fs_mgr/libdm/test_util.h

/*
 * Copyright (C) 2018 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef _LIBDM_TEST_UTILS_H_
#define _LIBDM_TEST_UTILS_H_

#include <android-base/unique_fd.h>
#include <stddef.h>

#include <chrono>
#include <string>

#include <libdm/dm.h>
#include <libdm/dm_table.h>

namespace android {
namespace dm {

// Create a temporary in-memory file. If size is non-zero, the file will be
// created with a fixed size.
android::base::unique_fd CreateTempFile(const std::string& name, size_t size);

// Helper to ensure that device mapper devices are released.
class TempDevice {
  public:
    TempDevice(const std::string& name, const DmTable& table)
        : dm_(DeviceMapper::Instance()), name_(name), valid_(false) {
        valid_ = dm_.CreateDevice(name, table, &path_, std::chrono::seconds(5));
    }
    TempDevice(TempDevice&& other) noexcept
        : dm_(other.dm_), name_(other.name_), path_(other.path_), valid_(other.valid_) {
        other.valid_ = false;
    }
    ~TempDevice() {
        if (valid_) {
            dm_.DeleteDevice(name_);
        }
    }
    bool Destroy() {
        if (!valid_) {
            return false;
        }
        valid_ = false;
        return dm_.DeleteDevice(name_);
    }
    std::string path() const { return path_; }
    const std::string& name() const { return name_; }
    bool valid() const { return valid_; }

    TempDevice(const TempDevice&) = delete;
    TempDevice& operator=(const TempDevice&) = delete;

    TempDevice& operator=(TempDevice&& other) noexcept {
        name_ = other.name_;
        valid_ = other.valid_;
        other.valid_ = false;
        return *this;
    }

  private:
    DeviceMapper& dm_;
    std::string name_;
    std::string path_;
    bool valid_;
};

}  // namespace dm
}  // namespace android

#endif  // _LIBDM_TEST_UTILS_H_