RAPPOR implementation

components/rappor/bloom_filter_unittest.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/rappor/bloom_filter.h"
+
+#include "components/rappor/byte_vector_utils.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace rappor {
+
+TEST(BloomFilterTest, TinyFilter) {
+  BloomFilter filter(1u, 4u, 0u);
+
+  // Size is 1 and it's initially empty
+  EXPECT_EQ(1u, filter.bytes().size());
+  EXPECT_EQ(0x00, filter.bytes()[0]);
+
+  // "Test" has a self-collision, and only sets 3 bits.
+  filter.AddString("Test");
+  EXPECT_EQ(0x2a, filter.bytes()[0]);
+
+  // Adding the same value shouldn't change anything.
+  filter.AddString("Test");
+  EXPECT_EQ(0x2a, filter.bytes()[0]);
+
+  BloomFilter filter2(1u, 4u, 0u);
+  EXPECT_EQ(0x00, filter2.bytes()[0]);
+  filter2.AddString("Bar");
+  EXPECT_EQ(0xa8, filter2.bytes()[0]);
+
+  // Adding a colliding string should just set new bits.
+  filter.AddString("Bar");
+  EXPECT_EQ(0xaa, filter.bytes()[0]);
+}
+
+TEST(BloomFilterTest, HugeFilter) {
+  // Create a 500 bit filter, and use a large seed offset to see if anything
+  // breaks.
+  BloomFilter filter(500u, 1u, 0xabdef123);
+
+  // Size is 500 and it's initially empty
+  EXPECT_EQ(500u, filter.bytes().size());
+  EXPECT_EQ(0, CountBits(filter.bytes()));
+
+  filter.AddString("Bar");
+  EXPECT_EQ(1, CountBits(filter.bytes()));
+
+  // Adding the same value shouldn't change anything.
+  filter.AddString("Bar");
+  EXPECT_EQ(1, CountBits(filter.bytes()));
+}
+
+}  // namespace rappor