tests/robustness: Refactor patch operation functions

Signed-off-by: Marek Siarkowicz <siarkowicz@google.com>

tests/robustness/validate/patch_history.go

@@ -16,12 +16,38 @@ package validate
 
 import (
 	"github.com/anishathalye/porcupine"
-
 	"go.etcd.io/etcd/tests/v3/robustness/model"
 	"go.etcd.io/etcd/tests/v3/robustness/traffic"
 )
 
+func patchedOperationHistory(reports []traffic.ClientReport) []porcupine.Operation {
+	allOperations := operations(reports)
+	uniqueEvents := uniqueWatchEvents(reports)
+	return patchOperationsWithWatchEvents(allOperations, uniqueEvents)
+}
+
+func operations(reports []traffic.ClientReport) []porcupine.Operation {
+	var ops []porcupine.Operation
+	for _, r := range reports {
+		ops = append(ops, r.OperationHistory.Operations()...)
+	}
+	return ops
+}
+
+func uniqueWatchEvents(reports []traffic.ClientReport) map[model.Event]traffic.TimedWatchEvent {
+	persisted := map[model.Event]traffic.TimedWatchEvent{}
+	for _, r := range reports {
+		for _, resp := range r.Watch {
+			for _, event := range resp.Events {
+				persisted[event.Event] = traffic.TimedWatchEvent{Time: resp.Time, WatchEvent: event}
+			}
+		}
+	}
+	return persisted
+}
+
 func patchOperationsWithWatchEvents(operations []porcupine.Operation, watchEvents map[model.Event]traffic.TimedWatchEvent) []porcupine.Operation {
+
 	newOperations := make([]porcupine.Operation, 0, len(operations))
 	lastObservedOperation := lastOperationObservedInWatch(operations, watchEvents)