222

backend/IM_API/Services/UserService.cs

@@ -6,6 +6,7 @@ using IM_API.Models;
 using IM_API.Tools;
 using Microsoft.EntityFrameworkCore;
 using StackExchange.Redis;
+using System.Text.Json;
 
 namespace IM_API.Services
 {
@@ -15,12 +16,16 @@ namespace IM_API.Services
         private readonly ILogger<UserService> _logger;
         private readonly IMapper _mapper;
         private readonly ICacheService _cacheService;
-        public UserService(ImContext imContext,ILogger<UserService> logger,IMapper mapper, ICacheService cacheService)
+        private readonly IDatabase _redis;
+        public UserService(
+            ImContext imContext,ILogger<UserService> logger,
+            IMapper mapper, ICacheService cacheService, IConnectionMultiplexer connectionMultiplexer)
         {
             this._context = imContext;
             this._logger = logger;
             this._mapper = mapper;
             _cacheService = cacheService;
+            _redis = connectionMultiplexer.GetDatabase();
         }
         #region 获取用户信息
         public async Task<UserInfoDto> GetUserInfoAsync(int userId)
@@ -87,5 +92,38 @@ namespace IM_API.Services
             return _mapper.Map<UserInfoDto>(user);
         }
         #endregion
+        #region 批量获取用户信息
+        public async Task<List<UserInfoDto>> GetUserInfoListAsync(List<int> ids)
+        {
+            //读取缓存中存在的用户，存在直接添加到结果列表
+            var idKeyArr = ids.Select(s => (RedisKey)RedisKeys.GetUserinfoKey(s.ToString())).ToArray();
+            var values = await _redis.StringGetAsync(idKeyArr);
+            List<User> results = [];
+            List<int> missingIds = [];
+            for(int i = 0; i < ids.Count; i++)
+            {
+                if (values[i].HasValue)
+                {
+                    results.Add(JsonSerializer.Deserialize<User>(values[i]));
+                }
+                else
+                {
+                    missingIds.Add(ids[i]);
+                }
+            }
+            //如果存在没有缓存的用户则进行查库
+            if (missingIds.Any())
+            {
+                var dbUsers = await _context.Users
+                    .Where(x => ids.Contains(x.Id)).ToListAsync();
+
+                results.AddRange(dbUsers);
+
+                var setTasks = dbUsers.Select(s => _cacheService.SetUserCacheAsync(s)).ToList();
+                await Task.WhenAll(setTasks);
+            }
+            return _mapper.Map<List<UserInfoDto>>(results);
+        }
+        #endregion
     }
 }