DocSpace-buildtools/common/services/ASC.Data.Backup.BackgroundTasks/Services/BackupCleanerService.cs

// (c) Copyright Ascensio System SIA 2010-2022
//
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// to the effect that Ascensio System SIA expressly excludes the warranty of non-infringement of
// any third-party rights.
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namespace ASC.Data.Backup.Services;

[Singletone]
internal sealed class BackupCleanerService : BackgroundService
{
    private readonly ILogger _logger;
    private readonly TimeSpan _backupCleanerPeriod;
    private readonly IServiceScopeFactory _scopeFactory;

    public BackupCleanerService(
        ConfigurationExtension configuration,
        ILogger<BackupCleanerService> logger,
        IServiceScopeFactory scopeFactory)
    {
        _scopeFactory = scopeFactory;
        _logger = logger;
        _backupCleanerPeriod = configuration.GetSetting<BackupSettings>("backup").Cleaner.Period;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        _logger.LogDebug("BackupCleanerService is starting.");

        stoppingToken.Register(() => _logger.LogDebug("#1 BackupCleanerService background task is stopping."));

        while (!stoppingToken.IsCancellationRequested)
        {
            _logger.LogDebug("BackupCleanerService background task is doing background work.");

            using var serviceScope = _scopeFactory.CreateScope();

            var registerInstanceService = serviceScope.ServiceProvider.GetService<IRegisterInstanceManager<BackupCleanerService>>();

            if (!await registerInstanceService.IsActive(RegisterInstanceWorkerService<BackupCleanerService>.InstanceId))
            {
                _logger.LogDebug($"BackupCleanerService background task with instance id {RegisterInstanceWorkerService<BackupCleanerService>.InstanceId} is't active.");

                await Task.Delay(1000, stoppingToken);

                continue;
            }

            ExecuteBackupCleaner(stoppingToken);

            await Task.Delay(_backupCleanerPeriod, stoppingToken);
        }

        _logger.LogDebug("BackupCleanerService background task is stopping.");
    }

    private void ExecuteBackupCleaner(CancellationToken stoppingToken)
    {
        using var serviceScope = _scopeFactory.CreateScope();

        var backupRepository = serviceScope.ServiceProvider.GetRequiredService<BackupRepository>();
        var backupStorageFactory = serviceScope.ServiceProvider.GetRequiredService<BackupStorageFactory>();

        _logger.LogDebug("started to clean expired backups");

        var backupsToRemove = backupRepository.GetExpiredBackupRecords();

        _logger.LogDebug("found {count} backups which are expired", backupsToRemove.Count);

        foreach (var scheduledBackups in backupRepository.GetScheduledBackupRecords().GroupBy(r => r.TenantId))
        {
            if (stoppingToken.IsCancellationRequested)
            {
                return;
            }

            var schedule = backupRepository.GetBackupSchedule(scheduledBackups.Key);

            if (schedule != null)
            {
                var scheduledBackupsToRemove = scheduledBackups.OrderByDescending(r => r.CreatedOn).Skip(schedule.BackupsStored).ToList();
                if (scheduledBackupsToRemove.Any())
                {
                    _logger.LogDebug("only last {storedCount} scheduled backup records are to keep for tenant {tenantId} so {removeCount} records must be removed", schedule.BackupsStored, schedule.TenantId, scheduledBackupsToRemove.Count);
                    backupsToRemove.AddRange(scheduledBackupsToRemove);
                }
            }
            else
            {
                backupsToRemove.AddRange(scheduledBackups);
            }
        }

        foreach (var backupRecord in backupsToRemove)
        {
            if (stoppingToken.IsCancellationRequested)
            {
                return;
            }

            try
            {
                var backupStorage = backupStorageFactory.GetBackupStorage(backupRecord);
                if (backupStorage == null)
                {
                    continue;
                }

                backupStorage.Delete(backupRecord.StoragePath);

                backupRepository.DeleteBackupRecord(backupRecord.Id);
            }
            catch (ProviderInfoArgumentException error)
            {
                _logger.LogWarning(error, "can't remove backup record " + backupRecord.Id);

                if (DateTime.UtcNow > backupRecord.CreatedOn.AddMonths(6))
                {
                    backupRepository.DeleteBackupRecord(backupRecord.Id);
                }
            }
            catch (Exception error)
            {
                _logger.LogWarning(error, "can't remove backup record: " + backupRecord.Id);
            }
        }

    }
}