-
Notifications
You must be signed in to change notification settings - Fork 0
/
local-search.xml
1082 lines (519 loc) · 172 KB
/
local-search.xml
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
<?xml version="1.0" encoding="utf-8"?>
<search>
<entry>
<title>Go Module 使用Github私有仓库</title>
<link href="/Go%E8%AF%AD%E8%A8%80%E5%BC%80%E5%8F%91/go-module-%E4%BD%BF%E7%94%A8github%E7%A7%81%E6%9C%89%E4%BB%93%E5%BA%93/"/>
<url>/Go%E8%AF%AD%E8%A8%80%E5%BC%80%E5%8F%91/go-module-%E4%BD%BF%E7%94%A8github%E7%A7%81%E6%9C%89%E4%BB%93%E5%BA%93/</url>
<content type="html"><![CDATA[<h1 id="Go-Module-使用Github私有仓库"><a href="#Go-Module-使用Github私有仓库" class="headerlink" title="Go Module 使用Github私有仓库"></a>Go Module 使用Github私有仓库</h1><h2 id="使用-Access-Token-进行访问"><a href="#使用-Access-Token-进行访问" class="headerlink" title="使用 Access Token 进行访问"></a>使用 Access Token 进行访问</h2><figure class="highlight powershell"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><code class="hljs powershell"><span class="hljs-built_in">PS</span> C:\Users\lukas><span class="hljs-built_in">Set-Variable</span> <span class="hljs-literal">-name</span> username <span class="hljs-literal">-value</span> lukas<br><span class="hljs-built_in">PS</span> C:\Users\lukas><span class="hljs-built_in">Set-Variable</span> <span class="hljs-literal">-name</span> access_token <span class="hljs-literal">-value</span> xxxxxxxxxxxx<br><span class="hljs-built_in">PS</span> C:\Users\lukas> go env <span class="hljs-literal">-w</span> GOPRIVATE=github.com/<span class="hljs-variable">$</span>{username}<br><span class="hljs-built_in">PS</span> C:\Users\lukas> git config -<span class="hljs-literal">-global</span> url.<span class="hljs-string">"https://<span class="hljs-variable">$</span>{username}:<span class="hljs-variable">$</span>{access_token}@github.com"</span>.insteadOf <span class="hljs-string">"https://github.com"</span><br><span class="hljs-built_in">PS</span> C:\Users\lukas> <span class="hljs-built_in">cd</span> D:\tmp<br><span class="hljs-built_in">PS</span> D:\tmp><br><span class="hljs-built_in">PS</span> D:\tmp> go get github.com/lukas/blueberry/examples<br>go: downloading github.com/lukas/blueberry/examples v0.<span class="hljs-number">0.0</span><span class="hljs-literal">-20240329033644</span><span class="hljs-literal">-5f967cf0e366</span><br>go: downloading github.com/lukas/blueberry v0.<span class="hljs-number">0.0</span><span class="hljs-literal">-20240329033644</span><span class="hljs-literal">-5f967cf0e366</span><br>go: added github.com/lukas/blueberry/examples v0.<span class="hljs-number">0.0</span><span class="hljs-literal">-20240329033644</span><span class="hljs-literal">-5f967cf0e366</span><br><span class="hljs-built_in">PS</span> D:\tmp><br></code></pre></td></tr></table></figure>]]></content>
<categories>
<category>Go语言开发</category>
</categories>
<tags>
<tag>Golang</tag>
</tags>
</entry>
<entry>
<title>包管理器vcpkg</title>
<link href="/CPP%E8%AF%AD%E8%A8%80%E5%BC%80%E5%8F%91/%E5%8C%85%E7%AE%A1%E7%90%86%E5%99%A8vcpkg/"/>
<url>/CPP%E8%AF%AD%E8%A8%80%E5%BC%80%E5%8F%91/%E5%8C%85%E7%AE%A1%E7%90%86%E5%99%A8vcpkg/</url>
<content type="html"><![CDATA[<h1 id="包管理器vcpkg"><a href="#包管理器vcpkg" class="headerlink" title="包管理器vcpkg"></a>包管理器vcpkg</h1><p>学习 Versioning 特性，并且使用 vcpkg 来管理 Cmake 项目的依赖。</p><h2 id="参考文章"><a href="#参考文章" class="headerlink" title="参考文章"></a>参考文章</h2><ul><li><a href="https://www.cnblogs.com/vcpkg/p/15019907.html">VCPKG 特性 - Versioning</a></li><li><a href="https://www.cnblogs.com/vcpkg/p/16791033.html">Manifest使用示例2 - 依赖多个vcpkg的历史版本库</a></li></ul>]]></content>
<categories>
<category>CPP语言开发</category>
</categories>
<tags>
<tag>vcpkg</tag>
</tags>
</entry>
<entry>
<title>Linux下scp命令</title>
<link href="/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/linux%E4%B8%8Bscp%E5%91%BD%E4%BB%A4/"/>
<url>/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/linux%E4%B8%8Bscp%E5%91%BD%E4%BB%A4/</url>
<content type="html"><![CDATA[<h1 id="Linux下scp命令"><a href="#Linux下scp命令" class="headerlink" title="Linux下scp命令"></a>Linux下scp命令</h1><p>scp可以进行简单的远程复制文件的功能。它是一个在各个主机之间进行复制或文件传输的一个命令工具。它使用一种同ssh一样的安全机制来进行文件的传输。</p><h2 id="scp常规的使用方式"><a href="#scp常规的使用方式" class="headerlink" title="scp常规的使用方式"></a>scp常规的使用方式</h2><p>注意：下面定义的远程计算机的主机域名是 <code>192.168.1.104</code>， 上传文件的路径是 <code>/usr/local/nginx/html/webs</code> 下面的文件；且 服务器的账号是 <code>root</code> ， 那么密码需要自己输入自己的密码即可。</p><p>从本地上传文件到远程计算机或服务器的命令如下：</p><p>先进入本地目录下，然后运行如下命令：</p><figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs shell">scp my_local_file.zip root@192.168.1.104:/usr/local/nginx/html/webs<br></code></pre></td></tr></table></figure><p>从远程主机复制文件到本地主机(下载)的命令如下：（假如远程文件是about.zip）<br> 先进入本地目录下，然后运行如下命令：</p><figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs shell">scp root@192.168.1.104:/usr/local/nginx/html/webs/about.zip .<br></code></pre></td></tr></table></figure><h2 id="多文件传输"><a href="#多文件传输" class="headerlink" title="多文件传输"></a>多文件传输</h2><p>从本地文件复制多个文件到远程主机（多个文件使用空格分隔开）<br>先进入本地目录下，然后运行如下命令：</p><figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs shell">scp index.css json.js root@192.168.1.104:/usr/local/nginx/html/webs<br></code></pre></td></tr></table></figure><p>从远程主机复制多个文件到当前目录<br>先进入本地目录下，然后运行如下命令：</p><figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs shell">scp root@192.168.1.104:/usr/local/nginx/html/webs/\{index.css,json.js\} .<br></code></pre></td></tr></table></figure><h2 id="复制整个文件夹-使用r-switch-并且指定目录"><a href="#复制整个文件夹-使用r-switch-并且指定目录" class="headerlink" title="复制整个文件夹(使用r switch 并且指定目录)"></a>复制整个文件夹(使用r switch 并且指定目录)</h2><p>从本地文件复制整个文件夹到远程主机上（文件夹假如是diff）<br>先进入本地目录下，然后运行如下命令：</p><figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs shell">scp -v -r diff root@192.168.1.104:/usr/local/nginx/html/webs<br></code></pre></td></tr></table></figure><p>从远程主机复制整个文件夹到本地目录下（文件夹假如是diff）<br>先进入本地目录下，然后运行如下命令：</p><figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs shell">scp -r root@192.168.1.104:/usr/local/nginx/html/webs/diff .<br></code></pre></td></tr></table></figure><h2 id="在两个远程主机之间复制文件"><a href="#在两个远程主机之间复制文件" class="headerlink" title="在两个远程主机之间复制文件"></a>在两个远程主机之间复制文件</h2><p>scp也可以把文件从一个远程主机复制到另一个远程主机上。<br>如下命令：</p><figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs shell">scp root@192.168.1.104:/usr/local/nginx/html/webs/xx.txt root@192.168.1.105:/usr/local/nginx/html/webs/<br></code></pre></td></tr></table></figure><h2 id="使用压缩来加快传输"><a href="#使用压缩来加快传输" class="headerlink" title="使用压缩来加快传输"></a>使用压缩来加快传输</h2><p>在文件传输的过程中，我们可以使用压缩文件来加快文件传输，我们可以使用 C选项来启用压缩功能，该文件在传输过程中被压缩，<br>在目的主机上被解压缩。</p><p>如下命令：</p><figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs shell">scp -vrC diff root@192.168.1.104:/usr/local/nginx/html/webs<br></code></pre></td></tr></table></figure>]]></content>
<categories>
<category>开发环境配置</category>
</categories>
<tags>
<tag>Linux</tag>
</tags>
</entry>
<entry>
<title>Linux下内存占用分析</title>
<link href="/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/linux%E4%B8%8B%E5%86%85%E5%AD%98%E5%8D%A0%E7%94%A8%E5%88%86%E6%9E%90/"/>
<url>/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/linux%E4%B8%8B%E5%86%85%E5%AD%98%E5%8D%A0%E7%94%A8%E5%88%86%E6%9E%90/</url>
<content type="html"><![CDATA[<h1 id="Linux下内存占用分析"><a href="#Linux下内存占用分析" class="headerlink" title="Linux下内存占用分析"></a>Linux下内存占用分析</h1><h2 id="使用-free-命令进行分析"><a href="#使用-free-命令进行分析" class="headerlink" title="使用 free 命令进行分析"></a>使用 free 命令进行分析</h2><figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><code class="hljs shell">[root@k8s-control-plane-02 ~]# free -lwh<br> total used free shared buffers cache available<br>Mem: 7.5Gi 4.7Gi 1.4Gi 72Mi 0B 1.4Gi 2.4Gi<br>Low: 7.5Gi 6.1Gi 1.4Gi<br>High: 0B 0B 0B<br>Swap: 0B 0B 0B<br>[root@k8s-control-plane-02 ~]#<br></code></pre></td></tr></table></figure><ul><li>Total(7.5Gi) = Low used(6.1Gi) + free(1.4Gi)</li><li>Low used(6.1Gi) = Mem used(4.7Gi) + cache(1.4Gi)</li></ul><h3 id="1-cache-字段说明"><a href="#1-cache-字段说明" class="headerlink" title="1. cache 字段说明"></a>1. cache 字段说明</h3><ul><li>cache: IO读缓存， 这个IO不只是文件IO，也可以是网络IO</li></ul><p>cache 就是缓存的意思。当系统读文件的时候，都是把数据从硬盘读到内存里，因为硬盘比内存慢很多，所以这个过程会很耗时。</p><p>为了提高效率，linux 会把读进来的文件在内存中缓存下来（因为读取相近部分的内容是程序很常见的情况），即使程序结束，cache 也不会被自动释放。</p><p>所以呢，如果有程序进行大量的读文件操作，你会发现内存使用率就上去了。</p><p>如果其他程序使用要使用内存的时候，linux 也会把这些没人使用的 cache 释放掉，给其他运行的程序使用。</p><p>手动去释放掉这部分内存：</p><figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs shell">echo 1 > /proc/sys/vm/drop_caches<br></code></pre></td></tr></table></figure><h3 id="2-buffer-字段说明"><a href="#2-buffer-字段说明" class="headerlink" title="2. buffer 字段说明"></a>2. buffer 字段说明</h3><ul><li>buffer: IO写缓存， 这个IO不只是文件IO，也可以是网络IO</li></ul><p>buffer 的意思和 cache 相近，不过稍有区别。</p><p>考虑内存写文件到硬盘的过程，因为硬盘太慢了，如果内存要等待数据写完之后才继续后面的操作，实在是效率很低的事情，也会影响程序的运行速度。</p><p>所以就有了 buffer，写到硬盘的数据会放到 buffer 里面，内存很快把数据写到 buffer，可以继续其他的工作，而硬盘可以在后台慢慢读出 buffer 中的数据，保存起来。这样就提高了读写的效率！</p><p>讲一个大家会经常遇到的例子，当我们把电脑里中的文件拷贝到 U 盘的时候，如果文件特别大，大家会遇到这种情况：明明看到文件已经拷贝完了，但系统还是会提示 U 盘正在使用中。这就是 buffer 的原因，拷贝程序把东西放到 buffer 之后，但是 U 盘还没有写完。</p><p>同样的，可以手动来 flush buffer 的内容，使用的命令是 sync。</p><h3 id="3-free-字段说明"><a href="#3-free-字段说明" class="headerlink" title="3. free 字段说明"></a>3. free 字段说明</h3><p>free 是真正尚未被使用的物理内存数量。</p><h3 id="4-available-字段说明"><a href="#4-available-字段说明" class="headerlink" title="4. available 字段说明"></a>4. available 字段说明</h3><p>available 是从应用程序的角度看到的可用内存数量。</p><p>Linux 内核为了提升磁盘操作的性能，会消耗一部分内存去缓存磁盘数据，就是我们介绍的 buffer 和 cache。所以对于内核来说，buffer 和 cache 都属于已经被使用的内存。</p><p>当应用程序需要内存时，如果没有足够的 free 内存可以用，内核就会从 buffer 和 cache 中回收内存来满足应用程序的请求。</p><p>所以从应用程序的角度来说，available = free + buffer + cache。请注意，这只是一个很理想的计算方式，实际中的数据往往有较大的误差。</p><h3 id="5-shared-字段说明"><a href="#5-shared-字段说明" class="headerlink" title="5. shared 字段说明"></a>5. shared 字段说明</h3><p>shared 被共享使用的物理内存大小，是进程间通信的一种方式。</p><h3 id="6-swap-字段说明"><a href="#6-swap-字段说明" class="headerlink" title="6. swap 字段说明"></a>6. swap 字段说明</h3><p>swap 是实现虚拟内存的重要概念。如果系统的负载太大，内存被用完，可能会出现严重的问题。</p><p>swap 就是把硬盘上一部分空间当做内存使用，正在运行程序会使用物理内存，把没有正在使用的内存放到硬盘，这叫做 swap out；而把硬盘 swap 部分的内存重新放到物理内存中，叫做 swap in。</p><p>swap 可以再逻辑上扩大内存空间，但是会造成系统变慢，因为硬盘读写速度很慢。linux 系统比较智能，会把那些不怎么频繁使用的内存放到 swap。</p><h3 id="7-proc-meminfo-文件"><a href="#7-proc-meminfo-文件" class="headerlink" title="7. /proc/meminfo 文件"></a>7. /proc/meminfo 文件</h3><p>其实 free 命令中的信息都来自于 /proc/meminfo 文件。/proc/meminfo 文件包含了更多更原始的信息，只是看起来不太直观：</p><figure class="highlight awk"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs awk">cat <span class="hljs-regexp">/proc/m</span>eminfo<br></code></pre></td></tr></table></figure><h2 id="查看内存占用较高的进程"><a href="#查看内存占用较高的进程" class="headerlink" title="查看内存占用较高的进程"></a>查看内存占用较高的进程</h2><h3 id="使用-top-命令"><a href="#使用-top-命令" class="headerlink" title="使用 top 命令"></a>使用 top 命令</h3><p>执行 top 命令之后， </p><ul><li>输入 大写P 是按 cpu利用率排序</li><li>输入 大写M 是按 内存占用率排序</li></ul>]]></content>
<categories>
<category>开发环境配置</category>
</categories>
</entry>
<entry>
<title>XFS文件系统异常断电修复</title>
<link href="/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/xfs%E6%96%87%E4%BB%B6%E7%B3%BB%E7%BB%9F%E5%BC%82%E5%B8%B8%E6%96%AD%E7%94%B5%E4%BF%AE%E5%A4%8D/"/>
<url>/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/xfs%E6%96%87%E4%BB%B6%E7%B3%BB%E7%BB%9F%E5%BC%82%E5%B8%B8%E6%96%AD%E7%94%B5%E4%BF%AE%E5%A4%8D/</url>
<content type="html"><![CDATA[<h1 id="XFS文件系统异常断电修复"><a href="#XFS文件系统异常断电修复" class="headerlink" title="XFS文件系统异常断电修复"></a>XFS文件系统异常断电修复</h1><h2 id="异常断电导致xfs文件系统出错"><a href="#异常断电导致xfs文件系统出错" class="headerlink" title="异常断电导致xfs文件系统出错"></a>异常断电导致xfs文件系统出错</h2><p>问题描述，因为异常断电，xfs文件系统异常，无法正常开机启动系统。</p><p>因为文件系统是基于lvm创建的， 开机启动时，提示 /dev/pve/root 无法挂载到 / ， 需要修复。</p><h3 id="如何修复？"><a href="#如何修复？" class="headerlink" title="如何修复？"></a>如何修复？</h3><p>因为磁盘是使用lvm创建的，所有需要先激活卷组和逻辑卷。</p><ol><li><p>扫描卷组</p><p> 使用 vgscan 扫描，可以发现一个叫 pve 的卷组</p></li><li><p>激活卷组</p> <figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs bash">vgchange -ay pve<br></code></pre></td></tr></table></figure><p> 注意： 激活卷组，只是激活而已，并没有挂载到系统</p></li></ol><ol start="3"><li><p>现在可以使用 lvscan 查看逻辑卷</p></li><li><p>修复之前，先尝试看能不能正常挂载</p> <figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><code class="hljs bash">mkdir /asdf<br>mount /dev/pve/root /asdf<br></code></pre></td></tr></table></figure><p> 执行 mount 命令发现，无法挂载</p></li><li><p>使用 xfs_repair 进行修复</p><p> 先使用 xfs_repair 进行修复。</p> <figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs bash">xfs_repair /dev/pve/root<br></code></pre></td></tr></table></figure><p> 如果不行，再使用 -L 选项强制修复， 此选项会清除文件系统的log日志。</p> <figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs bash">xfs_repair -L /dev/pve/root<br></code></pre></td></tr></table></figure></li><li><p>修复之后，尝试重新挂载</p> <figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><code class="hljs bash">mkdir /asdf<br>mount /dev/pve/root /asdf<br></code></pre></td></tr></table></figure><p> 执行 mount 命令后发现，现在可以正常挂载， 问题已修复。 可以重启。</p></li></ol><h2 id="lvm相关命令"><a href="#lvm相关命令" class="headerlink" title="lvm相关命令"></a>lvm相关命令</h2><p>dm是device mapper的意思，dm-0, dm-1的实体可以通过下面几个命令看出，lvm会把每个lv连接到一个/dev/dm-x的设备档，这个设备档并不是一个真正的磁盘，所以不会有分区表存在，不能把dm设备分区。</p><ol><li><code>iostat -d 1</code> ,可以查看device的实时I/O</li></ol><ol start="2"><li><p><code>dmsetup ls</code></p><p> <code>dmsetup info</code> 可以来查看dm设备（lvm）映射情况，可以看到主设备号，次设备号，看不到物理硬盘信息（sda/sdb）</p></li></ol>]]></content>
<categories>
<category>开发环境配置</category>
</categories>
<tags>
<tag>XFS文件系统</tag>
</tags>
</entry>
<entry>
<title>Ubuntu挂载Windows共享文件夹</title>
<link href="/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/ubuntu%E6%8C%82%E8%BD%BDwindows%E5%85%B1%E4%BA%AB%E6%96%87%E4%BB%B6%E5%A4%B9/"/>
<url>/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/ubuntu%E6%8C%82%E8%BD%BDwindows%E5%85%B1%E4%BA%AB%E6%96%87%E4%BB%B6%E5%A4%B9/</url>
<content type="html"><![CDATA[<h1 id="Ubuntu挂载Windows共享文件夹"><a href="#Ubuntu挂载Windows共享文件夹" class="headerlink" title="Ubuntu挂载Windows共享文件夹"></a>Ubuntu挂载Windows共享文件夹</h1><p>参考官方文档的配置： </p><ul><li><a href="https://wiki.ubuntu.com/MountWindowsSharesPermanently">https://wiki.ubuntu.com/MountWindowsSharesPermanently</a></li></ul><h2 id="软件安装"><a href="#软件安装" class="headerlink" title="软件安装"></a>软件安装</h2><figure class="highlight routeros"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs routeros">sudo apt-<span class="hljs-builtin-name">get</span> install cifs-utils<br></code></pre></td></tr></table></figure><h2 id="Windows配置"><a href="#Windows配置" class="headerlink" title="Windows配置"></a>Windows配置</h2><p>不要设置每个人都可以读写文件夹，选择一个用户，只允许这个用户可以读写共享文件夹。</p><h2 id="Ubuntu配置"><a href="#Ubuntu配置" class="headerlink" title="Ubuntu配置"></a>Ubuntu配置</h2><h3 id="etc-fstab-文件配置"><a href="#etc-fstab-文件配置" class="headerlink" title="/etc/fstab 文件配置"></a>/etc/fstab 文件配置</h3><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><code class="hljs conf"># /etc/fstab: static file system information.<br>#<br># Use 'blkid' to print the universally unique identifier for a<br># device; this may be used with UUID= as a more robust way to name devices<br># that works even if disks are added and removed. See fstab(5).<br>#<br># <file system> <mount point> <type> <options> <dump> <pass><br>/dev/mapper/vgubuntu-root / ext4 errors=remount-ro 0 1<br># /boot/efi was on /dev/sda2 during installation<br>UUID=FB79-6FAD /boot/efi vfat umask=0077 0 1<br>/dev/mapper/vgubuntu-swap_1 none swap sw 0 0<br><br>//172.17.0.1/diskd /mnt/d cifs uid=lukas,username=lukas,password=linux,iocharset=utf8 0<br>//172.17.0.1/diske /mnt/e cifs uid=lukas,username=lukas,password=linux,iocharset=utf8 0<br><br></code></pre></td></tr></table></figure><h3 id="配置选项说明"><a href="#配置选项说明" class="headerlink" title="配置选项说明"></a>配置选项说明</h3><ul><li>uid=lukas 这里是指定ubuntu用户，不指定的话，你会没有访问权限的。</li><li>username=lukas,password=linux 这里是windows用户名和密码， (设置windows共享的时候你指定的用户)</li></ul>]]></content>
<categories>
<category>开发环境配置</category>
</categories>
<tags>
<tag>Linux</tag>
<tag>Ubuntu</tag>
</tags>
</entry>
<entry>
<title>Linux系统网络配置</title>
<link href="/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/linux%E7%B3%BB%E7%BB%9F%E7%BD%91%E7%BB%9C%E9%85%8D%E7%BD%AE/"/>
<url>/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/linux%E7%B3%BB%E7%BB%9F%E7%BD%91%E7%BB%9C%E9%85%8D%E7%BD%AE/</url>
<content type="html"><![CDATA[<h1 id="Linux系统网络配置"><a href="#Linux系统网络配置" class="headerlink" title="Linux系统网络配置"></a>Linux系统网络配置</h1><p>下文说到需要配置网络的Linux系统，都是使用最小化安装，没有安装任何图形界面。</p><h2 id="RHEL-Rocky-Almalinux-Fedora-网络配置"><a href="#RHEL-Rocky-Almalinux-Fedora-网络配置" class="headerlink" title="RHEL/Rocky/Almalinux/Fedora 网络配置"></a>RHEL/Rocky/Almalinux/Fedora 网络配置</h2><h3 id="设置静态IP地址"><a href="#设置静态IP地址" class="headerlink" title="设置静态IP地址"></a>设置静态IP地址</h3><p>基于<code>nmcli</code>命令，一条命令即可完成静态IP配置，重启系统后生效。</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br></pre></td><td class="code"><pre><code class="hljs bash">nmcli connection modify \<br> <span class="hljs-string">"<span class="hljs-subst">$(nmcli -t -f NAME c show --active | awk '! /^lo/ { printf <span class="hljs-string">"%s\n"</span>, $0 }')</span>"</span> \<br> connection.autoconnect yes \<br> ipv4.method manual \<br> ipv4.addresses <span class="hljs-string">"172.17.1.116/16"</span> \<br> ipv4.gateway 172.17.0.2 \<br> ipv4.dns 8.8.8.8,8.8.4.4 \<br> ipv6.method disabled<br></code></pre></td></tr></table></figure><h2 id="Ubuntu-网络配置"><a href="#Ubuntu-网络配置" class="headerlink" title="Ubuntu 网络配置"></a>Ubuntu 网络配置</h2><p>Ubuntu使用netplan来管理网络，默认使用dhcp，设置静态IP地址需要手写配置文件。</p><p>参考官方文档的配置： <a href="https://ubuntu.com/server/docs/network-configuration">点击跳转</a></p><h3 id="设置DHCP"><a href="#设置DHCP" class="headerlink" title="设置DHCP"></a>设置DHCP</h3><p>Ubuntu 的 systemd-networkd 默认使用 /etc/machine-id 来识别机器，当虚拟机克隆的时候，他们都有一样的 /etc/machine-id 和 DHCP server，因此返回的都是同一个 ip 了。</p><p>手写配置文件，完整配置文件<code>00-installer-config.yaml</code>，内容如下：</p><figure class="highlight yaml"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><code class="hljs yaml"><span class="hljs-attr">network:</span><br> <span class="hljs-attr">ethernets:</span><br> <span class="hljs-attr">ens33:</span><br> <span class="hljs-attr">dhcp4:</span> <span class="hljs-literal">true</span><br> <span class="hljs-comment"># 加上这一行，可以避免克隆的虚拟机获取到相同的IP地址</span><br> <span class="hljs-attr">dhcp-identifier:</span> <span class="hljs-string">mac</span><br> <span class="hljs-attr">version:</span> <span class="hljs-number">2</span><br></code></pre></td></tr></table></figure><h3 id="设置静态IP地址-1"><a href="#设置静态IP地址-1" class="headerlink" title="设置静态IP地址"></a>设置静态IP地址</h3><p>手写配置文件，完整配置文件<code>00-installer-config.yaml</code>，内容如下：</p><figure class="highlight yaml"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><code class="hljs yaml"><span class="hljs-attr">network:</span><br> <span class="hljs-attr">ethernets:</span><br> <span class="hljs-attr">ens18:</span><br> <span class="hljs-attr">link-local:</span> [ <span class="hljs-string">ipv4</span> ] <br> <span class="hljs-attr">dhcp4:</span> <span class="hljs-literal">no</span><br> <span class="hljs-attr">addresses:</span><br> <span class="hljs-bullet">-</span> <span class="hljs-number">172.17</span><span class="hljs-number">.1</span><span class="hljs-number">.121</span><span class="hljs-string">/16</span><br> <span class="hljs-attr">gateway4:</span> <span class="hljs-number">172.17</span><span class="hljs-number">.0</span><span class="hljs-number">.2</span><br> <span class="hljs-attr">nameservers:</span><br> <span class="hljs-attr">addresses:</span> [<span class="hljs-number">8.8</span><span class="hljs-number">.8</span><span class="hljs-number">.8</span>, <span class="hljs-number">8.8</span><span class="hljs-number">.4</span><span class="hljs-number">.4</span>]<br> <span class="hljs-attr">version:</span> <span class="hljs-number">2</span><br></code></pre></td></tr></table></figure>]]></content>
<categories>
<category>开发环境配置</category>
</categories>
<tags>
<tag>Linux</tag>
</tags>
</entry>
<entry>
<title>Proxmox VE 安装与使用</title>
<link href="/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/proxmox-ve-%E5%AE%89%E8%A3%85%E4%B8%8E%E4%BD%BF%E7%94%A8/"/>
<url>/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/proxmox-ve-%E5%AE%89%E8%A3%85%E4%B8%8E%E4%BD%BF%E7%94%A8/</url>
<content type="html"><![CDATA[<h1 id="Proxmox-VE-安装与使用"><a href="#Proxmox-VE-安装与使用" class="headerlink" title="Proxmox VE 安装与使用"></a>Proxmox VE 安装与使用</h1><h2 id="Proxmox-VE-虚拟机解除锁定"><a href="#Proxmox-VE-虚拟机解除锁定" class="headerlink" title="Proxmox VE 虚拟机解除锁定"></a>Proxmox VE 虚拟机解除锁定</h2><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs bash">root@pve:~<span class="hljs-comment"># qm unlock 106</span><br></code></pre></td></tr></table></figure><h2 id="Proxmox-VE-虚拟机打标签"><a href="#Proxmox-VE-虚拟机打标签" class="headerlink" title="Proxmox VE 虚拟机打标签"></a>Proxmox VE 虚拟机打标签</h2><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><code class="hljs bash">root@pve:~<span class="hljs-comment"># qm set 121 -tags app</span><br>update VM 121: -tags app<br>root@pve:~<span class="hljs-comment">#</span><br></code></pre></td></tr></table></figure><h2 id="Proxmox-VE-虚拟机磁盘不释放"><a href="#Proxmox-VE-虚拟机磁盘不释放" class="headerlink" title="Proxmox VE 虚拟机磁盘不释放"></a>Proxmox VE 虚拟机磁盘不释放</h2><ol><li>问题描述</li></ol><p>PVE虚拟机磁盘删除大量文件后， 磁盘空间没有释放。</p><ol start="2"><li>解决方案</li></ol><p>关闭虚拟机， 在 硬件 选项里面， 双击 硬盘 ， 弹出的选项卡里面， 勾选 丢弃 。</p><p>开启虚拟机， ssh连上去， 执行 <code>fstrim -av</code> 命令。 命令执行成功之后， 磁盘空间就释放了。</p>]]></content>
<categories>
<category>开发环境配置</category>
</categories>
<tags>
<tag>Proxmox VE</tag>
</tags>
</entry>
<entry>
<title>Hyper-V安装PVE</title>
<link href="/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/hyper-v%E5%AE%89%E8%A3%85pve/"/>
<url>/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/hyper-v%E5%AE%89%E8%A3%85pve/</url>
<content type="html"><![CDATA[<h2 id="Hyper-V安装PVE"><a href="#Hyper-V安装PVE" class="headerlink" title="Hyper-V安装PVE"></a>Hyper-V安装PVE</h2><h3 id="创建虚拟机"><a href="#创建虚拟机" class="headerlink" title="创建虚拟机"></a>创建虚拟机</h3><p>创建第二代虚拟机， 记得关掉安全启动，不然iso没法引导。</p><h3 id="开启嵌套虚拟化"><a href="#开启嵌套虚拟化" class="headerlink" title="开启嵌套虚拟化"></a>开启嵌套虚拟化</h3><figure class="highlight powershell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs powershell"><span class="hljs-built_in">Set-VMProcessor</span> <span class="hljs-literal">-ExposeVirtualizationExtensions</span> <span class="hljs-variable">$true</span> <span class="hljs-literal">-VMName</span> PVE<br></code></pre></td></tr></table></figure><h3 id="新建NAT网络"><a href="#新建NAT网络" class="headerlink" title="新建NAT网络"></a>新建NAT网络</h3><figure class="highlight powershell"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><code class="hljs powershell"><span class="hljs-built_in">Set-VMProcessor</span> <span class="hljs-literal">-ExposeVirtualizationExtensions</span> <span class="hljs-variable">$true</span> <span class="hljs-literal">-VMName</span> PVE<br><br><span class="hljs-built_in">New-VMSwitch</span> <span class="hljs-literal">-SwitchName</span> <span class="hljs-string">"PVE-NAT"</span> <span class="hljs-literal">-SwitchType</span> Internal<br><br><span class="hljs-variable">$ifindex</span> = <span class="hljs-built_in">Get-NetAdapter</span> <span class="hljs-literal">-Name</span> <span class="hljs-string">"vEthernet (PVE-NAT)"</span> | <span class="hljs-built_in">Select-Object</span> <span class="hljs-literal">-ExpandProperty</span> <span class="hljs-string">'ifIndex'</span><br><br><span class="hljs-built_in">New-NetIPAddress</span> <span class="hljs-literal">-IPAddress</span> <span class="hljs-number">172.17</span>.<span class="hljs-number">0.2</span> <span class="hljs-literal">-PrefixLength</span> <span class="hljs-number">16</span> <span class="hljs-literal">-InterfaceIndex</span> <span class="hljs-variable">$ifindex</span><br><br><span class="hljs-built_in">New-NetNat</span> <span class="hljs-literal">-Name</span> PVE<span class="hljs-literal">-NAT</span> <span class="hljs-literal">-InternalIPInterfaceAddressPrefix</span> <span class="hljs-number">172.17</span>.<span class="hljs-number">0.2</span>/<span class="hljs-number">24</span><br></code></pre></td></tr></table></figure><p>关于Nat网络，在已经安装了 VMware workstation 的时候，其实不用重新创建。</p><p>在 Hyper-V 里面创建一个虚拟网络交换机，使用外部网络， 选中 VMware workstation 已经创建好的 VMnet8 就行了。 </p><p>这样 Hyper-V 创建的虚拟机就可以跟 VMware workstation 创建的虚拟机相互通信。 这是最便捷的方式了。</p><p>如果外部局域网想要访问 VMnet8 里面的虚拟机，那就在windows开启路由转发，并且通讯双方都配置静态路由。</p><h3 id="为PVE虚拟机启用MAC地址欺骗"><a href="#为PVE虚拟机启用MAC地址欺骗" class="headerlink" title="为PVE虚拟机启用MAC地址欺骗"></a>为PVE虚拟机启用MAC地址欺骗</h3><p>选中虚拟机， 进入设置，在网络适配器 》 高级功能里面，勾选 启用mac地址欺骗。</p><p>如果不启用的话， pve虚拟机里面创建的虚拟机，不能与windows通信。</p>]]></content>
<categories>
<category>开发环境配置</category>
</categories>
<tags>
<tag>Hyper-V</tag>
<tag>Proxmox VE</tag>
</tags>
</entry>
<entry>
<title>WSL常用命令</title>
<link href="/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/wsl%E5%B8%B8%E7%94%A8%E5%91%BD%E4%BB%A4/"/>
<url>/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/wsl%E5%B8%B8%E7%94%A8%E5%91%BD%E4%BB%A4/</url>
<content type="html"><![CDATA[<h1 id="WSL常用命令"><a href="#WSL常用命令" class="headerlink" title="WSL常用命令"></a>WSL常用命令</h1><figure class="highlight properties"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br></pre></td><td class="code"><pre><code class="hljs properties"><span class="hljs-attr">wsl</span> <span class="hljs-string">--help Help 命令</span><br><span class="hljs-attr">wsl</span> <span class="hljs-string">--status 检查 WSL 状态</span><br><span class="hljs-attr">wsl</span> <span class="hljs-string">--update 更新 WSL</span><br><span class="hljs-attr">wsl</span> <span class="hljs-string">--shutdown 关闭</span><br> <br> <br><span class="hljs-attr">wsl</span> <span class="hljs-string">-l 或 wsl --list 列出所有已安装虚拟机</span><br><span class="hljs-attr">wsl</span> <span class="hljs-string">-l -v 显示详细信息(也不怎么详细)</span><br><span class="hljs-attr">wsl</span> <span class="hljs-string">-l -o 列出网上可用的系统</span><br> <br> <br><span class="hljs-attr">wsl</span> <span class="hljs-string">-t ubuntu 关闭ubuntu</span><br><span class="hljs-attr">wsl</span> <span class="hljs-string">--shutdown 关闭所有系统及虚拟机引擎</span><br> <br> <br><span class="hljs-attr">wsl</span> <span class="hljs-string">-d ubuntu 启动ubuntu并进行终端</span><br><span class="hljs-attr">wsl</span> <span class="hljs-string">-u root 以root身份支行</span><br> <br> <br> <br> <br><span class="hljs-attr">wsl</span> <span class="hljs-string">--install 安装默认虚拟机(ubuntu)</span><br><span class="hljs-attr">wsl</span> <span class="hljs-string">-l -o 列出网上可用的系统</span><br> <br> <br><span class="hljs-attr">wsl</span> <span class="hljs-string">启动默认虚拟机并进入终端</span><br><span class="hljs-attr">wsl</span> <span class="hljs-string">-s 虚拟机名 进入默认虚拟机</span><br></code></pre></td></tr></table></figure>]]></content>
<categories>
<category>开发环境配置</category>
</categories>
<tags>
<tag>WSL2</tag>
</tags>
</entry>
<entry>
<title>Windows删除流氓文件夹</title>
<link href="/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/windows%E5%88%A0%E9%99%A4%E6%B5%81%E6%B0%93%E6%96%87%E4%BB%B6%E5%A4%B9/"/>
<url>/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/windows%E5%88%A0%E9%99%A4%E6%B5%81%E6%B0%93%E6%96%87%E4%BB%B6%E5%A4%B9/</url>
<content type="html"><![CDATA[<h1 id="Windows删除流氓文件夹"><a href="#Windows删除流氓文件夹" class="headerlink" title="Windows删除流氓文件夹"></a>Windows删除流氓文件夹</h1><h3 id="问题描述"><a href="#问题描述" class="headerlink" title="问题描述"></a>问题描述</h3><p>我们在使用电脑的过程中，尤其是办公，去创建一些文档，但是在删除的时候就删除不了了，系统提示“找不到该项目”，关于删除文件或者文件夹提示“找不到该项目”强删方法。</p><p>一个盘下面出现两个迅雷下载文件夹， 其中一个删不掉。</p><h3 id="解决方案"><a href="#解决方案" class="headerlink" title="解决方案"></a>解决方案</h3><p>新建一个压缩文件，将它添加进压缩文件时勾选“压缩后删除源文件”，针对文件夹同样有效。</p>]]></content>
<categories>
<category>开发环境配置</category>
</categories>
</entry>
<entry>
<title>Redis源码分析：前言</title>
<link href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90%EF%BC%9A%E5%89%8D%E8%A8%80/"/>
<url>/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90%EF%BC%9A%E5%89%8D%E8%A8%80/</url>
<content type="html"><![CDATA[<ul><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90%EF%BC%9A%E5%89%8D%E8%A8%80">Redis源码分析：前言</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%881%EF%BC%89%EF%BC%9A%E5%AD%97%E7%AC%A6%E4%B8%B2">Redis的数据结构（1）：字符串</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%882%EF%BC%89%EF%BC%9A%E9%93%BE%E8%A1%A8">Redis的数据结构（2）：链表</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%883%EF%BC%89%EF%BC%9A%E6%95%B4%E6%95%B0%E9%9B%86%E5%90%88">Redis的数据结构（3）：整数集合</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%884%EF%BC%89%EF%BC%9A%E5%AD%97%E5%85%B8">Redis的数据结构（4）：字典</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E7%BD%91%E7%BB%9CIO%EF%BC%881%EF%BC%89%EF%BC%9A%E4%BA%8B%E4%BB%B6%E9%A9%B1%E5%8A%A8">Redis的网络IO（1）：事件驱动</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E7%BD%91%E7%BB%9CIO%EF%BC%882%EF%BC%89%EF%BC%9A%E4%BA%8B%E4%BB%B6%E5%BE%AA%E7%8E%AF">Redis的网络IO（2）：事件循环</a></li></ul>]]></content>
<categories>
<category>Redis源码分析</category>
</categories>
<tags>
<tag>Redis</tag>
</tags>
</entry>
<entry>
<title>Redis的数据结构（1）：字符串</title>
<link href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%881%EF%BC%89%EF%BC%9A%E5%AD%97%E7%AC%A6%E4%B8%B2/"/>
<url>/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%881%EF%BC%89%EF%BC%9A%E5%AD%97%E7%AC%A6%E4%B8%B2/</url>
<content type="html"><![CDATA[<ul><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90%EF%BC%9A%E5%89%8D%E8%A8%80">Redis源码分析：前言</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%881%EF%BC%89%EF%BC%9A%E5%AD%97%E7%AC%A6%E4%B8%B2">Redis的数据结构（1）：字符串</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%882%EF%BC%89%EF%BC%9A%E9%93%BE%E8%A1%A8">Redis的数据结构（2）：链表</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%883%EF%BC%89%EF%BC%9A%E6%95%B4%E6%95%B0%E9%9B%86%E5%90%88">Redis的数据结构（3）：整数集合</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%884%EF%BC%89%EF%BC%9A%E5%AD%97%E5%85%B8">Redis的数据结构（4）：字典</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E7%BD%91%E7%BB%9CIO%EF%BC%881%EF%BC%89%EF%BC%9A%E4%BA%8B%E4%BB%B6%E9%A9%B1%E5%8A%A8">Redis的网络IO（1）：事件驱动</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E7%BD%91%E7%BB%9CIO%EF%BC%882%EF%BC%89%EF%BC%9A%E4%BA%8B%E4%BB%B6%E5%BE%AA%E7%8E%AF">Redis的网络IO（2）：事件循环</a></li></ul>]]></content>
<categories>
<category>Redis源码分析</category>
</categories>
<tags>
<tag>Redis</tag>
</tags>
</entry>
<entry>
<title>Redis的数据结构（2）：链表</title>
<link href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%882%EF%BC%89%EF%BC%9A%E9%93%BE%E8%A1%A8/"/>
<url>/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%882%EF%BC%89%EF%BC%9A%E9%93%BE%E8%A1%A8/</url>
<content type="html"><![CDATA[<ul><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90%EF%BC%9A%E5%89%8D%E8%A8%80">Redis源码分析：前言</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%881%EF%BC%89%EF%BC%9A%E5%AD%97%E7%AC%A6%E4%B8%B2">Redis的数据结构（1）：字符串</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%882%EF%BC%89%EF%BC%9A%E9%93%BE%E8%A1%A8">Redis的数据结构（2）：链表</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%883%EF%BC%89%EF%BC%9A%E6%95%B4%E6%95%B0%E9%9B%86%E5%90%88">Redis的数据结构（3）：整数集合</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%884%EF%BC%89%EF%BC%9A%E5%AD%97%E5%85%B8">Redis的数据结构（4）：字典</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E7%BD%91%E7%BB%9CIO%EF%BC%881%EF%BC%89%EF%BC%9A%E4%BA%8B%E4%BB%B6%E9%A9%B1%E5%8A%A8">Redis的网络IO（1）：事件驱动</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E7%BD%91%E7%BB%9CIO%EF%BC%882%EF%BC%89%EF%BC%9A%E4%BA%8B%E4%BB%B6%E5%BE%AA%E7%8E%AF">Redis的网络IO（2）：事件循环</a></li></ul>]]></content>
<categories>
<category>Redis源码分析</category>
</categories>
<tags>
<tag>Redis</tag>
</tags>
</entry>
<entry>
<title>Redis的数据结构（3）：整数集合</title>
<link href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%883%EF%BC%89%EF%BC%9A%E6%95%B4%E6%95%B0%E9%9B%86%E5%90%88/"/>
<url>/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%883%EF%BC%89%EF%BC%9A%E6%95%B4%E6%95%B0%E9%9B%86%E5%90%88/</url>
<content type="html"><![CDATA[<ul><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90%EF%BC%9A%E5%89%8D%E8%A8%80">Redis源码分析：前言</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%881%EF%BC%89%EF%BC%9A%E5%AD%97%E7%AC%A6%E4%B8%B2">Redis的数据结构（1）：字符串</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%882%EF%BC%89%EF%BC%9A%E9%93%BE%E8%A1%A8">Redis的数据结构（2）：链表</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%883%EF%BC%89%EF%BC%9A%E6%95%B4%E6%95%B0%E9%9B%86%E5%90%88">Redis的数据结构（3）：整数集合</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%884%EF%BC%89%EF%BC%9A%E5%AD%97%E5%85%B8">Redis的数据结构（4）：字典</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E7%BD%91%E7%BB%9CIO%EF%BC%881%EF%BC%89%EF%BC%9A%E4%BA%8B%E4%BB%B6%E9%A9%B1%E5%8A%A8">Redis的网络IO（1）：事件驱动</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E7%BD%91%E7%BB%9CIO%EF%BC%882%EF%BC%89%EF%BC%9A%E4%BA%8B%E4%BB%B6%E5%BE%AA%E7%8E%AF">Redis的网络IO（2）：事件循环</a></li></ul>]]></content>
<categories>
<category>Redis源码分析</category>
</categories>
<tags>
<tag>Redis</tag>
</tags>
</entry>
<entry>
<title>Redis的数据结构（4）：字典</title>
<link href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%884%EF%BC%89%EF%BC%9A%E5%AD%97%E5%85%B8/"/>
<url>/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%884%EF%BC%89%EF%BC%9A%E5%AD%97%E5%85%B8/</url>
<content type="html"><![CDATA[<ul><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90%EF%BC%9A%E5%89%8D%E8%A8%80">Redis源码分析：前言</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%881%EF%BC%89%EF%BC%9A%E5%AD%97%E7%AC%A6%E4%B8%B2">Redis的数据结构（1）：字符串</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%882%EF%BC%89%EF%BC%9A%E9%93%BE%E8%A1%A8">Redis的数据结构（2）：链表</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%883%EF%BC%89%EF%BC%9A%E6%95%B4%E6%95%B0%E9%9B%86%E5%90%88">Redis的数据结构（3）：整数集合</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%884%EF%BC%89%EF%BC%9A%E5%AD%97%E5%85%B8">Redis的数据结构（4）：字典</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E7%BD%91%E7%BB%9CIO%EF%BC%881%EF%BC%89%EF%BC%9A%E4%BA%8B%E4%BB%B6%E9%A9%B1%E5%8A%A8">Redis的网络IO（1）：事件驱动</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E7%BD%91%E7%BB%9CIO%EF%BC%882%EF%BC%89%EF%BC%9A%E4%BA%8B%E4%BB%B6%E5%BE%AA%E7%8E%AF">Redis的网络IO（2）：事件循环</a></li></ul>]]></content>
<categories>
<category>Redis源码分析</category>
</categories>
<tags>
<tag>Redis</tag>
</tags>
</entry>
<entry>
<title>Redis的网络IO（1）：事件驱动</title>
<link href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/redis%E7%9A%84%E7%BD%91%E7%BB%9Cio%EF%BC%881%EF%BC%89%EF%BC%9A%E4%BA%8B%E4%BB%B6%E9%A9%B1%E5%8A%A8/"/>
<url>/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/redis%E7%9A%84%E7%BD%91%E7%BB%9Cio%EF%BC%881%EF%BC%89%EF%BC%9A%E4%BA%8B%E4%BB%B6%E9%A9%B1%E5%8A%A8/</url>
<content type="html"><![CDATA[<ul><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90%EF%BC%9A%E5%89%8D%E8%A8%80">Redis源码分析：前言</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%881%EF%BC%89%EF%BC%9A%E5%AD%97%E7%AC%A6%E4%B8%B2">Redis的数据结构（1）：字符串</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%882%EF%BC%89%EF%BC%9A%E9%93%BE%E8%A1%A8">Redis的数据结构（2）：链表</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%883%EF%BC%89%EF%BC%9A%E6%95%B4%E6%95%B0%E9%9B%86%E5%90%88">Redis的数据结构（3）：整数集合</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%884%EF%BC%89%EF%BC%9A%E5%AD%97%E5%85%B8">Redis的数据结构（4）：字典</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E7%BD%91%E7%BB%9CIO%EF%BC%881%EF%BC%89%EF%BC%9A%E4%BA%8B%E4%BB%B6%E9%A9%B1%E5%8A%A8">Redis的网络IO（1）：事件驱动</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E7%BD%91%E7%BB%9CIO%EF%BC%882%EF%BC%89%EF%BC%9A%E4%BA%8B%E4%BB%B6%E5%BE%AA%E7%8E%AF">Redis的网络IO（2）：事件循环</a></li></ul>]]></content>
<categories>
<category>Redis源码分析</category>
</categories>
<tags>
<tag>Redis</tag>
</tags>
</entry>
<entry>
<title>Redis的网络IO（2）：事件循环</title>
<link href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/redis%E7%9A%84%E7%BD%91%E7%BB%9Cio%EF%BC%882%EF%BC%89%EF%BC%9A%E4%BA%8B%E4%BB%B6%E5%BE%AA%E7%8E%AF/"/>
<url>/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/redis%E7%9A%84%E7%BD%91%E7%BB%9Cio%EF%BC%882%EF%BC%89%EF%BC%9A%E4%BA%8B%E4%BB%B6%E5%BE%AA%E7%8E%AF/</url>
<content type="html"><![CDATA[<ul><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90%EF%BC%9A%E5%89%8D%E8%A8%80">Redis源码分析：前言</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%881%EF%BC%89%EF%BC%9A%E5%AD%97%E7%AC%A6%E4%B8%B2">Redis的数据结构（1）：字符串</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%882%EF%BC%89%EF%BC%9A%E9%93%BE%E8%A1%A8">Redis的数据结构（2）：链表</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%883%EF%BC%89%EF%BC%9A%E6%95%B4%E6%95%B0%E9%9B%86%E5%90%88">Redis的数据结构（3）：整数集合</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%EF%BC%884%EF%BC%89%EF%BC%9A%E5%AD%97%E5%85%B8">Redis的数据结构（4）：字典</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E7%BD%91%E7%BB%9CIO%EF%BC%881%EF%BC%89%EF%BC%9A%E4%BA%8B%E4%BB%B6%E9%A9%B1%E5%8A%A8">Redis的网络IO（1）：事件驱动</a></li><li><a href="/Redis%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90/Redis%E7%9A%84%E7%BD%91%E7%BB%9CIO%EF%BC%882%EF%BC%89%EF%BC%9A%E4%BA%8B%E4%BB%B6%E5%BE%AA%E7%8E%AF">Redis的网络IO（2）：事件循环</a></li></ul>]]></content>
<categories>
<category>Redis源码分析</category>
</categories>
<tags>
<tag>Redis</tag>
</tags>
</entry>
<entry>
<title>left join 与 right join 的区别</title>
<link href="/%E5%85%B3%E7%B3%BB%E6%95%B0%E6%8D%AE%E5%BA%93/left-join-%E4%B8%8E-right-join-%E7%9A%84%E5%8C%BA%E5%88%AB/"/>
<url>/%E5%85%B3%E7%B3%BB%E6%95%B0%E6%8D%AE%E5%BA%93/left-join-%E4%B8%8E-right-join-%E7%9A%84%E5%8C%BA%E5%88%AB/</url>
<content type="html"><![CDATA[<h2 id="left-join-与-right-join-的区别"><a href="#left-join-与-right-join-的区别" class="headerlink" title="left join 与 right join 的区别"></a>left join 与 right join 的区别</h2><h2 id="一、建表-SQL-Server"><a href="#一、建表-SQL-Server" class="headerlink" title="一、建表 (SQL Server)"></a>一、建表 (SQL Server)</h2><ol><li><p>创建 j1 表</p><figure class="highlight sql"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><code class="hljs sql"><span class="hljs-keyword">use</span> db1<br><span class="hljs-keyword">go</span><br><br><span class="hljs-keyword">create</span> <span class="hljs-keyword">table</span> dbo.j1<br>(<br> <span class="hljs-keyword">id</span> <span class="hljs-built_in">int</span> <span class="hljs-keyword">not</span> <span class="hljs-literal">null</span>,<br> <span class="hljs-keyword">name</span> <span class="hljs-built_in">varchar</span><br>)<br><span class="hljs-keyword">go</span> <br></code></pre></td></tr></table></figure></li></ol><p>表中数据：</p><table><thead><tr><th align="left">id</th><th align="left">name</th></tr></thead><tbody><tr><td align="left">1</td><td align="left">a</td></tr><tr><td align="left">2</td><td align="left">b</td></tr><tr><td align="left">3</td><td align="left">c</td></tr></tbody></table><ol start="2"><li>创建 j2 表</li></ol><figure class="highlight sql"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><code class="hljs sql"><span class="hljs-keyword">use</span> db1<br><span class="hljs-keyword">go</span><br><br><span class="hljs-keyword">create</span> <span class="hljs-keyword">table</span> dbo.j2<br>(<br> <span class="hljs-keyword">id</span> <span class="hljs-built_in">int</span> <span class="hljs-keyword">not</span> <span class="hljs-literal">null</span>,<br> <span class="hljs-keyword">name</span> <span class="hljs-built_in">varchar</span><br>)<br><span class="hljs-keyword">go</span><br></code></pre></td></tr></table></figure><p>表中数据：</p><table><thead><tr><th align="left">id</th><th align="left">name</th></tr></thead><tbody><tr><td align="left">2</td><td align="left">q</td></tr><tr><td align="left">3</td><td align="left">w</td></tr><tr><td align="left">2</td><td align="left">e</td></tr></tbody></table><h3 id="二、区别"><a href="#二、区别" class="headerlink" title="二、区别"></a>二、区别</h3><ol><li>j1 left join j2</li></ol><figure class="highlight sql"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><code class="hljs sql"><span class="hljs-keyword">select</span> j1.id <span class="hljs-keyword">as</span> j1id, j1.name <span class="hljs-keyword">as</span> j1name, j2.id <span class="hljs-keyword">as</span> j2id, j2.name <span class="hljs-keyword">as</span> j2name<br><span class="hljs-keyword">from</span> j1<br><span class="hljs-keyword">left</span> <span class="hljs-keyword">join</span> j2 <span class="hljs-keyword">on</span> j1.id = j2.id;<br></code></pre></td></tr></table></figure><p>left join 结果:</p><table><thead><tr><th align="left">j1id</th><th align="left">j1name</th><th align="left">j2id</th><th align="left">j2name</th></tr></thead><tbody><tr><td align="left">1</td><td align="left">a</td><td align="left">null</td><td align="left">null</td></tr><tr><td align="left">2</td><td align="left">b</td><td align="left">2</td><td align="left">q</td></tr><tr><td align="left">2</td><td align="left">b</td><td align="left">2</td><td align="left">e</td></tr><tr><td align="left">3</td><td align="left">c</td><td align="left">3</td><td align="left">w</td></tr></tbody></table><ol start="2"><li>j1 right join j2</li></ol><figure class="highlight sql"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><code class="hljs sql"><span class="hljs-keyword">select</span> j1.id <span class="hljs-keyword">as</span> j1id, j1.name <span class="hljs-keyword">as</span> j1name, j2.id <span class="hljs-keyword">as</span> j2id, j2.name <span class="hljs-keyword">as</span> j2name<br><span class="hljs-keyword">from</span> j1<br><span class="hljs-keyword">right</span> <span class="hljs-keyword">join</span> j2 <span class="hljs-keyword">on</span> j1.id = j2.id;<br></code></pre></td></tr></table></figure><p>right join 结果:</p><table><thead><tr><th align="left">j1id</th><th align="left">j1name</th><th align="left">j2id</th><th align="left">j2name</th></tr></thead><tbody><tr><td align="left">2</td><td align="left">b</td><td align="left">2</td><td align="left">q</td></tr><tr><td align="left">3</td><td align="left">c</td><td align="left">3</td><td align="left">w</td></tr><tr><td align="left">2</td><td align="left">b</td><td align="left">2</td><td align="left">e</td></tr></tbody></table><p>可以看出区别在于 id为1的记录。</p><ul><li>j1 left join j2 时， 以 j1 为主表， id为1的记录会显示在 join 结果中</li><li>j1 right join j2 时，以 j2 为主表， j2中不包含 id为1的记录， 因此id为1的记录不会显示在 join 结果中。</li></ul><p>总结： left join 的结果 跟 right join 的结果，其记录数量是不相同的。 具体结果需要具体分析。</p>]]></content>
<categories>
<category>关系数据库</category>
</categories>
<tags>
<tag>Database</tag>
</tags>
</entry>
<entry>
<title>Git安装与配置</title>
<link href="/Git%E4%BD%BF%E7%94%A8%E6%80%BB%E7%BB%93/git%E5%AE%89%E8%A3%85%E4%B8%8E%E9%85%8D%E7%BD%AE/"/>
<url>/Git%E4%BD%BF%E7%94%A8%E6%80%BB%E7%BB%93/git%E5%AE%89%E8%A3%85%E4%B8%8E%E9%85%8D%E7%BD%AE/</url>
<content type="html"><![CDATA[<h1 id="Git-SSH协议代理"><a href="#Git-SSH协议代理" class="headerlink" title="Git SSH协议代理"></a>Git SSH协议代理</h1><h2 id="Windows下面配置"><a href="#Windows下面配置" class="headerlink" title="Windows下面配置"></a>Windows下面配置</h2><p>在 <code>.ssh</code> 目录下，新建 <code>C:\Users\lukas\.ssh\config</code> 文件。</p><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><code class="hljs conf">proxyCommand "C:\Program Files\Git\mingw64\bin\connect" -S 127.0.0.1:5081 %h %p<br><br>Host github.com<br> User git<br> Port 22<br> Hostname github.com<br> <br>Host ssh.github.com<br> User git<br> Port 443<br> Hostname ssh.github.com<br></code></pre></td></tr></table></figure><ul><li>注意是 <code>C:\Users\lukas\.ssh\config</code> 文件, 而不是 <code>C:\Users\lukas\.gitconfig</code> 文件, 不要搞混了。</li><li><code>connect</code> 命令，只要安装了 <code>Git for windows</code> 就会有， 记得找到正确的位置。</li><li><code>127.0.0.1:5081</code> 是 socket5 服务器地址</li><li>不用写 <code>IdentityFile</code> 指令， 执行git命令时，会自动读取相关私钥文件；只要配置了相应的私钥，就不会有问题。</li></ul><h2 id="其他系统配置"><a href="#其他系统配置" class="headerlink" title="其他系统配置"></a>其他系统配置</h2><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br></pre></td><td class="code"><pre><code class="hljs conf">Host github.com *.github.com<br>User git<br># SSH默认端口22， HTTPS默认端口443<br>Port 22<br>Hostname %h<br># # 注意修改路径为你的路径<br># IdentityFile ~/.ssh/id_ed25519<br>AddKeysToAgent yes<br>TCPKeepAlive yes<br># Linux/Mac走 HTTP 代理，需要安装socat， brew install socat<br># ProxyCommand socat - PROXY:127.0.0.1:%h:%p,proxyport=8080<br># linux/Mac走 socks5 代理（如 Shadowsocks） nc是linux自带的工具<br># ProxyCommand nc -v -x 127.0.0.1:1080 %h %p<br><br># Windows走 HTTP 代理,connect是git自带的工具<br># ProxyCommand connect -H 127.0.0.1:7890 -a none %h %p<br># Windows走 socks5 代理（如 Shadowsocks）<br># ProxyCommand connect -S 127.0.0.1:7890 -a none %h %p<br></code></pre></td></tr></table></figure><h2 id="Git多平台换行符设置"><a href="#Git多平台换行符设置" class="headerlink" title="Git多平台换行符设置"></a>Git多平台换行符设置</h2><h3 id="core-autocrlf-配置选项"><a href="#core-autocrlf-配置选项" class="headerlink" title="core.autocrlf 配置选项"></a><code>core.autocrlf</code> 配置选项</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br></pre></td><td class="code"><pre><code class="hljs bash"><span class="hljs-comment"># 提交时转换为LF，检出时转换为CRLF</span><br>git config --global core.autocrlf <span class="hljs-literal">true</span><br><br><span class="hljs-comment"># 提交时转换为LF，检出时不转换</span><br>git config --global core.autocrlf input<br><br><span class="hljs-comment"># 提交检出均不转换</span><br>git config --global core.autocrlf <span class="hljs-literal">false</span><br></code></pre></td></tr></table></figure><h3 id="core-safecrlf-配置选项"><a href="#core-safecrlf-配置选项" class="headerlink" title="core.safecrlf 配置选项"></a><code>core.safecrlf</code> 配置选项</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br></pre></td><td class="code"><pre><code class="hljs bash"><span class="hljs-comment"># 拒绝提交包含混合换行符的文件</span><br>git config --global core.safecrlf <span class="hljs-literal">true</span><br><br><span class="hljs-comment"># 允许提交包含混合换行符的文件</span><br>git config --global core.safecrlf <span class="hljs-literal">false</span><br><br><span class="hljs-comment"># 提交包含混合换行符的文件时给出警告</span><br>git config --global core.safecrlf warn<br></code></pre></td></tr></table></figure><h3 id="换行符实际问题"><a href="#换行符实际问题" class="headerlink" title="换行符实际问题"></a>换行符实际问题</h3><p>Git跨平台工作时，才会碰到下面的问题， 如果一直在单一平台下工作，应该不会碰见该问题。</p><ol><li>问题描述</li></ol><ul><li>Windows 默认换行符 CRLF</li><li>Linux 默认换行符 LF</li><li>Mac 默认换行符 LF</li></ul><p>对于Git仓库中的文件，文件内如果出现非本平台的换行符，文件被视为整个被修改，从而导致出现下面这种情况：</p><ul><li>对于已经提交的文件， 由于换行符导致的问题， 被Git显示为未提交</li></ul><ol start="2"><li>问题解决方案</li></ol><p>Git跨平台下换行符使用原则： </p><ul><li>Git提交时统一使用 LF</li><li>Git检出时， 根据自己的平台来决定是否转换为CRLF</li><li>不要提交CRLF到仓库，提交时应该统一使用LF</li></ul><p>对于windows平台，推荐Git进行以下设置：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><code class="hljs bash">git config --global core.autocrlf <span class="hljs-literal">true</span><br>git config --global core.safecrlf <span class="hljs-literal">true</span><br></code></pre></td></tr></table></figure><p>这样配置的意思是：</p><ul><li>提交时自动转换为LF，检出时转换为CRLF</li><li>拒绝提交包含混合换行符的文件</li></ul><p>对于Linux/MAC平台，推荐Git进行以下设置：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><code class="hljs bash">git config --global core.autocrlf input<br>git config --global core.safecrlf <span class="hljs-literal">true</span><br></code></pre></td></tr></table></figure><p>这样配置的意思是：</p><ul><li>提交时自动转换为LF，检出时不转换为CRLF</li><li>拒绝提交包含混合换行符的文件</li></ul><ol start="3"><li>为什么要 拒绝提交包含混合换行符的文件 ？</li></ol><p>因为混合换行符会影响到 Git 的 diff 功能， 导致明明文件内容没有修改，却因为换行符，Git会显示文件被修改，从而影响到我们查看diff。</p>]]></content>
<categories>
<category>Git使用总结</category>
</categories>
<tags>
<tag>Git</tag>
</tags>
</entry>
<entry>
<title>EF Core设置Gin索引</title>
<link href="/PostgreSQL%E6%95%B0%E6%8D%AE%E5%BA%93/ef-core%E8%AE%BE%E7%BD%AEgin%E7%B4%A2%E5%BC%95/"/>
<url>/PostgreSQL%E6%95%B0%E6%8D%AE%E5%BA%93/ef-core%E8%AE%BE%E7%BD%AEgin%E7%B4%A2%E5%BC%95/</url>
<content type="html"><![CDATA[<h2 id="EF-Core中如何设置Gin索引"><a href="#EF-Core中如何设置Gin索引" class="headerlink" title="EF Core中如何设置Gin索引?"></a>EF Core中如何设置Gin索引?</h2><p><a href="https://stackoverflow.com/questions/54618858/can-jsonb-gin-indexes-be-specified-in-codefirst-entityframework-with-npgsql">https://stackoverflow.com/questions/54618858/can-jsonb-gin-indexes-be-specified-in-codefirst-entityframework-with-npgsql</a></p><hr><p>Since .ForNpgsqlHasMethod(“gin”) is obsolete, with EF Core 3.1 you can use this:</p><figure class="highlight c#"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><code class="hljs c#">metaBuilder<br> .HasIndex(x => x.DocumentNumber)<br> .HasMethod(<span class="hljs-string">"gin"</span>)<br> .HasOperators(<span class="hljs-string">"gin_trgm_ops"</span>);<br></code></pre></td></tr></table></figure><p>and your migration will look like this:</p><figure class="highlight c#"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><code class="hljs c#">migrationBuilder.CreateIndex(<br> name: <span class="hljs-string">"IX_DocumentContentMeta_DocumentNumber"</span>,<br> table: <span class="hljs-string">"DocumentContentMeta"</span>,<br> column: <span class="hljs-string">"DocumentNumber"</span>)<br> .Annotation(<span class="hljs-string">"Npgsql:IndexMethod"</span>, <span class="hljs-string">"gin"</span>)<br> .Annotation(<span class="hljs-string">"Npgsql:IndexOperators"</span>, <span class="hljs-keyword">new</span>[] { <span class="hljs-string">"gin_trgm_ops"</span> });<br></code></pre></td></tr></table></figure><hr><p>Well, actually u can do it like this</p><figure class="highlight c#"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br></pre></td><td class="code"><pre><code class="hljs c#"><span class="hljs-function"><span class="hljs-keyword">protected</span> <span class="hljs-keyword">override</span> <span class="hljs-keyword">void</span> <span class="hljs-title">OnModelCreating</span>(<span class="hljs-params">ModelBuilder modelBuilder</span>)</span><br><span class="hljs-function"></span>{<br> modelBuilder.Entity<Artist>()<br> .HasIndex(a => <span class="hljs-keyword">new</span> { a.Album })<br> .ForNpgsqlHasMethod(<span class="hljs-string">"gin"</span>);<br><br> <span class="hljs-keyword">base</span>.OnModelCreating(modelBuilder);<br>}<br></code></pre></td></tr></table></figure><p>and when u run ef add migration, the sql query generated will be like:</p><figure class="highlight sql"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs sql"><span class="hljs-keyword">CREATE</span> <span class="hljs-keyword">INDEX</span> ix_artist_album <span class="hljs-keyword">ON</span> artist <span class="hljs-keyword">USING</span> gin (<span class="hljs-string">"album"</span>);<br></code></pre></td></tr></table></figure><p>Documentation in Npgsql: <a href="http://www.npgsql.org/efcore/modeling/indexes.html">http://www.npgsql.org/efcore/modeling/indexes.html</a></p>]]></content>
<categories>
<category>PostgreSQL数据库</category>
</categories>
<tags>
<tag>EFCore</tag>
<tag>Gin</tag>
</tags>
</entry>
<entry>
<title>设计分布式日志系统</title>
<link href="/%E7%B3%BB%E7%BB%9F%E8%AE%BE%E8%AE%A1/%E8%AE%BE%E8%AE%A1%E5%88%86%E5%B8%83%E5%BC%8F%E6%97%A5%E5%BF%97%E7%B3%BB%E7%BB%9F/"/>
<url>/%E7%B3%BB%E7%BB%9F%E8%AE%BE%E8%AE%A1/%E8%AE%BE%E8%AE%A1%E5%88%86%E5%B8%83%E5%BC%8F%E6%97%A5%E5%BF%97%E7%B3%BB%E7%BB%9F/</url>
<content type="html"><![CDATA[]]></content>
<categories>
<category>系统设计</category>
</categories>
<tags>
<tag>Logging</tag>
</tags>
</entry>
<entry>
<title>PG生成RowNumber行号</title>
<link href="/PostgreSQL%E6%95%B0%E6%8D%AE%E5%BA%93/pg%E7%94%9F%E6%88%90rownumber%E8%A1%8C%E5%8F%B7/"/>
<url>/PostgreSQL%E6%95%B0%E6%8D%AE%E5%BA%93/pg%E7%94%9F%E6%88%90rownumber%E8%A1%8C%E5%8F%B7/</url>
<content type="html"><![CDATA[<h2 id="背景"><a href="#背景" class="headerlink" title="背景"></a>背景</h2><p>Oracle ROWNUM是一个虚拟列，每输出一行递增1。 </p><h2 id="Oracle-rownum"><a href="#Oracle-rownum" class="headerlink" title="Oracle rownum"></a>Oracle rownum</h2><p>通常被用于LIMIT输出记录数。 </p><pre><code class="hljs">SELECT ROWNUM, empno, ename, job FROM emp WHERE ROWNUM < 5 ORDER BY ename; rownum | empno | ename | job --------+-------+-------+---------- 2 | 7499 | ALLEN | SALESMAN 4 | 7566 | JONES | MANAGER 1 | 7369 | SMITH | CLERK 3 | 7521 | WARD | SALESMAN (4 rows) </code></pre><p>或者用于生成序列值。 </p><pre><code class="hljs">ALTER TABLE jobhist ADD seqno NUMBER(3); UPDATE jobhist SET seqno = ROWNUM; </code></pre><pre><code class="hljs">SELECT seqno, empno, TO_CHAR(startdate,'DD-MON-YY') AS start, job FROM jobhist; seqno | empno | start | job -------+-------+-----------+----------- 1 | 7369 | 17-DEC-80 | CLERK 2 | 7499 | 20-FEB-81 | SALESMAN 3 | 7521 | 22-FEB-81 | SALESMAN 4 | 7566 | 02-APR-81 | MANAGER 5 | 7654 | 28-SEP-81 | SALESMAN 6 | 7698 | 01-MAY-81 | MANAGER 7 | 7782 | 09-JUN-81 | MANAGER 8 | 7788 | 19-APR-87 | CLERK 9 | 7788 | 13-APR-88 | CLERK 10 | 7788 | 05-MAY-90 | ANALYST 11 | 7839 | 17-NOV-81 | PRESIDENT 12 | 7844 | 08-SEP-81 | SALESMAN 13 | 7876 | 23-MAY-87 | CLERK 14 | 7900 | 03-DEC-81 | CLERK 15 | 7900 | 15-JAN-83 | CLERK 16 | 7902 | 03-DEC-81 | ANALYST 17 | 7934 | 23-JAN-82 | CLERK (17 rows) </code></pre><h2 id="PostgreSQL-rownum"><a href="#PostgreSQL-rownum" class="headerlink" title="PostgreSQL rownum"></a>PostgreSQL rownum</h2><p>PostgreSQL 目前没有rownum虚拟列，但是实现同样的功能确很容易： </p><p>1、输出行号，使用临时序列 </p><pre><code class="hljs">postgres=# create temp sequence if not exists tmp_seq; postgres=# alter sequence tmp_seq restart with 1; postgres=# select nextval('tmp_seq') as rownum, * from test limit 10; rownum | id | info | crt_time --------+----+------+---------------------------- 1 | 1 | test | 2018-01-24 11:06:24.882708 2 | 2 | test | 2018-01-24 11:06:24.882708 3 | 3 | test | 2018-01-24 11:06:24.882708 4 | 4 | test | 2018-01-24 11:06:24.882708 5 | 5 | test | 2018-01-24 11:06:24.882708 6 | 6 | test | 2018-01-24 11:06:24.882708 7 | 7 | test | 2018-01-24 11:06:24.882708 8 | 8 | test | 2018-01-24 11:06:24.882708 9 | 9 | test | 2018-01-24 11:06:24.882708 10 | 10 | test | 2018-01-24 11:06:24.882708 (10 rows) </code></pre><p>2、输出行号，使用窗口函数 </p><pre><code class="hljs">postgres=# select row_number() over () as rownum, * from test limit 10; rownum | id | info | crt_time --------+----+------+---------------------------- 1 | 1 | test | 2018-01-24 11:06:24.882708 2 | 2 | test | 2018-01-24 11:06:24.882708 3 | 3 | test | 2018-01-24 11:06:24.882708 4 | 4 | test | 2018-01-24 11:06:24.882708 5 | 5 | test | 2018-01-24 11:06:24.882708 6 | 6 | test | 2018-01-24 11:06:24.882708 7 | 7 | test | 2018-01-24 11:06:24.882708 8 | 8 | test | 2018-01-24 11:06:24.882708 9 | 9 | test | 2018-01-24 11:06:24.882708 10 | 10 | test | 2018-01-24 11:06:24.882708 (10 rows) </code></pre><p>3、LIMIT，直接语法支持 </p><pre><code class="hljs">postgres=# select * from test limit 10; id | info | crt_time ----+------+---------------------------- 1 | test | 2018-01-24 11:06:24.882708 2 | test | 2018-01-24 11:06:24.882708 3 | test | 2018-01-24 11:06:24.882708 4 | test | 2018-01-24 11:06:24.882708 5 | test | 2018-01-24 11:06:24.882708 6 | test | 2018-01-24 11:06:24.882708 7 | test | 2018-01-24 11:06:24.882708 8 | test | 2018-01-24 11:06:24.882708 9 | test | 2018-01-24 11:06:24.882708 10 | test | 2018-01-24 11:06:24.882708 (10 rows) </code></pre><p>4、为某个字段生成序列值。 </p><pre><code class="hljs">postgres=# create temp sequence if not exists tmp_seq; postgres=# alter sequence tmp_seq restart with 1; postgres=# alter table test add column col1 int; ALTER TABLE postgres=# update test set col1=nextval('tmp_seq'); UPDATE 10000000 postgres=# select * from test limit 10; id | info | crt_time | col1 ----+------+----------------------------+------ 1 | test | 2018-01-24 11:06:24.882708 | 1 2 | test | 2018-01-24 11:06:24.882708 | 2 3 | test | 2018-01-24 11:06:24.882708 | 3 4 | test | 2018-01-24 11:06:24.882708 | 4 5 | test | 2018-01-24 11:06:24.882708 | 5 6 | test | 2018-01-24 11:06:24.882708 | 6 7 | test | 2018-01-24 11:06:24.882708 | 7 8 | test | 2018-01-24 11:06:24.882708 | 8 9 | test | 2018-01-24 11:06:24.882708 | 9 10 | test | 2018-01-24 11:06:24.882708 | 10 (10 rows) </code></pre>]]></content>
<categories>
<category>PostgreSQL数据库</category>
</categories>
<tags>
<tag>RowNumber</tag>
</tags>
</entry>
<entry>
<title>设计思路</title>
<link href="/%E7%B3%BB%E7%BB%9F%E8%AE%BE%E8%AE%A1/%E8%AE%BE%E8%AE%A1%E6%80%9D%E8%B7%AF/"/>
<url>/%E7%B3%BB%E7%BB%9F%E8%AE%BE%E8%AE%A1/%E8%AE%BE%E8%AE%A1%E6%80%9D%E8%B7%AF/</url>
<content type="html"><![CDATA[<ol><li>业界可参考的解决方案</li></ol>]]></content>
<categories>
<category>系统设计</category>
</categories>
</entry>
<entry>
<title>Git常用命令总结</title>
<link href="/Git%E4%BD%BF%E7%94%A8%E6%80%BB%E7%BB%93/git%E5%B8%B8%E7%94%A8%E5%91%BD%E4%BB%A4%E6%80%BB%E7%BB%93/"/>
<url>/Git%E4%BD%BF%E7%94%A8%E6%80%BB%E7%BB%93/git%E5%B8%B8%E7%94%A8%E5%91%BD%E4%BB%A4%E6%80%BB%E7%BB%93/</url>
<content type="html"><![CDATA[<h2 id="Git分支合并"><a href="#Git分支合并" class="headerlink" title="Git分支合并"></a>Git分支合并</h2><h3 id="分支合并之前怎么检测是否有冲突？"><a href="#分支合并之前怎么检测是否有冲突？" class="headerlink" title="分支合并之前怎么检测是否有冲突？"></a>分支合并之前怎么检测是否有冲突？</h3><p>场景举例：</p><ol><li><p>个人分支：personal</p></li><li><p>项目主干分支：master</p></li><li><p>开发人员在个人分支上进行特性开发，期间可能会往远端库推送多次，最终会合入到主干分支</p></li></ol><p>怎么检测？</p><p>通过三路合并检测：</p><ol><li><p>通过<code>git merge-base personal master</code>找出共同的节点，称之为：base_sha</p></li><li><p>通过<code>git merge-tree base_sha personal master</code>获取合并后的结果</p></li><li><p>如果输出有<code>changed in both</code>字样，那说明存在冲突</p></li></ol><p>总结</p><ol><li><p>定期拉取主干分支，更新到个人分支，保持与主干分支差异最想</p></li><li><p>开发完成后，尽快合入 </p></li><li><p>根据冲突提前检测，统计出频繁冲突文件列表，能够提前预警</p></li></ol><h3 id="怎么进行git-rebase合并分支？"><a href="#怎么进行git-rebase合并分支？" class="headerlink" title="怎么进行git rebase合并分支？"></a>怎么进行<code>git rebase</code>合并分支？</h3><h2 id="Git日志"><a href="#Git日志" class="headerlink" title="Git日志"></a>Git日志</h2><h3 id="怎么查看最近三次的提交信息？"><a href="#怎么查看最近三次的提交信息？" class="headerlink" title="怎么查看最近三次的提交信息？"></a>怎么查看最近三次的提交信息？</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs bash">git <span class="hljs-built_in">log</span> -3<br></code></pre></td></tr></table></figure><h3 id="git-走代理"><a href="#git-走代理" class="headerlink" title="git:// 走代理"></a><code>git://</code> 走代理</h3><p>~/.ssh/config 文件权限 600</p><figure class="highlight routeros"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><code class="hljs routeros">[lukas@localhost pygyme]$ cat ~/.ssh/config<br>Host github.com *.github.com<br> <span class="hljs-built_in"> User </span>git<br> Hostname %h<br> ProxyCommand nc -x 172.17.0.1:7890 %h %p<br>[lukas@localhost pygyme]$<br>[lukas@localhost yum.repos.d]$ ls -l ~/.ssh/config<br>-rw------- 1 lukas lukas 74 3月 10 21:41 /home/lukas/.ssh/config<br>[lukas@localhost yum.repos.d]$<br></code></pre></td></tr></table></figure>]]></content>
<categories>
<category>Git使用总结</category>
</categories>
<tags>
<tag>Git</tag>
</tags>
</entry>
<entry>
<title>GDB调试C++</title>
<link href="/CPP%E8%AF%AD%E8%A8%80%E5%BC%80%E5%8F%91/gdb%E8%B0%83%E8%AF%95c/"/>
<url>/CPP%E8%AF%AD%E8%A8%80%E5%BC%80%E5%8F%91/gdb%E8%B0%83%E8%AF%95c/</url>
<content type="html"><![CDATA[<h2 id="GDB调试基础"><a href="#GDB调试基础" class="headerlink" title="GDB调试基础"></a>GDB调试基础</h2><ol><li>命令行传参</li></ol><figure class="highlight routeros"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs routeros">(gdb) <span class="hljs-builtin-name">set</span> args<span class="hljs-built_in"> aaa </span>bbb<br></code></pre></td></tr></table></figure><h2 id="参考教程"><a href="#参考教程" class="headerlink" title="参考教程"></a>参考教程</h2><figure class="highlight awk"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><code class="hljs awk"><span class="hljs-number">100</span>个GDB小技巧<br>https:<span class="hljs-regexp">//</span>wizardforcel.gitbooks.io<span class="hljs-regexp">/100-gdb-tips/</span>content/<span class="hljs-keyword">break</span>-on-linenum.html<br></code></pre></td></tr></table></figure><figure class="highlight awk"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><code class="hljs awk">gdb 调试利器<br>https:<span class="hljs-regexp">//</span>linuxtools-rst.readthedocs.io<span class="hljs-regexp">/zh_CN/</span>latest<span class="hljs-regexp">/tool/g</span>db.html<br></code></pre></td></tr></table></figure>]]></content>
<categories>
<category>CPP语言开发</category>
</categories>
<tags>
<tag>Linux</tag>
<tag>GDB</tag>
</tags>
</entry>
<entry>
<title>Fedora X11开发环境</title>
<link href="/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/fedora-x11%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83/"/>
<url>/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E9%85%8D%E7%BD%AE/fedora-x11%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83/</url>
<content type="html"><![CDATA[<h2 id="Windows系统"><a href="#Windows系统" class="headerlink" title="Windows系统"></a>Windows系统</h2><p>安装 vcxsrv, xshell, xftp。</p><p>clion在Windows上可以远程linux开发，但是调试多个tcp程序不如命令行手动gdb来的实在。<br>调试redis源码也要用gdb，反正无论怎样都是要用gdb调试的，逃不开躲不过，还是尽早适应的好。</p><p>不在xshell中用vim写C++，而是通过X11使用vscode写C++。不使用vscode调试C++，而是在命令行手动gdb进行调试。</p><p>vim的配置太恶心了，要什么功能都要用插件去实现，选插件然后配置太麻烦，关键的是没法保证实现想要的效果，浪费生命浪费时间。</p><p>抛弃vim，拥抱vscode，从我做起！</p><p>在windows上跑虚拟机才是正解，linux开发环境使用X11更加方便，只要CPU够强、内存够大，鱼与熊掌可以兼得。</p><h2 id="Fedora34系统环境从零开始"><a href="#Fedora34系统环境从零开始" class="headerlink" title="Fedora34系统环境从零开始"></a>Fedora34系统环境从零开始</h2><h3 id="系统安装"><a href="#系统安装" class="headerlink" title="系统安装"></a>系统安装</h3><h4 id="1-使用-Fedora-Workstation-Live-x86-64-34-1-2-iso-安装系统"><a href="#1-使用-Fedora-Workstation-Live-x86-64-34-1-2-iso-安装系统" class="headerlink" title="1. 使用 Fedora-Workstation-Live-x86_64-34-1.2.iso 安装系统"></a>1. 使用 <code>Fedora-Workstation-Live-x86_64-34-1.2.iso</code> 安装系统</h4><p>开发环境使用 Workstation版， 不用Server版。配置默认为字符界面，桌面在需要时再进行切换。</p><p>自定义LVM磁盘分区, 设置登录账号。</p><h4 id="2-更新系统"><a href="#2-更新系统" class="headerlink" title="2. 更新系统"></a>2. 更新系统</h4><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs bash">[lukas@fedora muduo]$ dnf update<br></code></pre></td></tr></table></figure><h4 id="3-调整运行级别"><a href="#3-调整运行级别" class="headerlink" title="3. 调整运行级别"></a>3. 调整运行级别</h4><p>配置默认为字符界面，这样虚拟机需要的运行资源占用少。</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs bash">[lukas@fedora muduo]$ systemctl set-default runlevel3.target<br></code></pre></td></tr></table></figure><h4 id="4-C-编译工具"><a href="#4-C-编译工具" class="headerlink" title="4. C++编译工具"></a>4. C++编译工具</h4><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><code class="hljs bash">dnf install -y boost boost-devel zlib-devel curl-devel \<br>protobuf protobuf-devel cmake gcc gcc-c++ gdb make \<br>tmux git vim openssh-server<br><br>dnf install -y clang clang-devel clang-libs llvm llvm-doc \<br>llvm-devel clang-tools-extra clang-analyzer<br></code></pre></td></tr></table></figure><h4 id="5-VSCode"><a href="#5-VSCode" class="headerlink" title="5. VSCode"></a>5. VSCode</h4><p>5.1 按文档安装</p><figure class="highlight awk"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs awk">https:<span class="hljs-regexp">//</span>code.visualstudio.com<span class="hljs-regexp">/docs/</span>setup/linux<br></code></pre></td></tr></table></figure><p>5.2 launch.json 示例</p><figure class="highlight json"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br></pre></td><td class="code"><pre><code class="hljs json">{<br> <span class="hljs-comment">// 使用 IntelliSense 了解相关属性。 </span><br> <span class="hljs-comment">// 悬停以查看现有属性的描述。</span><br> <span class="hljs-comment">// 欲了解更多信息，请访问: https://go.microsoft.com/fwlink/?linkid=830387</span><br> <span class="hljs-attr">"version"</span>: <span class="hljs-string">"0.2.0"</span>,<br> <span class="hljs-attr">"configurations"</span>: [<br> {<br> <span class="hljs-attr">"name"</span>: <span class="hljs-string">"asio_chat_server"</span>,<br> <span class="hljs-attr">"type"</span>: <span class="hljs-string">"cppdbg"</span>,<br> <span class="hljs-attr">"request"</span>: <span class="hljs-string">"launch"</span>,<br> <span class="hljs-attr">"program"</span>: <span class="hljs-string">"${workspaceFolder}/build/bin/asio_chat_server"</span>,<br> <span class="hljs-attr">"args"</span>: [<span class="hljs-string">"4000"</span>],<br> <span class="hljs-attr">"stopAtEntry"</span>: <span class="hljs-literal">false</span>,<br> <span class="hljs-attr">"cwd"</span>: <span class="hljs-string">"${fileDirname}"</span>,<br> <span class="hljs-attr">"environment"</span>: [],<br> <span class="hljs-attr">"externalConsole"</span>: <span class="hljs-literal">false</span>,<br> <span class="hljs-attr">"MIMode"</span>: <span class="hljs-string">"gdb"</span>,<br> <span class="hljs-attr">"setupCommands"</span>: [<br> {<br> <span class="hljs-attr">"description"</span>: <span class="hljs-string">"为 gdb 启用整齐打印"</span>,<br> <span class="hljs-attr">"text"</span>: <span class="hljs-string">"-enable-pretty-printing"</span>,<br> <span class="hljs-attr">"ignoreFailures"</span>: <span class="hljs-literal">true</span><br> }<br> ],<br> <span class="hljs-attr">"preLaunchTask"</span>: <span class="hljs-string">"build-all"</span><br> }<br> ]<br>}<br></code></pre></td></tr></table></figure><p>5.3 tasks.json 示例</p><figure class="highlight json"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br></pre></td><td class="code"><pre><code class="hljs json">{<br> <span class="hljs-attr">"version"</span>: <span class="hljs-string">"2.0.0"</span>,<br> <span class="hljs-attr">"tasks"</span>: [<br> {<br> <span class="hljs-attr">"label"</span>: <span class="hljs-string">"build-all"</span>,<br> <span class="hljs-attr">"type"</span>: <span class="hljs-string">"shell"</span>,<br> <span class="hljs-attr">"command"</span>: <span class="hljs-string">"/usr/bin/bash vscode.sh"</span>,<br> <span class="hljs-attr">"problemMatcher"</span>: [],<br> <span class="hljs-attr">"group"</span>: {<br> <span class="hljs-attr">"kind"</span>: <span class="hljs-string">"build"</span>,<br> <span class="hljs-attr">"isDefault"</span>: <span class="hljs-literal">true</span><br> }<br> }<br> ]<br><br>}<br></code></pre></td></tr></table></figure><p>菜单 终端 -> 运行生成任务(Ctrl+Shift+B), 会运行 tasks.json 中 <code>"isDefault": true</code> 的task。</p><h2 id="X11环境下的输入法"><a href="#X11环境下的输入法" class="headerlink" title="X11环境下的输入法"></a>X11环境下的输入法</h2><p>Fedora默认输入法是Ibus，当运行级别为3的时候，Ibus相关的服务不是开机启动的，需要你在xshell连上之后，手动启动ibus。</p><h3 id="0-用到的包"><a href="#0-用到的包" class="headerlink" title="0. 用到的包"></a>0. 用到的包</h3><figure class="highlight angelscript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br></pre></td><td class="code"><pre><code class="hljs angelscript">[<span class="hljs-symbol">lukas@</span>localhost yum.repos.d]$ rpm -qa | grep ^ibus<br>ibus-libs<span class="hljs-number">-1.5</span><span class="hljs-number">.24</span><span class="hljs-number">-5.f</span>c34.x86_64<br>ibus-gtk2<span class="hljs-number">-1.5</span><span class="hljs-number">.24</span><span class="hljs-number">-5.f</span>c34.x86_64<br>ibus-gtk3<span class="hljs-number">-1.5</span><span class="hljs-number">.24</span><span class="hljs-number">-5.f</span>c34.x86_64<br>ibus<span class="hljs-number">-1.5</span><span class="hljs-number">.24</span><span class="hljs-number">-5.f</span>c34.x86_64<br>ibus-setup<span class="hljs-number">-1.5</span><span class="hljs-number">.24</span><span class="hljs-number">-5.f</span>c34.noarch<br>ibus-libzhuyin<span class="hljs-number">-1.10</span><span class="hljs-number">.0</span><span class="hljs-number">-2.f</span>c34.x86_64<br>ibus-m17n<span class="hljs-number">-1.4</span><span class="hljs-number">.9</span><span class="hljs-number">-1.f</span>c34.x86_64<br>ibus-libpinyin<span class="hljs-number">-1.12</span><span class="hljs-number">.0</span><span class="hljs-number">-3.f</span>c34.x86_64<br>ibus-anthy-python<span class="hljs-number">-1.5</span><span class="hljs-number">.12</span><span class="hljs-number">-7.f</span>c34.noarch<br>ibus-anthy<span class="hljs-number">-1.5</span><span class="hljs-number">.12</span><span class="hljs-number">-7.f</span>c34.x86_64<br>ibus-hangul<span class="hljs-number">-1.5</span><span class="hljs-number">.4</span><span class="hljs-number">-5.f</span>c34.x86_64<br>ibus-typing-booster<span class="hljs-number">-2.15</span><span class="hljs-number">.16</span><span class="hljs-number">-1.f</span>c34.noarch<br>[<span class="hljs-symbol">lukas@</span>localhost yum.repos.d]$<br></code></pre></td></tr></table></figure><figure class="highlight apache"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs apache"><span class="hljs-attribute">sudo</span> dnf install ibus-libs ibus-gtk<span class="hljs-number">2</span> ibus-gtk<span class="hljs-number">3</span> ibus ibus-setup ibus-libzhuyin ibus-m<span class="hljs-number">17</span>n ibus-libpinyin ibus-anthy-python ibus-anthy ibus-hangul ibus-typing-booster xsel<br></code></pre></td></tr></table></figure><h3 id="1-复制粘贴"><a href="#1-复制粘贴" class="headerlink" title="1. 复制粘贴"></a>1. 复制粘贴</h3><figure class="highlight cmake"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs cmake">sudo dnf -y <span class="hljs-keyword">install</span> xsel<br></code></pre></td></tr></table></figure><h3 id="1-设置快捷键"><a href="#1-设置快捷键" class="headerlink" title="1. 设置快捷键"></a>1. 设置快捷键</h3><figure class="highlight elixir"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs elixir">[lukas<span class="hljs-variable">@fedora</span> muduo]<span class="hljs-variable">$ </span>ibus-setup<br></code></pre></td></tr></table></figure><p>在程序窗口中设置为 Ctrl + 空格</p><h3 id="2-设置Ibus相关环境变量"><a href="#2-设置Ibus相关环境变量" class="headerlink" title="2. 设置Ibus相关环境变量"></a>2. 设置Ibus相关环境变量</h3><figure class="highlight routeros"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><code class="hljs routeros"><span class="hljs-builtin-name">export</span> <span class="hljs-attribute">XIM</span>=ibus<br><span class="hljs-builtin-name">export</span> <span class="hljs-attribute">GTK_IM_MODULE</span>=ibus<br><span class="hljs-builtin-name">export</span> <span class="hljs-attribute">QT_IM_MODULE</span>=ibus<br><span class="hljs-builtin-name">export</span> <span class="hljs-attribute">XIM_PROGRAM</span>=<span class="hljs-string">"ibus-daemon"</span><br><span class="hljs-builtin-name">export</span> <span class="hljs-attribute">XMODIFIERS</span>=<span class="hljs-string">"@im=ibus"</span><br></code></pre></td></tr></table></figure><p>在 ~/.bashrc 里面添加</p><h3 id="3-手动启动Ibus守护进程"><a href="#3-手动启动Ibus守护进程" class="headerlink" title="3. 手动启动Ibus守护进程"></a>3. 手动启动Ibus守护进程</h3><figure class="highlight ebnf"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs ebnf"><span class="hljs-attribute">ibus-daemon -x -d</span><br></code></pre></td></tr></table></figure><h3 id="4-剪切板复制粘贴"><a href="#4-剪切板复制粘贴" class="headerlink" title="4. 剪切板复制粘贴"></a>4. 剪切板复制粘贴</h3><figure class="highlight nginx"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs nginx"><span class="hljs-attribute">ForwardX11</span> <span class="hljs-literal">yes</span><br></code></pre></td></tr></table></figure><p>修改ssh配置，在 <code>/etc/ssh/ssh_config</code> 文件配置上述选项。<br>vmware中启用剪切板复制粘贴。</p><h2 id="X11环境下可能出现的问题"><a href="#X11环境下可能出现的问题" class="headerlink" title="X11环境下可能出现的问题"></a>X11环境下可能出现的问题</h2><ol><li>文本输入时，按了字母数字外的键盘按键，出现一直输入222222222222222222222222无法停止的现象</li></ol><p>这是一个偶尔出现的状况，不太清楚原因，没找到彻底的解决办法。</p><p>解决办法： 关闭程序，重新开启程序</p>]]></content>
<categories>
<category>开发环境配置</category>
</categories>
<tags>
<tag>Linux</tag>
<tag>Fedora</tag>
<tag>X11</tag>
</tags>
</entry>
<entry>
<title>HTTP请求参数处理</title>
<link href="/NET%E5%BC%80%E5%8F%91/http%E8%AF%B7%E6%B1%82%E5%8F%82%E6%95%B0%E5%A4%84%E7%90%86/"/>
<url>/NET%E5%BC%80%E5%8F%91/http%E8%AF%B7%E6%B1%82%E5%8F%82%E6%95%B0%E5%A4%84%E7%90%86/</url>
<content type="html"><![CDATA[<h2 id="HTTP请求参数枚举类型的处理"><a href="#HTTP请求参数枚举类型的处理" class="headerlink" title="HTTP请求参数枚举类型的处理"></a>HTTP请求参数枚举类型的处理</h2><p>业务上使用枚举类型，标识业务某一类的类型，代码上更加可读。</p><p>枚举其实是一个int类型的数字，那么在传参的时候，直接使用int类型作为请求参数的类型，后面再转换成业务相关的枚举类型，进行比较等操作。</p><h2 id="HTTP请求参数日期时间类型的处理"><a href="#HTTP请求参数日期时间类型的处理" class="headerlink" title="HTTP请求参数日期时间类型的处理"></a>HTTP请求参数日期时间类型的处理</h2><h3 id="前端给后端传参？"><a href="#前端给后端传参？" class="headerlink" title="前端给后端传参？"></a>前端给后端传参？</h3><p>使用时间戳</p><p> 这么做</p><h3 id="后端给前端返回结果"><a href="#后端给前端返回结果" class="headerlink" title="后端给前端返回结果"></a>后端给前端返回结果</h3><p> 涉及到时区的处理，前端后端要有统一的约定。<br> 例如： 统一使用utc时间，不同时区的时间处理，交给不同时区的web和客户端去具体处理。</p>]]></content>
<categories>
<category>.NET开发</category>
</categories>
<tags>
<tag>AspNetCore</tag>
</tags>
</entry>
<entry>
<title>PostgreSQL时间戳</title>
<link href="/PostgreSQL%E6%95%B0%E6%8D%AE%E5%BA%93/postgresql%E6%97%B6%E9%97%B4%E6%88%B3/"/>
<url>/PostgreSQL%E6%95%B0%E6%8D%AE%E5%BA%93/postgresql%E6%97%B6%E9%97%B4%E6%88%B3/</url>
<content type="html"><![CDATA[<h2 id="DataGrip设置时区"><a href="#DataGrip设置时区" class="headerlink" title="DataGrip设置时区"></a>DataGrip设置时区</h2><p>DataGrip时区默认是 UTC+0, 不是UTC+8, 在连接属性里面设置UTC+8。</p><h3 id="操作步骤"><a href="#操作步骤" class="headerlink" title="操作步骤"></a>操作步骤</h3><ol><li>右键打开你想要修改的数据库连接的Properties菜单；</li><li>点击Advanced按钮；</li><li>在VM options后面写入-Duser.timezone=Asia/Shanghai，就可以啦；</li><li>断开数据库连接，重新执行一条SQL就可以看到效果了。</li></ol><h2 id="PG中时间戳类型的查询写法"><a href="#PG中时间戳类型的查询写法" class="headerlink" title="PG中时间戳类型的查询写法"></a>PG中时间戳类型的查询写法</h2><h3 id="时间戳存储"><a href="#时间戳存储" class="headerlink" title="时间戳存储"></a>时间戳存储</h3><p>对于timestamp with time zone，内部存储的值总是 UTC （全球统一时间，以前也叫格林威治时间GMT）。<br>如果一个输入值有明确的时区声明， 那么它将用该时区合适的偏移量转换成 UTC。<br>如果在输入串里没有时区声明， 那么它就被假设是在系统的TimeZone参数里的那个时区，然后使用这个 timezone时区的偏移转换成 UTC。 </p><h3 id="双冒号语法"><a href="#双冒号语法" class="headerlink" title="双冒号语法"></a>双冒号语法</h3><figure class="highlight coffeescript"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs coffeescript">:: 操作符 =<span class="hljs-function">=></span> PostgreSQL风格的类型转换<br></code></pre></td></tr></table></figure><p>在PostgreSQL数据库中，双冒号:: 是用于类型转换的，比如’2010-01-01’::date。</p><h3 id="时间戳查询"><a href="#时间戳查询" class="headerlink" title="时间戳查询"></a>时间戳查询</h3><figure class="highlight sql"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br></pre></td><td class="code"><pre><code class="hljs sql"><br><span class="hljs-keyword">SET</span> TIMEZONE <span class="hljs-keyword">TO</span> <span class="hljs-string">'Asia/Shanghai'</span>;<br><br><span class="hljs-keyword">select</span> <span class="hljs-keyword">current_timestamp</span>;<br><br><span class="hljs-keyword">select</span> <span class="hljs-string">'2021-12-18 19:53:49.985033+08'</span>::<span class="hljs-built_in">timestamp</span> <span class="hljs-keyword">with</span> <span class="hljs-built_in">time</span> zone;<br><br><span class="hljs-keyword">select</span> <span class="hljs-string">'2021-12-18 19:53:49+08'</span>::<span class="hljs-built_in">timestamp</span> <span class="hljs-keyword">with</span> <span class="hljs-built_in">time</span> zone;<br><br><span class="hljs-keyword">select</span> * <span class="hljs-keyword">from</span> <span class="hljs-string">"Order"</span> <span class="hljs-keyword">where</span> <span class="hljs-string">"CreationTime"</span> = <span class="hljs-string">'2021-12-19 15:49:31.210972+08'</span>::<span class="hljs-built_in">timestamp</span> <span class="hljs-keyword">with</span> <span class="hljs-built_in">time</span> zone;<br><br><span class="hljs-keyword">select</span> * <span class="hljs-keyword">from</span> <span class="hljs-string">"Order"</span><br><span class="hljs-keyword">where</span> <span class="hljs-string">"PaymentTime"</span> <br><span class="hljs-keyword">between</span> <span class="hljs-string">'2021-12-19 15:13:10.024023+08'</span>::<span class="hljs-built_in">timestamp</span> <span class="hljs-keyword">with</span> <span class="hljs-built_in">time</span> zone<br><span class="hljs-keyword">and</span> <span class="hljs-string">'2021-12-19 16:45:15.108045+08'</span>::<span class="hljs-built_in">timestamp</span> <span class="hljs-keyword">with</span> <span class="hljs-built_in">time</span> zone;<br><br></code></pre></td></tr></table></figure><h2 id="程序中时间戳类型的选择"><a href="#程序中时间戳类型的选择" class="headerlink" title="程序中时间戳类型的选择"></a>程序中时间戳类型的选择</h2><h3 id="C-类型DateTime和DateTimeOffset的选择"><a href="#C-类型DateTime和DateTimeOffset的选择" class="headerlink" title="C#类型DateTime和DateTimeOffset的选择"></a>C#类型DateTime和DateTimeOffset的选择</h3><p>在程序中统一使用UTC时间，http请求参数使用DateTimeOffset；<br>在参数解析绑定时，DateTimeOffset类型会自动带上本地时区的Offset，<br>而 DateTime 不会有时区信息，Kind属性值是DateTimeKind.Unspecified，</p><p>前端给后端传时间戳，后端收到转成utc时间(使用DateTimeOffset类型)，这样可以避免处理时区的问题。</p><figure class="highlight c#"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br></pre></td><td class="code"><pre><code class="hljs c#">[<span class="hljs-meta">HttpGet</span>]<br>[<span class="hljs-meta">Route(<span class="hljs-meta-string">"date1"</span>)</span>]<br><span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">async</span> Task<JsonResult> <span class="hljs-title">DatetimeOffset1</span>(<span class="hljs-params">DateTime dt</span>)</span><br><span class="hljs-function"></span>{<br> <span class="hljs-comment">// http://localhost:9000/api/date1?dt=2021-12-19 15:13:10</span><br> <span class="hljs-comment">// "2021-12-19T15:13:10"</span><br><br> <span class="hljs-keyword">var</span> a = <span class="hljs-number">1</span>;<br><br> <span class="hljs-keyword">return</span> <span class="hljs-keyword">await</span> Task.FromResult(<span class="hljs-keyword">new</span> JsonResult(dt));<br>}<br><br>[<span class="hljs-meta">HttpGet</span>]<br>[<span class="hljs-meta">Route(<span class="hljs-meta-string">"date2"</span>)</span>]<br><span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">async</span> Task<JsonResult> <span class="hljs-title">DatetimeOffset2</span>(<span class="hljs-params">DateTimeOffset dt</span>)</span><br><span class="hljs-function"></span>{<br> <span class="hljs-comment">// http://localhost:9000/api/date2?dt=2021-12-19 15:13:10</span><br> <span class="hljs-comment">// "2021-12-19T15:13:10+08:00"</span><br><br> <span class="hljs-keyword">var</span> a = <span class="hljs-number">1</span>;<br><br> <span class="hljs-keyword">return</span> <span class="hljs-keyword">await</span> Task.FromResult(<span class="hljs-keyword">new</span> JsonResult(dt));<br>}<br></code></pre></td></tr></table></figure><h3 id="JsonResult中DateTimeOffset的格式化"><a href="#JsonResult中DateTimeOffset的格式化" class="headerlink" title="JsonResult中DateTimeOffset的格式化"></a>JsonResult中DateTimeOffset的格式化</h3><ol><li>编写自定义转换器</li></ol><figure class="highlight c#"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br></pre></td><td class="code"><pre><code class="hljs c#"><span class="hljs-keyword">using</span> System;<br><span class="hljs-keyword">using</span> System.Globalization;<br><span class="hljs-keyword">using</span> System.Text.Json;<br><span class="hljs-keyword">using</span> System.Text.Json.Serialization;<br><br><span class="hljs-keyword">namespace</span> <span class="hljs-title">Practical.Api.Helper</span><br>{<br> <span class="hljs-keyword">public</span> <span class="hljs-keyword">class</span> <span class="hljs-title">DateTimeOffsetConverter</span> : <span class="hljs-title">JsonConverter</span><<span class="hljs-title">DateTimeOffset</span>><br> {<br> <span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">override</span> DateTimeOffset <span class="hljs-title">Read</span>(<span class="hljs-params"><span class="hljs-keyword">ref</span> Utf8JsonReader reader, </span></span><br><span class="hljs-function"><span class="hljs-params"> Type typeToConvert, </span></span><br><span class="hljs-function"><span class="hljs-params"> JsonSerializerOptions options</span>)</span><br><span class="hljs-function"></span> {<br> <span class="hljs-keyword">return</span> DateTimeOffset<br> .ParseExact(reader.GetString(), <span class="hljs-string">"yyyy-MM-dd HH:mm:ss"</span>, CultureInfo.InvariantCulture);<br> }<br><br> <span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">override</span> <span class="hljs-keyword">void</span> <span class="hljs-title">Write</span>(<span class="hljs-params">Utf8JsonWriter writer, </span></span><br><span class="hljs-function"><span class="hljs-params"> DateTimeOffset <span class="hljs-keyword">value</span>, </span></span><br><span class="hljs-function"><span class="hljs-params"> JsonSerializerOptions options</span>)</span><br><span class="hljs-function"></span> {<br> writer.WriteStringValue(<span class="hljs-keyword">value</span>.ToLocalTime()<br> .ToString(<span class="hljs-string">"yyyy-MM-dd HH:mm:ss"</span>, CultureInfo.InvariantCulture));<br> }<br> }<br>}<br></code></pre></td></tr></table></figure><ol start="2"><li>StartUp类中配置序列化选项</li></ol><figure class="highlight c#"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br></pre></td><td class="code"><pre><code class="hljs c#"><span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">ConfigureServices</span>(<span class="hljs-params">IServiceCollection services</span>)</span><br><span class="hljs-function"></span>{<br><br> services.AddControllers()<br> .AddJsonOptions(op => op.JsonSerializerOptions<br> .Converters.Add(<span class="hljs-keyword">new</span> DateTimeOffsetConverter()));<br> services.AddSwaggerGen(c =><br> {<br> c.SwaggerDoc(<span class="hljs-string">"v1"</span>, <span class="hljs-keyword">new</span> OpenApiInfo { Title = <span class="hljs-string">"Practical.API"</span>, Version = <span class="hljs-string">"v1"</span> });<br> });<br><br> RegisterMediatR(services);<br>}<br></code></pre></td></tr></table></figure><ol start="3"><li>Newtonsoft.Json库使用JsonSerializerSettings进行设置</li></ol><figure class="highlight routeros"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><code class="hljs routeros">var<span class="hljs-built_in"> settings </span>= new JsonSerializerSettings()<br>{<br> DateFormatString = <span class="hljs-string">"yyyy-MM-dd HH:mm:ss"</span>,<br> DateTimeZoneHandling = DateTimeZoneHandling.Local<br>};<br></code></pre></td></tr></table></figure><p>参考文章：<br><a href="https://docs.microsoft.com/en-us/dotnet/standard/serialization/system-text-json-converters-how-to?pivots=dotnet-6-0#sample-basic-converter">https://docs.microsoft.com/en-us/dotnet/standard/serialization/system-text-json-converters-how-to?pivots=dotnet-6-0#sample-basic-converter</a></p><h3 id="JS时间戳的转换"><a href="#JS时间戳的转换" class="headerlink" title="JS时间戳的转换"></a>JS时间戳的转换</h3><p>首先要清楚JavaScript与Unix的时间戳的区别：</p><p>JavaScript时间戳：是指格林威治时间1970年01月01日00时00分00秒(北京时间1970年01月01日08时00分00秒)起至现在的总毫秒数。</p><p>Unix时间戳：是指格林威治时间1970年01月01日00时00分00秒(北京时间1970年01月01日08时00分00秒)起至现在的总秒数。</p><p>可以看出JavaScript时间戳总毫秒数，Unix时间戳是总秒数。</p><p>比如同样是的 2016/11/03 12:30:00 ，转换为JavaScript时间戳为 1478147400000；转换为Unix时间戳为 1478147400。</p><ol><li>C# DateTime转换为JavaScript时间戳</li></ol><figure class="highlight c#"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><code class="hljs c#"> <span class="hljs-comment">// 当地时区</span><br>System.DateTime startTime = TimeZone.CurrentTimeZone<br> .ToLocalTime(<span class="hljs-keyword">new</span> System.DateTime(<span class="hljs-number">1970</span>, <span class="hljs-number">1</span>, <span class="hljs-number">1</span>));<br><span class="hljs-keyword">long</span> timeStamp = (<span class="hljs-keyword">long</span>)(DateTime.Now - startTime).TotalMilliseconds; <span class="hljs-comment">// 相差毫秒数</span><br>System.Console.WriteLine(timeStamp);<br></code></pre></td></tr></table></figure><ol start="2"><li>JavaScript时间戳转换为C# DateTime</li></ol><figure class="highlight c#"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><code class="hljs c#"><span class="hljs-keyword">long</span> jsTimeStamp = <span class="hljs-number">1478169023479</span>;<br> <span class="hljs-comment">// 当地时区</span><br>System.DateTime startTime = TimeZone.CurrentTimeZone<br> .ToLocalTime(<span class="hljs-keyword">new</span> System.DateTime(<span class="hljs-number">1970</span>, <span class="hljs-number">1</span>, <span class="hljs-number">1</span>));<br>DateTime dt = startTime.AddMilliseconds(jsTimeStamp);<br>System.Console.WriteLine(dt.ToString(<span class="hljs-string">"yyyy/MM/dd HH:mm:ss:ffff"</span>));<br><br><span class="hljs-keyword">var</span> udt1 = DateTimeOffset.FromUnixTimeSeconds(<span class="hljs-number">1478147400</span>);<br><span class="hljs-keyword">var</span> udt2 = DateTimeOffset.FromUnixTimeMilliseconds(<span class="hljs-number">1478147400000</span>);<br></code></pre></td></tr></table></figure><ol start="3"><li>JavaScript获取时间戳与时间戳转化</li></ol><p>Javascript 获取当前时间戳（毫秒级别）：</p><figure class="highlight js"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br></pre></td><td class="code"><pre><code class="hljs js">第一种方法：结果：<span class="hljs-number">1470220594000</span><br><br><span class="hljs-keyword">var</span> timestamp1 = <span class="hljs-built_in">Date</span>.parse( <span class="hljs-keyword">new</span> <span class="hljs-built_in">Date</span>());<br><br><br>第二种方法：结果：<span class="hljs-number">1470220608533</span><br><br><span class="hljs-keyword">var</span> timestamp2 = ( <span class="hljs-keyword">new</span> <span class="hljs-built_in">Date</span>()).valueOf();<br><br><br>第三种方法：结果：<span class="hljs-number">1470220608533</span><br><br><span class="hljs-keyword">var</span> timestamp3 = <span class="hljs-keyword">new</span> <span class="hljs-built_in">Date</span>().getTime();<br></code></pre></td></tr></table></figure><p>第一种获取的时间戳是精确到秒。<br>第二种和第三种是获取的时间戳精确到毫秒。</p><p>获取时间戳的方法还有：<br>+new Date();<br>Date.now(); // 这个ES5才添加的方法<br>还有 new Date - 0;</p><hr><p>获取指定时间的时间戳：</p><figure class="highlight js"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs js"><span class="hljs-keyword">new</span> <span class="hljs-built_in">Date</span>(<span class="hljs-string">"2016-08-03 00:00:00"</span>);<br></code></pre></td></tr></table></figure><p>时间戳转化成时间：</p><figure class="highlight js"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><code class="hljs js"><span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">timetrans</span>(<span class="hljs-params">date</span>)</span>{<br> <span class="hljs-keyword">var</span> date = <span class="hljs-keyword">new</span> <span class="hljs-built_in">Date</span>(date*<span class="hljs-number">1000</span>);<span class="hljs-comment">//如果date为13位不需要乘1000</span><br> <span class="hljs-keyword">var</span> Y = date.getFullYear() + <span class="hljs-string">'-'</span>;<br> <span class="hljs-keyword">var</span> M = (date.getMonth()+<span class="hljs-number">1</span> < <span class="hljs-number">10</span> ? <span class="hljs-string">'0'</span>+(date.getMonth()+<span class="hljs-number">1</span>) : date.getMonth()+<span class="hljs-number">1</span>) + <span class="hljs-string">'-'</span>;<br> <span class="hljs-keyword">var</span> D = (date.getDate() < <span class="hljs-number">10</span> ? <span class="hljs-string">'0'</span> + (date.getDate()) : date.getDate()) + <span class="hljs-string">' '</span>;<br> <span class="hljs-keyword">var</span> h = (date.getHours() < <span class="hljs-number">10</span> ? <span class="hljs-string">'0'</span> + date.getHours() : date.getHours()) + <span class="hljs-string">':'</span>;<br> <span class="hljs-keyword">var</span> m = (date.getMinutes() <<span class="hljs-number">10</span> ? <span class="hljs-string">'0'</span> + date.getMinutes() : date.getMinutes()) + <span class="hljs-string">':'</span>;<br> <span class="hljs-keyword">var</span> s = (date.getSeconds() <<span class="hljs-number">10</span> ? <span class="hljs-string">'0'</span> + date.getSeconds() : date.getSeconds());<br> <span class="hljs-keyword">return</span> Y+M+D+h+m+s;<br>}<br></code></pre></td></tr></table></figure>]]></content>
<categories>
<category>PostgreSQL数据库</category>
</categories>
<tags>
<tag>Timestamp</tag>
</tags>
</entry>
<entry>
<title>HTTP协议认证</title>
<link href="/HTTP%E5%8D%8F%E8%AE%AE/http%E5%8D%8F%E8%AE%AE%E8%AE%A4%E8%AF%81/"/>
<url>/HTTP%E5%8D%8F%E8%AE%AE/http%E5%8D%8F%E8%AE%AE%E8%AE%A4%E8%AF%81/</url>
<content type="html"><![CDATA[<h2 id="简介"><a href="#简介" class="headerlink" title="简介"></a>简介</h2><p>在HTTP协议中，包含了认证相关的内容。</p><h2 id="RFC7235中的内容"><a href="#RFC7235中的内容" class="headerlink" title="RFC7235中的内容"></a>RFC7235中的内容</h2><p>在HTTP协议中，包含了认证相关的内容。</p>]]></content>
<categories>
<category>HTTP协议</category>
</categories>
<tags>
<tag>Authentication</tag>
</tags>
</entry>
<entry>
<title>Go协程的设计</title>
<link href="/Go%E8%AF%AD%E8%A8%80%E5%BC%80%E5%8F%91/go%E5%8D%8F%E7%A8%8B%E7%9A%84%E8%AE%BE%E8%AE%A1/"/>
<url>/Go%E8%AF%AD%E8%A8%80%E5%BC%80%E5%8F%91/go%E5%8D%8F%E7%A8%8B%E7%9A%84%E8%AE%BE%E8%AE%A1/</url>
<content type="html"><![CDATA[<h2 id="参考文章"><a href="#参考文章" class="headerlink" title="参考文章"></a>参考文章</h2><p><a href="https://www.zhihu.com/question/20862617">https://www.zhihu.com/question/20862617</a><br><a href="https://chasecs.github.io/posts/go-scheduler-introduction/">https://chasecs.github.io/posts/go-scheduler-introduction/</a><br><a href="https://morsmachine.dk/go-scheduler">https://morsmachine.dk/go-scheduler</a></p>]]></content>
<categories>
<category>Go语言开发</category>
</categories>
<tags>
<tag>Go-Runtime</tag>
</tags>
</entry>
<entry>
<title>Gin的用法</title>
<link href="/Go%E8%AF%AD%E8%A8%80%E5%BC%80%E5%8F%91/gin%E7%9A%84%E7%94%A8%E6%B3%95/"/>
<url>/Go%E8%AF%AD%E8%A8%80%E5%BC%80%E5%8F%91/gin%E7%9A%84%E7%94%A8%E6%B3%95/</url>
<content type="html"><![CDATA[<p>Gin 是一个web框架</p>]]></content>
<categories>
<category>Go语言开发</category>
</categories>
<tags>
<tag>Gin</tag>
</tags>
</entry>
<entry>
<title>GORM的用法</title>
<link href="/Go%E8%AF%AD%E8%A8%80%E5%BC%80%E5%8F%91/gorm%E7%9A%84%E7%94%A8%E6%B3%95/"/>
<url>/Go%E8%AF%AD%E8%A8%80%E5%BC%80%E5%8F%91/gorm%E7%9A%84%E7%94%A8%E6%B3%95/</url>
<content type="html"><![CDATA[<h2 id="迁移-AutoMigrate"><a href="#迁移-AutoMigrate" class="headerlink" title="迁移(AutoMigrate)"></a>迁移(AutoMigrate)</h2><ol><li>介绍<br>GORM 的 AutoMigrate() 方法用于自动迁移 ORM 的 Schemas。所谓 “迁移” 就是刷新数据库中的表格定义，使其保持最新（只增不减）。</li></ol><p>AutoMigrate 会创建（新的）表、缺少的外键、约束、列和索引，并且会更改现有列的类型（如果其大小、精度、是否为空可更改的话）。但不会删除未使用的列，以保护现存的数据。</p><ol start="2"><li>数据库版本控制</li></ol><p>需要注意的是，GORM 虽然提供了不错的数据库迁移功能，但是距离理想的 “版本控制” 仍有距离。不支持，包括：版本记录、版本回退、版本选择。这些都需要开发者自行封装。</p><p>这玩意跟 EF Core 比起来就是个弟弟，弱的不能再弱，凑合用！</p><h2 id="参考文章"><a href="#参考文章" class="headerlink" title="参考文章"></a>参考文章</h2><p><a href="https://blog.51cto.com/u_15301988/3079977">https://blog.51cto.com/u_15301988/3079977</a></p>]]></content>
<categories>
<category>Go语言开发</category>
</categories>
<tags>
<tag>GORM</tag>
</tags>
</entry>
<entry>
<title>Pgx-tern迁移的用法</title>
<link href="/Go%E8%AF%AD%E8%A8%80%E5%BC%80%E5%8F%91/pgx-tern%E8%BF%81%E7%A7%BB%E7%9A%84%E7%94%A8%E6%B3%95/"/>
<url>/Go%E8%AF%AD%E8%A8%80%E5%BC%80%E5%8F%91/pgx-tern%E8%BF%81%E7%A7%BB%E7%9A%84%E7%94%A8%E6%B3%95/</url>
<content type="html"><![CDATA[<p>tern 是一个 pgx 配套的pg迁移工具。</p>]]></content>
<categories>
<category>Go语言开发</category>
</categories>
<tags>
<tag>PGX</tag>
<tag>Tern</tag>
</tags>
</entry>
<entry>
<title>自定义配置HttpClient</title>
<link href="/NET%E5%BC%80%E5%8F%91/%E8%87%AA%E5%AE%9A%E4%B9%89%E9%85%8D%E7%BD%AEhttpclient/"/>
<url>/NET%E5%BC%80%E5%8F%91/%E8%87%AA%E5%AE%9A%E4%B9%89%E9%85%8D%E7%BD%AEhttpclient/</url>
<content type="html"><![CDATA[<h2 id="完全封装-HttpClient"><a href="#完全封装-HttpClient" class="headerlink" title="完全封装 HttpClient"></a>完全封装 HttpClient</h2><ol><li>自定义 HttpClientFactory 请求类</li></ol><figure class="highlight c#"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br></pre></td><td class="code"><pre><code class="hljs c#"><span class="hljs-keyword">public</span> <span class="hljs-keyword">interface</span> <span class="hljs-title">ISampleClient</span><br>{<br> <span class="hljs-function">Task<<span class="hljs-keyword">string</span>> <span class="hljs-title">GetData</span>(<span class="hljs-params"></span>)</span>;<br>}<br><br><span class="hljs-keyword">public</span> <span class="hljs-keyword">class</span> <span class="hljs-title">SampleClient</span> : <span class="hljs-title">ISampleClient</span><br>{<br> <span class="hljs-keyword">private</span> <span class="hljs-keyword">readonly</span> HttpClient _client;<br><br> <span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-title">SampleClient</span>(<span class="hljs-params">HttpClient httpClient</span>)</span><br><span class="hljs-function"></span> {<br> httpClient.BaseAddress = <span class="hljs-keyword">new</span> Uri(<span class="hljs-string">"https://api.SampleClient.com/"</span>);<br> httpClient.DefaultRequestHeaders.Add(<span class="hljs-string">"Accept"</span>, <span class="hljs-string">"application/json"</span>);<br> httpClient.DefaultRequestHeaders.Add(<span class="hljs-string">"User-Agent"</span>, <span class="hljs-string">"HttpClientFactory-Sample"</span>);<br> _client = httpClient;<br> }<br><br> <span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">async</span> Task<<span class="hljs-keyword">string</span>> <span class="hljs-title">GetData</span>(<span class="hljs-params"></span>)</span><br><span class="hljs-function"></span> {<br> <span class="hljs-keyword">return</span> <span class="hljs-keyword">await</span> _client.GetStringAsync(<span class="hljs-string">"/"</span>);<br> }<br>}<br></code></pre></td></tr></table></figure><ol start="2"><li>在Startup.cs中ConfigureService方法中注册SampleClient</li></ol><figure class="highlight c#"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs c#">services.AddHttpClient<ISampleClient, SampleClient>();<br></code></pre></td></tr></table></figure><ol start="3"><li>从容器获取实例</li></ol><figure class="highlight c#"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br></pre></td><td class="code"><pre><code class="hljs c#"><span class="hljs-keyword">public</span> <span class="hljs-keyword">class</span> <span class="hljs-title">ValuesController</span> : <span class="hljs-title">Controller</span><br>{<br> <span class="hljs-keyword">private</span> <span class="hljs-keyword">readonly</span> ISampleClient _sampleClient;;<br><br> <span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-title">ValuesController</span>(<span class="hljs-params">ISampleClient sampleClient</span>)</span><br><span class="hljs-function"></span> {<br> _sampleClient = sampleClient;<br> }<br><br> [<span class="hljs-meta">HttpGet</span>]<br> <span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">async</span> Task<ActionResult> <span class="hljs-title">Get</span>(<span class="hljs-params"></span>)</span><br><span class="hljs-function"></span> {<br> <span class="hljs-keyword">string</span> result = <span class="hljs-keyword">await</span> _sampleClient.GetData();<br> <span class="hljs-keyword">return</span> Ok(result);<br> }<br>}<br></code></pre></td></tr></table></figure>]]></content>
<categories>
<category>.NET开发</category>
</categories>
<tags>
<tag>AspNetCore</tag>
</tags>
</entry>
<entry>
<title>指定AspNetCore运行地址的方法</title>
<link href="/NET%E5%BC%80%E5%8F%91/%E6%8C%87%E5%AE%9Aaspnetcore%E8%BF%90%E8%A1%8C%E5%9C%B0%E5%9D%80%E7%9A%84%E6%96%B9%E6%B3%95/"/>
<url>/NET%E5%BC%80%E5%8F%91/%E6%8C%87%E5%AE%9Aaspnetcore%E8%BF%90%E8%A1%8C%E5%9C%B0%E5%9D%80%E7%9A%84%E6%96%B9%E6%B3%95/</url>
<content type="html"><![CDATA[<h1 id="How-to-specify-the-port-an-ASP-NET-Core-application-is-hosted-on"><a href="#How-to-specify-the-port-an-ASP-NET-Core-application-is-hosted-on" class="headerlink" title="How to specify the port an ASP.NET Core application is hosted on?"></a>How to specify the port an ASP.NET Core application is hosted on?</h1><p>In ASP.NET Core 3.1, there are 4 main ways to specify a custom port:</p><h3 id="Using-command-line-arguments-by-starting-your-NET-application-with-–urls-url"><a href="#Using-command-line-arguments-by-starting-your-NET-application-with-–urls-url" class="headerlink" title="Using command line arguments, by starting your .NET application with –urls=[url]:"></a>Using command line arguments, by starting your .NET application with –urls=[url]:</h3><figure class="highlight powershell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs powershell">dotnet run -<span class="hljs-literal">-urls</span>=http://localhost:<span class="hljs-number">5001</span>/<br></code></pre></td></tr></table></figure><h3 id="Using-appsettings-json-by-adding-a-Urls-node"><a href="#Using-appsettings-json-by-adding-a-Urls-node" class="headerlink" title="Using appsettings.json, by adding a Urls node:"></a>Using appsettings.json, by adding a Urls node:</h3><figure class="highlight json"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><code class="hljs json">{<br> <span class="hljs-attr">"Urls"</span>: <span class="hljs-string">"http://localhost:5001"</span><br>}<br></code></pre></td></tr></table></figure><h3 id="Using-environment-variables-with-ASPNETCORE-URLS-http-localhost-5001"><a href="#Using-environment-variables-with-ASPNETCORE-URLS-http-localhost-5001" class="headerlink" title="Using environment variables, with ASPNETCORE_URLS=http://localhost:5001/."></a>Using environment variables, with ASPNETCORE_URLS=<a href="http://localhost:5001/">http://localhost:5001/</a>.</h3><h3 id="Using-UseUrls-if-you-prefer-doing-it-programmatically"><a href="#Using-UseUrls-if-you-prefer-doing-it-programmatically" class="headerlink" title="Using UseUrls(), if you prefer doing it programmatically:"></a>Using UseUrls(), if you prefer doing it programmatically:</h3><figure class="highlight c#"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br></pre></td><td class="code"><pre><code class="hljs C#"><span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">class</span> <span class="hljs-title">Program</span><br>{<br> <span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> <span class="hljs-title">Main</span>(<span class="hljs-params"><span class="hljs-keyword">string</span>[] args</span>)</span> =><br> CreateHostBuilder(args).Build().Run();<br><br> <span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> IHostBuilder <span class="hljs-title">CreateHostBuilder</span>(<span class="hljs-params"><span class="hljs-keyword">string</span>[] args</span>)</span> =><br> Host.CreateDefaultBuilder(args)<br> .ConfigureWebHostDefaults(builder =><br> {<br> builder.UseStartup<Startup>();<br> builder.UseUrls(<span class="hljs-string">"http://localhost:5001/"</span>);<br> });<br>}<br></code></pre></td></tr></table></figure><p>Or, if you’re still using the web host builder instead of the generic host builder:</p><figure class="highlight c#"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><code class="hljs C#"><span class="hljs-keyword">public</span> <span class="hljs-keyword">class</span> <span class="hljs-title">Program</span><br>{<br> <span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> <span class="hljs-title">Main</span>(<span class="hljs-params"><span class="hljs-keyword">string</span>[] args</span>)</span> =><br> <span class="hljs-keyword">new</span> WebHostBuilder()<br> .UseKestrel()<br> .UseContentRoot(Directory.GetCurrentDirectory())<br> .UseIISIntegration()<br> .UseStartup<Startup>()<br> .UseUrls(<span class="hljs-string">"http://localhost:5001/"</span>)<br> .Build()<br> .Run();<br>}<br></code></pre></td></tr></table></figure>]]></content>
<categories>
<category>.NET开发</category>
</categories>
<tags>
<tag>AspNetCore</tag>
</tags>
</entry>
<entry>
<title>Polly的用法</title>
<link href="/NET%E5%BC%80%E5%8F%91/polly%E7%9A%84%E7%94%A8%E6%B3%95/"/>
<url>/NET%E5%BC%80%E5%8F%91/polly%E7%9A%84%E7%94%A8%E6%B3%95/</url>
<content type="html"><![CDATA[<p>要详细了解就去看仓库的英文wiki，上面介绍的很详细，搜到的英文翻译很烂，中文跟英文意思相差很大！</p><table><thead><tr><th>Policy</th><th>前提</th><th align="center">Aka</th><th>How does the policy mitigate?</th></tr></thead><tbody><tr><td><strong>Retry</strong> <br/>(policy family)<br/><sub>(<a href="#retry">quickstart</a> ; <a href="https://github.com/App-vNext/Polly/wiki/Retry">deep</a>)</sub></td><td>许多故障是暂时的，在一段时间后会正常</td><td align="center">“Maybe it’s just a blip”</td><td>允许配置自动重试</td></tr><tr><td><strong>Circuit-breaker</strong><br/>(policy family)<br/><sub>(<a href="#circuit-breaker">quickstart</a> ; <a href="https://github.com/App-vNext/Polly/wiki/Circuit-Breaker">deep</a>)</sub></td><td>当系统发生严重故障时，快速响应请求失败比让用户等待要好。</td><td align="center"></td><td></td></tr><tr><td>避免故障系统过载有助于恢复系统。 <br/><br/>Protecting a faulting system from overload can help it recover.</td><td>“Stop doing it if it hurts” <br/><br/>“Give that system a break”</td><td align="center">当系统错误超过预配置的数量，系统将断路一段时间。</td><td></td></tr><tr><td><strong>Timeout</strong><br/><sub>(<a href="#timeout">quickstart</a> ; <a href="https://github.com/App-vNext/Polly/wiki/Timeout">deep</a>)</sub></td><td>超出一定时间的等待，想要得到正确的结果是不太可能的。</td><td align="center">“Don’t wait forever”</td><td>保证调用者不需要等待超过设置的超时。</td></tr><tr><td><strong>Bulkhead Isolation</strong><br/><sub>(<a href="#bulkhead">quickstart</a> ; <a href="https://github.com/App-vNext/Polly/wiki/Bulkhead">deep</a>)</sub></td><td>When a process faults, multiple failing calls backing up can easily swamp resource (eg threads/CPU) in a host.<br/><br/>A faulting downstream system can also cause ‘backed-up’ failing calls upstream.<br/><br/>Both risk a faulting process bringing down a wider system.</td><td align="center">“One fault shouldn’t sink the whole ship”</td><td>Constrains the governed actions to a fixed-size resource pool, isolating their potential to affect others.</td></tr><tr><td><strong>Cache</strong><br/><sub>(<a href="#cache">quickstart</a> ; <a href="https://github.com/App-vNext/Polly/wiki/Cache">deep</a>)</sub></td><td>Some proportion of requests may be similar.</td><td align="center">“You’ve asked that one before”</td><td>Provides a response from cache if known. <br/><br/>Stores responses automatically in cache, when first retrieved.</td></tr><tr><td><strong>Fallback</strong><br/><sub>(<a href="#fallback">quickstart</a> ; <a href="https://github.com/App-vNext/Polly/wiki/Fallback">deep</a>)</sub></td><td>Things will still fail - plan what you will do when that happens.</td><td align="center">“Degrade gracefully”</td><td>Defines an alternative value to be returned (or action to be executed) on failure.</td></tr><tr><td><strong>PolicyWrap</strong><br/><sub>(<a href="#policywrap">quickstart</a> ; <a href="https://github.com/App-vNext/Polly/wiki/PolicyWrap">deep</a>)</sub></td><td>Different faults require different strategies; resilience means using a combination.</td><td align="center">“Defence in depth”</td><td>Allows any of the above policies to be combined flexibly.</td></tr></tbody></table><h2 id="请求重试"><a href="#请求重试" class="headerlink" title="请求重试"></a>请求重试</h2><p>当发生请求异常或网络错误时, 就重新尝试N次。</p><img src="/NET%E5%BC%80%E5%8F%91/polly%E7%9A%84%E7%94%A8%E6%B3%95/how-polly-retry-works-2.png" class="" title="Polly重试工作流程"><h2 id="请求超时"><a href="#请求超时" class="headerlink" title="请求超时"></a>请求超时</h2><p>当系统超过一定时间的等待，我们就几乎可以判断不可能会有成功的结果。<br>比如平时一个网络请求瞬间就完成了，如果有一次网络请求超过了 30 秒还没完成，我们就知道这次大概率是不会返回成功的结果了。<br>因此，我们需要设置系统的超时时间，避免系统长时间做无谓的等待。</p><figure class="highlight c#"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><code class="hljs c#"><span class="hljs-comment">// 超时时间不能超过 30 秒，否则就认为是错误的结果，并执行回调。</span><br>Policy.Timeout(<span class="hljs-number">30</span>, onTimeout: (context, timespan, task) =><br>{<br> <span class="hljs-comment">// do something</span><br>});<br></code></pre></td></tr></table></figure><h2 id="请求断路-Circuit-breaker"><a href="#请求断路-Circuit-breaker" class="headerlink" title="请求断路(Circuit-breaker)"></a>请求断路(Circuit-breaker)</h2><p>断路： 等待一段时间后再继续。</p><p>当系统遇到严重问题时，快速回馈失败比让用户/调用者等待要好，限制系统出错的体量，有助于系统恢复。<br>比如，当我们去调一个第三方的 API，有很长一段时间 API 都没有响应，可能对方服务器瘫痪了。<br>如果我们的系统还不停地重试，不仅会加重系统的负担，还会可能导致系统其它任务受影响。<br>所以，当系统出错的次数超过了指定的阈值，就要中断当前线路，等待一段时间后再继续。</p><figure class="highlight c#"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><code class="hljs c#"><span class="hljs-comment">// 当系统出现两次异常时，就停下来，等待 1 分钟后再继续。</span><br>Policy.Handle<SomeException>()<br> .CircuitBreaker(<span class="hljs-number">2</span>, TimeSpan.FromMinutes(<span class="hljs-number">1</span>));<br></code></pre></td></tr></table></figure><h2 id="AspNetCore实践使用"><a href="#AspNetCore实践使用" class="headerlink" title="AspNetCore实践使用"></a>AspNetCore实践使用</h2><figure class="highlight c#"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><code class="hljs c#"><span class="hljs-keyword">public</span> <span class="hljs-keyword">class</span> <span class="hljs-title">SendCloudMailProvider</span> : <span class="hljs-title">INoticeProvider</span><br>{<br> <span class="hljs-keyword">private</span> <span class="hljs-keyword">readonly</span> HttpClient _httpClient;<br> <span class="hljs-keyword">private</span> <span class="hljs-keyword">readonly</span> ILogger _logger;<br><br> <span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-title">SendCloudMailProvider</span>(<span class="hljs-params">HttpClient httpClient, ILogger<SendCloudMailProvider> logger</span>)</span><br><span class="hljs-function"></span> {<br> _httpClient = httpClient;<br> _logger = logger;<br> }<br>}<br></code></pre></td></tr></table></figure><figure class="highlight c#"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br></pre></td><td class="code"><pre><code class="hljs c#"><span class="hljs-keyword">using</span> Polly;<br><span class="hljs-keyword">using</span> Polly.Extensions.Http;<br><br>services.AddHttpClient<INoticeProvider, SendCloudMailProvider>()<br> .AddPolicyHandler(GetRetryPolicy())<br> .AddPolicyHandler(GetCircuitBreakerPolicy());<br><br><span class="hljs-comment">// 重试策略</span><br><span class="hljs-function"><span class="hljs-keyword">static</span> IAsyncPolicy<HttpResponseMessage> <span class="hljs-title">GetRetryPolicy</span>(<span class="hljs-params"></span>)</span><br><span class="hljs-function"></span>{<br> <span class="hljs-keyword">return</span> HttpPolicyExtensions<br> .HandleTransientHttpError()<br> .OrResult(msg => msg.StatusCode == System.Net.HttpStatusCode.NotFound)<br> .WaitAndRetryAsync(<span class="hljs-number">3</span>, retryAttempt => TimeSpan.FromMilliseconds(<span class="hljs-number">500</span>));<br>}<br><br><span class="hljs-comment">// 断路策略</span><br><span class="hljs-function"><span class="hljs-keyword">static</span> IAsyncPolicy<HttpResponseMessage> <span class="hljs-title">GetCircuitBreakerPolicy</span>(<span class="hljs-params"></span>)</span><br><span class="hljs-function"></span>{<br> <span class="hljs-keyword">return</span> HttpPolicyExtensions<br> .HandleTransientHttpError()<br> .CircuitBreakerAsync(<span class="hljs-number">5</span>, TimeSpan.FromSeconds(<span class="hljs-number">30</span>));<br>}<br></code></pre></td></tr></table></figure>]]></content>
<categories>
<category>.NET开发</category>
</categories>
<tags>
<tag>AspNetCore</tag>
</tags>
</entry>
<entry>
<title>TaskScheduler</title>
<link href="/NET%E5%BC%80%E5%8F%91/taskscheduler/"/>
<url>/NET%E5%BC%80%E5%8F%91/taskscheduler/</url>
<content type="html"><![CDATA[<p>Async Await 异步的实现原理，老是被问到， 看了Go的调度器文章，设计上感觉跟这个很相似。</p><p>这应该会是一个系列文章， 一篇写不下的， 欠的债慢慢还！</p><h2 id="参考文章"><a href="#参考文章" class="headerlink" title="参考文章"></a>参考文章</h2><p><a href="https://stackoverflow.com/questions/14177891/understanding-async-await-in-c-sharp">https://stackoverflow.com/questions/14177891/understanding-async-await-in-c-sharp</a><br><a href="https://blog.stephencleary.com/2012/02/async-and-await.html">https://blog.stephencleary.com/2012/02/async-and-await.html</a><br><a href="https://stackoverflow.com/questions/17320595/replacing-the-task-scheduler-in-c-sharp-with-a-custom-built-one">https://stackoverflow.com/questions/17320595/replacing-the-task-scheduler-in-c-sharp-with-a-custom-built-one</a><br><a href="https://www.codeproject.com/Articles/31971/Understanding-SynchronizationContext-Part-I">https://www.codeproject.com/Articles/31971/Understanding-SynchronizationContext-Part-I</a><br><a href="https://stackoverflow.com/questions/15428604/how-to-run-a-task-on-a-custom-taskscheduler-using-await">https://stackoverflow.com/questions/15428604/how-to-run-a-task-on-a-custom-taskscheduler-using-await</a><br><a href="https://docs.microsoft.com/en-us/dotnet/api/system.threading.tasks.taskscheduler?view=net-6.0">https://docs.microsoft.com/en-us/dotnet/api/system.threading.tasks.taskscheduler?view=net-6.0</a><br><a href="https://docs.microsoft.com/en-us/dotnet/api/system.threading.tasks.taskscheduler?view=net-6.0#Sync">https://docs.microsoft.com/en-us/dotnet/api/system.threading.tasks.taskscheduler?view=net-6.0#Sync</a><br><a href="https://devblogs.microsoft.com/pfxteam/taskscheduler-fromcurrentsynchronizationcontext/">https://devblogs.microsoft.com/pfxteam/taskscheduler-fromcurrentsynchronizationcontext/</a></p>]]></content>
<categories>
<category>.NET开发</category>
</categories>
<tags>
<tag>AsyncAwait</tag>
</tags>
</entry>
<entry>
<title>HTTPS OCSP响应的坑</title>
<link href="/HTTP%E5%8D%8F%E8%AE%AE/https-ocsp%E5%93%8D%E5%BA%94%E7%9A%84%E5%9D%91/"/>
<url>/HTTP%E5%8D%8F%E8%AE%AE/https-ocsp%E5%93%8D%E5%BA%94%E7%9A%84%E5%9D%91/</url>
<content type="html"><![CDATA[<p>由于https使用的是 Let’s Encrypt 签发的免费证书，部署的环境是在企业内部网络，完全与外网隔离，无法联网。</p><h2 id="DNS污染问题"><a href="#DNS污染问题" class="headerlink" title="DNS污染问题"></a>DNS污染问题</h2><ol><li>修改hosts, 避免DNS污染</li></ol><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><code class="hljs bash"><span class="hljs-comment"># /etc/hosts1</span><br><br>23.32.3.72 ocsp.int-x3.letsencrypt.org<br></code></pre></td></tr></table></figure><h2 id="请求OCSP响应"><a href="#请求OCSP响应" class="headerlink" title="请求OCSP响应"></a>请求OCSP响应</h2><p>下面是完整的响应信息：</p><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br></pre></td><td class="code"><pre><code class="hljs bash">$ openssl ocsp -issuer ca.cer -cert website.cer -no_nonce -text \<br> -url http://ocsp.int-x3.letsencrypt.org -text -respout ocsp_stapling_file<br><br>OCSP Request Data:<br> Version: 1 (0x0)<br> Requestor List:<br> Certificate ID:<br> Hash Algorithm: sha1<br> Issuer Name Hash: 7EE66AE7729AB3FCF8A220646C16A12D6071085D<br> Issuer Key Hash: A84A6A63047DDDBAE6D139B7A64565EFF3A8ECA1<br> Serial Number: 04470F9AA9CA09D7D2AE20F5C7056964194C<br>OCSP Response Data:<br> OCSP Response Status: successful (0x0)<br> Response Type: Basic OCSP Response<br> Version: 1 (0x0)<br> Responder Id: C = US, O = Let<span class="hljs-string">'s Encrypt, CN = Let'</span>s Encrypt Authority X3<br> Produced At: Jul 2 19:16:00 2020 GMT<br> Responses:<br> Certificate ID:<br> Hash Algorithm: sha1<br> Issuer Name Hash: 7EE66AE7729AB3FCF8A220646C16A12D6071085D<br> Issuer Key Hash: A84A6A63047DDDBAE6D139B7A64565EFF3A8ECA1<br> Serial Number: 04470F9AA9CA09D7D2AE20F5C7056964194C<br> Cert Status: good<br> This Update: Jul 2 19:00:00 2020 GMT<br> Next Update: Jul 9 19:00:00 2020 GMT<br><br> Signature Algorithm: sha256WithRSAEncryption<br> 0c:d4:98:31:05:89:ea:40:21:4a:71:be:81:f9:cf:0b:be:c3:<br> 8e:a9:ed:3f:73:fe:a7:65:c2:64:23:a7:c3:02:1a:7b:89:db:<br> 6f:26:20:01:a7:98:1f:87:8f:61:bd:74:59:83:a1:10:d2:75:<br> b5:7e:ea:08:2d:6e:e0:44:99:38:38:02:43:e1:3b:3b:54:15:<br> 9b:8a:a8:b2:01:92:04:34:81:8d:87:7b:86:c4:84:ba:8c:09:<br> a1:bb:fd:3a:2b:a1:8a:bd:e7:f9:22:a6:0c:00:83:29:57:39:<br> ef:43:0e:28:2c:0c:47:50:4d:2f:a4:68:e1:93:35:63:d3:1b:<br> 55:f0:67:a2:c0:d2:6f:6e:19:3d:a0:e9:94:3a:03:6c:11:54:<br> 80:ba:8b:56:d8:d0:c1:00:ca:e3:6d:20:aa:9e:f8:e1:d5:28:<br> 90:ab:21:1f:64:c4:ef:59:89:5a:30:87:c4:23:<span class="hljs-built_in">cd</span>:e1:77:6f:<br> a4:f5:3c:58:a2:1e:f9:5e:e1:41:9f:1a:1f:26:64:68:18:68:<br> 4c:30:1a:5a:65:26:6a:ec:96:45:1d:06:01:e8:e1:42:93:cc:<br> 43:c8:b3:fd:43:20:ac:6c:c2:3c:e1:c0:29:4c:6f:dc:43:18:<br> 27:87:d2:50:8a:ed:47:2b:de:45:cc:ea:45:a6:ec:af:20:f1:<br> d7:ab:54:32<br>_.mes.haorizi.cn.cer: good<br> This Update: Jul 2 19:00:00 2020 GMT<br> Next Update: Jul 9 19:00:00 2020 GMT<br>Response verify OK<br><br></code></pre></td></tr></table></figure><h2 id="OCSP响应有效期"><a href="#OCSP响应有效期" class="headerlink" title="OCSP响应有效期"></a>OCSP响应有效期</h2><p>具体的坑就在这里： 一次OCSP响应有效期为7天</p><figure class="highlight text"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><code class="hljs text">This Update: Jul 2 19:00:00 2020 GMT<br>Next Update: Jul 9 19:00:00 2020 GMT<br></code></pre></td></tr></table></figure><p>通过将OCSP响应保持为文件，配置到Nginx中，从而避免进行在线对证书进行验证； 对于能够联网的nginx服务器来说，一次OCSP响应有效期为7天是没有问题的，到期之后再一次进行更新即可；可我们的服务器是在企业内网，无法连接外网，这就导致了在IE浏览器访问慢的问题。</p><p>在部署Nginx时，采取了一系列优化手段去提升浏览器访问网站首页的速度，此时访问速度真是快的飞起，给人一种秒开的感觉，然后就开心的下班了。问题发生在七天后，此时的OCSP响应已经过期，现在用IE浏览器去打开，真是比蜗牛还慢；但是如果用谷歌浏览器去访问，依然是快的飞起；使用火狐浏览器，直接无法访问，提示 <code>SEC_ERROR_OCSP_OLD_RESPONSE</code> OCSP响应信息过期。</p>]]></content>
<categories>
<category>HTTP协议</category>
</categories>
<tags>
<tag>HTTPS</tag>
<tag>OCSP</tag>
</tags>
</entry>
<entry>
<title>哈希函数：MurmurHash</title>
<link href="/%E5%93%88%E5%B8%8C/%E5%93%88%E5%B8%8C%E5%87%BD%E6%95%B0%EF%BC%9Amurmurhash/"/>
<url>/%E5%93%88%E5%B8%8C/%E5%93%88%E5%B8%8C%E5%87%BD%E6%95%B0%EF%BC%9Amurmurhash/</url>
<content type="html"><![CDATA[<h2 id="MurmurHash算法"><a href="#MurmurHash算法" class="headerlink" title="MurmurHash算法"></a>MurmurHash算法</h2><figure class="highlight c++"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br></pre></td><td class="code"><pre><code class="hljs c++"><span class="hljs-function"><span class="hljs-keyword">void</span> <span class="hljs-title">AsyncLogging::append</span><span class="hljs-params">(<span class="hljs-keyword">const</span> <span class="hljs-keyword">char</span>* logline, <span class="hljs-keyword">int</span> len)</span></span><br><span class="hljs-function"></span>{<br> <span class="hljs-function">muduo::MutexLockGuard <span class="hljs-title">lock</span><span class="hljs-params">(mutex_)</span></span>;<br> <span class="hljs-keyword">if</span> (currentBuffer_->avail() > len)<br> {<br> currentBuffer_->append(logline, len);<br> }<br> <span class="hljs-keyword">else</span><br> {<br> buffers_.push_back(<span class="hljs-built_in">std</span>::move(currentBuffer_));<br><br> <span class="hljs-keyword">if</span> (nextBuffer_)<br> {<br> currentBuffer_ = <span class="hljs-built_in">std</span>::move(nextBuffer_);<br> }<br> <span class="hljs-keyword">else</span><br> {<br> currentBuffer_.reset(<span class="hljs-keyword">new</span> Buffer); <span class="hljs-comment">// Rarely happens</span><br> }<br> currentBuffer_->append(logline, len);<br> cond_.notify();<br> }<br>}<br></code></pre></td></tr></table></figure>]]></content>
<categories>
<category>哈希</category>
</categories>
<tags>
<tag>一致性哈希</tag>
<tag>MurmurHash</tag>
</tags>