[API Epic 1/4] Metric api prototype

metric/config.go

@@ -0,0 +1,67 @@
+// 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 metric // import "go.opentelemetry.io/otel/metric"
+
+// MeterConfig contains options for Meters.
+type MeterConfig struct {
+	instrumentationVersion string
+	schemaURL              string
+}
+
+// InstrumentationVersion is the version of the library providing instrumentation.
+func (cfg MeterConfig) InstrumentationVersion() string {
+	return cfg.instrumentationVersion
+}
+
+// SchemaURL is the schema_url of the library providing instrumentation.
+func (cfg MeterConfig) SchemaURL() string {
+	return cfg.schemaURL
+}
+
+// MeterOption is an interface for applying Meter options.
+type MeterOption interface {
+	// ApplyMeter is used to set a MeterOption value of a MeterConfig.
+	applyMeter(*MeterConfig)
+}
+
+// NewMeterConfig creates a new MeterConfig and applies
+// all the given options.
+func NewMeterConfig(opts ...MeterOption) MeterConfig {
+	var config MeterConfig
+	for _, o := range opts {
+		o.applyMeter(&config)
+	}
+	return config
+}
+
+type meterOptionFunc func(*MeterConfig)
+
+func (fn meterOptionFunc) applyMeter(cfg *MeterConfig) {
+	fn(cfg)
+}
+
+// WithInstrumentationVersion sets the instrumentation version.
+func WithInstrumentationVersion(version string) MeterOption {
+	return meterOptionFunc(func(config *MeterConfig) {
+		config.instrumentationVersion = version
+	})
+}
+
+// WithSchemaURL sets the schema URL.
+func WithSchemaURL(schemaURL string) MeterOption {
+	return meterOptionFunc(func(config *MeterConfig) {
+		config.schemaURL = schemaURL
+	})
+}

metric/doc.go

@@ -0,0 +1,23 @@
+// 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 metric provides an implementation of the metrics part of the
+OpenTelemetry API.
+
+This package is currently in a pre-GA phase. Backwards incompatible changes
+may be introduced in subsequent minor version releases as we work to track the
+evolving OpenTelemetry specification and user feedback.
+*/
+package metric // import "go.opentelemetry.io/otel/metric"

metric/go.mod

@@ -0,0 +1,69 @@
+module go.opentelemetry.io/otel/metric
+
+go 1.16
+
+require go.opentelemetry.io/otel v1.3.0
+
+replace go.opentelemetry.io/otel => ../
+
+replace go.opentelemetry.io/otel/bridge/opencensus => ../bridge/opencensus
+
+replace go.opentelemetry.io/otel/bridge/opentracing => ../bridge/opentracing
+
+replace go.opentelemetry.io/otel/example/jaeger => ../example/jaeger
+
+replace go.opentelemetry.io/otel/example/namedtracer => ../example/namedtracer
+
+replace go.opentelemetry.io/otel/example/opencensus => ../example/opencensus
+
+replace go.opentelemetry.io/otel/example/otel-collector => ../example/otel-collector
+
+replace go.opentelemetry.io/otel/example/prom-collector => ../example/prom-collector
+
+replace go.opentelemetry.io/otel/example/prometheus => ../example/prometheus
+
+replace go.opentelemetry.io/otel/example/zipkin => ../example/zipkin
+
+replace go.opentelemetry.io/otel/exporters/prometheus => ../exporters/prometheus
+
+replace go.opentelemetry.io/otel/exporters/jaeger => ../exporters/jaeger
+
+replace go.opentelemetry.io/otel/exporters/zipkin => ../exporters/zipkin
+
+replace go.opentelemetry.io/otel/internal/tools => ../internal/tools
+
+replace go.opentelemetry.io/otel/metric => ./
+
+replace go.opentelemetry.io/otel/sdk => ../sdk
+
+replace go.opentelemetry.io/otel/sdk/export/metric => ../sdk/export/metric
+
+replace go.opentelemetry.io/otel/sdk/metric => ../sdk/metric
+
+replace go.opentelemetry.io/otel/trace => ../trace
+
+replace go.opentelemetry.io/otel/example/passthrough => ../example/passthrough
+
+replace go.opentelemetry.io/otel/exporters/otlp/otlptrace => ../exporters/otlp/otlptrace
+
+replace go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc => ../exporters/otlp/otlptrace/otlptracegrpc
+
+replace go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp => ../exporters/otlp/otlptrace/otlptracehttp
+
+replace go.opentelemetry.io/otel/exporters/otlp/otlpmetric => ../exporters/otlp/otlpmetric
+
+replace go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc => ../exporters/otlp/otlpmetric/otlpmetricgrpc
+
+replace go.opentelemetry.io/otel/exporters/stdout/stdoutmetric => ../exporters/stdout/stdoutmetric
+
+replace go.opentelemetry.io/otel/exporters/stdout/stdouttrace => ../exporters/stdout/stdouttrace
+
+replace go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp => ../exporters/otlp/otlpmetric/otlpmetrichttp
+
+replace go.opentelemetry.io/otel/bridge/opencensus/test => ../bridge/opencensus/test
+
+replace go.opentelemetry.io/otel/example/fib => ../example/fib
+
+replace go.opentelemetry.io/otel/schema => ../schema
+
+replace go.opentelemetry.io/otel/exporters/otlp/internal/retry => ../exporters/otlp/internal/retry

metric/go.sum

@@ -0,0 +1,15 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
+github.com/google/go-cmp v0.5.7 h1:81/ik6ipDQS2aGcBfIN5dHDB36BwrStyeAQquSYCV4o=
+github.com/google/go-cmp v0.5.7/go.mod h1:n+brtR0CgQNWTVd5ZUFpTBC8YFBDLK/h/bpaJ8/DtOE=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

metric/instrument/asyncfloat64/asyncfloat64.go

@@ -0,0 +1,70 @@
+// 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 asyncfloat64 // import "go.opentelemetry.io/otel/metric/instrument/asyncfloat64"
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric/instrument"
+)
+
+// Instruments provides access to individual instruments.
+type Instruments interface {
+	// Counter creates an instrument for recording increasing values.
+	Counter(name string, opts ...instrument.Option) (Counter, error)
+
+	// UpDownCounter creates an instrument for recording changes of a value.
+	UpDownCounter(name string, opts ...instrument.Option) (UpDownCounter, error)
+
+	// Gauge creates an instrument for recording the current value.
+	Gauge(name string, opts ...instrument.Option) (Gauge, error)
+}
+
+// Counter is an instrument that records increasing values.
+type Counter interface {
+	// Observe records the state of the instrument.
+	//
+	// It is only valid to call this within a callback. If called outside of the
+	// registered callback it should have no effect on the instrument, and an
+	// error will be reported via the error handeling
+	Observe(ctx context.Context, x float64, attrs ...attribute.KeyValue)
+
+	instrument.Asynchronous
+}
+
+// UpDownCounter is an instrument that records increasing or decresing values.
+type UpDownCounter interface {
+	// Observe records the state of the instrument.
+	//
+	// It is only valid to call this within a callback. If called outside of the
+	// registered callback it should have no effect on the instrument, and an
+	// error will be reported via the error handeling
+	Observe(ctx context.Context, x float64, attrs ...attribute.KeyValue)
+
+	instrument.Asynchronous
+}
+
+// Gauge is an instrument that records independent readings.
+type Gauge interface {
+	// Observe records the state of the instrument.
+	//
+	// It is only valid to call this within a callback. If called outside of the
+	// registered callback it should have no effect on the instrument, and an
+	// error will be reported via the error handeling
+	Observe(ctx context.Context, x float64, attrs ...attribute.KeyValue)
+
+	instrument.Asynchronous
+}

metric/instrument/asyncint64/asyncint64.go

@@ -0,0 +1,70 @@
+// 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 asyncint64 // import "go.opentelemetry.io/otel/metric/instrument/asyncint64"
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric/instrument"
+)
+
+// Instruments provides access to individual instruments.
+type Instruments interface {
+	// Counter creates an instrument for recording increasing values.
+	Counter(name string, opts ...instrument.Option) (Counter, error)
+
+	// UpDownCounter creates an instrument for recording changes of a value.
+	UpDownCounter(name string, opts ...instrument.Option) (UpDownCounter, error)
+
+	// Gauge creates an instrument for recording the current value.
+	Gauge(name string, opts ...instrument.Option) (Gauge, error)
+}
+
+// Counter is an instrument that records increasing values.
+type Counter interface {
+	// Observe records the state of the instrument.
+	//
+	// It is only valid to call this within a callback. If called outside of the
+	// registered callback it should have no effect on the instrument, and an
+	// error will be reported via the error handeling
+	Observe(ctx context.Context, x int64, attrs ...attribute.KeyValue)
+
+	instrument.Asynchronous
+}
+
+// UpDownCounter is an instrument that records increasing or decresing values.
+type UpDownCounter interface {
+	// Observe records the state of the instrument.
+	//
+	// It is only valid to call this within a callback. If called outside of the
+	// registered callback it should have no effect on the instrument, and an
+	// error will be reported via the error handeling
+	Observe(ctx context.Context, x int64, attrs ...attribute.KeyValue)
+
+	instrument.Asynchronous
+}
+
+// Gauge is an instrument that records independent readings.
+type Gauge interface {
+	// Observe records the state of the instrument.
+	//
+	// It is only valid to call this within a callback. If called outside of the
+	// registered callback it should have no effect on the instrument, and an
+	// error will be reported via the error handeling
+	Observe(ctx context.Context, x int64, attrs ...attribute.KeyValue)
+
+	instrument.Asynchronous
+}

metric/instrument/config.go

@@ -0,0 +1,70 @@
+// 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 "go.opentelemetry.io/otel/metric/unit"
+
+// Config contains options for metric instrument descriptors.
+type Config struct {
+	description string
+	unit        unit.Unit
+}
+
+// Description describes the instrument in human-readable terms.
+func (cfg Config) Description() string {
+	return cfg.description
+}
+
+// Unit describes the measurement unit for a instrument.
+func (cfg Config) Unit() unit.Unit {
+	return cfg.unit
+}
+
+// Option is an interface for applying metric instrument options.
+type Option interface {
+	// ApplyMeter is used to set a Option value of a
+	// Config.
+	applyInstrument(*Config)
+}
+
+// NewConfig creates a new Config
+// and applies all the given options.
+func NewConfig(opts ...Option) Config {
+	var config Config
+	for _, o := range opts {
+		o.applyInstrument(&config)
+	}
+	return config
+}
+
+type optionFunc func(*Config)
+
+func (fn optionFunc) applyInstrument(cfg *Config) {
+	fn(cfg)
+}
+
+// WithDescription applies provided description.
+func WithDescription(desc string) Option {
+	return optionFunc(func(cfg *Config) {
+		cfg.description = desc
+	})
+}
+
+// WithUnit applies provided unit.
+func WithUnit(unit unit.Unit) Option {
+	return optionFunc(func(cfg *Config) {
+		cfg.unit = unit
+	})
+}