Merge branch 'couchbase/mad-hatter' into master

* branch 'couchbase/mad-hatter':
  MB-41804: Track correct number of vbuckets in each state

Change-Id: I768047d78a5de4daa33ae6ca0dc60937f3524d99

Author: jameseh96

engines/ep/tests/module_tests/kv_bucket_test.cc

@@ -1669,6 +1669,31 @@ TEST_P(KVBucketParamTest, VBucketDiskStatsENOENT) {
     EXPECT_EQ(expected, store->getPerVBucketDiskStats({}, mockStatFn));
 }
 
+TEST_P(KVBucketParamTest, VbucketStateCounts) {
+    // confirm the vbMap correctly changes the number of vbuckets in a given
+    // state when vbuckets change state
+    auto vbA = Vbid(0);
+    auto vbB = Vbid(1);
+
+    auto expectVbCounts = [this](uint16_t active, uint16_t replica) {
+        auto message = "Expected " + std::to_string(active) + " active and " +
+                       std::to_string(replica) + " replica vbs";
+        EXPECT_EQ(active, store->getNumOfVBucketsInState(vbucket_state_active))
+                << message;
+        EXPECT_EQ(replica,
+                  store->getNumOfVBucketsInState(vbucket_state_replica))
+                << message;
+    };
+    store->setVBucketState(vbA, vbucket_state_active);
+    expectVbCounts(1, 0);
+    store->setVBucketState(vbB, vbucket_state_active);
+    expectVbCounts(2, 0);
+    store->setVBucketState(vbA, vbucket_state_replica);
+    expectVbCounts(1, 1);
+    store->setVBucketState(vbB, vbucket_state_replica);
+    expectVbCounts(0, 2);
+}
+
 class StoreIfTest : public KVBucketTest {
 public:
     void SetUp() override {