Tidy up consumer/consumererror package. (#2768)

* Tidy up `consumer/consumererror` package.

* Updated docblocks for grammar and consistency
* Added `IsPartial()` predicate to match `IsPermanent()`
* Ensured tests for `PartialError` test the public interface

Remove `PartialError` and replace with individual signal error types

Refactor consumererror signal extraction to simplify exporterhelper request interface

* Rename consumererror signal error types to align with rest of codebase

* Rename `onPartialError` to `onError` in `exporterhelper.request` interface

* Provide conversion methods to consumererror signal error types.

This moves the accessors for signal data to methods on the individual error types
and provides As<Signal>() package functions that behave as targeted versions of
the errors.As() function.

* Avoid unnecessary allocation, fixup docs

CHANGELOG.md

@@ -2,6 +2,12 @@
 
 ## Unreleased
 
+## 🛑 Breaking changes 🛑
+
+- Refactored `consumererror` package (#2768)
+  - Eliminated `PartialError` type in favor of signal-specific types
+  - Renamed `CombineErrors` to `Combine`
+
 ## v0.23.0 Beta
 
 ## 🛑 Breaking changes 🛑

config/configcheck/configcheck.go

@@ -56,7 +56,7 @@ func ValidateConfigFromFactories(factories component.Factories) error {
 		}
 	}
 
-	return consumererror.CombineErrors(errs)
+	return consumererror.Combine(errs)
 }
 
 // ValidateConfig enforces that given configuration object is following the patterns
@@ -109,7 +109,7 @@ func validateConfigDataType(t reflect.Type) error {
 		// reflect.UnsafePointer.
 	}
 
-	if err := consumererror.CombineErrors(errs); err != nil {
+	if err := consumererror.Combine(errs); err != nil {
 		return fmt.Errorf(
 			"type %q from package %q has invalid config settings: %v",
 			t.Name(),

consumer/consumererror/combineerrors.go → consumer/consumererror/combine.go

@@ -19,8 +19,14 @@ import (
 	"strings"
 )
 
-// CombineErrors converts a list of errors into one error.
-func CombineErrors(errs []error) error {
+// Combine converts a list of errors into one error.
+//
+// If any of the errors in errs are Permanent then the returned
+// error will also be Permanent.
+//
+// Any signal data associated with an error from this package
+// will be discarded.
+func Combine(errs []error) error {
 	numErrors := len(errs)
 	if numErrors == 0 {
 		// No errors

consumer/consumererror/combineerrors_test.go → consumer/consumererror/combine_test.go

@@ -19,7 +19,7 @@ import (
 	"testing"
 )
 
-func TestCombineErrors(t *testing.T) {
+func TestCombine(t *testing.T) {
 	testCases := []struct {
 		errors            []error
 		expected          string
@@ -53,15 +53,15 @@ func TestCombineErrors(t *testing.T) {
 	}
 
 	for _, tc := range testCases {
-		got := CombineErrors(tc.errors)
+		got := Combine(tc.errors)
 		if (got == nil) != tc.expectNil {
-			t.Errorf("CombineErrors(%v) == nil? Got: %t. Want: %t", tc.errors, got == nil, tc.expectNil)
+			t.Errorf("Combine(%v) == nil? Got: %t. Want: %t", tc.errors, got == nil, tc.expectNil)
 		}
 		if got != nil && tc.expected != got.Error() {
-			t.Errorf("CombineErrors(%v) = %q. Want: %q", tc.errors, got, tc.expected)
+			t.Errorf("Combine(%v) = %q. Want: %q", tc.errors, got, tc.expected)
 		}
 		if tc.expectedPermanent && !IsPermanent(got) {
-			t.Errorf("CombineErrors(%v) = %q. Want: consumererror.permanent", tc.errors, got)
+			t.Errorf("Combine(%v) = %q. Want: consumererror.permanent", tc.errors, got)
 		}
 	}
 }

consumer/consumererror/permanenterror.go → consumer/consumererror/permanent.go

@@ -25,9 +25,6 @@ type permanent struct {
 	err error
 }
 
-// permanentError exists to test errors for "IsPermanent"
-var permanentError = &permanent{}
-
 // Permanent wraps an error to indicate that it is a permanent error, i.e.: an
 // error that will be always returned if its source receives the same inputs.
 func Permanent(err error) error {
@@ -42,8 +39,8 @@ func (p permanent) Error() string {
 // is used to indicate that a given error will always be returned in the case
 // that its sources receives the same input.
 func IsPermanent(err error) bool {
-	if err != nil {
-		return errors.As(err, permanentError)
+	if err == nil {
+		return false
 	}
-	return false
+	return errors.As(err, &permanent{})
 }

consumer/consumererror/signalerrors.go

@@ -0,0 +1,108 @@
+// 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 consumererror
+
+import (
+	"errors"
+
+	"go.opentelemetry.io/collector/consumer/pdata"
+)
+
+// Traces is an error that may carry associated Trace data for a subset of received data
+// that faiiled to be processed or sent.
+type Traces struct {
+	error
+	failed pdata.Traces
+}
+
+// NewTraces creates a Traces that can encapsulate received data that failed to be processed or sent.
+func NewTraces(err error, failed pdata.Traces) error {
+	return Traces{
+		error:  err,
+		failed: failed,
+	}
+}
+
+// AsTraces finds the first error in err's chain that can be assigned to target. If such an error is found
+// it is assigned to target and true is returned, otherwise false is returned.
+func AsTraces(err error, target *Traces) bool {
+	if err == nil {
+		return false
+	}
+	return errors.As(err, target)
+}
+
+// GetTraces returns failed traces from the associated error.
+func (err Traces) GetTraces() pdata.Traces {
+	return err.failed
+}
+
+// Logs is an error that may carry associated Log data for a subset of received data
+// that faiiled to be processed or sent.
+type Logs struct {
+	error
+	failed pdata.Logs
+}
+
+// NewLogs creates a Logs that can encapsulate received data that failed to be processed or sent.
+func NewLogs(err error, failed pdata.Logs) error {
+	return Logs{
+		error:  err,
+		failed: failed,
+	}
+}
+
+// AsLogs finds the first error in err's chain that can be assigned to target. If such an error is found
+// it is assigned to target and true is returned, otherwise false is returned.
+func AsLogs(err error, target *Logs) bool {
+	if err == nil {
+		return false
+	}
+	return errors.As(err, target)
+}
+
+// GetLogs returns failed logs from the associated error.
+func (err Logs) GetLogs() pdata.Logs {
+	return err.failed
+}
+
+// Metrics is an error that may carry associated Metrics data for a subset of received data
+// that faiiled to be processed or sent.
+type Metrics struct {
+	error
+	failed pdata.Metrics
+}
+
+// NewMetrics creates a Metrics that can encapsulate received data that failed to be processed or sent.
+func NewMetrics(err error, failed pdata.Metrics) error {
+	return Metrics{
+		error:  err,
+		failed: failed,
+	}
+}
+
+// AsMetrics finds the first error in err's chain that can be assigned to target. If such an error is found
+// it is assigned to target and true is returned, otherwise false is returned.
+func AsMetrics(err error, target *Metrics) bool {
+	if err == nil {
+		return false
+	}
+	return errors.As(err, target)
+}
+
+// GetMetrics returns failed metrics from the associated error.
+func (err Metrics) GetMetrics() pdata.Metrics {
+	return err.failed
+}

consumer/consumererror/partialerror_test.go → consumer/consumererror/signalerrors_test.go

@@ -23,26 +23,38 @@ import (
 	"go.opentelemetry.io/collector/internal/testdata"
 )
 
-func TestPartialError(t *testing.T) {
+func TestTraces(t *testing.T) {
 	td := testdata.GenerateTraceDataOneSpan()
 	err := fmt.Errorf("some error")
-	partialErr := PartialTracesError(err, td)
-	assert.Equal(t, err.Error(), partialErr.Error())
-	assert.Equal(t, td, partialErr.(PartialError).failed)
+	traceErr := NewTraces(err, td)
+	assert.Equal(t, err.Error(), traceErr.Error())
+	var target Traces
+	assert.False(t, AsTraces(nil, &target))
+	assert.False(t, AsTraces(err, &target))
+	assert.True(t, AsTraces(traceErr, &target))
+	assert.Equal(t, td, target.GetTraces())
 }
 
-func TestPartialErrorLogs(t *testing.T) {
+func TestLogs(t *testing.T) {
 	td := testdata.GenerateLogDataOneLog()
 	err := fmt.Errorf("some error")
-	partialErr := PartialLogsError(err, td)
-	assert.Equal(t, err.Error(), partialErr.Error())
-	assert.Equal(t, td, partialErr.(PartialError).failedLogs)
+	logsErr := NewLogs(err, td)
+	assert.Equal(t, err.Error(), logsErr.Error())
+	var target Logs
+	assert.False(t, AsLogs(nil, &target))
+	assert.False(t, AsLogs(err, &target))
+	assert.True(t, AsLogs(logsErr, &target))
+	assert.Equal(t, td, target.GetLogs())
 }
 
-func TestPartialErrorMetrics(t *testing.T) {
+func TestMetrics(t *testing.T) {
 	td := testdata.GenerateMetricsOneMetric()
 	err := fmt.Errorf("some error")
-	partialErr := PartialMetricsError(err, td)
-	assert.Equal(t, err.Error(), partialErr.Error())
-	assert.Equal(t, td, partialErr.(PartialError).failedMetrics)
+	metricErr := NewMetrics(err, td)
+	assert.Equal(t, err.Error(), metricErr.Error())
+	var target Metrics
+	assert.False(t, AsMetrics(nil, &target))
+	assert.False(t, AsMetrics(err, &target))
+	assert.True(t, AsMetrics(metricErr, &target))
+	assert.Equal(t, td, target.GetMetrics())
 }

consumer/fanoutconsumer/cloningconsumer.go

@@ -56,7 +56,7 @@ func (mfc metricsCloningConsumer) ConsumeMetrics(ctx context.Context, md pdata.M
 		}
 	}
 
-	return consumererror.CombineErrors(errs)
+	return consumererror.Combine(errs)
 }
 
 // NewTracesCloning wraps multiple traces consumers in a single one and clones the data
@@ -93,7 +93,7 @@ func (tfc tracesCloningConsumer) ConsumeTraces(ctx context.Context, td pdata.Tra
 		}
 	}
 
-	return consumererror.CombineErrors(errs)
+	return consumererror.Combine(errs)
 }
 
 // NewLogsCloning wraps multiple trace consumers in a single one and clones the data
@@ -130,5 +130,5 @@ func (lfc logsCloningConsumer) ConsumeLogs(ctx context.Context, ld pdata.Logs) e
 		}
 	}
 
-	return consumererror.CombineErrors(errs)
+	return consumererror.Combine(errs)
 }

consumer/fanoutconsumer/consumer.go

@@ -48,7 +48,7 @@ func (mfc metricsConsumer) ConsumeMetrics(ctx context.Context, md pdata.Metrics)
 			errs = append(errs, err)
 		}
 	}
-	return consumererror.CombineErrors(errs)
+	return consumererror.Combine(errs)
 }
 
 // NewTraces wraps multiple trace consumers in a single one.
@@ -72,7 +72,7 @@ func (tfc traceConsumer) ConsumeTraces(ctx context.Context, td pdata.Traces) err
 			errs = append(errs, err)
 		}
 	}
-	return consumererror.CombineErrors(errs)
+	return consumererror.Combine(errs)
 }
 
 // NewLogs wraps multiple log consumers in a single one.
@@ -96,5 +96,5 @@ func (lfc logsConsumer) ConsumeLogs(ctx context.Context, ld pdata.Logs) error {
 			errs = append(errs, err)
 		}
 	}
-	return consumererror.CombineErrors(errs)
+	return consumererror.Combine(errs)
 }

exporter/exporterhelper/common.go

@@ -23,7 +23,6 @@ import (
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/component/componenthelper"
 	"go.opentelemetry.io/collector/config/configmodels"
-	"go.opentelemetry.io/collector/consumer/consumererror"
 )
 
 // ComponentSettings for timeout. The timeout applies to individual attempts to send data to the backend.
@@ -46,8 +45,9 @@ type request interface {
 	// setContext updates the Context of the requests.
 	setContext(context.Context)
 	export(ctx context.Context) error
-	// Returns a new request that contains the items left to be sent.
-	onPartialError(consumererror.PartialError) request
+	// Returns a new request may contain the items left to be sent if some items failed to process and can be retried.
+	// Otherwise, it should return the original request.
+	onError(error) request
 	// Returns the count of spans/metric points or log records.
 	count() int
 }