Finish conversion from bloom filter to prefix set in safe browsing.

chrome/browser/safe_browsing/bloom_filter_unittest.cc

-// Copyright (c) 2012 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 "chrome/browser/safe_browsing/bloom_filter.h"
-
-#include <limits.h>
-
-#include <set>
-#include <vector>
-
-#include "base/file_util.h"
-#include "base/logging.h"
-#include "base/memory/ref_counted.h"
-#include "base/path_service.h"
-#include "base/rand_util.h"
-#include "base/scoped_temp_dir.h"
-#include "base/string_util.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-namespace {
-
-SBPrefix GenHash() {
-  return static_cast<SBPrefix>(base::RandUint64());
-}
-
-}
-
-TEST(SafeBrowsingBloomFilter, BloomFilterUse) {
-  // Use a small number for unit test so it's not slow.
-  int count = 1000;
-
-  // Build up the bloom filter.
-  scoped_refptr<BloomFilter> filter(
-      new BloomFilter(count * BloomFilter::kBloomFilterSizeRatio));
-
-  typedef std::set<SBPrefix> Values;
-  Values values;
-  for (int i = 0; i < count; ++i) {
-    SBPrefix value = GenHash();
-    values.insert(value);
-    filter->Insert(value);
-  }
-  EXPECT_TRUE(filter->CheckChecksum());
-
-  // Check serialization works.
-  char* data_copy = new char[filter->size()];
-  memcpy(data_copy, filter->data(), filter->size());
-  scoped_refptr<BloomFilter> filter_copy(
-      new BloomFilter(data_copy, filter->size(), filter->hash_keys_));
-  EXPECT_TRUE(filter_copy->CheckChecksum());
-
-  // Check no false negatives by ensuring that every time we inserted exists.
-  for (Values::const_iterator i = values.begin(); i != values.end(); ++i)
-    EXPECT_TRUE(filter_copy->Exists(*i));
-
-  // Check false positive error rate by checking the same number of items that
-  // we inserted, but of different values, and calculating what percentage are
-  // "found".
-  int found_count = 0;
-  int checked = 0;
-  while (true) {
-    SBPrefix value = GenHash();
-    if (values.count(value))
-      continue;
-
-    if (filter_copy->Exists(value))
-      found_count++;
-
-    checked++;
-    if (checked == count)
-      break;
-  }
-
-  // The FP rate should be 1.2%.  Keep a large margin of error because we don't
-  // want to fail this test because we happened to randomly pick a lot of FPs.
-  double fp_rate = found_count * 100.0 / count;
-  CHECK(fp_rate < 5.0);
-
-  VLOG(1) << "For safe browsing bloom filter of size " << count
-          << ", the FP rate was " << fp_rate << " %";
-}
-
-// Test that we can read and write the bloom filter file.
-TEST(SafeBrowsingBloomFilter, BloomFilterFile) {
-  // Create initial filter.
-  const int kTestEntries = BloomFilter::kBloomFilterMinSize;
-  scoped_refptr<BloomFilter> filter_write(
-      new BloomFilter(kTestEntries * BloomFilter::kBloomFilterSizeRatio));
-
-  for (int i = 0; i < kTestEntries; ++i)
-    filter_write->Insert(GenHash());
-  EXPECT_TRUE(filter_write->CheckChecksum());
-
-  // Remove any left over test filters and serialize.
-  ScopedTempDir temp_dir;
-  ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
-  FilePath filter_path = temp_dir.path().AppendASCII("SafeBrowsingTestFilter");
-  ASSERT_TRUE(filter_write->WriteFile(filter_path));
-
-  // Create new empty filter and load from disk.
-  BloomFilter* filter = BloomFilter::LoadFile(filter_path);
-  ASSERT_TRUE(filter != NULL);
-  scoped_refptr<BloomFilter> filter_read(filter);
-  EXPECT_TRUE(filter_read->CheckChecksum());
-
-  // Check data consistency.
-  EXPECT_EQ(filter_write->hash_keys_.size(), filter_read->hash_keys_.size());
-
-  for (size_t i = 0; i < filter_write->hash_keys_.size(); ++i)
-    EXPECT_EQ(filter_write->hash_keys_[i], filter_read->hash_keys_[i]);
-
-  EXPECT_EQ(filter_write->size(), filter_read->size());
-
-  EXPECT_EQ(0,
-      memcmp(filter_write->data(), filter_read->data(), filter_read->size()));
-}