int, error)
	// Complete must be called when the operation DataWriter is done.
	Complete() error
}

DataWriter is used to write paged data to the backend

type DataWriterGeneric

type DataWriterGeneric interface {

	// Write writes the passed ID/obj to the current page
	Write(context.Context, ID, interface{}) (int, error)

	// CutPage completes the current page and start a new one.  It
	//  returns the length in bytes of the cut page.
	CutPage(context.Context) (int, error)

	// Complete must be called when the operation DataWriter is done.
	Complete(context.Context) error
}

DataWriterGeneric writes objects instead of byte slices

type ID

type ID []byte

ID in TempoDB

type IndexReader

type IndexReader interface {
	At(ctx context.Context, i int) (*Record, error)
	Find(ctx context.Context, id ID) (*Record, int, error)
}

IndexReader is used to abstract away the details of an index. Currently only used in the paged finder, it could eventually provide a way to support multiple index formats. IndexReader is the primary abstraction point for supporting multiple index formats.

type IndexWriter

type IndexWriter interface {
	// Write returns a byte representation of the provided Records
	Write([]Record) ([]byte, error)
}

IndexWriter is used to write paged indexes

type ObjectCombiner

type ObjectCombiner interface {
	// Combine objects encoded using dataEncoding. The returned object must
	// use the same dataEncoding. Returns a bool indicating if it the objects required combining and
	// the combined slice
	Combine(dataEncoding string, objs ...[]byte) ([]byte, bool)
}

ObjectCombiner is used to combine two objects in the backend

type ObjectReaderWriter

type ObjectReaderWriter interface {
	MarshalObjectToWriter(id ID, b []byte, w io.Writer) (int, error)
	UnmarshalObjectFromReader(r io.Reader) (ID, []byte, error)
	UnmarshalAndAdvanceBuffer(buffer []byte) ([]byte, ID, []byte, error)
}

ObjectReaderWriter represents a library of methods to read and write at the object level

type Record

type Record struct {
	ID     ID
	Start  uint64
	Length uint32
}

Record represents the location of an ID in an object file

type RecordReaderWriter

type RecordReaderWriter interface {
	MarshalRecords(records []Record) ([]byte, error)
	MarshalRecordsToBuffer(records []Record, buffer []byte) error
	RecordCount(b []byte) int
	UnmarshalRecord(buff []byte) Record
	RecordLength() int
}

RecordReaderWriter represents a library of methods to read and write records

type Records

type Records []Record

Records is a slice of *Record

func (Records) At

func (r Records) At(_ context.Context, i int) (*Record, error)

At implements IndexReader

func (Records) Find

func (r Records) Find(_ context.Context, id ID) (*Record, int, error)

Find implements IndexReader

type ShardedBloomFilter

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

func NewBloom

func NewBloom(fp float64, shardSize, estimatedObjects uint) *ShardedBloomFilter

NewBloom creates a ShardedBloomFilter

func (*ShardedBloomFilter) Add

func (b *ShardedBloomFilter) Add(traceID []byte)

func (*ShardedBloomFilter) GetShardCount

func (b *ShardedBloomFilter) GetShardCount() int

func (*ShardedBloomFilter) Marshal

func (b *ShardedBloomFilter) Marshal() ([][]byte, error)

Marshal is a wrapper around bloom.WriteTo

func (*ShardedBloomFilter) Test

func (b *ShardedBloomFilter) Test(traceID []byte) bool

Test implements bloom.Test -> required only for testing