UDP-receiver - improve high-scale performance by skipping usage of decoder when nop encoding is defined

.chloggen/pkg-stanza-input-udp-dont-call-decode-on-nop.yaml

@@ -0,0 +1,27 @@
+# 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. filelogreceiver)
+component: pkg/stanza
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Improve performance by not calling decode when nop encoding is defined
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [28899]
+
+# (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:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# 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: []

pkg/stanza/operator/input/udp/udp.go

@@ -314,10 +314,14 @@ func truncateMaxLog(data []byte) (token []byte) {
 }
 
 func (u *Input) handleMessage(ctx context.Context, remoteAddr net.Addr, dec *decode.Decoder, log []byte) {
-	decoded, err := dec.Decode(log)
-	if err != nil {
-		u.Errorw("Failed to decode data", zap.Error(err))
-		return
+	decoded := log
+	if u.encoding != encoding.Nop {
+		var err error
+		decoded, err = dec.Decode(log)
+		if err != nil {
+			u.Errorw("Failed to decode data", zap.Error(err))
+			return
+		}
 	}
 
 	entry, err := u.NewEntry(string(decoded))