ensure the last page returns null

Author: Bulat Shakirzyanov

src/Cassandra/FutureValue.php

@@ -0,0 +1,50 @@
+<?php
+
+/**
+ * Copyright 2015 DataStax, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Cassandra;
+
+/**
+ * A future that always resolves in a value.
+ */
+final class FutureValue implements Future
+{
+    /**
+     * Actual value to resolve this future with.
+     *
+     * @var mixed
+     */
+    private $value;
+
+    /**
+     * Creates a future value.
+     *
+     * @param mixed $value a value to resolve this future with.
+     */
+    public function __construct($value)
+    {
+        $this->value = $value;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function get($timeout = null)
+    {
+        return $this->value;
+    }
+}

src/Cassandra/Rows.php

@@ -198,6 +198,10 @@ public function nextPage($timeout = null)
      */
     public function nextPageAsync()
     {
+        if (isLastPage()) {
+            return new FutureValue(null);
+        }
+
         try {
             cassandra_statement_set_paging_state($this->statement, $this->resource);
         } catch (Exception $e) {