[processor/deltatocumulative]: initial structure (#30706)

_tracking issue:
https://github.com/open-telemetry/opentelemetry-collector-contrib/issues/30705_

Adds basic component structure without any actual functionality as
advised by `CONTRIBUTING.md`.

.github/CODEOWNERS

@@ -151,6 +151,7 @@ pkg/winperfcounters/                                     @open-telemetry/collect
 processor/attributesprocessor/                           @open-telemetry/collector-contrib-approvers @boostchicken
 processor/cumulativetodeltaprocessor/                    @open-telemetry/collector-contrib-approvers @TylerHelmuth
 processor/datadogprocessor/                              @open-telemetry/collector-contrib-approvers @mx-psi @dineshg13
+processor/deltatocumulativeprocessor/                    @open-telemetry/collector-contrib-approvers @sh0rez
 processor/deltatorateprocessor/                          @open-telemetry/collector-contrib-approvers @Aneurysm9
 processor/filterprocessor/                               @open-telemetry/collector-contrib-approvers @TylerHelmuth @boostchicken
 processor/groupbyattrsprocessor/                         @open-telemetry/collector-contrib-approvers @rnishtala-sumo

.github/ISSUE_TEMPLATE/bug_report.yaml

@@ -147,6 +147,7 @@ body:
       - processor/attributes
       - processor/cumulativetodelta
       - processor/datadog
+      - processor/deltatocumulative
       - processor/deltatorate
       - processor/filter
       - processor/groupbyattrs

.github/ISSUE_TEMPLATE/feature_request.yaml

@@ -141,6 +141,7 @@ body:
       - processor/attributes
       - processor/cumulativetodelta
       - processor/datadog
+      - processor/deltatocumulative
       - processor/deltatorate
       - processor/filter
       - processor/groupbyattrs

.github/ISSUE_TEMPLATE/other.yaml

@@ -141,6 +141,7 @@ body:
       - processor/attributes
       - processor/cumulativetodelta
       - processor/datadog
+      - processor/deltatocumulative
       - processor/deltatorate
       - processor/filter
       - processor/groupbyattrs

processor/deltatocumulativeprocessor/Makefile

@@ -0,0 +1 @@
+include ../../Makefile.Common

processor/deltatocumulativeprocessor/README.md

@@ -0,0 +1,29 @@
+# Delta to cumulative processor
+
+<!-- status autogenerated section -->
+| Status        |           |
+| ------------- |-----------|
+| Stability     | [development]: metrics   |
+| Distributions | [contrib] |
+| Warnings      | [Statefulness](#warnings) |
+| Issues        | [![Open issues](https://img.shields.io/github/issues-search/open-telemetry/opentelemetry-collector-contrib?query=is%3Aissue%20is%3Aopen%20label%3Aprocessor%2Fdeltatocumulative%20&label=open&color=orange&logo=opentelemetry)](https://github.com/open-telemetry/opentelemetry-collector-contrib/issues?q=is%3Aopen+is%3Aissue+label%3Aprocessor%2Fdeltatocumulative) [![Closed issues](https://img.shields.io/github/issues-search/open-telemetry/opentelemetry-collector-contrib?query=is%3Aissue%20is%3Aclosed%20label%3Aprocessor%2Fdeltatocumulative%20&label=closed&color=blue&logo=opentelemetry)](https://github.com/open-telemetry/opentelemetry-collector-contrib/issues?q=is%3Aclosed+is%3Aissue+label%3Aprocessor%2Fdeltatocumulative) |
+| [Code Owners](https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/CONTRIBUTING.md#becoming-a-code-owner)    | [@sh0rez](https://www.github.com/sh0rez) |
+
+[development]: https://github.com/open-telemetry/opentelemetry-collector#development
+[contrib]: https://github.com/open-telemetry/opentelemetry-collector-releases/tree/main/distributions/otelcol-contrib
+<!-- end autogenerated section -->
+
+
+## Description
+
+The delta to cumulative processor (`deltatocumulativeprocessor`) converts
+metrics from delta temporality to cumulative, by accumulating samples in memory.
+
+## Configuration
+
+``` yaml
+processors:
+    deltatocumulative:
+```
+
+There is no further configuration required. All delta samples are converted to cumulative.

processor/deltatocumulativeprocessor/config.go

@@ -0,0 +1,16 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package deltatocumulativeprocessor // import "github.com/open-telemetry/opentelemetry-collector-contrib/processor/deltatocumulativeprocessor"
+
+import (
+	"go.opentelemetry.io/collector/component"
+)
+
+var _ component.ConfigValidator = (*Config)(nil)
+
+type Config struct{}
+
+func (c *Config) Validate() error {
+	return nil
+}

processor/deltatocumulativeprocessor/doc.go

@@ -0,0 +1,8 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+//go:generate mdatagen metadata.yaml
+
+// package deltatocumulativeprocessor implements a processor which
+// converts metrics from delta temporality to cumulative.
+package deltatocumulativeprocessor // import "github.com/open-telemetry/opentelemetry-collector-contrib/processor/deltatocumulativeprocessor"

processor/deltatocumulativeprocessor/factory.go

@@ -0,0 +1,36 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package deltatocumulativeprocessor // import "github.com/open-telemetry/opentelemetry-collector-contrib/processor/deltatocumulativeprocessor"
+
+import (
+	"context"
+	"fmt"
+
+	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/consumer"
+	"go.opentelemetry.io/collector/processor"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/processor/deltatocumulativeprocessor/internal/metadata"
+)
+
+func NewFactory() processor.Factory {
+	return processor.NewFactory(
+		metadata.Type,
+		createDefaultConfig,
+		processor.WithMetrics(createMetricsProcessor, metadata.MetricsStability),
+	)
+}
+
+func createDefaultConfig() component.Config {
+	return &Config{}
+}
+
+func createMetricsProcessor(_ context.Context, set processor.CreateSettings, cfg component.Config, next consumer.Metrics) (processor.Metrics, error) {
+	pcfg, ok := cfg.(*Config)
+	if !ok {
+		return nil, fmt.Errorf("configuration parsing error")
+	}
+
+	return newProcessor(pcfg, set.Logger, next), nil
+}

processor/deltatocumulativeprocessor/go.mod

@@ -0,0 +1,37 @@
+module github.com/open-telemetry/opentelemetry-collector-contrib/processor/deltatocumulativeprocessor
+
+go 1.20
+
+require (
+	go.opentelemetry.io/collector/component v0.93.1-0.20240125183026-3cacd40b27e8
+	go.opentelemetry.io/collector/consumer v0.93.1-0.20240125183026-3cacd40b27e8
+	go.opentelemetry.io/collector/pdata v1.0.2-0.20240125183026-3cacd40b27e8
+	go.opentelemetry.io/collector/processor v0.93.1-0.20240125183026-3cacd40b27e8
+	go.opentelemetry.io/otel/metric v1.22.0
+	go.opentelemetry.io/otel/trace v1.22.0
+	go.uber.org/zap v1.26.0
+)
+
+require (
+	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
+	github.com/json-iterator/go v1.1.12 // indirect
+	github.com/knadh/koanf/maps v0.1.1 // indirect
+	github.com/knadh/koanf/providers/confmap v0.1.0 // indirect
+	github.com/knadh/koanf/v2 v2.0.1 // indirect
+	github.com/mitchellh/copystructure v1.2.0 // indirect
+	github.com/mitchellh/mapstructure v1.5.1-0.20231216201459-8508981c8b6c // indirect
+	github.com/mitchellh/reflectwalk v1.0.2 // indirect
+	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
+	github.com/modern-go/reflect2 v1.0.2 // indirect
+	go.opentelemetry.io/collector/config/configtelemetry v0.93.1-0.20240125183026-3cacd40b27e8 // indirect
+	go.opentelemetry.io/collector/confmap v0.93.1-0.20240125183026-3cacd40b27e8 // indirect
+	go.opentelemetry.io/otel v1.22.0 // indirect
+	go.uber.org/multierr v1.11.0 // indirect
+	golang.org/x/net v0.20.0 // indirect
+	golang.org/x/sys v0.16.0 // indirect
+	golang.org/x/text v0.14.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20231002182017-d307bd883b97 // indirect
+	google.golang.org/grpc v1.60.1 // indirect
+	google.golang.org/protobuf v1.32.0 // indirect
+)

processor/deltatocumulativeprocessor/metadata.yaml

@@ -0,0 +1,10 @@
+type: deltatocumulative
+
+status:
+  class: processor
+  stability:
+    development: [metrics]
+  distributions: [contrib]
+  warnings: [Statefulness]
+  codeowners:
+    active: [sh0rez]