1 files changed, 142 insertions, 0 deletions
diff --git a/mfbt/tests/TestBloomFilter.cpp b/mfbt/tests/TestBloomFilter.cpp
new file mode 100644
index 0000000000..a233858826
--- /dev/null
+++ b/mfbt/tests/TestBloomFilter.cpp
@@ -0,0 +1,142 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/Assertions.h"
+#include "mozilla/BloomFilter.h"
+#include "mozilla/UniquePtr.h"
+
+#include <stddef.h>
+#include <stdint.h>
+
+using mozilla::BitBloomFilter;
+using mozilla::CountingBloomFilter;
+
+class FilterChecker {
+ public:
+  explicit FilterChecker(uint32_t aHash) : mHash(aHash) {}
+
+  uint32_t hash() const { return mHash; }
+
+ private:
+  uint32_t mHash;
+};
+
+void testBitBloomFilter() {
+  const mozilla::UniquePtr filter =
+      mozilla::MakeUnique<BitBloomFilter<12, FilterChecker>>();
+  MOZ_RELEASE_ASSERT(filter);
+
+  FilterChecker one(1);
+  FilterChecker two(0x20000);
+
+  filter->add(&one);
+  MOZ_RELEASE_ASSERT(filter->mightContain(&one), "Filter should contain 'one'");
+
+  MOZ_RELEASE_ASSERT(!filter->mightContain(&two),
+                     "Filter claims to contain 'two' when it should not");
+
+  // Test multiple addition
+  filter->add(&two);
+  MOZ_RELEASE_ASSERT(filter->mightContain(&two),
+                     "Filter should contain 'two' after 'two' is added");
+  filter->add(&two);
+  MOZ_RELEASE_ASSERT(filter->mightContain(&two),
+                     "Filter should contain 'two' after 'two' is added again");
+
+  filter->clear();
+
+  MOZ_RELEASE_ASSERT(!filter->mightContain(&one), "clear() failed to work");
+  MOZ_RELEASE_ASSERT(!filter->mightContain(&two), "clear() failed to work");
+}
+
+void testCountingBloomFilter() {
+  const mozilla::UniquePtr filter =
+      mozilla::MakeUnique<CountingBloomFilter<12, FilterChecker>>();
+  MOZ_RELEASE_ASSERT(filter);
+
+  FilterChecker one(1);
+  FilterChecker two(0x20000);
+  FilterChecker many(0x10000);
+  FilterChecker multiple(0x20001);
+
+  filter->add(&one);
+  MOZ_RELEASE_ASSERT(filter->mightContain(&one), "Filter should contain 'one'");
+
+  MOZ_RELEASE_ASSERT(!filter->mightContain(&multiple),
+                     "Filter claims to contain 'multiple' when it should not");
+
+  MOZ_RELEASE_ASSERT(filter->mightContain(&many),
+                     "Filter should contain 'many' (false positive)");
+
+  filter->add(&two);
+  MOZ_RELEASE_ASSERT(filter->mightContain(&multiple),
+                     "Filter should contain 'multiple' (false positive)");
+
+  // Test basic removals
+  filter->remove(&two);
+  MOZ_RELEASE_ASSERT(
+      !filter->mightContain(&multiple),
+      "Filter claims to contain 'multiple' when it should not after two "
+      "was removed");
+
+  // Test multiple addition/removal
+  const size_t FILTER_SIZE = 255;
+  for (size_t i = 0; i < FILTER_SIZE - 1; ++i) {
+    filter->add(&two);
+  }
+  MOZ_RELEASE_ASSERT(
+      filter->mightContain(&multiple),
+      "Filter should contain 'multiple' after 'two' added lots of times "
+      "(false positive)");
+
+  for (size_t i = 0; i < FILTER_SIZE - 1; ++i) {
+    filter->remove(&two);
+  }
+  MOZ_RELEASE_ASSERT(
+      !filter->mightContain(&multiple),
+      "Filter claims to contain 'multiple' when it should not after two "
+      "was removed lots of times");
+
+  // Test overflowing the filter buckets
+  for (size_t i = 0; i < FILTER_SIZE + 1; ++i) {
+    filter->add(&two);
+  }
+  MOZ_RELEASE_ASSERT(
+      filter->mightContain(&multiple),
+      "Filter should contain 'multiple' after 'two' added lots more "
+      "times (false positive)");
+
+  for (size_t i = 0; i < FILTER_SIZE + 1; ++i) {
+    filter->remove(&two);
+  }
+  MOZ_RELEASE_ASSERT(
+      filter->mightContain(&multiple),
+      "Filter claims to not contain 'multiple' even though we should "
+      "have run out of space in the buckets (false positive)");
+  MOZ_RELEASE_ASSERT(
+      filter->mightContain(&two),
+      "Filter claims to not contain 'two' even though we should have "
+      "run out of space in the buckets (false positive)");
+
+  filter->remove(&one);
+
+  MOZ_RELEASE_ASSERT(
+      !filter->mightContain(&one),
+      "Filter should not contain 'one', because we didn't overflow its "
+      "bucket");
+
+  filter->clear();
+
+  MOZ_RELEASE_ASSERT(!filter->mightContain(&multiple),
+                     "clear() failed to work");
+}
+
+int main() {
+  testBitBloomFilter();
+  testCountingBloomFilter();
+
+  return 0;
+}