Merge commit 'bf963253ecfd367b49081a26c1b5c410558aecfc' into unstable

Former-commit-id: 10986ae3a801c13013ec74880dd1f7969c284d01

src/db.cpp

@@ -665,7 +665,7 @@ int parseScanCursorOrReply(client *c, robj *o, unsigned long *cursor) {
 }
 
 /* This command implements SCAN, HSCAN and SSCAN commands.
- * If object 'o' is passed, then it must be a Hash or Set object, otherwise
+ * If object 'o' is passed, then it must be a Hash, Set or Zset object, otherwise
  * if 'o' is NULL the command will operate on the dictionary associated with
  * the current database.
  *
@@ -681,6 +681,7 @@ void scanGenericCommand(client *c, robj_roptr o, unsigned long cursor) {
     listNode *node, *nextnode;
     long count = 10;
     sds pat = NULL;
+    sds typename = NULL;
     int patlen = 0, use_pattern = 0;
     dict *ht;
 
@@ -717,6 +718,10 @@ void scanGenericCommand(client *c, robj_roptr o, unsigned long cursor) {
             use_pattern = !(pat[0] == '*' && patlen == 1);
 
             i += 2;
+        } else if (!strcasecmp(c->argv[i]->ptr, "type") && o == NULL && j >= 2) {
+            /* SCAN for a particular type only applies to the db dict */
+            typename = c->argv[i+1]->ptr;
+            i+= 2;
         } else {
             addReply(c,shared.syntaxerr);
             goto cleanup;
@@ -811,6 +816,31 @@ void scanGenericCommand(client *c, robj_roptr o, unsigned long cursor) {
             }
         }
 
+        /* Filter an element if it isn't the type we want. */
+        if (!filter && o == NULL && typename){
+            robj* typecheck;
+            char *type;
+            typecheck = lookupKeyReadWithFlags(c->db, kobj, LOOKUP_NOTOUCH);
+            if (typecheck == NULL) {
+                type = "none";
+            } else {
+                switch(typecheck->type) {
+                case OBJ_STRING: type = "string"; break;
+                case OBJ_LIST: type = "list"; break;
+                case OBJ_SET: type = "set"; break;
+                case OBJ_ZSET: type = "zset"; break;
+                case OBJ_HASH: type = "hash"; break;
+                case OBJ_STREAM: type = "stream"; break;
+                case OBJ_MODULE: {
+                    moduleValue *mv = typecheck->ptr;
+                    type = mv->type->name;
+                }; break;
+                default: type = "unknown"; break;
+                }
+            }
+            if (strcasecmp((char*) typename, type)) filter = 1;
+        }
+
         /* Filter element if it is an expired key. */
         if (!filter && o == nullptr && expireIfNeeded(c->db, kobj)) filter = 1;
 

tests/unit/scan.tcl

@@ -53,6 +53,51 @@ start_server {tags {"scan"}} {
         assert_equal 100 [llength $keys]
     }
 
+    test "SCAN TYPE" {
+        r flushdb
+        # populate only creates strings
+        r debug populate 1000
+
+        # Check non-strings are excluded
+        set cur 0
+        set keys {}
+        while 1 {
+            set res [r scan $cur type "list"]
+            set cur [lindex $res 0]
+            set k [lindex $res 1]
+            lappend keys {*}$k
+            if {$cur == 0} break
+        }
+
+        assert_equal 0 [llength $keys]
+
+        # Check strings are included
+        set cur 0
+        set keys {}
+        while 1 {
+            set res [r scan $cur type "string"]
+            set cur [lindex $res 0]
+            set k [lindex $res 1]
+            lappend keys {*}$k
+            if {$cur == 0} break
+        }
+
+        assert_equal 1000 [llength $keys]
+
+        # Check all three args work together
+        set cur 0
+        set keys {}
+        while 1 {
+            set res [r scan $cur type "string" match "key:*" count 10]
+            set cur [lindex $res 0]
+            set k [lindex $res 1]
+            lappend keys {*}$k
+            if {$cur == 0} break
+        }
+
+        assert_equal 1000 [llength $keys]
+    }
+
     foreach enc {intset hashtable} {
         test "SSCAN with encoding $enc" {
             # Create the Set