OpenTween/Connection/LazyJson.cs

   1 // OpenTween - Client of Twitter
   2 // Copyright (c) 2016 kim_upsilon (@kim_upsilon) <https://upsilo.net/~upsilon/>
   3 // All rights reserved.
   4 //
   5 // This file is part of OpenTween.
   6 //
   7 // This program is free software; you can redistribute it and/or modify it
   8 // under the terms of the GNU General Public License as published by the Free
   9 // Software Foundation; either version 3 of the License, or (at your option)
  10 // any later version.
  11 //
  12 // This program is distributed in the hope that it will be useful, but
  13 // WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14 // or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  15 // for more details.
  16 //
  17 // You should have received a copy of the GNU General Public License along
  18 // with this program. If not, see <http://www.gnu.org/licenses/>, or write to
  19 // the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
  20 // Boston, MA 02110-1301, USA.
  21
  22 using System;
  23 using System.Collections.Generic;
  24 using System.Linq;
  25 using System.Net.Http;
  26 using System.Runtime.Serialization;
  27 using System.Text;
  28 using System.Threading.Tasks;
  29 using OpenTween.Api;
  30
  31 namespace OpenTween.Connection
  32 {
  33     /// <summary>
  34     /// HTTP レスポンスの受信と JSON のパース処理を延期させるクラス
  35     /// </summary>
  36     public sealed class LazyJson<T> : IDisposable
  37     {
  38         public HttpResponseMessage Response { get; }
  39
  40         private T instance;
  41         private bool completed = false;
  42
  43         public LazyJson(HttpResponseMessage response)
  44         {
  45             this.Response = response;
  46         }
  47
  48         internal LazyJson(T instance)
  49         {
  50             this.Response = null;
  51
  52             this.instance = instance;
  53             this.completed = true;
  54         }
  55
  56         public async Task<T> LoadJsonAsync()
  57         {
  58             if (this.completed)
  59                 return this.instance;
  60
  61             using (var content = this.Response.Content)
  62             {
  63                 var responseText = await content.ReadAsStringAsync()
  64                     .ConfigureAwait(false);
  65
  66                 try
  67                 {
  68                     this.instance = MyCommon.CreateDataFromJson<T>(responseText);
  69                     this.completed = true;
  70
  71                     return this.instance;
  72                 }
  73                 catch (SerializationException ex)
  74                 {
  75                     throw TwitterApiException.CreateFromException(ex, responseText);
  76                 }
  77             }
  78         }
  79
  80         public void Dispose()
  81         {
  82             this.Response?.Dispose();
  83         }
  84     }
  85
  86     public static class LazyJson
  87     {
  88         public static LazyJson<T> Create<T>(T instance)
  89             => new LazyJson<T>(instance);
  90     }
  91
  92     public static class LazyJsonTaskExtension
  93     {
  94         public static async Task IgnoreResponse<T>(this Task<LazyJson<T>> task)
  95         {
  96             using (var lazyJson = await task.ConfigureAwait(false))
  97             {
  98                 // レスポンスボディを読み込まず破棄する
  99             }
 100         }
 101     }
 102 }