From 0960371c07a81e5b061dbc84247869475df13fb0 Mon Sep 17 00:00:00 2001
From: xanish <danishali7866@gmail.com>
Date: Thu, 17 Oct 2024 01:34:08 +0530
Subject: [PATCH] Add best effort mechanism to return non-expired randomkey in
 128 tries

---
 internal/eval/eval.go      | 24 ++++++++++++++++++------
 internal/eval/eval_test.go |  7 +++++--
 2 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/internal/eval/eval.go b/internal/eval/eval.go
index 1b4dfe62c2..604e0c9acd 100644
--- a/internal/eval/eval.go
+++ b/internal/eval/eval.go
@@ -5147,13 +5147,25 @@ func evalRANDOMKEY(args []string, store *dstore.Store) *EvalResponse {
 	}
 
 	if len(availKeys) > 0 {
-		randKeyIdx, err := rand.Int(rand.Reader, big.NewInt(int64(len(availKeys))))
-		if err != nil {
-			return &EvalResponse{Result: nil,
-				Error: errors.New(string(diceerrors.NewErrWithMessage("could not generate a random key seed")))}
-		}
+		maxIters := 128
+		for range maxIters {
+			randKeyIdx, err := rand.Int(rand.Reader, big.NewInt(int64(len(availKeys))))
+			if err != nil {
+				continue
+			}
 
-		return &EvalResponse{Result: availKeys[randKeyIdx.Uint64()], Error: nil}
+			randKey := availKeys[randKeyIdx.Uint64()]
+			keyObj := store.Get(randKey)
+			if keyObj == nil {
+				continue
+			}
+
+			currTimeMs := uint64(utils.GetCurrentTime().UnixMilli())
+			expireTimeMs, isExpirySet := dstore.GetExpiry(keyObj, store)
+			if (isExpirySet && expireTimeMs > currTimeMs) || !isExpirySet {
+				return &EvalResponse{Result: clientio.Encode(randKey, false), Error: nil}
+			}
+		}
 	}
 
 	return &EvalResponse{Result: clientio.RespNIL, Error: nil}
diff --git a/internal/eval/eval_test.go b/internal/eval/eval_test.go
index 689707d53e..327c49b1a1 100644
--- a/internal/eval/eval_test.go
+++ b/internal/eval/eval_test.go
@@ -1166,11 +1166,14 @@ func testEvalRANDOMKEY(t *testing.T, store *dstore.Store) {
 		results := make(map[string]int)
 		for i := 0; i < 10000; i++ {
 			result := evalRANDOMKEY([]string{}, store)
-			results[result.Result.(string)]++
+			if res, ok := result.Result.([]byte); ok {
+				results[string(res)]++
+			}
 		}
 
 		for key, _ := range data {
-			if results[key] == 0 {
+			returnedKey := clientio.Encode(key, false)
+			if results[string(returnedKey)] == 0 {
 				t.Errorf("key %s was never returned", key)
 			}
 		}