Add pcommon.Map helper to add a key to the map if does not exists

Signed-off-by: Bogdan Drutu <[email protected]>

Author: bogdandrutu

.chloggen/get-or-put-empty.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: pdata
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add pcommon.Map helper to add a key to the map if does not exists
+
+# One or more tracking issues or pull requests related to the change
+issues: [14023]
+
+# (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: [api]

pdata/pcommon/map.go

@@ -121,6 +121,18 @@ func (m Map) PutEmpty(k string) Value {
 	return newValue(&(*m.getOrig())[len(*m.getOrig())-1].Value, m.getState())
 }
 
+// GetOrPutEmpty returns the Value associated with the key and true (loaded) if the key exists in the map,
+// otherwise inserts an empty value to the map under the given key and returns the inserted value
+// and false (loaded).
+func (m Map) GetOrPutEmpty(k string) (Value, bool) {
+	m.getState().AssertMutable()
+	if av, existing := m.Get(k); existing {
+		return av, true
+	}
+	*m.getOrig() = append(*m.getOrig(), otlpcommon.KeyValue{Key: k})
+	return newValue(&(*m.getOrig())[len(*m.getOrig())-1].Value, m.getState()), false
+}
+
 // PutStr performs the Insert or Update action. The Value is
 // inserted to the map that did not originally have the key. The key/value is
 // updated to the map where the key already existed.