base/i18n/number_formatting.cc

   1 // Copyright (c) 2012 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 "base/i18n/number_formatting.h"
   6
   7 #include "base/format_macros.h"
   8 #include "base/lazy_instance.h"
   9 #include "base/logging.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/strings/string_util.h"
  12 #include "base/strings/stringprintf.h"
  13 #include "base/strings/utf_string_conversions.h"
  14 #include "third_party/icu/source/common/unicode/ustring.h"
  15 #include "third_party/icu/source/i18n/unicode/numfmt.h"
  16
  17 namespace base {
  18
  19 namespace {
  20
  21 // A simple wrapper around icu::NumberFormat that allows for resetting it
  22 // (as LazyInstance does not).
  23 struct NumberFormatWrapper {
  24   NumberFormatWrapper() {
  25     Reset();
  26   }
  27
  28   void Reset() {
  29     // There's no ICU call to destroy a NumberFormat object other than
  30     // operator delete, so use the default Delete, which calls operator delete.
  31     // This can cause problems if a different allocator is used by this file
  32     // than by ICU.
  33     UErrorCode status = U_ZERO_ERROR;
  34     number_format.reset(icu::NumberFormat::createInstance(status));
  35     DCHECK(U_SUCCESS(status));
  36   }
  37
  38   scoped_ptr<icu::NumberFormat> number_format;
  39 };
  40
  41 LazyInstance<NumberFormatWrapper> g_number_format_int =
  42     LAZY_INSTANCE_INITIALIZER;
  43 LazyInstance<NumberFormatWrapper> g_number_format_float =
  44     LAZY_INSTANCE_INITIALIZER;
  45
  46 }  // namespace
  47
  48 string16 FormatNumber(int64 number) {
  49   icu::NumberFormat* number_format =
  50       g_number_format_int.Get().number_format.get();
  51
  52   if (!number_format) {
  53     // As a fallback, just return the raw number in a string.
  54     return UTF8ToUTF16(StringPrintf("%" PRId64, number));
  55   }
  56   icu::UnicodeString ustr;
  57   number_format->format(number, ustr);
  58
  59   return string16(ustr.getBuffer(), static_cast<size_t>(ustr.length()));
  60 }
  61
  62 string16 FormatDouble(double number, int fractional_digits) {
  63   icu::NumberFormat* number_format =
  64       g_number_format_float.Get().number_format.get();
  65
  66   if (!number_format) {
  67     // As a fallback, just return the raw number in a string.
  68     return UTF8ToUTF16(StringPrintf("%f", number));
  69   }
  70   number_format->setMaximumFractionDigits(fractional_digits);
  71   number_format->setMinimumFractionDigits(fractional_digits);
  72   icu::UnicodeString ustr;
  73   number_format->format(number, ustr);
  74
  75   return string16(ustr.getBuffer(), static_cast<size_t>(ustr.length()));
  76 }
  77
  78 namespace testing {
  79
  80 void ResetFormatters() {
  81   g_number_format_int.Get().Reset();
  82   g_number_format_float.Get().Reset();
  83 }
  84
  85 }  // namespace testing
  86
  87 }  // namespace base