feat: Redis 토큰 캐시 관리 구현 (#154)

- ITokenCacheService 인터페이스 및 Redis 기반 TokenCacheService 구현
- Key: device:token:{serviceId}:{deviceId}, TTL: 1시간
- PushWorker single 발송 시 캐시 우선 조회, 미스 시 DB 조회 후 캐시 저장
- DeviceService 등록/수정/삭제/수신동의 변경 시 캐시 무효화
- RedisConnection에 GetServer() 메서드 추가 (서비스별 전체 무효화용)

Closes #154

SPMS.Application/Interfaces/ITokenCacheService.cs

@@ -0,0 +1,11 @@
+namespace SPMS.Application.Interfaces;
+
+public interface ITokenCacheService
+{
+    Task<CachedDeviceInfo?> GetDeviceInfoAsync(long serviceId, long deviceId);
+    Task SetDeviceInfoAsync(long serviceId, long deviceId, CachedDeviceInfo info);
+    Task InvalidateAsync(long serviceId, long deviceId);
+    Task InvalidateByServiceAsync(long serviceId);
+}
+
+public record CachedDeviceInfo(string Token, int Platform, bool IsActive, bool PushAgreed);

SPMS.Application/Services/DeviceService.cs

@@ -13,11 +13,16 @@ public class DeviceService : IDeviceService
 {
     private readonly IDeviceRepository _deviceRepository;
     private readonly IUnitOfWork _unitOfWork;
+    private readonly ITokenCacheService _tokenCache;
 
-    public DeviceService(IDeviceRepository deviceRepository, IUnitOfWork unitOfWork)
+    public DeviceService(
+        IDeviceRepository deviceRepository,
+        IUnitOfWork unitOfWork,
+        ITokenCacheService tokenCache)
     {
         _deviceRepository = deviceRepository;
         _unitOfWork = unitOfWork;
+        _tokenCache = tokenCache;
     }
 
     public async Task<DeviceRegisterResponseDto> RegisterAsync(long serviceId, DeviceRegisterRequestDto request)
@@ -35,6 +40,7 @@ public class DeviceService : IDeviceService
             existing.UpdatedAt = DateTime.UtcNow;
             _deviceRepository.Update(existing);
             await _unitOfWork.SaveChangesAsync();
+            await _tokenCache.InvalidateAsync(serviceId, existing.Id);
 
             return new DeviceRegisterResponseDto { DeviceId = existing.Id, IsNew = false };
         }
@@ -97,6 +103,7 @@ public class DeviceService : IDeviceService
         device.UpdatedAt = DateTime.UtcNow;
         _deviceRepository.Update(device);
         await _unitOfWork.SaveChangesAsync();
+        await _tokenCache.InvalidateAsync(serviceId, device.Id);
     }
 
     public async Task DeleteAsync(long serviceId, DeviceDeleteRequestDto request)
@@ -109,6 +116,7 @@ public class DeviceService : IDeviceService
         device.UpdatedAt = DateTime.UtcNow;
         _deviceRepository.Update(device);
         await _unitOfWork.SaveChangesAsync();
+        await _tokenCache.InvalidateAsync(serviceId, device.Id);
     }
 
     public async Task<DeviceListResponseDto> GetListAsync(long serviceId, DeviceListRequestDto request)
@@ -169,6 +177,7 @@ public class DeviceService : IDeviceService
             device.MktAgreeUpdatedAt = DateTime.UtcNow;
         _deviceRepository.Update(device);
         await _unitOfWork.SaveChangesAsync();
+        await _tokenCache.InvalidateAsync(serviceId, device.Id);
     }
 
     private static Platform ParsePlatform(string platform)

SPMS.Infrastructure/Caching/RedisConnection.cs

@@ -50,6 +50,15 @@ public class RedisConnection : IAsyncDisposable
         }
     }
 
+    public IServer? GetServer()
+    {
+        if (_connection is not { IsConnected: true })
+            return null;
+
+        var endpoint = _connection.GetEndPoints().FirstOrDefault();
+        return endpoint != null ? _connection.GetServer(endpoint) : null;
+    }
+
     private static string MaskConnectionString(string connectionString)
     {
         var parts = connectionString.Split(',');

SPMS.Infrastructure/Caching/TokenCacheService.cs

@@ -0,0 +1,102 @@
+using System.Text.Json;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using SPMS.Application.Interfaces;
+using SPMS.Application.Settings;
+using StackExchange.Redis;
+
+namespace SPMS.Infrastructure.Caching;
+
+public class TokenCacheService : ITokenCacheService
+{
+    private readonly RedisConnection _redis;
+    private readonly RedisSettings _settings;
+    private readonly ILogger<TokenCacheService> _logger;
+
+    private static readonly TimeSpan CacheTtl = TimeSpan.FromHours(1);
+
+    public TokenCacheService(
+        RedisConnection redis,
+        IOptions<RedisSettings> settings,
+        ILogger<TokenCacheService> logger)
+    {
+        _redis = redis;
+        _settings = settings.Value;
+        _logger = logger;
+    }
+
+    public async Task<CachedDeviceInfo?> GetDeviceInfoAsync(long serviceId, long deviceId)
+    {
+        try
+        {
+            var db = await _redis.GetDatabaseAsync();
+            var value = await db.StringGetAsync(BuildKey(serviceId, deviceId));
+
+            if (value.IsNullOrEmpty)
+                return null;
+
+            return JsonSerializer.Deserialize<CachedDeviceInfo>(value!);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "토큰 캐시 조회 실패: serviceId={ServiceId}, deviceId={DeviceId}",
+                serviceId, deviceId);
+            return null;
+        }
+    }
+
+    public async Task SetDeviceInfoAsync(long serviceId, long deviceId, CachedDeviceInfo info)
+    {
+        try
+        {
+            var db = await _redis.GetDatabaseAsync();
+            var json = JsonSerializer.Serialize(info);
+            await db.StringSetAsync(BuildKey(serviceId, deviceId), json, CacheTtl);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "토큰 캐시 저장 실패: serviceId={ServiceId}, deviceId={DeviceId}",
+                serviceId, deviceId);
+        }
+    }
+
+    public async Task InvalidateAsync(long serviceId, long deviceId)
+    {
+        try
+        {
+            var db = await _redis.GetDatabaseAsync();
+            await db.KeyDeleteAsync(BuildKey(serviceId, deviceId));
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "토큰 캐시 무효화 실패: serviceId={ServiceId}, deviceId={DeviceId}",
+                serviceId, deviceId);
+        }
+    }
+
+    public async Task InvalidateByServiceAsync(long serviceId)
+    {
+        try
+        {
+            var db = await _redis.GetDatabaseAsync();
+            var server = _redis.GetServer();
+            if (server == null) return;
+
+            var pattern = $"{_settings.InstanceName}device:token:{serviceId}:*";
+            var keys = server.Keys(pattern: pattern).ToArray();
+
+            if (keys.Length > 0)
+                await db.KeyDeleteAsync(keys);
+
+            _logger.LogInformation("서비스 토큰 캐시 전체 무효화: serviceId={ServiceId}, 삭제={Count}건",
+                serviceId, keys.Length);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "서비스 토큰 캐시 전체 무효화 실패: serviceId={ServiceId}", serviceId);
+        }
+    }
+
+    private string BuildKey(long serviceId, long deviceId) =>
+        $"{_settings.InstanceName}device:token:{serviceId}:{deviceId}";
+}

SPMS.Infrastructure/DependencyInjection.cs

@@ -58,6 +58,7 @@ public static class DependencyInjection
         services.AddSingleton<IDuplicateChecker, DuplicateChecker>();
         services.AddSingleton<IScheduleCancelStore, ScheduleCancelStore>();
         services.AddSingleton<IBulkJobStore, BulkJobStore>();
+        services.AddSingleton<ITokenCacheService, TokenCacheService>();
 
         // RabbitMQ
         services.Configure<RabbitMQSettings>(configuration.GetSection(RabbitMQSettings.SectionName));

SPMS.Infrastructure/Workers/PushWorker.cs

@@ -25,6 +25,7 @@ public class PushWorker : BackgroundService
     private readonly IServiceScopeFactory _scopeFactory;
     private readonly IDuplicateChecker _duplicateChecker;
     private readonly IBulkJobStore _bulkJobStore;
+    private readonly ITokenCacheService _tokenCache;
     private readonly IFcmSender _fcmSender;
     private readonly IApnsSender _apnsSender;
     private readonly ILogger<PushWorker> _logger;
@@ -35,6 +36,7 @@ public class PushWorker : BackgroundService
         IServiceScopeFactory scopeFactory,
         IDuplicateChecker duplicateChecker,
         IBulkJobStore bulkJobStore,
+        ITokenCacheService tokenCache,
         IFcmSender fcmSender,
         IApnsSender apnsSender,
         ILogger<PushWorker> logger)
@@ -44,6 +46,7 @@ public class PushWorker : BackgroundService
         _scopeFactory = scopeFactory;
         _duplicateChecker = duplicateChecker;
         _bulkJobStore = bulkJobStore;
+        _tokenCache = tokenCache;
         _fcmSender = fcmSender;
         _apnsSender = apnsSender;
         _logger = logger;
@@ -289,9 +292,36 @@ public class PushWorker : BackgroundService
                 var devices = new List<Device>();
                 foreach (var id in deviceIds)
                 {
+                    // Redis 캐시 우선 조회
+                    var cached = await _tokenCache.GetDeviceInfoAsync(message.ServiceId, id);
+                    if (cached != null)
+                    {
+                        if (cached.IsActive && cached.PushAgreed)
+                        {
+                            devices.Add(new Device
+                            {
+                                Id = id,
+                                ServiceId = message.ServiceId,
+                                DeviceToken = cached.Token,
+                                Platform = (Platform)cached.Platform,
+                                IsActive = true,
+                                PushAgreed = true
+                            });
+                        }
+                        continue;
+                    }
+
+                    // 캐시 미스 → DB 조회 후 캐시 저장
                     var device = await deviceRepo.GetByIdAndServiceAsync(id, message.ServiceId);
-                    if (device is { IsActive: true, PushAgreed: true })
-                        devices.Add(device);
+                    if (device != null)
+                    {
+                        await _tokenCache.SetDeviceInfoAsync(message.ServiceId, id,
+                            new CachedDeviceInfo(device.DeviceToken, (int)device.Platform,
+                                device.IsActive, device.PushAgreed));
+
+                        if (device is { IsActive: true, PushAgreed: true })
+                            devices.Add(device);
+                    }
                 }
                 return devices;
             }