implement TTL and EXPIRE commands (DiceDB#1465)

internal/cmd/cmd_expire.go

@@ -0,0 +1,56 @@
+package cmd
+
+import (
+	"strconv"
+
+	"github.com/dicedb/dice/internal/server/utils"
+	dstore "github.com/dicedb/dice/internal/store"
+	"github.com/dicedb/dicedb-go/wire"
+)
+
+var cEXPIRE = &DiceDBCommand{
+	Name:      "EXPIRE",
+	HelpShort: "EXPIRE sets an expiry(in seconds) on a specified key",
+	Eval:      evalEXPIRE,
+}
+
+func init() {
+	commandRegistry.AddCommand(cEXPIRE)
+}
+
+func evalEXPIRE(c *Cmd, s *dstore.Store) (*CmdRes, error) {
+	if len(c.C.Args) <= 1 {
+		return cmdResNil, errWrongArgumentCount("EXPIRE")
+	}
+
+	var key = c.C.Args[0]
+	exDurationSec, err := strconv.ParseInt(c.C.Args[1], 10, 64)
+
+	if err != nil || exDurationSec < 0 {
+		return cmdResNil, errInvalidExpireTime("EXPIRE")
+	}
+
+	obj := s.Get(key)
+
+	if obj == nil {
+		return &CmdRes{R: &wire.Response{
+			Value: &wire.Response_VInt{VInt: 0},
+		}}, nil
+	}
+
+	isExpirySet, err2 := dstore.EvaluateAndSetExpiry(c.C.Args[2:], utils.AddSecondsToUnixEpoch(exDurationSec), key, s)
+
+	if err2 != nil {
+		return cmdResNil, err2
+	}
+
+	if isExpirySet {
+		return &CmdRes{R: &wire.Response{
+			Value: &wire.Response_VInt{VInt: 1},
+		}}, nil
+	}
+
+	return &CmdRes{R: &wire.Response{
+		Value: &wire.Response_VInt{VInt: 0},
+	}}, nil
+}

internal/cmd/cmd_ttl.go

@@ -0,0 +1,47 @@
+package cmd
+
+import (
+	"github.com/dicedb/dice/internal/server/utils"
+	dstore "github.com/dicedb/dice/internal/store"
+	"github.com/dicedb/dicedb-go/wire"
+)
+
+var cTTL = &DiceDBCommand{
+	Name:      "TTL",
+	HelpShort: "TTL return the remaining time to live of a key that has an expiration set",
+	Eval:      evalTTL,
+}
+
+func init() {
+	commandRegistry.AddCommand(cTTL)
+}
+
+func evalTTL(c *Cmd, s *dstore.Store) (*CmdRes, error) {
+	if len(c.C.Args) != 1 {
+		return cmdResNil, errWrongArgumentCount("TTL")
+	}
+
+	var key = c.C.Args[0]
+
+	obj := s.Get(key)
+
+	if obj == nil {
+		return &CmdRes{R: &wire.Response{
+			Value: &wire.Response_VInt{VInt: -2},
+		}}, nil
+	}
+
+	exp, isExpirySet := dstore.GetExpiry(obj, s)
+
+	if !isExpirySet {
+		return &CmdRes{R: &wire.Response{
+			Value: &wire.Response_VInt{VInt: -1},
+		}}, nil
+	}
+
+	durationMs := exp - uint64(utils.GetCurrentTime().UnixMilli())
+
+	return &CmdRes{R: &wire.Response{
+		Value: &wire.Response_VInt{VInt: int64(durationMs / 1000)},
+	}}, nil
+}

internal/store/expire.go

@@ -126,7 +126,7 @@ func EvaluateAndSetExpiry(subCommands []string, newExpiry int64, key string,
 			}
 		case LT:
 			ltCmd = true
-			if prevExpiry != nil && *prevExpiry < uint64(newExpInMilli) {
+			if prevExpiry == nil || *prevExpiry < uint64(newExpInMilli) {
 				shouldSetExpiry = false
 			}
 		default: