From fa29266526349e1688d0991b8a1fb69bb8dac1ce Mon Sep 17 00:00:00 2001
From: antirez <antirez@gmail.com>
Date: Mon, 10 Mar 2014 15:26:10 +0100
Subject: [PATCH] Cluster: evalGetKey() added for EVAL/EVALSHA.

Previously we used zunionInterGetKeys(), however after this function was
fixed to account for the destination key (not needed when the API was
designed for "diskstore") the two set of commands can no longer be served
by an unique keys-extraction function.
---
 src/db.c    | 23 +++++++++++++++++++++++
 src/redis.c |  4 ++--
 src/redis.h |  1 +
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/src/db.c b/src/db.c
index 243ed195f..913e03a00 100644
--- a/src/db.c
+++ b/src/db.c
@@ -998,6 +998,29 @@ int *zunionInterGetKeys(struct redisCommand *cmd, robj **argv, int argc, int *nu
     return keys;
 }
 
+/* Helper function to extract keys from the following commands:
+ * EVAL <script> <num-keys> <key> <key> ... <key> [more stuff]
+ * EVALSHA <script> <num-keys> <key> <key> ... <key> [more stuff] */
+int *evalGetKeys(struct redisCommand *cmd, robj **argv, int argc, int *numkeys) {
+    int i, num, *keys;
+    REDIS_NOTUSED(cmd);
+
+    num = atoi(argv[2]->ptr);
+    /* Sanity check. Don't return any key if the command is going to
+     * reply with syntax error. */
+    if (num > (argc-3)) {
+        *numkeys = 0;
+        return NULL;
+    }
+
+    keys = zmalloc(sizeof(int)*num);
+
+    /* Add all key positions for argv[3...n] to keys[] */
+    for (i = 0; i < num; i++) keys[i] = 3+i;
+
+    return keys;
+}
+
 /* Slot to Key API. This is used by Redis Cluster in order to obtain in
  * a fast way a key that belongs to a specified hash slot. This is useful
  * while rehashing the cluster. */
diff --git a/src/redis.c b/src/redis.c
index e018d2809..2c0e28070 100644
--- a/src/redis.c
+++ b/src/redis.c
@@ -259,8 +259,8 @@ struct redisCommand redisCommandTable[] = {
     {"dump",dumpCommand,2,"ar",0,NULL,1,1,1,0,0},
     {"object",objectCommand,-2,"r",0,NULL,2,2,2,0,0},
     {"client",clientCommand,-2,"ar",0,NULL,0,0,0,0,0},
-    {"eval",evalCommand,-3,"s",0,zunionInterGetKeys,0,0,0,0,0},
-    {"evalsha",evalShaCommand,-3,"s",0,zunionInterGetKeys,0,0,0,0,0},
+    {"eval",evalCommand,-3,"s",0,evalGetKeys,0,0,0,0,0},
+    {"evalsha",evalShaCommand,-3,"s",0,evalGetKeys,0,0,0,0,0},
     {"slowlog",slowlogCommand,-2,"r",0,NULL,0,0,0,0,0},
     {"script",scriptCommand,-2,"ras",0,NULL,0,0,0,0,0},
     {"time",timeCommand,1,"rR",0,NULL,0,0,0,0,0},
diff --git a/src/redis.h b/src/redis.h
index 6ea0c22c6..03ff7c84a 100644
--- a/src/redis.h
+++ b/src/redis.h
@@ -1240,6 +1240,7 @@ int parseScanCursorOrReply(redisClient *c, robj *o, unsigned long *cursor);
 int *getKeysFromCommand(struct redisCommand *cmd, robj **argv, int argc, int *numkeys);
 void getKeysFreeResult(int *result);
 int *zunionInterGetKeys(struct redisCommand *cmd,robj **argv, int argc, int *numkeys);
+int *evalGetKeys(struct redisCommand *cmd, robj **argv, int argc, int *numkeys);
 
 /* Cluster */
 void clusterInit(void);