Changes and fixes for the new DELIFEQ command

DELIFEQ was added in valkey-io#1975 but had some issues.

Do some refactoring to reduce the number of lines of code,
write commands need to increment dirty and we can propagate
it as DEL command.

Signed-off-by: Binbin <binloveplay1314@qq.com>

Author: enjoy-binbin

src/commands.def

@@ -11341,7 +11341,7 @@ struct COMMAND_STRUCT serverCommandTable[] = {
 {MAKE_CMD("append","Appends a string to the value of a key. Creates the key if it doesn't exist.","O(1). The amortized time complexity is O(1) assuming the appended value is small and the already present value is of any size, since the dynamic string library used by the server will double the free space available on every reallocation.","2.0.0",CMD_DOC_NONE,NULL,NULL,"string",COMMAND_GROUP_STRING,APPEND_History,0,APPEND_Tips,0,appendCommand,3,CMD_WRITE|CMD_DENYOOM|CMD_FAST,ACL_CATEGORY_STRING,APPEND_Keyspecs,1,NULL,2),.args=APPEND_Args},
 {MAKE_CMD("decr","Decrements the integer value of a key by one. Uses 0 as initial value if the key doesn't exist.","O(1)","1.0.0",CMD_DOC_NONE,NULL,NULL,"string",COMMAND_GROUP_STRING,DECR_History,0,DECR_Tips,0,decrCommand,2,CMD_WRITE|CMD_DENYOOM|CMD_FAST,ACL_CATEGORY_STRING,DECR_Keyspecs,1,NULL,1),.args=DECR_Args},
 {MAKE_CMD("decrby","Decrements a number from the integer value of a key. Uses 0 as initial value if the key doesn't exist.","O(1)","1.0.0",CMD_DOC_NONE,NULL,NULL,"string",COMMAND_GROUP_STRING,DECRBY_History,0,DECRBY_Tips,0,decrbyCommand,3,CMD_WRITE|CMD_DENYOOM|CMD_FAST,ACL_CATEGORY_STRING,DECRBY_Keyspecs,1,NULL,2),.args=DECRBY_Args},
-{MAKE_CMD("delifeq","Delete key if value matches string.","O(1)","9.0.0",CMD_DOC_NONE,NULL,NULL,"string",COMMAND_GROUP_STRING,DELIFEQ_History,0,DELIFEQ_Tips,0,delifeqCommand,3,CMD_WRITE,ACL_CATEGORY_STRING,DELIFEQ_Keyspecs,1,NULL,2),.args=DELIFEQ_Args},
+{MAKE_CMD("delifeq","Delete key if value matches string.","O(1)","9.0.0",CMD_DOC_NONE,NULL,NULL,"string",COMMAND_GROUP_STRING,DELIFEQ_History,0,DELIFEQ_Tips,0,delifeqCommand,3,CMD_FAST|CMD_WRITE,ACL_CATEGORY_STRING,DELIFEQ_Keyspecs,1,NULL,2),.args=DELIFEQ_Args},
 {MAKE_CMD("get","Returns the string value of a key.","O(1)","1.0.0",CMD_DOC_NONE,NULL,NULL,"string",COMMAND_GROUP_STRING,GET_History,0,GET_Tips,0,getCommand,2,CMD_READONLY|CMD_FAST,ACL_CATEGORY_STRING,GET_Keyspecs,1,NULL,1),.args=GET_Args},
 {MAKE_CMD("getdel","Returns the string value of a key after deleting the key.","O(1)","6.2.0",CMD_DOC_NONE,NULL,NULL,"string",COMMAND_GROUP_STRING,GETDEL_History,0,GETDEL_Tips,0,getdelCommand,2,CMD_WRITE|CMD_FAST,ACL_CATEGORY_STRING,GETDEL_Keyspecs,1,NULL,1),.args=GETDEL_Args},
 {MAKE_CMD("getex","Returns the string value of a key after setting its expiration time.","O(1)","6.2.0",CMD_DOC_NONE,NULL,NULL,"string",COMMAND_GROUP_STRING,GETEX_History,0,GETEX_Tips,0,getexCommand,-2,CMD_WRITE|CMD_FAST,ACL_CATEGORY_STRING,GETEX_Keyspecs,1,NULL,2),.args=GETEX_Args},

src/commands/delifeq.json

@@ -7,6 +7,7 @@
         "arity": 3,
         "function": "delifeqCommand",
         "command_flags": [
+            "FAST",
             "WRITE"
         ],
         "acl_categories": [

src/t_string.c

@@ -384,30 +384,24 @@ void psetexCommand(client *c) {
     setGenericCommand(c, OBJ_PX | OBJ_ARGV3, c->argv[1], c->argv[3], c->argv[2], UNIT_MILLISECONDS, NULL, NULL, NULL);
 }
 
+/* DELIFEQ key value */
 void delifeqCommand(client *c) {
-    robj *existing_value = lookupKeyWrite(c->db, c->argv[1]);
-
-    if (existing_value == NULL) {
-        addReplyLongLong(c, 0);
-        return;
-    }
-
-    if (checkType(c, existing_value, OBJ_STRING)) {
-        /* Error reply already sent */
-        return;
-    }
+    robj *o;
+    if ((o = lookupKeyWriteOrReply(c, c->argv[1], shared.czero)) == NULL || checkType(c, o, OBJ_STRING)) return;
 
-    if (compareStringObjects(existing_value, c->argv[2]) != 0) {
-        addReplyLongLong(c, 0);
+    if (compareStringObjects(o, c->argv[2]) != 0) {
+        addReply(c, shared.czero);
         return;
     }
 
-    if (!dbSyncDelete(c->db, c->argv[1])) {
-        addReplyLongLong(c, 0);
-        return;
-    }
+    serverAssert(dbSyncDelete(c->db, c->argv[1]));
 
-    addReplyLongLong(c, 1);
+    /* Propagate as DEL command */
+    rewriteClientCommandVector(c, 2, shared.del, c->argv[1]);
+    signalModifiedKey(c, c->db, c->argv[1]);
+    notifyKeyspaceEvent(NOTIFY_GENERIC, "del", c->argv[1], c->db->id);
+    server.dirty++;
+    addReply(c, shared.cone);
 }
 
 int getGenericCommand(client *c) {

tests/unit/type/string.tcl

@@ -777,6 +777,18 @@ if {[string match {*jemalloc*} [s mem_allocator]]} {
         assert_error "WRONGTYPE*" {r delifeq foo "test"}
     }
 
+    test {DELIFEQ propagate as DEL command to replica} {
+        set repl [attach_to_replication_stream]
+        r set foo bar
+        r delifeq foo bar
+        assert_replication_stream $repl {
+            {select *}
+            {set foo bar}
+            {del foo}
+        }
+        close_replication_stream $repl
+    } {} {needs:repl}
+
 if {[string match {*jemalloc*} [s mem_allocator]]} {
     test {Memory usage of embedded string value} {
         # Check that we can fit 9 bytes of key + value into a 32 byte