1// Copyright (c) 2011 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 "ui/base/text/bytes_formatting.h"
6
7#include "base/i18n/number_formatting.h"
8#include "base/logging.h"
9#include "base/strings/string_util.h"
10#include "base/strings/utf_string_conversions.h"
11#include "grit/ui_strings.h"
12#include "ui/base/l10n/l10n_util.h"
13
14namespace ui {
15
16namespace {
17
18// Byte suffix string constants. These both must match the DataUnits enum.
19const int kByteStrings[] = {
20  IDS_APP_BYTES,
21  IDS_APP_KIBIBYTES,
22  IDS_APP_MEBIBYTES,
23  IDS_APP_GIBIBYTES,
24  IDS_APP_TEBIBYTES,
25  IDS_APP_PEBIBYTES
26};
27
28const int kSpeedStrings[] = {
29  IDS_APP_BYTES_PER_SECOND,
30  IDS_APP_KIBIBYTES_PER_SECOND,
31  IDS_APP_MEBIBYTES_PER_SECOND,
32  IDS_APP_GIBIBYTES_PER_SECOND,
33  IDS_APP_TEBIBYTES_PER_SECOND,
34  IDS_APP_PEBIBYTES_PER_SECOND
35};
36
37string16 FormatBytesInternal(int64 bytes,
38                             DataUnits units,
39                             bool show_units,
40                             const int* const suffix) {
41  DCHECK(units >= DATA_UNITS_BYTE && units <= DATA_UNITS_PEBIBYTE);
42  if (bytes < 0) {
43    NOTREACHED() << "Negative bytes value";
44    return string16();
45  }
46
47  // Put the quantity in the right units.
48  double unit_amount = static_cast<double>(bytes);
49  for (int i = 0; i < units; ++i)
50    unit_amount /= 1024.0;
51
52  int fractional_digits = 0;
53  if (bytes != 0 && units != DATA_UNITS_BYTE && unit_amount < 100)
54    fractional_digits = 1;
55
56  string16 result = base::FormatDouble(unit_amount, fractional_digits);
57
58  if (show_units)
59    result = l10n_util::GetStringFUTF16(suffix[units], result);
60
61  return result;
62}
63
64}  // namespace
65
66DataUnits GetByteDisplayUnits(int64 bytes) {
67  // The byte thresholds at which we display amounts. A byte count is displayed
68  // in unit U when kUnitThresholds[U] <= bytes < kUnitThresholds[U+1].
69  // This must match the DataUnits enum.
70  static const int64 kUnitThresholds[] = {
71    0,                // DATA_UNITS_BYTE,
72    3 * (1LL << 10),  // DATA_UNITS_KIBIBYTE,
73    2 * (1LL << 20),  // DATA_UNITS_MEBIBYTE,
74    1LL << 30,        // DATA_UNITS_GIBIBYTE,
75    1LL << 40,        // DATA_UNITS_TEBIBYTE,
76    1LL << 50         // DATA_UNITS_PEBIBYTE,
77  };
78
79  if (bytes < 0) {
80    NOTREACHED() << "Negative bytes value";
81    return DATA_UNITS_BYTE;
82  }
83
84  int unit_index = arraysize(kUnitThresholds);
85  while (--unit_index > 0) {
86    if (bytes >= kUnitThresholds[unit_index])
87      break;
88  }
89
90  DCHECK(unit_index >= DATA_UNITS_BYTE && unit_index <= DATA_UNITS_PEBIBYTE);
91  return DataUnits(unit_index);
92}
93
94string16 FormatBytesWithUnits(int64 bytes, DataUnits units, bool show_units) {
95  return FormatBytesInternal(bytes, units, show_units, kByteStrings);
96}
97
98string16 FormatSpeedWithUnits(int64 bytes, DataUnits units, bool show_units) {
99  return FormatBytesInternal(bytes, units, show_units, kSpeedStrings);
100}
101
102string16 FormatBytes(int64 bytes) {
103  return FormatBytesWithUnits(bytes, GetByteDisplayUnits(bytes), true);
104}
105
106string16 FormatSpeed(int64 bytes) {
107  return FormatSpeedWithUnits(bytes, GetByteDisplayUnits(bytes), true);
108}
109
110}  // namespace ui
111