Add filter argument to ringbuffer readMany() method and a test for it…

… API-1294 (hazelcast#1414)

* add filter argument to ringbuffer readMany() method and a test for it

* fix some typos

src/proxy/Ringbuffer.ts

@@ -156,13 +156,22 @@ export interface Ringbuffer<E> extends DistributedObject {
      * until further items become available, and it can read at least the
      * minimum number of items.
      *
+     * `filter` argument is provided to select only the items that are needed
+     * to be read. If the filter is not provided, all items will be read.
+     * Otherwise, only the items where the filter function returns true are returned.
+     * Using filters is a good way to prevent getting items that are of no value
+     * to the receiver. This reduces the amount of IO and the number of operations being executed,
+     * and can result in a significant performance improvement. Note that,
+     * filtering logic must be defined on the server-side.
+     *
      * @param startSequence sequence number of the first item to be read.
      * @param minCount minimum number of items to be read.
      * @param maxCount maximum number of items to be read.
+     * @param filter optional filter to be applied to the items
      * @throws RangeError if `startSequence` is smaller than `0`,
      *                      or if `minCount` smaller than `0`,
      *                      or if `minCount` larger than `maxCount`,
      *                      or if `maxCount` larger than `1000` (to prevent overloading)
      */
-    readMany(startSequence: number | Long, minCount: number, maxCount: number): Promise<ReadResultSet<E>>;
+    readMany(startSequence: number | Long, minCount: number, maxCount: number, filter?: any): Promise<ReadResultSet<E>>;
 }

test/integration/backward_compatible/parallel/ringbuffer/RingbufferProxyTest.js

@@ -158,4 +158,13 @@ describe('RingbufferProxyTest', function () {
         const size = await rb.size();
         expect(size.toNumber()).to.equal(2);
     });
+
+    it('readMany correctly works with a filter', async function () {
+        await rb.addAll(['item1', 'prefixedItem2', 'prefixedItem3']);
+        const items = await rb.readMany(0, 1, 3, new PrefixFilter('prefixed'));
+        expect(items.get(0)).to.equal('prefixedItem2');
+        expect(items.get(1)).to.equal('prefixedItem3');
+        expect(items.getReadCount()).to.equal(3);
+        expect(items.size()).to.equal(2);
+    });
 });