vendor: update buildkit to master@8b7bcb900d3c

Signed-off-by: Justin Chadwell <me@jedevc.com>

vendor/go.opentelemetry.io/otel/metric/instrument/asyncfloat64.go

@@ -0,0 +1,130 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package instrument // import "go.opentelemetry.io/otel/metric/instrument"
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/attribute"
+)
+
+// Float64Observable describes a set of instruments used asynchronously to
+// record float64 measurements once per collection cycle. Observations of
+// these instruments are only made within a callback.
+//
+// Warning: methods may be added to this interface in minor releases.
+type Float64Observable interface {
+	Asynchronous
+
+	float64Observable()
+}
+
+// Float64ObservableCounter is an instrument used to asynchronously record
+// increasing float64 measurements once per collection cycle. Observations are
+// only made within a callback for this instrument. The value observed is
+// assumed the to be the cumulative sum of the count.
+//
+// Warning: methods may be added to this interface in minor releases.
+type Float64ObservableCounter interface{ Float64Observable }
+
+// Float64ObservableUpDownCounter is an instrument used to asynchronously
+// record float64 measurements once per collection cycle. Observations are only
+// made within a callback for this instrument. The value observed is assumed
+// the to be the cumulative sum of the count.
+//
+// Warning: methods may be added to this interface in minor releases.
+type Float64ObservableUpDownCounter interface{ Float64Observable }
+
+// Float64ObservableGauge is an instrument used to asynchronously record
+// instantaneous float64 measurements once per collection cycle. Observations
+// are only made within a callback for this instrument.
+//
+// Warning: methods may be added to this interface in minor releases.
+type Float64ObservableGauge interface{ Float64Observable }
+
+// Float64Observer is a recorder of float64 measurements.
+//
+// Warning: methods may be added to this interface in minor releases.
+type Float64Observer interface {
+	Observe(value float64, attributes ...attribute.KeyValue)
+}
+
+// Float64Callback is a function registered with a Meter that makes
+// observations for a Float64Observerable instrument it is registered with.
+// Calls to the Float64Observer record measurement values for the
+// Float64Observable.
+//
+// The function needs to complete in a finite amount of time and the deadline
+// of the passed context is expected to be honored.
+//
+// The function needs to make unique observations across all registered
+// Float64Callbacks. Meaning, it should not report measurements with the same
+// attributes as another Float64Callbacks also registered for the same
+// instrument.
+//
+// The function needs to be concurrent safe.
+type Float64Callback func(context.Context, Float64Observer) error
+
+// Float64ObserverConfig contains options for Asynchronous instruments that
+// observe float64 values.
+type Float64ObserverConfig struct {
+	description string
+	unit        string
+	callbacks   []Float64Callback
+}
+
+// NewFloat64ObserverConfig returns a new Float64ObserverConfig with all opts
+// applied.
+func NewFloat64ObserverConfig(opts ...Float64ObserverOption) Float64ObserverConfig {
+	var config Float64ObserverConfig
+	for _, o := range opts {
+		config = o.applyFloat64Observer(config)
+	}
+	return config
+}
+
+// Description returns the Config description.
+func (c Float64ObserverConfig) Description() string {
+	return c.description
+}
+
+// Unit returns the Config unit.
+func (c Float64ObserverConfig) Unit() string {
+	return c.unit
+}
+
+// Callbacks returns the Config callbacks.
+func (c Float64ObserverConfig) Callbacks() []Float64Callback {
+	return c.callbacks
+}
+
+// Float64ObserverOption applies options to float64 Observer instruments.
+type Float64ObserverOption interface {
+	applyFloat64Observer(Float64ObserverConfig) Float64ObserverConfig
+}
+
+type float64ObserverOptionFunc func(Float64ObserverConfig) Float64ObserverConfig
+
+func (fn float64ObserverOptionFunc) applyFloat64Observer(cfg Float64ObserverConfig) Float64ObserverConfig {
+	return fn(cfg)
+}
+
+// WithFloat64Callback adds callback to be called for an instrument.
+func WithFloat64Callback(callback Float64Callback) Float64ObserverOption {
+	return float64ObserverOptionFunc(func(cfg Float64ObserverConfig) Float64ObserverConfig {
+		cfg.callbacks = append(cfg.callbacks, callback)
+		return cfg
+	})
+}