1 files changed, 59 insertions, 0 deletions
diff --git a/predicate-search/src/test/java/com/yahoo/search/predicate/utils/PostingListSearchTest.java b/predicate-search/src/test/java/com/yahoo/search/predicate/utils/PostingListSearchTest.java
new file mode 100644
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--- /dev/null
+++ b/predicate-search/src/test/java/com/yahoo/search/predicate/utils/PostingListSearchTest.java
@@ -0,0 +1,59 @@
+// Copyright 2016 Yahoo Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.search.predicate.utils;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * @author bjorncs
+ */
+public class PostingListSearchTest {
+
+    @Test
+    public void require_that_search_find_index_of_first_element_higher() {
+        int[] values = {2, 8, 4000, 4001, 4100, 10000, 10000000};
+        int length = values.length;
+        assertEquals(0, PostingListSearch.interpolationSearch(values, 0, length, 1));
+        for (int value = 3; value < 8; value++) {
+            assertEquals(1, PostingListSearch.interpolationSearch(values, 0, length, value));
+        }
+        assertEquals(2, PostingListSearch.interpolationSearch(values, 0, length, 8));
+        assertEquals(values.length, PostingListSearch.interpolationSearch(values, 0, length, 10000000));
+        assertEquals(values.length, PostingListSearch.interpolationSearch(values, 0, length, 10000001));
+    }
+
+    @Test
+    public void require_that_search_is_correct_for_one_size_arrays() {
+        int[] values = {100};
+        assertEquals(0, PostingListSearch.interpolationSearch(values, 0, 1, 0));
+        assertEquals(0, PostingListSearch.interpolationSearch(values, 0, 1, 99));
+        assertEquals(1, PostingListSearch.interpolationSearch(values, 0, 1, 100));
+        assertEquals(1, PostingListSearch.interpolationSearch(values, 0, 1, 101));
+        assertEquals(1, PostingListSearch.interpolationSearch(values, 0, 1, 10000));
+    }
+
+    @Test
+    public void require_that_search_is_correct_for_sub_arrays() {
+        int[] values = {0, 2, 8, 4000, 4001, 4100};
+        assertEquals(1, PostingListSearch.interpolationSearch(values, 1, 2, 1));
+        assertEquals(2, PostingListSearch.interpolationSearch(values, 1, 2, 2));
+        assertEquals(2, PostingListSearch.interpolationSearch(values, 1, 4, 2));
+        assertEquals(4, PostingListSearch.interpolationSearch(values, 1, 4, 4000));
+        assertEquals(5, PostingListSearch.interpolationSearch(values, 1, 5, 4001));
+        assertEquals(5, PostingListSearch.interpolationSearch(values, 1, 5, 4101));
+    }
+
+    @Test
+    public void require_that_search_is_correct_for_large_arrays() {
+        int length = 10000;
+        int[] values = new int[length];
+        for (int i = 0; i < length; i++) {
+            values[i] = 2 * i;
+        }
+        assertEquals(1, PostingListSearch.interpolationSearch(values, 1, length, 0));
+        assertEquals(1227, PostingListSearch.interpolationSearch(values, 1, length, 2452));
+        assertEquals(1227, PostingListSearch.interpolationSearch(values, 1, length, 2453));
+        assertEquals(1228, PostingListSearch.interpolationSearch(values, 1, length, 2454));
+    }
+}