[component] Make InstanceID immutable

.chloggen/immutable-instance-id.yaml

@@ -0,0 +1,25 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: 'enhancement'
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: componentstatus
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Make componentstatus.InstanceID immutable.
+
+# One or more tracking issues or pull requests related to the change
+issues: [10494]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

component/componentstatus/instance.go

@@ -3,14 +3,89 @@
 
 package componentstatus // import "go.opentelemetry.io/collector/component/componentstatus"
 
-import "go.opentelemetry.io/collector/component"
+import (
+	"slices"
+	"sort"
+	"strings"
+
+	"go.opentelemetry.io/collector/component"
+)
 
 // InstanceID uniquely identifies a component instance
 //
 // TODO: consider moving this struct to a new package/module like `extension/statuswatcher`
 // https://github.com/open-telemetry/opentelemetry-collector/issues/10764
+// pipelineDelim is the delimiter for internal representation of pipeline
+// component IDs.
+const pipelineDelim = byte(0x20)
+
+// InstanceID uniquely identifies a component instance.
 type InstanceID struct {
-	ID          component.ID
-	Kind        component.Kind
-	PipelineIDs map[component.ID]struct{}
+	componentID component.ID
+	kind        component.Kind
+	pipelineIDs string // IDs encoded as a string so InstanceID is Comparable.
+}
+
+// NewInstanceID returns an ID that uniquely identifies a component.
+func NewInstanceID(componentID component.ID, kind component.Kind, pipelineIDs ...component.ID) *InstanceID {
+	instanceID := &InstanceID{
+		componentID: componentID,
+		kind:        kind,
+	}
+	instanceID.addPipelines(pipelineIDs)
+	return instanceID
+}
+
+// ComponentID returns the ComponentID associated with this instance.
+func (id *InstanceID) ComponentID() component.ID {
+	return id.componentID
+}
+
+// Kind returns the component Kind associated with this instance.
+func (id *InstanceID) Kind() component.Kind {
+	return id.kind
+}
+
+// AllPipelineIDs calls f for each pipeline this instance is associated with. If
+// f returns false it will stop iteration.
+func (id *InstanceID) AllPipelineIDs(f func(component.ID) bool) {
+	var bs []byte
+	for _, b := range []byte(id.pipelineIDs) {
+		if b != pipelineDelim {
+			bs = append(bs, b)
+			continue
+		}
+		pipelineID := component.ID{}
+		err := pipelineID.UnmarshalText(bs)
+		bs = bs[:0]
+		if err != nil {
+			continue
+		}
+		if !f(pipelineID) {
+			break
+		}
+	}
+}
+
+// WithPipelines returns a new InstanceID updated to include the given
+// pipelineIDs.
+func (id *InstanceID) WithPipelines(pipelineIDs ...component.ID) *InstanceID {
+	instanceID := &InstanceID{
+		componentID: id.componentID,
+		kind:        id.kind,
+		pipelineIDs: id.pipelineIDs,
+	}
+	instanceID.addPipelines(pipelineIDs)
+	return instanceID
+}
+
+func (id *InstanceID) addPipelines(pipelineIDs []component.ID) {
+	delim := string(pipelineDelim)
+	strIDs := strings.Split(id.pipelineIDs, delim)
+	for _, pID := range pipelineIDs {
+		strIDs = append(strIDs, pID.String())
+	}
+	sort.Strings(strIDs)
+	strIDs = slices.Compact(strIDs)
+	id.pipelineIDs = strings.Join(strIDs, delim) + delim
 }

component/componentstatus/instance_test.go

@@ -0,0 +1,94 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package componentstatus
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"go.opentelemetry.io/collector/component"
+)
+
+func TestInstanceID(t *testing.T) {
+	traces := component.MustNewID("traces")
+	tracesA := component.MustNewIDWithName("traces", "a")
+	tracesB := component.MustNewIDWithName("traces", "b")
+	tracesC := component.MustNewIDWithName("traces", "c")
+
+	idTracesA := NewInstanceID(traces, component.KindReceiver, tracesA)
+	idTracesAll := NewInstanceID(traces, component.KindReceiver, tracesA, tracesB, tracesC)
+	assert.NotEqual(t, idTracesA, idTracesAll)
+
+	assertHasPipelines := func(t *testing.T, instanceID *InstanceID, expectedPipelineIDs []component.ID) {
+		var pipelineIDs []component.ID
+		instanceID.AllPipelineIDs(func(id component.ID) bool {
+			pipelineIDs = append(pipelineIDs, id)
+			return true
+		})
+		assert.Equal(t, expectedPipelineIDs, pipelineIDs)
+	}
+
+	for _, tc := range []struct {
+		name        string
+		id1         *InstanceID
+		id2         *InstanceID
+		pipelineIDs []component.ID
+	}{
+		{
+			name:        "equal instances",
+			id1:         idTracesA,
+			id2:         NewInstanceID(traces, component.KindReceiver, tracesA),
+			pipelineIDs: []component.ID{tracesA},
+		},
+		{
+			name:        "equal instances - out of order",
+			id1:         idTracesAll,
+			id2:         NewInstanceID(traces, component.KindReceiver, tracesC, tracesB, tracesA),
+			pipelineIDs: []component.ID{tracesA, tracesB, tracesC},
+		},
+		{
+			name:        "with pipelines",
+			id1:         idTracesAll,
+			id2:         idTracesA.WithPipelines(tracesB, tracesC),
+			pipelineIDs: []component.ID{tracesA, tracesB, tracesC},
+		},
+		{
+			name:        "with pipelines - out of order",
+			id1:         idTracesAll,
+			id2:         idTracesA.WithPipelines(tracesC, tracesB),
+			pipelineIDs: []component.ID{tracesA, tracesB, tracesC},
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			assert.Equal(t, tc.id1, tc.id2)
+			assertHasPipelines(t, tc.id1, tc.pipelineIDs)
+			assertHasPipelines(t, tc.id2, tc.pipelineIDs)
+		})
+	}
+}
+
+func TestAllPipelineIDs(t *testing.T) {
+	instanceID := NewInstanceID(
+		component.MustNewID("traces"),
+		component.KindReceiver,
+		component.MustNewIDWithName("traces", "a"),
+		component.MustNewIDWithName("traces", "b"),
+		component.MustNewIDWithName("traces", "c"),
+	)
+
+	count := 0
+	instanceID.AllPipelineIDs(func(id component.ID) bool {
+		count++
+		return true
+	})
+	assert.Equal(t, 3, count)
+
+	count = 0
+	instanceID.AllPipelineIDs(func(id component.ID) bool {
+		count++
+		return false
+	})
+	assert.Equal(t, 1, count)
+
+}

internal/e2e/status_test.go

@@ -105,7 +105,7 @@ func Test_ComponentStatusReporting_SharedInstance(t *testing.T) {
 	assert.Equal(t, 5, len(eventsReceived))
 
 	for instanceID, events := range eventsReceived {
-		if instanceID.ID == component.NewID(component.MustNewType("test")) {
+		if instanceID.ComponentID() == component.NewID(component.MustNewType("test")) {
 			for i, e := range events {
 				if i == 0 {
 					assert.Equal(t, componentstatus.StatusStarting, e.Status())

otelcol/collector_test.go

@@ -149,7 +149,7 @@ func TestComponentStatusWatcher(t *testing.T) {
 	changedComponents := map[*componentstatus.InstanceID][]componentstatus.Status{}
 	var mux sync.Mutex
 	onStatusChanged := func(source *componentstatus.InstanceID, event *componentstatus.Event) {
-		if source.ID.Type() != unhealthyProcessorFactory.Type() {
+		if source.ComponentID().Type() != unhealthyProcessorFactory.Type() {
 			return
 		}
 		mux.Lock()
@@ -200,7 +200,7 @@ func TestComponentStatusWatcher(t *testing.T) {
 
 		for k, v := range changedComponents {
 			// All processors must report a status change with the same ID
-			assert.EqualValues(t, component.NewID(unhealthyProcessorFactory.Type()), k.ID)
+			assert.EqualValues(t, component.NewID(unhealthyProcessorFactory.Type()), k.ComponentID())
 			// And all must have a valid startup sequence
 			assert.Equal(t, startupStatuses(v), v)
 		}

service/extensions/extensions.go

@@ -198,10 +198,7 @@ func New(ctx context.Context, set Settings, cfg Config, options ...Option) (*Ext
 	}
 
 	for _, extID := range cfg {
-		instanceID := &componentstatus.InstanceID{
-			ID:   extID,
-			Kind: component.KindExtension,
-		}
+		instanceID := componentstatus.NewInstanceID(extID, component.KindExtension)
 		extSet := extension.Settings{
 			ID:                extID,
 			TelemetrySettings: set.Telemetry,

service/internal/graph/graph.go

@@ -197,67 +197,51 @@ func (g *Graph) createNodes(set Settings) error {
 func (g *Graph) createReceiver(pipelineID, recvID component.ID) *receiverNode {
 	rcvrNode := newReceiverNode(pipelineID.Type(), recvID)
 	if node := g.componentGraph.Node(rcvrNode.ID()); node != nil {
-		g.instanceIDs[node.ID()].PipelineIDs[pipelineID] = struct{}{}
+		instanceID := g.instanceIDs[node.ID()]
+		g.instanceIDs[node.ID()] = instanceID.WithPipelines(pipelineID)
 		return node.(*receiverNode)
 	}
 	g.componentGraph.AddNode(rcvrNode)
-	g.instanceIDs[rcvrNode.ID()] = &componentstatus.InstanceID{
-		ID:   recvID,
-		Kind: component.KindReceiver,
-		PipelineIDs: map[component.ID]struct{}{
-			pipelineID: {},
-		},
-	}
+	g.instanceIDs[rcvrNode.ID()] = componentstatus.NewInstanceID(
+		recvID, component.KindReceiver, pipelineID,
+	)
 	return rcvrNode
 }
 
 func (g *Graph) createProcessor(pipelineID, procID component.ID) *processorNode {
 	procNode := newProcessorNode(pipelineID, procID)
 	g.componentGraph.AddNode(procNode)
-	g.instanceIDs[procNode.ID()] = &componentstatus.InstanceID{
-		ID:   procID,
-		Kind: component.KindProcessor,
-		PipelineIDs: map[component.ID]struct{}{
-			pipelineID: {},
-		},
-	}
+	g.instanceIDs[procNode.ID()] = componentstatus.NewInstanceID(
+		procID, component.KindProcessor, pipelineID,
+	)
 	return procNode
 }
 
 func (g *Graph) createExporter(pipelineID, exprID component.ID) *exporterNode {
 	expNode := newExporterNode(pipelineID.Type(), exprID)
 	if node := g.componentGraph.Node(expNode.ID()); node != nil {
-		g.instanceIDs[expNode.ID()].PipelineIDs[pipelineID] = struct{}{}
+		instanceID := g.instanceIDs[expNode.ID()]
+		g.instanceIDs[expNode.ID()] = instanceID.WithPipelines(pipelineID)
 		return node.(*exporterNode)
 	}
 	g.componentGraph.AddNode(expNode)
-	g.instanceIDs[expNode.ID()] = &componentstatus.InstanceID{
-		ID:   expNode.componentID,
-		Kind: component.KindExporter,
-		PipelineIDs: map[component.ID]struct{}{
-			pipelineID: {},
-		},
-	}
+	g.instanceIDs[expNode.ID()] = componentstatus.NewInstanceID(
+		expNode.componentID, component.KindExporter, pipelineID,
+	)
 	return expNode
 }
 
 func (g *Graph) createConnector(exprPipelineID, rcvrPipelineID, connID component.ID) *connectorNode {
 	connNode := newConnectorNode(exprPipelineID.Type(), rcvrPipelineID.Type(), connID)
 	if node := g.componentGraph.Node(connNode.ID()); node != nil {
 		instanceID := g.instanceIDs[connNode.ID()]
-		instanceID.PipelineIDs[exprPipelineID] = struct{}{}
-		instanceID.PipelineIDs[rcvrPipelineID] = struct{}{}
+		g.instanceIDs[connNode.ID()] = instanceID.WithPipelines(exprPipelineID, rcvrPipelineID)
 		return node.(*connectorNode)
 	}
 	g.componentGraph.AddNode(connNode)
-	g.instanceIDs[connNode.ID()] = &componentstatus.InstanceID{
-		ID:   connNode.componentID,
-		Kind: component.KindConnector,
-		PipelineIDs: map[component.ID]struct{}{
-			exprPipelineID: {},
-			rcvrPipelineID: {},
-		},
-	}
+	g.instanceIDs[connNode.ID()] = componentstatus.NewInstanceID(
+		connNode.componentID, component.KindConnector, exprPipelineID, rcvrPipelineID,
+	)
 	return connNode
 }
 
@@ -429,8 +413,8 @@ func (g *Graph) StartAll(ctx context.Context, host *Host) error {
 			g.telemetry.Logger.WithOptions(zap.AddStacktrace(zap.DPanicLevel)).
 				Error("Failed to start component",
 					zap.Error(compErr),
-					zap.String("type", instanceID.Kind.String()),
-					zap.String("id", instanceID.ID.String()),
+					zap.String("type", instanceID.Kind().String()),
+					zap.String("id", instanceID.ComponentID().String()),
 				)
 			return compErr
 		}

service/internal/graph/graph_test.go

@@ -2260,12 +2260,12 @@ func TestStatusReportedOnStartupShutdown(t *testing.T) {
 	eSdErr := &testNode{id: component.MustNewIDWithName("e_sd_err", "1"), shutdownErr: assert.AnError}
 
 	instanceIDs := map[*testNode]*componentstatus.InstanceID{
-		rNoErr: {ID: rNoErr.id},
-		rStErr: {ID: rStErr.id},
-		rSdErr: {ID: rSdErr.id},
-		eNoErr: {ID: eNoErr.id},
-		eStErr: {ID: eStErr.id},
-		eSdErr: {ID: eSdErr.id},
+		rNoErr: componentstatus.NewInstanceID(rNoErr.id, component.KindReceiver),
+		rStErr: componentstatus.NewInstanceID(rStErr.id, component.KindReceiver),
+		rSdErr: componentstatus.NewInstanceID(rSdErr.id, component.KindReceiver),
+		eNoErr: componentstatus.NewInstanceID(eNoErr.id, component.KindExporter),
+		eStErr: componentstatus.NewInstanceID(eStErr.id, component.KindExporter),
+		eSdErr: componentstatus.NewInstanceID(eSdErr.id, component.KindExporter),
 	}
 
 	// compare two maps of status events ignoring timestamp