chrome/browser/extensions/activity_log/hashed_ad_network_database.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/extensions/activity_log/hashed_ad_network_database.h"
   6
   7 #include <algorithm>  // std::binary_search
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "base/logging.h"
  12 #include "base/macros.h"
  13 #include "base/stl_util.h"
  14 #include "base/strings/string_number_conversions.h"
  15 #include "chrome/browser/extensions/activity_log/hashed_ad_networks.h"
  16 #include "crypto/sha2.h"
  17 #include "url/gurl.h"
  18
  19 namespace extensions {
  20
  21 namespace {
  22
  23 typedef char shorthash[8];
  24
  25 bool CompareEntries(const char* entry1, const char* entry2) {
  26   return strcmp(entry1, entry2) < 0;
  27 }
  28
  29 }
  30
  31 HashedAdNetworkDatabase::HashedAdNetworkDatabase()
  32     : entries_(kHashedAdNetworks),
  33       num_entries_(kNumHashedAdNetworks) {
  34 }
  35
  36 HashedAdNetworkDatabase::~HashedAdNetworkDatabase() {
  37 }
  38
  39 bool HashedAdNetworkDatabase::IsAdNetwork(const GURL& url) const {
  40 // The list should be sorted. Check once in debug builds.
  41 #if DCHECK_IS_ON()
  42   static bool is_sorted = false;
  43   if (!is_sorted) {
  44     std::vector<std::string> list;
  45     for (int i = 0; i < num_entries_; ++i)
  46       list.push_back(std::string(entries_[i]));
  47     is_sorted = base::STLIsSorted(list);
  48   }
  49   DCHECK(is_sorted);
  50 #endif
  51
  52   shorthash hash;
  53   crypto::SHA256HashString(url.host(), hash, sizeof(shorthash));
  54   std::string hex_encoded = base::HexEncode(hash, sizeof(shorthash));
  55   return std::binary_search(entries_,
  56                             entries_ + num_entries_,
  57                             hex_encoded.c_str(),
  58                             CompareEntries);
  59 }
  60
  61 }  // namespace extensions