feat(server): support for persist command #345 (#354)

fix(server): support for persist command #345

Co-authored-by: Boaz Sade <boaz@dragonflydb.io>

docs/api_status.md

@@ -177,7 +177,7 @@ with respect to Memcached and Redis APIs.
   - [X] EVAL
   - [X] EVALSHA
   - [ ] OBJECT
-  - [ ] PERSIST
+  - [x] PERSIST
   - [X] PTTL
   - [ ] RESTORE
   - [X] SCRIPT LOAD/EXISTS

src/server/generic_family.cc

@@ -29,6 +29,8 @@ using namespace facade;
 
 namespace {
 
+OpStatus OpPersist(const OpArgs& op_args, string_view key);
+
 class Renamer {
  public:
   Renamer(ShardId source_id) : src_sid_(source_id) {
@@ -177,6 +179,22 @@ struct ScanOpts {
   unsigned bucket_id = UINT_MAX;
 };
 
+OpStatus OpPersist(const OpArgs& op_args, string_view key) {
+  auto& db_slice = op_args.shard->db_slice();
+  auto [it, expire_it] = db_slice.FindExt(op_args.db_cntx, key);
+
+  if (!IsValid(it)) {
+    return OpStatus::KEY_NOTFOUND;
+  } else {
+    if (IsValid(expire_it)) {
+      // The SKIPPED not really used, just placeholder for error
+      return db_slice.UpdateExpire(op_args.db_cntx.db_index, it, 0) ? OpStatus::OK
+                                                                    : OpStatus::SKIPPED;
+    }
+    return OpStatus::OK;  // fall though - this is the default
+  }
+}
+
 bool ScanCb(const OpArgs& op_args, PrimeIterator it, const ScanOpts& opts, StringVec* res) {
   auto& db_slice = op_args.shard->db_slice();
   if (it->second.HasExpire()) {
@@ -348,6 +366,15 @@ void GenericFamily::Exists(CmdArgList args, ConnectionContext* cntx) {
   return (*cntx)->SendLong(result.load(memory_order_release));
 }
 
+void GenericFamily::Persist(CmdArgList args, ConnectionContext* cntx) {
+  string_view key = ArgS(args, 1);
+
+  auto cb = [&](Transaction* t, EngineShard* shard) { return OpPersist(t->GetOpArgs(shard), key); };
+
+  OpStatus status = cntx->transaction->ScheduleSingleHop(move(cb));
+  (*cntx)->SendLong(status == OpStatus::OK);
+}
+
 void GenericFamily::Expire(CmdArgList args, ConnectionContext* cntx) {
   string_view key = ArgS(args, 1);
   string_view sec = ArgS(args, 2);
@@ -1036,6 +1063,7 @@ void GenericFamily::Register(CommandRegistry* registry) {
             << CI{"EXISTS", CO::READONLY | CO::FAST, -2, 1, -1, 1}.HFUNC(Exists)
             << CI{"EXPIRE", CO::WRITE | CO::FAST, 3, 1, 1, 1}.HFUNC(Expire)
             << CI{"EXPIREAT", CO::WRITE | CO::FAST, 3, 1, 1, 1}.HFUNC(ExpireAt)
+            << CI{"PERSIST", CO::WRITE | CO::FAST, 2, 1, 1, 1}.HFUNC(Persist)
             << CI{"KEYS", CO::READONLY, 2, 0, 0, 0}.HFUNC(Keys)
             << CI{"PEXPIREAT", CO::WRITE | CO::FAST, 3, 1, 1, 1}.HFUNC(PexpireAt)
             << CI{"RENAME", CO::WRITE, 3, 1, 2, 1}.HFUNC(Rename)

src/server/generic_family.h

@@ -46,6 +46,7 @@ class GenericFamily {
   static void Exists(CmdArgList args, ConnectionContext* cntx);
   static void Expire(CmdArgList args, ConnectionContext* cntx);
   static void ExpireAt(CmdArgList args, ConnectionContext* cntx);
+  static void Persist(CmdArgList args, ConnectionContext* cntx);
   static void Keys(CmdArgList args, ConnectionContext* cntx);
   static void PexpireAt(CmdArgList args, ConnectionContext* cntx);
   static void Stick(CmdArgList args, ConnectionContext* cntx);

src/server/generic_family_test.cc

@@ -282,21 +282,28 @@ TEST_F(GenericFamilyTest, Sort) {
   // numeric
   ASSERT_THAT(Run({"sort", "list-1"}).GetVec(), ElementsAre("1.2", "2.20", "3.5", "10.1", "200"));
   // string
-  ASSERT_THAT(Run({"sort", "list-1", "ALPHA"}).GetVec(), ElementsAre("1.2", "10.1", "2.20", "200", "3.5"));
+  ASSERT_THAT(Run({"sort", "list-1", "ALPHA"}).GetVec(),
+              ElementsAre("1.2", "10.1", "2.20", "200", "3.5"));
   // desc numeric
-  ASSERT_THAT(Run({"sort", "list-1", "DESC"}).GetVec(), ElementsAre("200", "10.1", "3.5", "2.20", "1.2"));
+  ASSERT_THAT(Run({"sort", "list-1", "DESC"}).GetVec(),
+              ElementsAre("200", "10.1", "3.5", "2.20", "1.2"));
   // desc strig
-  ASSERT_THAT(Run({"sort", "list-1", "DESC", "ALPHA"}).GetVec(), ElementsAre("3.5", "200", "2.20", "10.1", "1.2"));
+  ASSERT_THAT(Run({"sort", "list-1", "DESC", "ALPHA"}).GetVec(),
+              ElementsAre("3.5", "200", "2.20", "10.1", "1.2"));
   // limits
-  ASSERT_THAT(Run({"sort", "list-1", "LIMIT", "0", "5"}).GetVec(), ElementsAre("1.2", "2.20", "3.5", "10.1", "200"));
+  ASSERT_THAT(Run({"sort", "list-1", "LIMIT", "0", "5"}).GetVec(),
-  ASSERT_THAT(Run({"sort", "list-1", "LIMIT", "0", "10"}).GetVec(), ElementsAre("1.2", "2.20", "3.5", "10.1", "200"));
+              ElementsAre("1.2", "2.20", "3.5", "10.1", "200"));
+  ASSERT_THAT(Run({"sort", "list-1", "LIMIT", "0", "10"}).GetVec(),
+              ElementsAre("1.2", "2.20", "3.5", "10.1", "200"));
   ASSERT_THAT(Run({"sort", "list-1", "LIMIT", "2", "2"}).GetVec(), ElementsAre("3.5", "10.1"));
   ASSERT_THAT(Run({"sort", "list-1", "LIMIT", "1", "1"}), "2.20");
   ASSERT_THAT(Run({"sort", "list-1", "LIMIT", "4", "2"}), "200");
   ASSERT_THAT(Run({"sort", "list-1", "LIMIT", "5", "2"}), ArrLen(0));
   // limits desc
-  ASSERT_THAT(Run({"sort", "list-1", "DESC", "LIMIT", "0", "5"}).GetVec(), ElementsAre("200", "10.1", "3.5", "2.20", "1.2"));
+  ASSERT_THAT(Run({"sort", "list-1", "DESC", "LIMIT", "0", "5"}).GetVec(),
-  ASSERT_THAT(Run({"sort", "list-1", "DESC", "LIMIT", "2", "2"}).GetVec(), ElementsAre("3.5", "2.20"));
+              ElementsAre("200", "10.1", "3.5", "2.20", "1.2"));
+  ASSERT_THAT(Run({"sort", "list-1", "DESC", "LIMIT", "2", "2"}).GetVec(),
+              ElementsAre("3.5", "2.20"));
   ASSERT_THAT(Run({"sort", "list-1", "DESC", "LIMIT", "1", "1"}), "10.1");
   ASSERT_THAT(Run({"sort", "list-1", "DESC", "LIMIT", "5", "2"}), ArrLen(0));
 
@@ -304,9 +311,12 @@ TEST_F(GenericFamilyTest, Sort) {
   Run({"del", "set-1"});
   Run({"sadd", "set-1", "5.3", "4.4", "60", "99.9", "100", "9"});
   ASSERT_THAT(Run({"sort", "set-1"}).GetVec(), ElementsAre("4.4", "5.3", "9", "60", "99.9", "100"));
-  ASSERT_THAT(Run({"sort", "set-1", "ALPHA"}).GetVec(), ElementsAre("100", "4.4", "5.3", "60", "9", "99.9"));
+  ASSERT_THAT(Run({"sort", "set-1", "ALPHA"}).GetVec(),
-  ASSERT_THAT(Run({"sort", "set-1", "DESC"}).GetVec(), ElementsAre("100", "99.9", "60", "9", "5.3", "4.4"));
+              ElementsAre("100", "4.4", "5.3", "60", "9", "99.9"));
-  ASSERT_THAT(Run({"sort", "set-1", "DESC", "ALPHA"}).GetVec(), ElementsAre("99.9", "9", "60", "5.3", "4.4", "100"));
+  ASSERT_THAT(Run({"sort", "set-1", "DESC"}).GetVec(),
+              ElementsAre("100", "99.9", "60", "9", "5.3", "4.4"));
+  ASSERT_THAT(Run({"sort", "set-1", "DESC", "ALPHA"}).GetVec(),
+              ElementsAre("99.9", "9", "60", "5.3", "4.4", "100"));
 
   // Test intset sort
   Run({"del", "intset-1"});
@@ -354,4 +364,16 @@ TEST_F(GenericFamilyTest, Time) {
   }
 }
 
+TEST_F(GenericFamilyTest, Persist) {
+  auto resp = Run({"set", "mykey", "somevalue"});
+  EXPECT_EQ(resp, "OK");
+  // Key without expiration time - return 1
+  EXPECT_EQ(1, CheckedInt({"persist", "mykey"}));
+  // set expiration time and try again
+  resp = Run({"EXPIRE", "mykey", "10"});
+  EXPECT_EQ(10, CheckedInt({"TTL", "mykey"}));
+  EXPECT_EQ(1, CheckedInt({"persist", "mykey"}));
+  EXPECT_EQ(-1, CheckedInt({"TTL", "mykey"}));
+}
+
 }  // namespace dfly