io.opencensus.contrib.http

Class HttpClientHandler<Q,P,C>

java.lang.Object

io.opencensus.contrib.http.HttpClientHandler<Q,P,C>

Type Parameters:

Q - the HTTP request entity.

P - the HTTP response entity.

C - the type of the carrier.

@ExperimentalApi
public class HttpClientHandler<Q,P,C>
extends Object

This helper class provides routine methods to instrument HTTP clients.

Since:

0.19

Constructor Summary

Constructors

Constructor and Description
HttpClientHandler(io.opencensus.trace.Tracer tracer, HttpExtractor<Q,P> extractor, io.opencensus.trace.propagation.TextFormat textFormat, io.opencensus.trace.propagation.TextFormat.Setter<C> setter) Creates a HttpClientHandler with given parameters.

Method Summary

Modifier and Type	Method and Description
io.opencensus.trace.Span	getSpanFromContext(HttpRequestContext context) Retrieves Span from the HttpRequestContext.
void	handleEnd(HttpRequestContext context, Q request, P response, Throwable error) Close an HTTP span and records stats specific to the request.
void	handleMessageReceived(HttpRequestContext context, long bytes) Instrument an HTTP span after a message is received.
void	handleMessageSent(HttpRequestContext context, long bytes) Instrument an HTTP span after a message is sent.
HttpRequestContext	handleStart(io.opencensus.trace.Span parent, C carrier, Q request) Instrument a request for tracing and stats before it is sent.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

HttpClientHandler

public HttpClientHandler(io.opencensus.trace.Tracer tracer,
                         HttpExtractor<Q,P> extractor,
                         io.opencensus.trace.propagation.TextFormat textFormat,
                         io.opencensus.trace.propagation.TextFormat.Setter<C> setter)

Creates a HttpClientHandler with given parameters.

Parameters:

tracer - the Open Census tracing component.

extractor - the HttpExtractor used to extract information from the request/response.

textFormat - the TextFormat used in HTTP propagation.

setter - the setter used when injecting information to the carrier.

Since:

0.19

Method Detail

handleStart

public HttpRequestContext handleStart(@Nullable
                                      io.opencensus.trace.Span parent,
                                      C carrier,
                                      Q request)

Instrument a request for tracing and stats before it is sent.

This method will create a span in current context to represent the HTTP call. The created span will be serialized and propagated to the server.

The generated span will NOT be set as current context. User can control when to enter the scope of this span. Use AbstractHttpHandler.getSpanFromContext(io.opencensus.contrib.http.HttpRequestContext) to retrieve the span.

Parameters:

parent - the parent Span. null indicates using current span.

carrier - the entity that holds the HTTP information.

request - the request entity.

Returns:

the HttpRequestContext that contains stats and trace data associated with the request.

Since:

0.19

handleEnd

public void handleEnd(HttpRequestContext context,
                      @Nullable
                      Q request,
                      @Nullable
                      P response,
                      @Nullable
                      Throwable error)

Close an HTTP span and records stats specific to the request.

This method will set status of the span and end it. Additionally it will record measurements associated with the request.

Parameters:

context - the HttpRequestContext returned from handleStart(Span, Object, Object)

request - the HTTP request entity.

response - the HTTP response entity. null means invalid response.

error - the error occurs when processing the response.

Since:

0.19

handleMessageSent

public final void handleMessageSent(HttpRequestContext context,
                                    long bytes)

Instrument an HTTP span after a message is sent. Typically called for every chunk of request or response is sent.

Parameters:

context - request specific HttpRequestContext

bytes - bytes sent.

Since:

0.19

handleMessageReceived

public final void handleMessageReceived(HttpRequestContext context,
                                        long bytes)

Instrument an HTTP span after a message is received. Typically called for every chunk of request or response is received.

Parameters:

context - request specific HttpRequestContext

bytes - bytes received.

Since:

0.19

getSpanFromContext

public io.opencensus.trace.Span getSpanFromContext(HttpRequestContext context)

Retrieves Span from the HttpRequestContext.

Parameters:

context - request specific HttpRequestContext

Returns:

Span associated with the request.

Since:

0.19