From 4521115b1767081f17acf67d154c69e1a589c0bb Mon Sep 17 00:00:00 2001
From: antirez <antirez@gmail.com>
Date: Thu, 28 Feb 2013 15:11:05 +0100
Subject: [PATCH] Cluster: new field in cluster node structure, "numslots".

Before a relatively slow popcount() operation was needed every time we
needed to get the number of slots served by a given cluster node.
Now we just need to check an integer that is taken in sync with the
bitmap.
---
 src/cluster.c | 5 +++++
 src/redis.h   | 1 +
 2 files changed, 6 insertions(+)

diff --git a/src/cluster.c b/src/cluster.c
index 3670f4821..584d837ce 100644
--- a/src/cluster.c
+++ b/src/cluster.c
@@ -330,6 +330,7 @@ clusterNode *createClusterNode(char *nodename, int flags) {
         getRandomHexChars(node->name, REDIS_CLUSTER_NAMELEN);
     node->flags = flags;
     memset(node->slots,0,sizeof(node->slots));
+    node->numslots = 0;
     node->numslaves = 0;
     node->slaves = NULL;
     node->slaveof = NULL;
@@ -884,6 +885,8 @@ int clusterProcessPacket(clusterLink *link) {
                         }
                     }
                 }
+                sender->numslots =
+                    popcount(sender->slots,sizeof(sender->slots));
             }
         }
 
@@ -1332,6 +1335,7 @@ int clusterNodeSetSlotBit(clusterNode *n, int slot) {
     int bit = slot&7;
     int old = (n->slots[byte] & (1<<bit)) != 0;
     n->slots[byte] |= 1<<bit;
+    if (!old) n->numslots++;
     return old;
 }
 
@@ -1341,6 +1345,7 @@ int clusterNodeClearSlotBit(clusterNode *n, int slot) {
     int bit = slot&7;
     int old = (n->slots[byte] & (1<<bit)) != 0;
     n->slots[byte] &= ~(1<<bit);
+    if (old) n->numslots--;
     return old;
 }
 
diff --git a/src/redis.h b/src/redis.h
index 6a6d72d92..14d26f44c 100644
--- a/src/redis.h
+++ b/src/redis.h
@@ -553,6 +553,7 @@ struct clusterNode {
     char name[REDIS_CLUSTER_NAMELEN]; /* Node name, hex string, sha1-size */
     int flags;      /* REDIS_NODE_... */
     unsigned char slots[REDIS_CLUSTER_SLOTS/8]; /* slots handled by this node */
+    int numslots;   /* Number of slots handled by this node */
     int numslaves;  /* Number of slave nodes, if this is a master */
     struct clusterNode **slaves; /* pointers to slave nodes */
     struct clusterNode *slaveof; /* pointer to the master node */