Repository: grpc/grpc-go
File: experimental/stats/metrics.go (Go)

Code before:
 *
 * 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 stats contains experimental metrics/stats API's.
package stats

import (
	"google.golang.org/grpc/internal"
	"google.golang.org/grpc/stats"
)

// MetricsRecorder records on metrics derived from metric registry.
type MetricsRecorder interface {
	// RecordInt64Count records the measurement alongside labels on the int
	// count associated with the provided handle.
	RecordInt64Count(handle *Int64CountHandle, incr int64, labels ...string)
	// RecordFloat64Count records the measurement alongside labels on the float
	// count associated with the provided handle.
	RecordFloat64Count(handle *Float64CountHandle, incr float64, labels ...string)
	// RecordInt64Histo records the measurement alongside labels on the int
	// histo associated with the provided handle.
	RecordInt64Histo(handle *Int64HistoHandle, incr int64, labels ...string)
	// RecordFloat64Histo records the measurement alongside labels on the float
	// histo associated with the provided handle.
	RecordFloat64Histo(handle *Float64HistoHandle, incr float64, labels ...string)
	// RecordInt64Gauge records the measurement alongside labels on the int
	// gauge associated with the provided handle.
	RecordInt64Gauge(handle *Int64GaugeHandle, incr int64, labels ...string)
	// RecordInt64UpDownCounter records the measurement alongside labels on the int
	// count associated with the provided handle.
	RecordInt64UpDownCount(handle *Int64UpDownCountHandle, incr int64, labels ...string)
	// RegisterAsyncReporter registers a reporter to produce metric values for
	// only the listed descriptors. The returned function must be called when
	// the metrics are no longer needed, which will remove the reporter. The
	// returned method needs to be idempotent and concurrent safe.
	RegisterAsyncReporter(reporter AsyncMetricReporter, descriptors ...AsyncMetric) func()

	// EnforceMetricsRecorderEmbedding is included to force implementers to embed
	// another implementation of this interface, allowing gRPC to add methods

Review comment (suggestion):
Can you mention in the godoc that implementors must embed `UnimplementedMetricsRecorder`? It may not be obvious to users.

Code after:
 *
 * 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 stats contains experimental metrics/stats API's.
package stats

import (
	"google.golang.org/grpc/internal"
	"google.golang.org/grpc/stats"
)

// MetricsRecorder records on metrics derived from metric registry.
// Implementors must embed UnimplementedMetricsRecorder.
type MetricsRecorder interface {
	// RecordInt64Count records the measurement alongside labels on the int
	// count associated with the provided handle.
	RecordInt64Count(handle *Int64CountHandle, incr int64, labels ...string)
	// RecordFloat64Count records the measurement alongside labels on the float
	// count associated with the provided handle.
	RecordFloat64Count(handle *Float64CountHandle, incr float64, labels ...string)
	// RecordInt64Histo records the measurement alongside labels on the int
	// histo associated with the provided handle.
	RecordInt64Histo(handle *Int64HistoHandle, incr int64, labels ...string)
	// RecordFloat64Histo records the measurement alongside labels on the float
	// histo associated with the provided handle.
	RecordFloat64Histo(handle *Float64HistoHandle, incr float64, labels ...string)
	// RecordInt64Gauge records the measurement alongside labels on the int
	// gauge associated with the provided handle.
	RecordInt64Gauge(handle *Int64GaugeHandle, incr int64, labels ...string)
	// RecordInt64UpDownCounter records the measurement alongside labels on the int
	// count associated with the provided handle.
	RecordInt64UpDownCount(handle *Int64UpDownCountHandle, incr int64, labels ...string)
	// RegisterAsyncReporter registers a reporter to produce metric values for
	// only the listed descriptors. The returned function must be called when
	// the metrics are no longer needed, which will remove the reporter. The
	// returned method needs to be idempotent and concurrent safe.
	RegisterAsyncReporter(reporter AsyncMetricReporter, descriptors ...AsyncMetric) func()

	// EnforceMetricsRecorderEmbedding is included to force implementers to embed