From 1bcf67a75f775b342653505465b5e8ee03974809 Mon Sep 17 00:00:00 2001 From: antirez Date: Thu, 5 Feb 2015 11:28:45 +0100 Subject: [PATCH] dict.c: dictGetRandomKeys() optimization for big->small table case. Related to issue #2306. --- src/dict.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/src/dict.c b/src/dict.c index fbcdd35f..e197266e 100644 --- a/src/dict.c +++ b/src/dict.c @@ -704,7 +704,14 @@ unsigned int dictGetRandomKeys(dict *d, dictEntry **des, unsigned int count) { /* Invariant of the dict.c rehashing: up to the indexes already * visited in ht[0] during the rehashing, there are no populated * buckets, so we can skip ht[0] for indexes between 0 and idx-1. */ - if (j == 0 && i < d->rehashidx) continue; + if (tables == 2 && j == 0 && i < d->rehashidx) { + /* Moreover, if we are currently out of range in the second + * table, there will be no elements in both tables up to + * the current rehashing index, so we jump if possible. + * (this happens when going from big to small table). */ + if (i >= d->ht[1].size) i = d->rehashidx; + continue; + } if (i >= d->ht[j].size) continue; /* Out of range for this table. */ dictEntry *he = d->ht[j].table[i]; while (he) {