Merge pull request #287 from Abdi-dd/master

Implementing Count functionality in SSCAN

cmd_set.go

@@ -3,6 +3,7 @@
 package miniredis
 
 import (
+	"fmt"
 	"strconv"
 	"strings"
 
@@ -613,6 +614,7 @@ func (m *Miniredis) cmdSscan(c *server.Peer, cmd string, args []string) {
 		key       string
 		value     int
 		cursor    int
+		count     int
 		withMatch bool
 		match     string
 	}
@@ -631,13 +633,18 @@ func (m *Miniredis) cmdSscan(c *server.Peer, cmd string, args []string) {
 				c.WriteError(msgSyntaxError)
 				return
 			}
-			_, err := strconv.Atoi(args[1])
-			if err != nil {
+			count, err := strconv.Atoi(args[1])
+			if err != nil || count < 0 {
 				setDirty(c)
 				c.WriteError(msgInvalidInt)
 				return
 			}
-			// We do nothing with count.
+			if count == 0 {
+				setDirty(c)
+				c.WriteError(msgSyntaxError)
+				return
+			}
+			opts.count = count
 			args = args[2:]
 			continue
 		}
@@ -660,29 +667,38 @@ func (m *Miniredis) cmdSscan(c *server.Peer, cmd string, args []string) {
 	withTx(m, c, func(c *server.Peer, ctx *connCtx) {
 		db := m.db(ctx.selectedDB)
 		// return _all_ (matched) keys every time
-
-		if opts.cursor != 0 {
-			// invalid cursor
-			c.WriteLen(2)
-			c.WriteBulk("0") // no next cursor
-			c.WriteLen(0)    // no elements
-			return
-		}
 		if db.exists(opts.key) && db.t(opts.key) != "set" {
 			c.WriteError(ErrWrongType.Error())
 			return
 		}
-
 		members := db.setMembers(opts.key)
 		if opts.withMatch {
 			members, _ = matchKeys(members, opts.match)
 		}
-
+		low := opts.cursor
+		high := low + opts.count
+		// validate high is correct
+		if high > len(members) || high == 0 {
+			high = len(members)
+		}
+		if opts.cursor > high {
+			// invalid cursor
+			c.WriteLen(2)
+			c.WriteBulk("0") // no next cursor
+			c.WriteLen(0)    // no elements
+			return
+		}
+		cursorValue := low + opts.count
+		if cursorValue > len(members) {
+			cursorValue = 0 // no next cursor
+		}
+		members = members[low:high]
 		c.WriteLen(2)
-		c.WriteBulk("0") // no next cursor
+		c.WriteBulk(fmt.Sprintf("%d", cursorValue))
 		c.WriteLen(len(members))
 		for _, k := range members {
 			c.WriteBulk(k)
 		}
+
 	})
 }

cmd_set_test.go

@@ -750,7 +750,6 @@ func TestSscan(t *testing.T) {
 	// We cheat with sscan. It always returns everything.
 
 	s.SetAdd("set", "value1", "value2")
-
 	// No problem
 	mustDo(t, c,
 		"SSCAN", "set", "0",
@@ -817,14 +816,56 @@ func TestSscan(t *testing.T) {
 			"SSCAN", "set", "0", "COUNT",
 			proto.Error(msgSyntaxError),
 		)
+		mustDo(t, c,
+			"SSCAN", "set", "0", "COUNT", "0",
+			proto.Error(msgSyntaxError),
+		)
 		mustDo(t, c,
 			"SSCAN", "set", "0", "COUNT", "noint",
 			proto.Error(msgInvalidInt),
 		)
+		mustDo(t, c,
+			"SSCAN", "set", "0", "COUNT", "-3",
+			proto.Error(msgInvalidInt),
+		)
 		s.Set("str", "value")
 		mustDo(t, c,
 			"SSCAN", "str", "0",
 			proto.Error(msgWrongType),
 		)
 	})
+
+	s.SetAdd("largeset", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v8")
+	mustDo(t, c,
+		"SSCAN", "largeset", "0", "COUNT", "3",
+		proto.Array(
+			proto.String("3"),
+			proto.Array(
+				proto.String("v1"),
+				proto.String("v2"),
+				proto.String("v3"),
+			),
+		),
+	)
+	mustDo(t, c,
+		"SSCAN", "largeset", "3", "COUNT", "3",
+		proto.Array(
+			proto.String("6"),
+			proto.Array(
+				proto.String("v4"),
+				proto.String("v5"),
+				proto.String("v6"),
+			),
+		),
+	)
+	mustDo(t, c,
+		"SSCAN", "largeset", "6", "COUNT", "3",
+		proto.Array(
+			proto.String("0"),
+			proto.Array(
+				proto.String("v7"),
+				proto.String("v8"),
+			),
+		),
+	)
 }

integration/set_test.go

@@ -314,6 +314,8 @@ func TestSscan(t *testing.T) {
 		c.Do("SSCAN", "set", "0", "MATCH", "anoth*")
 		c.Do("SSCAN", "set", "0", "MATCH", "anoth*", "COUNT", "100")
 		c.Do("SSCAN", "set", "0", "COUNT", "100", "MATCH", "anoth*")
+		c.DoLoosely("SSCAN", "set", "0", "COUNT", "1") // cursor differs
+		c.DoLoosely("SSCAN", "set", "0", "COUNT", "2") // cursor differs
 
 		// Can't really test multiple keys.
 		// c.Do("SET", "key2", "value2")
@@ -323,6 +325,7 @@ func TestSscan(t *testing.T) {
 		c.Error("wrong number", "SSCAN")
 		c.Error("wrong number", "SSCAN", "noint")
 		c.Error("not an integer", "SSCAN", "set", "0", "COUNT", "noint")
+		c.Error("syntax error", "SSCAN", "set", "0", "COUNT", "0")
 		c.Error("syntax error", "SSCAN", "set", "0", "COUNT")
 		c.Error("syntax error", "SSCAN", "set", "0", "MATCH")
 		c.Error("syntax error", "SSCAN", "set", "0", "garbage")