| // Copyright 2017 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/installer/util/experiment_labels.h" |
| |
| #include <vector> |
| |
| #include "base/strings/string_split.h" |
| #include "base/strings/stringprintf.h" |
| |
| namespace installer { |
| |
| namespace { |
| |
| constexpr base::StringPiece16::value_type kNameValueSeparator = L'='; |
| constexpr base::StringPiece16::value_type kValueExpirationSeparator = L'|'; |
| constexpr base::StringPiece16::value_type kLabelSeparator = L';'; |
| |
| // Returns a vector of string pieces, one for each "name=value|expiration" |
| // group in |value|. |
| std::vector<base::StringPiece16> Parse(base::StringPiece16 value) { |
| static constexpr base::char16 kLabelSeparatorString[] = {kLabelSeparator, |
| L'\0'}; |
| return base::SplitStringPiece(value, kLabelSeparatorString, |
| base::TRIM_WHITESPACE, |
| base::SPLIT_WANT_NONEMPTY); |
| } |
| |
| // Returns an abbreviated day name for a zero-based |day_of_week|. |
| const wchar_t* AbbreviatedDayOfWeek(int day_of_week) { |
| // Matches the abbreviated day names from the ICU "en" locale. |
| static constexpr const wchar_t* kDays[] = {L"Sun", L"Mon", L"Tue", L"Wed", |
| L"Thu", L"Fri", L"Sat"}; |
| return kDays[day_of_week]; |
| } |
| |
| // Returns an abbreviated month name for a one-based |month|. |
| const wchar_t* AbbreviatedMonth(int month) { |
| // Matches the abbreviated month names from the ICU "en" locale. |
| static constexpr const wchar_t* kMonths[] = {L"Jan", L"Feb", L"Mar", L"Apr", |
| L"May", L"Jun", L"Jul", L"Aug", |
| L"Sep", L"Oct", L"Nov", L"Dec"}; |
| return kMonths[month - 1]; |
| } |
| |
| // Returns a formatted string given a date that is compatible with Omaha (see |
| // https://github.com/google/omaha/blob/master/omaha/base/time.cc#L132). |
| base::string16 FormatDate(base::Time date) { |
| base::Time::Exploded exploded_time; |
| date.UTCExplode(&exploded_time); |
| |
| // "Fri, 14 Aug 2015 16:13:03 GMT" |
| return base::StringPrintf(L"%ls, %02d %ls %04d %02d:%02d:%02d GMT", |
| AbbreviatedDayOfWeek(exploded_time.day_of_week), |
| exploded_time.day_of_month, |
| AbbreviatedMonth(exploded_time.month), |
| exploded_time.year, exploded_time.hour, |
| exploded_time.minute, exploded_time.second); |
| } |
| |
| // Appends "label_name=label_value|expiration" to |label|. |
| void AppendLabel(base::StringPiece16 label_name, |
| base::StringPiece16 label_value, |
| base::Time expiration, |
| base::string16* label) { |
| // 29 characters for the expiration date plus the two separators makes 31. |
| label->reserve(label->size() + label_name.size() + label_value.size() + 31); |
| label_name.AppendToString(label); |
| label->push_back(kNameValueSeparator); |
| label_value.AppendToString(label); |
| label->push_back(kValueExpirationSeparator); |
| label->append(FormatDate(expiration)); |
| } |
| |
| } // namespace |
| |
| ExperimentLabels::ExperimentLabels(const base::string16& value) |
| : value_(value) {} |
| |
| base::StringPiece16 ExperimentLabels::GetValueForLabel( |
| base::StringPiece16 label_name) const { |
| DCHECK(!label_name.empty()); |
| |
| return FindLabel(label_name).second; |
| } |
| |
| void ExperimentLabels::SetValueForLabel(base::StringPiece16 label_name, |
| base::StringPiece16 label_value, |
| base::TimeDelta lifetime) { |
| DCHECK(!label_name.empty()); |
| DCHECK(!label_value.empty()); |
| DCHECK(!lifetime.is_zero()); |
| |
| SetValueForLabel(label_name, label_value, base::Time::Now() + lifetime); |
| } |
| |
| void ExperimentLabels::SetValueForLabel(base::StringPiece16 label_name, |
| base::StringPiece16 label_value, |
| base::Time expiration) { |
| DCHECK(!label_name.empty()); |
| DCHECK(!label_value.empty()); |
| |
| LabelAndValue label_and_value = FindLabel(label_name); |
| if (label_and_value.first.empty()) { |
| // This label doesn't already exist -- append it to the raw value. |
| if (!value_.empty()) |
| value_.push_back(kLabelSeparator); |
| AppendLabel(label_name, label_value, expiration, &value_); |
| } else { |
| // Replace the existing value and expiration. |
| // Get the stuff before the old label. |
| base::string16 new_label(value_, 0, |
| label_and_value.first.data() - value_.data()); |
| // Append the new label. |
| AppendLabel(label_name, label_value, expiration, &new_label); |
| // Find the stuff after the old label and append it. |
| size_t next_separator = value_.find( |
| kLabelSeparator, |
| (label_and_value.second.data() + label_and_value.second.size()) - |
| value_.data()); |
| if (next_separator != base::string16::npos) |
| new_label.append(value_, next_separator, base::string16::npos); |
| // Presto. |
| new_label.swap(value_); |
| } |
| } |
| |
| ExperimentLabels::LabelAndValue ExperimentLabels::FindLabel( |
| base::StringPiece16 label_name) const { |
| DCHECK(!label_name.empty()); |
| |
| std::vector<base::StringPiece16> labels = Parse(value_); |
| for (const auto& label : labels) { |
| if (label.size() < label_name.size() + 2 || |
| !label.starts_with(label_name) || |
| label[label_name.size()] != kNameValueSeparator) { |
| continue; |
| } |
| size_t value_start = label_name.size() + 1; |
| size_t value_end = label.find(kValueExpirationSeparator, value_start); |
| if (value_end == base::StringPiece16::npos) |
| break; |
| return std::make_pair(label, |
| label.substr(value_start, value_end - value_start)); |
| } |
| return LabelAndValue(); |
| } |
| |
| } // namespace installer |