[chore][pkg/stanza] Cleanup retain operator files (#32068)

Contributes to #32058

pkg/stanza/operator/transformer/retain/retain.go → pkg/stanza/operator/transformer/retain/config.go

@@ -4,7 +4,6 @@
 package retain // import "github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/operator/transformer/retain"
 
 import (
-	"context"
 	"fmt"
 	"strings"
 
@@ -68,48 +67,3 @@ func (c Config) Build(logger *zap.SugaredLogger) (operator.Operator, error) {
 	}
 	return retainOp, nil
 }
-
-// Transformer keeps the given fields and deletes the rest.
-type Transformer struct {
-	helper.TransformerOperator
-	Fields             []entry.Field
-	AllBodyFields      bool
-	AllAttributeFields bool
-	AllResourceFields  bool
-}
-
-// Process will process an entry with a retain transformation.
-func (p *Transformer) Process(ctx context.Context, entry *entry.Entry) error {
-	return p.ProcessWith(ctx, entry, p.Transform)
-}
-
-// Transform will apply the retain operation to an entry
-func (p *Transformer) Transform(e *entry.Entry) error {
-	newEntry := entry.New()
-	newEntry.ObservedTimestamp = e.ObservedTimestamp
-	newEntry.Timestamp = e.Timestamp
-
-	if !p.AllResourceFields {
-		newEntry.Resource = e.Resource
-	}
-	if !p.AllAttributeFields {
-		newEntry.Attributes = e.Attributes
-	}
-	if !p.AllBodyFields {
-		newEntry.Body = e.Body
-	}
-
-	for _, field := range p.Fields {
-		val, ok := e.Get(field)
-		if !ok {
-			continue
-		}
-		err := newEntry.Set(field, val)
-		if err != nil {
-			return err
-		}
-	}
-
-	*e = *newEntry
-	return nil
-}

pkg/stanza/operator/transformer/retain/transformer.go

@@ -0,0 +1,56 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package retain // import "github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/operator/transformer/retain"
+
+import (
+	"context"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/entry"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/operator/helper"
+)
+
+// Transformer keeps the given fields and deletes the rest.
+type Transformer struct {
+	helper.TransformerOperator
+	Fields             []entry.Field
+	AllBodyFields      bool
+	AllAttributeFields bool
+	AllResourceFields  bool
+}
+
+// Process will process an entry with a retain transformation.
+func (t *Transformer) Process(ctx context.Context, entry *entry.Entry) error {
+	return t.ProcessWith(ctx, entry, t.Transform)
+}
+
+// Transform will apply the retain operation to an entry
+func (t *Transformer) Transform(e *entry.Entry) error {
+	newEntry := entry.New()
+	newEntry.ObservedTimestamp = e.ObservedTimestamp
+	newEntry.Timestamp = e.Timestamp
+
+	if !t.AllResourceFields {
+		newEntry.Resource = e.Resource
+	}
+	if !t.AllAttributeFields {
+		newEntry.Attributes = e.Attributes
+	}
+	if !t.AllBodyFields {
+		newEntry.Body = e.Body
+	}
+
+	for _, field := range t.Fields {
+		val, ok := e.Get(field)
+		if !ok {
+			continue
+		}
+		err := newEntry.Set(field, val)
+		if err != nil {
+			return err
+		}
+	}
+
+	*e = *newEntry
+	return nil
+}