This uses the strongly typed key to get the value rather than
type switching on the value itself.
Change-Id: I8f72d1d9cac0191b0565c14d8a1108459ee6df36
Reviewed-on: https://go-review.googlesource.com/c/tools/+/225379
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
Now that keys are solidly typed, we can use them for the metrics.
This prevents accidentally using the wrong type of key, and
allows us to use the typed accesorrs rather than the raw value.
Change-Id: I553bd8e12128d3f00a3e926dbd3bfd420cd3f135
Reviewed-on: https://go-review.googlesource.com/c/tools/+/225378
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
This separates the concerns of tag collections that have to be iterated
and tag collections that need lookup by key.
Also make it so that events just carry a plain slice of tags.
We pass a TagMap down through the exporters and allow it to be
extended on the way.
We no longer need the event.Query method (or the event type)
We now exclusivley use Key as the identity, and no longer have a
common core implementation but just implement it directly in each
type.
This removes some confusion that was causing the same key through
different paths to end up with a different identity.
Change-Id: I61e47adcb397f4ca83dd90342b021dd8e9571ed3
Reviewed-on: https://go-review.googlesource.com/c/tools/+/224278
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
This change updates the metrics tutorial to include example code for
exporting traces from go tools.
Change-Id: Ie1d3c373ed4308ef0160f6389b74c642b348bed6
Reviewed-on: https://go-review.googlesource.com/c/tools/+/225061
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This change updates the metrics tutorial to be compatible with the new event system.
Change-Id: I8b75f6b02d241bc9dede01cfac167a982f1df67c
Reviewed-on: https://go-review.googlesource.com/c/tools/+/225058
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This allows us to hide the implementation details of how tags are stored on a
context from the normal interface, to allow us to explore more efficient
mechanisms.
The current storage is not intended as the most efficient choice, this cl is
about isolating the API so we can experiment with benchmarks in the future.
Change-Id: Ib101416bccd8ecdee269cee636b1564d51e1da8a
Reviewed-on: https://go-review.googlesource.com/c/tools/+/222854
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
This change updates the metric exporting tutorial to use oragent to spin
up OpenCensus, Prometheus, and Zipkin all at once using docker-compose
rather than manually setting each one up. This allows developers to set
up an environment for testing metrics and traces with minimal effort.
While oragent also spins up Zipkin for traces, the tutorial does not yet
have a section outlining how to export traces from Go tools. A section
for traces will added in a later CL.
Change-Id: I07f49977f7ab49995853ff8ee8eb6ccdf6ef1642
Reviewed-on: https://go-review.googlesource.com/c/tools/+/224258
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
This changes the way keys work, there is still a single internal key
implementation for performance reasons, but the public interface is a set of key
implementations that have type safe Of and Get methods.
This also hides the implemenation of Tag so that we can modify the storage form
and find a more efficient storage if needed.
Change-Id: I6a39cc75c2824c6a92e52d59f16e82e876f16e9c
Reviewed-on: https://go-review.googlesource.com/c/tools/+/223137
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Rather than building cusom events and driving the exporter, the test now
registers a custom exporter and then uses the normal higher level methods to
deliver events to it.
This means we are testing the actual information that would arise in a user
program, and also means we no longer have to expose internal features just for
tests.
Metrics are not fully converted yet.
Change-Id: I63248a480fb1b3e6274dce0c2e1d66904d055978
Reviewed-on: https://go-review.googlesource.com/c/tools/+/222849
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
This allows early exporters to adjust the event for later ones.
This is used to lookup key values from the context if needed.
Also add a Query type event which is intended to perform all event
modifications but nothing else, and is used to lookup values from
the context. This cleans up a weirdness where the current lookup
presumes there will be an exporter with a matching mechanism.
Change-Id: I835d1e0b2511553c30f94b7becfe7b7b5462c111
Reviewed-on: https://go-review.googlesource.com/c/tools/+/223657
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
This moves the actual trace test into its own file so that it can easily
be seen separately from the functions that support all tests.
Change-Id: I1d30cf8a712377ca79a5de77b85412c881177f43
Reviewed-on: https://go-review.googlesource.com/c/tools/+/223397
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
This makes keys a pointer, which reduces the allocations during logging, and has
a significant improvement in memory and cpu cost when there is no exporter.
Packing a string into an interface requires a 16 byte allocation, packing a pointer
does not.
name old time/op new time/op delta
/LogNoExporter-8 4.39µs ± 2% 3.83µs ± 2% -12.74% (p=0.000 n=18+20)
/Log-8 23.5µs ± 2% 22.6µs ± 1% -4.20% (p=0.000 n=19+18)
name old alloc/op new alloc/op delta
/LogNoExporter-8 1.70kB ± 0% 1.38kB ± 0% -18.78% (p=0.000 n=20+20)
/Log-8 4.91kB ± 0% 4.91kB ± 0% ~ (p=1.000 n=20+20)
name old allocs/op new allocs/op delta
/LogNoExporter-8 83.0 ± 0% 63.0 ± 0% -24.10% (p=0.000 n=20+20)
/Log-8 163 ± 0% 163 ± 0% ~ (all equal)
Change-Id: Iec127f1bff8d5c8f4bd0a6d9f6d8fc4b8bc740b2
Reviewed-on: https://go-review.googlesource.com/c/tools/+/222599
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
This is now the only package that is exposed to normal use, and should
be the only thing to appear in libraries.
Change-Id: I90ee47c6519f30db16ff5d5d2910be86e91e5df2
Reviewed-on: https://go-review.googlesource.com/c/tools/+/222557
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
deliver detach to the exporter as an event rather than hard coding the
span detach behavior.
Change-Id: I87b6e2a3596fea338908c11ba0b219176b6305bf
Reviewed-on: https://go-review.googlesource.com/c/tools/+/222542
Reviewed-by: Robert Findley <rfindley@google.com>
This means that tags also become cheap if there is no exporter and cleans up the
mess with how spans, tags and logs were related.
Also fixes the currently broken metrics that relied on the span tags.
Change-Id: I8e56b6218a60fd31a1f6c8d329dbb2cab1b9254d
Reviewed-on: https://go-review.googlesource.com/c/tools/+/222065
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
We no longer use the span as the core type of tracing, instead that is an
artifact of the exporter, and start and end tracing is just event based.
This both makes the interface normalized, and also means the null exporter case
is considerably cheaper in memory and cpu.
See below for benchstat changes
name old time/op new time/op delta
TracingNoExporter-8 4.19µs ±12% 2.71µs ±11% -35.33% (p=0.000 n=20+20)
Tracing-8 24.1µs ± 3% 5.1µs ±17% -78.66% (p=0.000 n=16+20)
name old alloc/op new alloc/op delta
TracingNoExporter-8 2.32kB ± 0% 0.40kB ± 0% -82.76% (p=0.000 n=20+20)
Tracing-8 6.32kB ± 0% 2.32kB ± 0% -63.30% (p=0.000 n=20+20)
name old allocs/op new allocs/op delta
TracingNoExporter-8 35.0 ± 0% 15.0 ± 0% -57.14% (p=0.000 n=20+20)
Tracing-8 215 ± 0% 35 ± 0% -83.72% (p=0.000 n=20+20)
Change-Id: I3cf25871fa49584819504b5c19aa580e5dd03395
Reviewed-on: https://go-review.googlesource.com/c/tools/+/221740
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
These are just like the logging benchmarks but for tracing instead.
Also makes the log writer write out tracing events as well if it is
not in only errors mode
Change-Id: Ie00d7c80f7e2b9433787603261950f70ab1c1e9d
Reviewed-on: https://go-review.googlesource.com/c/tools/+/221739
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
This adds a type to events and makes the logging calls use it.
Change-Id: Iaa50fe2e332caae611b1e00424c878a3bc479feb
Reviewed-on: https://go-review.googlesource.com/c/tools/+/221741
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
We change the main exporter to be stored and fetched using atomics rather
than aquiring a mutex for a mild (but significant in the disabled case) speedup.
Also has the benefit of not holding a global lock over all telemetry operations.
benchstat of logging benchmatks before and after:
name old time/op new time/op delta
Baseline-8 329ns ± 2% 327ns ± 2% ~ (p=0.181 n=19+17)
LoggingNoExporter-8 3.08µs ± 3% 2.42µs ± 2% -21.42% (p=0.000 n=20+19)
Logging-8 13.7µs ± 2% 13.2µs ± 1% -3.49% (p=0.000 n=19+19)
LoggingStdlib-8 5.39µs ± 3% 5.41µs ± 2% ~ (p=0.177 n=19+20)
This is a replacement for https://go-review.googlesource.com/c/tools/+/212244
but built on the single exporter principle rather than the exporter list.
Change-Id: Icc99319c4357e0bcb63386c64372a733e8a76796
Reviewed-on: https://go-review.googlesource.com/c/tools/+/221218
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
It is never invoked anyway, and it provices no useful benefit while complicating
the implementation, as it is the only non context aware method.
Change-Id: Id5a99439fedafdf4d71285e36103b4854cf3635a
Reviewed-on: https://go-review.googlesource.com/c/tools/+/221540
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Instead we only have a single exporter, and it must delegate behaviour
to any other exporters it wants to include.
This removes a whole collection of suprises caused by init functions adding
new exporters to a list, as well as generally making things faster, at the small
expense of needing to implement a custom exporter if you want to combine the
features of a few other exporters.
This is essentially the opposite of https://go-review.googlesource.com/c/tools/+/212243
which will now be abandoned in favor of this approach.
Change-Id: Icacb4c1f0f40f99ddd1d82c73d4f25a3486e56ce
Reviewed-on: https://go-review.googlesource.com/c/tools/+/220857
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Robert Findley <rfindley@google.com>
Make all the benchmarks cleanly pass around the context to remove a non logging
difference.
Rename the non logging calls benchmark to Baseline
Change-Id: I24a33b0a817df403fb43c53b5f097bc1e9418af4
Reviewed-on: https://go-review.googlesource.com/c/tools/+/220520
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
the current implementation likes to sort maps, so we make sure
tag lists are in sorted order already so that a stable encoder
produces the same result
Change-Id: Ia7ce05f35edb636817c354d9df02de753a48fe1d
Reviewed-on: https://go-review.googlesource.com/c/tools/+/210216
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
There was a fragment of a sentence that must have been from a previous version
(as it talks about a return value for a function that does not have one).
Change-Id: I9d154fe10711344f93e1d49b68a811dbc9772710
Reviewed-on: https://go-review.googlesource.com/c/tools/+/212241
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
has no impact because there are no use cases that don't set it to true right now
Change-Id: I2bc485226078c710bdc36397b96755cdce82d9cc
Reviewed-on: https://go-review.googlesource.com/c/tools/+/212242
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Now the tests are at a high enough level, we can
switch them to using the full exporter by bulding
a fake http client to bind it to. This lets us
use the true public interface and also excercise
more of the functionality in the tests.
With this we are now ready to replace the entire
implementation safely.
Change-Id: Ifdbf6230de3ec7c7c5381c840b135cb7a0bc1e55
Reviewed-on: https://go-review.googlesource.com/c/tools/+/209161
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
rather than testing events or metrics directly, we
test them in the context of a full message that would
get sent to the agent
Change-Id: I238a7f9ab7b1456d1b4b2bac2519d814928f2283
Reviewed-on: https://go-review.googlesource.com/c/tools/+/209098
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
this is needed to move to a model where we do not need to have
the wire form at all
Change-Id: I3b3693e027b568de4e8b4d10f7d5dd022a616e2e
Reviewed-on: https://go-review.googlesource.com/c/tools/+/208958
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
convert to wire form only when we need to encode it
Change-Id: Ib36ee2fbef773241a30b9aa707ebf311119b8705
Reviewed-on: https://go-review.googlesource.com/c/tools/+/208658
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Nathan Dias <nathan.dias@orijtech.com>
This is the same changes we already made to the trace tests, where we check the
encoded json instead of the wire structs, and we make the tests external using
the public encoding function only
Change-Id: I289d46dd5ad0efe0b2fba0a71b188b4f9edc5676
Reviewed-on: https://go-review.googlesource.com/c/tools/+/208504
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
This merges all the metrics tests into something that converts top level metrics
only, and relies on that to cover all the lower level functions
This is in preparation for moving the tests to be external without exposing all
those functions.
Change-Id: Iecce1ddc522db9fc926817e4e748d718cbc740a9
Reviewed-on: https://go-review.googlesource.com/c/tools/+/208499
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
It is sufficient to just compact the JSON to compare it rather than
bothering to decode it.
Change-Id: Ied39d462eec77623187422a9c58f83f8d1630269
Reviewed-on: https://go-review.googlesource.com/c/tools/+/208498
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
This change updates initializations of DistributionValue to pass in a pointer for
BucketOptions rather than a value so that the custom MarshalJSON for
*BucketOptionsExplicit will be called when marshalling distributions.
Updates golang/go#33819
Change-Id: I6d1a393dfa67d626bf5cdd2cfbc0c931d376f60c
Reviewed-on: https://go-review.googlesource.com/c/tools/+/208401
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This change adds a README that describes how to export metrics from
Go tools to Prometheus via OpenCensus.
Updates golang/go#33819
Change-Id: Ic417b539fd5ef95fee642321bd30997146cbedb3
Reviewed-on: https://go-review.googlesource.com/c/tools/+/208400
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
This change adds a custom MarshalJSON method to BucketOptionsExplicit for
marshalling parity with protobuf/jsonpb. This allows the OpenCensus service
to correctly decode a distribution's BucketOptions.
Updates golang/go#33819
Change-Id: Ia9dc868e1cbfc32a956f6a276dfd1591f7d4d31a
Reviewed-on: https://go-review.googlesource.com/c/tools/+/208398
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This change adds a custom MarshalJSON func to Point so that values
are formatted the same way jsonpb formats them. This allows the
OpenCensus service to determine the concrete type of the point's
value when unmarshaling.
What works:
* Points with Int64, Double, and Distribution values will marshal correctly.
What does not work:
* Points with Summary values will not marshal.
Updates golang/go#33819
Change-Id: Ia76ebff4e0e2b6ff2ddf72b8d6187f49069d4cad
Reviewed-on: https://go-review.googlesource.com/c/tools/+/207838
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
They now call a public encode function and have no knowledge of the private
conversion functions or any of the contents of the wire package.
Change-Id: I4364a4d9d1efe4bc872627556e537936b5880231
Reviewed-on: https://go-review.googlesource.com/c/tools/+/207903
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
do it just as we are encoding, this is in preparation for making the
encoding faster and cheaper
Change-Id: Ic9715e2750adf276eac152e321d96e249190eacb
Reviewed-on: https://go-review.googlesource.com/c/tools/+/207902
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
This will allow us to use the public API to generate the events.
This avoids creating the structs by hand.
It also helps tests the other API.
Change-Id: Ic90cbbaf6fc97c2a3e6a5ff64dccdff0d65ec865
Reviewed-on: https://go-review.googlesource.com/c/tools/+/206885
Run-TryBot: Ian Cottrell <iancottrell@google.com>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
This checks against the json form rather than the wire structs
This will allow the encoding method to change without the test changing.
Change-Id: Iefe84cc03bc6e82627acd031e0991c31b4fed315
Reviewed-on: https://go-review.googlesource.com/c/tools/+/206884
Run-TryBot: Ian Cottrell <iancottrell@google.com>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
This change attaches start timestamps to timeseries and end
timestamps to the points in each timeseries. Int64Data,
Float64Data, HistogramInt64Data, and HistogramFloat64Data
have also had an EndTime field added to keep track of the last
time the metric was updated.
What works:
* Start and end timestamps will now be attached to timeseries.
What does not work yet:
* MetricDescriptors will not have a unit attached.
* No labels will be attached to timeseries.
* Distributions will not have SumOfSquaredDeviation attached.
Updates golang/go#33819
Change-Id: I692e1676bb1e31de26c1f799b96428fc9a55d6c7
Reviewed-on: https://go-review.googlesource.com/c/tools/+/203060
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
This change adds support for converting HistogramFloat64Data and
HistogramInt64Data to *wire.Metric. Timestamps are not attached
as they are not yet available.
What works:
* convertMetric will now convert HistogramInt64Data and
HistogramFloat64Data to *wire.Metric.
What does not work yet:
* StartTime and EndTime will not be attached to timeseries and
points.
* MetricDescriptors will not have a unit attached.
* No labels will be attached to timeseries.
* Distributions will not have SumOfSquaredDeviation attached.
Updates golang/go#33819
Change-Id: Iee52ab751542ee1ade07ef32120de853b41fd27b
Reviewed-on: https://go-review.googlesource.com/c/tools/+/200538
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Histogram data still needs to be converted and
timestamps are not attached as they are not yet available.
What works:
* convertMetric will now convert Int64Data and Float64Data.
What does not work yet:
* Histogram64Int and Histogram64Float will still not be converted.
* StartTime and EndTime will not be attached to timeseries and points.
* MetricDescriptors will not have a unit attached.
* no labels will be attached to timeseries.
Updates golang/go#33819
Change-Id: I65f9af716ba6282e809d0a9d10777d70475e4c83
GitHub-Last-Rev: 10820a9971e1f4c0529fadc567b2533256c2e961
GitHub-Pull-Request: golang/tools#170
Reviewed-on: https://go-review.googlesource.com/c/tools/+/199857
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Ian Cottrell <iancottrell@google.com>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
