shareobjectspoolsize implemented in reds.conf, in order to control the pool size when object sharing is on

TODO

@@ -29,6 +29,7 @@ AFTER 1.0 stable release
    side the type also takes an hash table with key->score mapping, so that when
    there is an update we lookup the current score and can traverse the tree.
  * BITMAP type
+ * LRANGE 4 0 should return the same elements as LRANGE 0 4 but in reverse order
 
 FUTURE HINTS
 

redis.c

@@ -1046,6 +1046,11 @@ static void loadServerConfig(char *filename) {
             if ((server.shareobjects = yesnotoi(argv[1])) == -1) {
                 err = "argument must be 'yes' or 'no'"; goto loaderr;
             }
+        } else if (!strcasecmp(argv[0],"shareobjectspoolsize") && argc == 2) {
+            server.sharingpoolsize = atoi(argv[1]);
+            if (server.sharingpoolsize < 1) {
+                err = "invalid object sharing pool size"; goto loaderr;
+            }
         } else if (!strcasecmp(argv[0],"daemonize") && argc == 2) {
             if ((server.daemonize = yesnotoi(argv[1])) == -1) {
                 err = "argument must be 'yes' or 'no'"; goto loaderr;

redis.conf

@@ -118,4 +118,15 @@ glueoutputbuf yes
 # string in your dataset, but performs lookups against the shared objects
 # pool so it uses more CPU and can be a bit slower. Usually it's a good
 # idea.
+#
+# When object sharing is enabled (shareobjects yes) you can use
+# shareobjectspoolsize to control the size of the pool used in order to try
+# object sharing. A bigger pool size will lead to better sharing capabilities.
+# In general you want this value to be at least the double of the number of
+# very common strings you have in your dataset.
+#
+# WARNING: object sharing is experimental, don't enable this feature
+# in production before of Redis 1.0-stable. Still please try this feature in
+# your development environment so that we can test it better.
 shareobjects no
+shareobjectspoolsize 1024