[interna/sharedcomponent] Use a ring buffer to restrict remembered status count

.chloggen/fix-sharedcomponent-memory-issue.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: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: internal/sharedcomponent
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Fixed bug where sharedcomponent would use too much memory remembering all the previously reported statuses
+
+# One or more tracking issues or pull requests related to the change
+issues: [11826]
+
+# (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: []

internal/sharedcomponent/sharedcomponent.go

@@ -7,8 +7,8 @@
 package sharedcomponent // import "go.opentelemetry.io/collector/internal/sharedcomponent"
 
 import (
+	"container/ring"
 	"context"
-	"slices"
 	"sync"
 
 	"go.opentelemetry.io/collector/component"
@@ -77,7 +77,7 @@
 			c.hostWrapper = &hostWrapper{
 				host:           host,
 				sources:        make([]componentstatus.Reporter, 0),
-				previousEvents: make([]*componentstatus.Event, 0),
+				previousEvents: ring.New(5),
 			}
 			statusReporter, isStatusReporter := host.(componentstatus.Reporter)
 			if isStatusReporter {
@@ -108,19 +108,30 @@
 type hostWrapper struct {
 	host           component.Host
 	sources        []componentstatus.Reporter
-	previousEvents []*componentstatus.Event
+	previousEvents *ring.Ring
 	lock           sync.Mutex
 }
 
 func (h *hostWrapper) GetExtensions() map[component.ID]component.Component {
 	return h.host.GetExtensions()
 }
 
+func (h *hostWrapper) hasEvent(e *componentstatus.Event) bool {
+	hasEvent := false
+	h.previousEvents.Do(func(a any) {
+		if previousEvent, ok := a.(*componentstatus.Event); ok && previousEvent == e {
+			hasEvent = true
+		}
+	})
+	return hasEvent
+}
+
 func (h *hostWrapper) Report(e *componentstatus.Event) {
 	// Only remember an event if it will be emitted and it has not been sent already.
 	h.lock.Lock()
-	if len(h.sources) > 0 && !slices.Contains(h.previousEvents, e) {
-		h.previousEvents = append(h.previousEvents, e)
+	if len(h.sources) > 0 && !h.hasEvent(e) {
+		h.previousEvents.Value = e
+		h.previousEvents = h.previousEvents.Next()
 	}
 	h.lock.Unlock()
 
@@ -133,9 +144,11 @@
 
 func (h *hostWrapper) addSource(s componentstatus.Reporter) {
 	h.lock.Lock()
-	for _, e := range h.previousEvents {
-		s.Report(e)
-	}
+	h.previousEvents.Do(func(a any) {
+		if e, ok := a.(*componentstatus.Event); ok {
+			s.Report(e)
+		}
+	})
 	h.lock.Unlock()
 
 	h.lock.Lock()