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// Copyright (c) 2012 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/delete_reg_value_work_item.h"
#include "base/logging.h"
#include "base/strings/string_util.h"
#include "base/win/registry.h"
#include "chrome/installer/util/logging_installer.h"
using base::win::RegKey;
DeleteRegValueWorkItem::DeleteRegValueWorkItem(HKEY predefined_root,
const std::wstring& key_path,
REGSAM wow64_access,
const std::wstring& value_name)
: predefined_root_(predefined_root),
key_path_(key_path),
value_name_(value_name),
wow64_access_(wow64_access),
status_(DELETE_VALUE),
previous_type_(0) {
DCHECK(wow64_access == 0 ||
wow64_access == KEY_WOW64_32KEY ||
wow64_access == KEY_WOW64_64KEY);
}
DeleteRegValueWorkItem::~DeleteRegValueWorkItem() {
}
bool DeleteRegValueWorkItem::Do() {
if (status_ != DELETE_VALUE) {
// we already did something.
LOG(ERROR) << "multiple calls to Do()";
return false;
}
status_ = VALUE_UNCHANGED;
RegKey key;
DWORD type = 0;
DWORD size = 0;
LONG result = key.Open(predefined_root_,
key_path_.c_str(),
KEY_READ | KEY_WRITE | wow64_access_);
if (result == ERROR_SUCCESS)
result = key.ReadValue(value_name_.c_str(), NULL, &size, &type);
if (result == ERROR_FILE_NOT_FOUND) {
LOG(INFO) << "(delete value) Key: " << key_path_ << " or Value: "
<< value_name_ << " does not exist.";
status_ = VALUE_NOT_FOUND;
return true;
}
if (result == ERROR_SUCCESS) {
if (!size) {
previous_type_ = type;
} else {
previous_value_.resize(size);
result = key.ReadValue(value_name_.c_str(), &previous_value_[0], &size,
&previous_type_);
if (result != ERROR_SUCCESS) {
previous_value_.erase();
VLOG(1) << "Failed to save original value. Error: " << result;
}
}
}
result = key.DeleteValue(value_name_.c_str());
if (result != ERROR_SUCCESS) {
VLOG(1) << "Failed to delete value " << value_name_ << " error: " << result;
return false;
}
status_ = VALUE_DELETED;
return true;
}
void DeleteRegValueWorkItem::Rollback() {
if (status_ == DELETE_VALUE || status_ == VALUE_ROLLED_BACK)
return;
if (status_ == VALUE_UNCHANGED || status_ == VALUE_NOT_FOUND) {
status_ = VALUE_ROLLED_BACK;
VLOG(1) << "rollback: setting unchanged, nothing to do";
return;
}
// At this point only possible state is VALUE_DELETED.
RegKey key;
LONG result = key.Open(predefined_root_,
key_path_.c_str(),
KEY_READ | KEY_WRITE | wow64_access_);
if (result == ERROR_SUCCESS) {
// try to restore the previous value
DWORD previous_size = static_cast<DWORD>(previous_value_.size());
const char* previous_value =
previous_size ? &previous_value_[0] : NULL;
result = key.WriteValue(value_name_.c_str(), previous_value,
previous_size, previous_type_);
VLOG_IF(1, result != ERROR_SUCCESS) << "rollback: restoring "
<< value_name_ << " error: " << result;
} else {
VLOG(1) << "can not open " << key_path_ << " error: " << result;
}
}
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