base/scoped_environment_variable_override.cc

   1 // Copyright 2017 The Chromium Authors
   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/scoped_environment_variable_override.h"
   6
   7 #include "base/environment.h"
   8
   9 namespace base {
  10
  11 ScopedEnvironmentVariableOverride::ScopedEnvironmentVariableOverride(
  12     const std::string& variable_name,
  13     const std::string& value,
  14     bool unset_var)
  15     : environment_(Environment::Create()),
  16       variable_name_(variable_name),
  17       overridden_(false),
  18       was_set_(false) {
  19   was_set_ = environment_->GetVar(variable_name, &old_value_);
  20   if (unset_var)
  21     overridden_ = environment_->UnSetVar(variable_name);
  22   else
  23     overridden_ = environment_->SetVar(variable_name, value);
  24 }
  25
  26 ScopedEnvironmentVariableOverride::ScopedEnvironmentVariableOverride(
  27     const std::string& variable_name,
  28     const std::string& value)
  29     : ScopedEnvironmentVariableOverride(variable_name, value, false) {}
  30
  31 ScopedEnvironmentVariableOverride::ScopedEnvironmentVariableOverride(
  32     const std::string& variable_name)
  33     : ScopedEnvironmentVariableOverride(variable_name, "", true) {}
  34
  35 ScopedEnvironmentVariableOverride::ScopedEnvironmentVariableOverride(
  36     ScopedEnvironmentVariableOverride&&) = default;
  37
  38 ScopedEnvironmentVariableOverride& ScopedEnvironmentVariableOverride::operator=(
  39     ScopedEnvironmentVariableOverride&&) = default;
  40
  41 ScopedEnvironmentVariableOverride::~ScopedEnvironmentVariableOverride() {
  42   if (environment_ && overridden_) {
  43     if (was_set_)
  44       environment_->SetVar(variable_name_, old_value_);
  45     else
  46       environment_->UnSetVar(variable_name_);
  47   }
  48 }
  49
  50 }  // namespace base