import Tracer from 'opentracing/src/tracer.js'

public class | source

Tracer

Direct Subclass:

Singleton

Tracer is the entry-point between the instrumentation API and the tracing implementation.

The default object acts as a no-op implementation.

Constructor Summary

Public Constructor
public	constructor(imp: *) Note: this constructor should not be called directly by consumers of this code.

Method Summary

Public Methods
public	flush(done: function(err: objectg)) Request that any buffered or in-memory data is flushed out of the process.
public	imp(): object Handle to implementation object.
public	inject(span: Span, format: string, carrier: any) Injects the information about the given span into the carrier so that the span can propogate across inter-process barriers.
public	join(operationName: string, format: string, carrier: any): Span Returns a new Span object with the given operation name using the trace information from the carrier.
public	startSpan(nameOrFields: string \| object, fields: object): Span Starts and returns a new Span representing a logical unit of work.

Public Constructors

public constructor(imp: *) source

Note: this constructor should not be called directly by consumers of this code. The singleton's initNewTracer() method should be invoked instead.

Params:

Name	Type	Attribute	Description
imp	*

Public Methods

public flush(done: function(err: objectg)) source

Request that any buffered or in-memory data is flushed out of the process.

Params:

Name	Type	Attribute	Description
done	function(err: objectg)		optional callback function with the signature `function(err)` that will be called as soon as the flush completes. `err` should be null or undefined if the flush was successful.

public imp(): object source

Handle to implementation object.

Use of this method is discouraged as it greatly reduces the portability of the calling code. Use only when implementation-specific functionality must be used and cannot accessed otherwise.

Return:

object

An implementation-dependent object.

public inject(span: Span, format: string, carrier: any) source

Injects the information about the given span into the carrier so that the span can propogate across inter-process barriers.

See FORMAT_TEXT_MAP and FORMAT_BINARY for the two required carriers.

Consider this pseudocode example:

var clientSpan = ...;
...
// Inject clientSpan into a text carrier.
var textCarrier = {};
Tracer.inject(clientSpan, Tracer.FORMAT_TEXT_MAP, textCarrier);
// Incorporate the textCarrier into the outbound HTTP request header
// map.
outboundHTTPReq.headers.extend(textCarrier);
// ... send the httpReq

For FORMAT_BINARY, inject() will set the buffer field to an Array-like (Array, ArrayBuffer, or TypedBuffer) object containing the injected binary data. Any valid Object can be used as long as the buffer field of the object can be set.

Params:

Name	Type	Attribute	Description
span	Span		the span whose information should be injected into the carrier.
format	string		the format of the carrier.
carrier	any		see the method description for details on the carrier object.

public join(operationName: string, format: string, carrier: any): Span source

Returns a new Span object with the given operation name using the trace information from the carrier.

See FORMAT_TEXT_MAP and FORMAT_BINARY for the two required carriers.

Consider this pseudocode example:

// Use the inbound HTTP request's headers as a text map carrier.
var textCarrier = inboundHTTPReq.headers;
var serverSpan = Tracer.join(
    "operation name", Tracer.FORMAT_TEXT_MAP, textCarrier);

For FORMAT_BINARY, carrier is expected to have a field named buffer that contains an Array-like object (Array, ArrayBuffer, or TypedBuffer).

Params:

Name	Type	Attribute	Description
operationName	string		operation name to use on the newly created span.
format	string		the format of the carrier.
carrier	any		the type of the carrier object is determined by the format.

Return:

Span

public startSpan(nameOrFields: string | object, fields: object): Span source

Starts and returns a new Span representing a logical unit of work.

Params:

Name	Type	Attribute	Description
nameOrFields	string \| object		if the given argument is a string, it is the name of the operation and the second `fields` argument is optional. If it is an object, it is treated as the fields argument and a second argument should not be provided.
fields	object	optional	the fields to set on the newly created span.
fields.operationName	string	optional	the name to use for the newly created span. Required if called with a single argument.
fields.parent	Span	optional	the parent of the newly created span
fields.tags	object	optional	set of key-value pairs which will be set as tags on the newly created Span. Ownership of the object is passed to the created span for efficiency reasons (the caller should not modify this object after calling startSpan).
fields.startTime	number	optional	a manually specified start time for the created Span object. The time should be specified in milliseconds as Unix timestamp. Decimal value are supported to represent time values with sub-millisecond accuracy.

Return:

Span	a new Span object.