components/language_usage_metrics/language_usage_metrics.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 "components/language_usage_metrics/language_usage_metrics.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/metrics/sparse_histogram.h"
  10 #include "base/strings/string_tokenizer.h"
  11 #include "base/strings/string_util.h"
  12
  13 namespace {
  14 void RecordAcceptLanguage(int language_code) {
  15   UMA_HISTOGRAM_SPARSE_SLOWLY("LanguageUsage.AcceptLanguage",
  16                               language_code);
  17 }
  18 }  // namespace
  19
  20 namespace language_usage_metrics {
  21
  22 // static
  23 void LanguageUsageMetrics::RecordAcceptLanguages(
  24     const std::string& accept_languages) {
  25   std::set<int> languages;
  26   ParseAcceptLanguages(accept_languages, &languages);
  27   std::for_each(languages.begin(), languages.end(), RecordAcceptLanguage);
  28 }
  29
  30 // static
  31 void LanguageUsageMetrics::RecordApplicationLanguage(
  32     const std::string& application_locale) {
  33   const int language_code = ToLanguageCode(application_locale);
  34   if (language_code != 0)
  35     UMA_HISTOGRAM_SPARSE_SLOWLY("LanguageUsage.ApplicationLanguage",
  36                                 language_code);
  37 }
  38
  39 // static
  40 int LanguageUsageMetrics::ToLanguageCode(const std::string& locale) {
  41   base::StringTokenizer parts(locale, "-_");
  42   if (!parts.GetNext())
  43     return 0;
  44
  45   std::string language_part = base::ToLowerASCII(parts.token());
  46
  47   int language_code = 0;
  48   for (std::string::iterator it = language_part.begin();
  49        it != language_part.end(); ++it) {
  50     char ch = *it;
  51     if (ch < 'a' || 'z' < ch)
  52       return 0;
  53
  54     language_code <<= 8;
  55     language_code += ch;
  56   }
  57
  58   return language_code;
  59 }
  60
  61 // static
  62 void LanguageUsageMetrics::ParseAcceptLanguages(
  63     const std::string& accept_languages,
  64     std::set<int>* languages) {
  65   languages->clear();
  66   base::StringTokenizer locales(accept_languages, ",");
  67   while (locales.GetNext()) {
  68     const int language_code = ToLanguageCode(locales.token());
  69     if (language_code != 0)
  70       languages->insert(language_code);
  71   }
  72 }
  73
  74 }  // namespace language_usage_metrics