From 5577130451e8ba6ceeac07137f45915a069706a9 Mon Sep 17 00:00:00 2001
From: antirez <antirez@gmail.com>
Date: Tue, 20 Mar 2018 11:52:34 +0100
Subject: [PATCH] CG: Make XINFO Great Again (and more Redis-ish).

With XINFO out of the blue I invented a new syntax for commands never
used in Redis in the past... Let's fix it and make it

        Great Again!!11one (TM)
---
 src/server.c   |  2 +-
 src/t_stream.c | 54 ++++++++++++++++++++++++++++++++------------------
 2 files changed, 36 insertions(+), 20 deletions(-)

diff --git a/src/server.c b/src/server.c
index 803d609c..7c7a719f 100644
--- a/src/server.c
+++ b/src/server.c
@@ -312,7 +312,7 @@ struct redisCommand redisCommandTable[] = {
     {"xack",xackCommand,-3,"wF",0,NULL,1,1,1,0,0},
     {"xpending",xpendingCommand,-3,"r",0,NULL,1,1,1,0,0},
     {"xclaim",xclaimCommand,-5,"wF",0,NULL,1,1,1,0,0},
-    {"xinfo",xinfoCommand,-2,"r",0,NULL,1,1,1,0,0},
+    {"xinfo",xinfoCommand,-2,"r",0,NULL,2,2,1,0,0},
     {"post",securityWarningCommand,-1,"lt",0,NULL,0,0,0,0,0},
     {"host:",securityWarningCommand,-1,"lt",0,NULL,0,0,0,0,0},
     {"latency",latencyCommand,-2,"aslt",0,NULL,0,0,0,0,0}
diff --git a/src/t_stream.c b/src/t_stream.c
index f2da0100..37f08572 100644
--- a/src/t_stream.c
+++ b/src/t_stream.c
@@ -1926,34 +1926,52 @@ void xclaimCommand(client *c) {
     preventCommandPropagation(c);
 }
 
-/* XINFO <key> [CONSUMERS group|GROUPS|STREAM]. STREAM is the default */
+/* XINFO CONSUMERS key group
+ * XINFO GROUPS <key>
+ * XINFO STREAM <key>
+ * XINFO <key> (alias of XINFO STREAM key)
+ * XINFO HELP. */
 void xinfoCommand(client *c) {
     const char *help[] = {
-"<key> CONSUMERS <groupname>  -- Show consumer groups of group <groupname>.",
-"<key> GROUPS                 -- Show the stream consumer groups.",
-"<key> STREAM                 -- Show information about the stream.",
-"<key> (without subcommand)   -- Alias for <key> STREAM.",
-"<key> HELP                   -- Prints this help.",
+"CONSUMERS <key> <groupname>  -- Show consumer groups of group <groupname>.",
+"GROUPS <key>                 -- Show the stream consumer groups.",
+"STREAM <key>                 -- Show information about the stream.",
+"<key>                        -- Alias for STREAM <key>.",
+"HELP                         -- Print this help.",
 NULL
     };
     stream *s = NULL;
-    char *opt = c->argc > 2 ? c->argv[2]->ptr : "STREAM"; /* Subcommand. */
+    char *opt;
+    robj *key;
+
+    /* HELP is special. Handle it ASAP. */
+    if (!strcasecmp(c->argv[1]->ptr,"HELP")) {
+        addReplyHelp(c, help);
+        return;
+    }
+
+    /* Handle the fact that no subcommand means "STREAM". */
+    if (c->argc == 2) {
+        opt = "STREAM";
+        key = c->argv[1];
+    } else {
+        opt = c->argv[1]->ptr;
+        key = c->argv[2];
+    }
 
     /* Lookup the key now, this is common for all the subcommands but HELP. */
-    if (c->argc >= 2 && strcasecmp(opt,"HELP")) {
-        robj *o = lookupKeyWriteOrReply(c,c->argv[1],shared.nokeyerr);
-        if (o == NULL) return;
-        s = o->ptr;
-    }
+    robj *o = lookupKeyWriteOrReply(c,key,shared.nokeyerr);
+    if (o == NULL) return;
+    s = o->ptr;
 
     /* Dispatch the different subcommands. */
     if (!strcasecmp(opt,"CONSUMERS") && c->argc == 4) {
-        /* XINFO <key> CONSUMERS <group>. */
+        /* XINFO CONSUMERS <key> <group>. */
         streamCG *cg = streamLookupCG(s,c->argv[3]->ptr);
         if (cg == NULL) {
             addReplyErrorFormat(c, "-NOGROUP No such consumer group '%s' "
                                    "for key name '%s'",
-                                   c->argv[3]->ptr, c->argv[1]->ptr);
+                                   c->argv[3]->ptr, key->ptr);
             return;
         }
 
@@ -1977,7 +1995,7 @@ NULL
         }
         raxStop(&ri);
     } else if (!strcasecmp(opt,"GROUPS") && c->argc == 3) {
-        /* XINFO <key> GROUPS. */
+        /* XINFO GROUPS <key>. */
         if (s->cgroups == NULL) {
             addReplyMultiBulkLen(c,0);
             return;
@@ -2001,7 +2019,7 @@ NULL
     } else if (c->argc == 2 ||
                (!strcasecmp(opt,"STREAM") && c->argc == 3))
     {
-        /* XINFO <key> STREAM (or the alias XINFO <key>). */
+        /* XINFO STREAM <key> (or the alias XINFO <key>). */
         addReplyMultiBulkLen(c,12);
         addReplyStatus(c,"length");
         addReplyLongLong(c,s->length);
@@ -2026,10 +2044,8 @@ NULL
         count = streamReplyWithRange(c,s,&start,&end,1,1,NULL,NULL,
                                      STREAM_RWR_RAWENTRIES,NULL);
         if (!count) addReply(c,shared.nullbulk);
-    } else if (!strcasecmp(opt,"HELP")) {
-        addReplyHelp(c, help);
     } else {
-        addReplyError(c,"syntax error, try 'XINFO anykey HELP'");
+        addReplyError(c,"syntax error, try 'XINFO HELP'");
     }
 }