correlation

Documentation

Overview

This package implements the correlation functionality as specified in the OpenTelemetry specification. Currently it provides a data structure for storing correlations (Map) and a way of putting Map object into the context and retrieving it from context.

Index

• Variables
• func ContextWithMap(ctx context.Context, m Map) context.Context
• func DefaultHTTPPropagator() propagation.HTTPPropagator
• func NewContext(ctx context.Context, keyvalues ...core.KeyValue) context.Context
• type CorrelationContext
  • func (CorrelationContext) Extract(ctx context.Context, supplier propagation.HTTPSupplier) context.Context
  • func (CorrelationContext) GetAllKeys() []string
  • func (CorrelationContext) Inject(ctx context.Context, supplier propagation.HTTPSupplier)
• type Map
  • func MapFromContext(ctx context.Context) Map
  • func NewEmptyMap() Map
  • func NewMap(update MapUpdate) Map
  • func (m Map) Apply(update MapUpdate) Map
  • func (m Map) Foreach(f func(kv core.KeyValue) bool)
  • func (m Map) HasValue(k core.Key) bool
  • func (m Map) Len() int
  • func (m Map) Value(k core.Key) (core.Value, bool)
• type MapUpdate

Variables

var CorrelationContextHeader = "Correlation-Context"

CorrelationContextHeader is specified by W3C.

Functions

func ContextWithMap

func ContextWithMap(ctx context.Context, m Map) context.Context

ContextWithMap returns a context with the Map entered into it.

func DefaultHTTPPropagator

func DefaultHTTPPropagator() propagation.HTTPPropagator

DefaultHTTPPropagator returns the default context correlation HTTP propagator.

func NewContext

func NewContext(ctx context.Context, keyvalues ...core.KeyValue) context.Context

NewContext returns a context with the map from passed context updated with the passed key-value pairs.

Types

type CorrelationContext

type CorrelationContext struct{}

CorrelationContext propagates Key:Values in W3C CorrelationContext format. nolint:golint

func (CorrelationContext) Extract

func (CorrelationContext) Extract(ctx context.Context, supplier propagation.HTTPSupplier) context.Context

Extract implements HTTPExtractor.

func (CorrelationContext) GetAllKeys

func (CorrelationContext) GetAllKeys() []string

GetAllKeys implements HTTPPropagator.

func (CorrelationContext) Inject

func (CorrelationContext) Inject(ctx context.Context, supplier propagation.HTTPSupplier)

Inject implements HTTPInjector.

type Map

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

Map is an immutable storage for correlations.

func MapFromContext

func MapFromContext(ctx context.Context) Map

MapFromContext gets the current Map from a Context.

func NewEmptyMap

func NewEmptyMap() Map

NewEmptyMap creates an empty correlations map.

func NewMap

func NewMap(update MapUpdate) Map

NewMap creates a map with the contents of the update applied. In this function, having an update with DropSingleK or DropMultiK makes no sense - those fields are effectively ignored.

func (Map) Apply

func (m Map) Apply(update MapUpdate) Map

Apply creates a copy of the map with the contents of the update applied. Apply will first drop the keys from DropSingleK and DropMultiK, then add key-value pairs from SingleKV and MultiKV.

func (Map) Foreach

func (m Map) Foreach(f func(kv core.KeyValue) bool)

Foreach calls a passed callback once on each key-value pair until all the key-value pairs of the map were iterated or the callback returns false, whichever happens first.

func (Map) HasValue

func (m Map) HasValue(k core.Key) bool

HasValue returns a boolean value indicating whether the key exist in the map.

func (Map) Len

func (m Map) Len() int

Len returns a length of the map.

func (Map) Value

func (m Map) Value(k core.Key) (core.Value, bool)

Value gets a value from correlations map and returns a boolean value indicating whether the key exist in the map.

type MapUpdate

type MapUpdate struct {
	// DropSingleK contains a single key to be dropped from
	// correlations. Use this to avoid an overhead of a slice
	// allocation if there is only one key to drop.
	DropSingleK core.Key
	// DropMultiK contains all the keys to be dropped from
	// correlations.
	DropMultiK []core.Key

	// SingleKV contains a single key-value pair to be added to
	// correlations. Use this to avoid an overhead of a slice
	// allocation if there is only one key-value pair to add.
	SingleKV core.KeyValue
	// MultiKV contains all the key-value pairs to be added to
	// correlations.
	MultiKV []core.KeyValue
}

MapUpdate contains information about correlation changes to be made.