Add SINTERCARD/ZINTERCARD Commands (#8946)

Add SINTERCARD and ZINTERCARD commands that are similar to
ZINTER and SINTER but only return the cardinality with minimum
processing and memory overheads.

Co-authored-by: Oran Agra <oran@redislabs.com>

2 files changed, 22 insertions, 3 deletions

diff --git a/tests/unit/type/set.tcl b/tests/unit/type/set.tcl
index 463dc5859..9c512726d 100644
--- a/tests/unit/type/set.tcl
+++ b/tests/unit/type/set.tcl
@@ -143,6 +143,10 @@ start_server {
         r srem myset 1 2 3 4 5 6 7 8
     } {3}
 
+    test "SINTERCARD against non-existing key" {
+        assert_equal 0 [r sintercard non-existing-key]
+    }
+
     foreach {type} {hashtable intset} {
         for {set i 1} {$i <= 5} {incr i} {
             r del [format "set%d{t}" $i]
@@ -182,6 +186,10 @@ start_server {
             assert_equal [list 195 196 197 198 199 $large] [lsort [r sinter set1{t} set2{t}]]
         }
 
+        test "SINTERCARD with two sets - $type" {
+            assert_equal 6 [r sintercard set1{t} set2{t}]
+        }
+
         test "SINTERSTORE with two sets - $type" {
             r sinterstore setres{t} set1{t} set2{t}
             assert_encoding $type setres{t}
@@ -211,6 +219,10 @@ start_server {
             assert_equal [list 195 199 $large] [lsort [r sinter set1{t} set2{t} set3{t}]]
         }
 
+        test "SINTERCARD against three sets - $type" {
+            assert_equal 3 [r sintercard set1{t} set2{t} set3{t}]
+        }
+
         test "SINTERSTORE with three sets - $type" {
             r sinterstore setres{t} set1{t} set2{t} set3{t}
             assert_equal [list 195 199 $large] [lsort [r smembers setres{t}]]
diff --git a/tests/unit/type/zset.tcl b/tests/unit/type/zset.tcl
index 1f2f00576..75d51bb2e 100644
--- a/tests/unit/type/zset.tcl
+++ b/tests/unit/type/zset.tcl
@@ -647,10 +647,11 @@ start_server {tags {"zset"}} {
             assert_equal 0 [r exists dst_key{t}]
         }
 
-        test "ZUNION/ZINTER/ZDIFF against non-existing key - $encoding" {
+        test "ZUNION/ZINTER/ZINTERCARD/ZDIFF against non-existing key - $encoding" {
             r del zseta
             assert_equal {} [r zunion 1 zseta]
             assert_equal {} [r zinter 1 zseta]
+            assert_equal 0 [r zintercard 1 zseta]
             assert_equal {} [r zdiff 1 zseta]
         }
 
@@ -662,12 +663,13 @@ start_server {tags {"zset"}} {
             r zrange zsetc{t} 0 -1 withscores
         } {a 1 b 2}
 
-        test "ZUNION/ZINTER/ZDIFF with empty set - $encoding" {
+        test "ZUNION/ZINTER/ZINTERCARD/ZDIFF with empty set - $encoding" {
             r del zseta{t} zsetb{t}
             r zadd zseta{t} 1 a
             r zadd zseta{t} 2 b
             assert_equal {a 1 b 2} [r zunion 2 zseta{t} zsetb{t} withscores]
             assert_equal {} [r zinter 2 zseta{t} zsetb{t} withscores]
+            assert_equal 0 [r zintercard 2 zseta{t} zsetb{t}]
             assert_equal {a 1 b 2} [r zdiff 2 zseta{t} zsetb{t} withscores]
         }
 
@@ -684,7 +686,7 @@ start_server {tags {"zset"}} {
             assert_equal {a 1 b 3 d 3 c 5} [r zrange zsetc{t} 0 -1 withscores]
         }
 
-        test "ZUNION/ZINTER/ZDIFF with integer members - $encoding" {
+        test "ZUNION/ZINTER/ZINTERCARD/ZDIFF with integer members - $encoding" {
             r del zsetd{t} zsetf{t}
             r zadd zsetd{t} 1 1
             r zadd zsetd{t} 2 2
@@ -695,6 +697,7 @@ start_server {tags {"zset"}} {
 
             assert_equal {1 2 2 2 4 4 3 6} [r zunion 2 zsetd{t} zsetf{t} withscores]
             assert_equal {1 2 3 6} [r zinter 2 zsetd{t} zsetf{t} withscores]
+            assert_equal 2 [r zintercard 2 zsetd{t} zsetf{t}]
             assert_equal {2 2} [r zdiff 2 zsetd{t} zsetf{t} withscores]
         }
 
@@ -747,6 +750,10 @@ start_server {tags {"zset"}} {
             assert_equal {b 3 c 5} [r zinter 2 zseta{t} zsetb{t} withscores]
         }
 
+        test "ZINTERCARD basics - $encoding" {
+            assert_equal 2 [r zintercard 2 zseta{t} zsetb{t}]
+        }
+
         test "ZINTER RESP3 - $encoding" {
             r hello 3
             assert_equal {{b 3.0} {c 5.0}} [r zinter 2 zseta{t} zsetb{t} withscores]