smalltalk - 当我在处理 http 请求时保存 Pharo 图像会发生什么？

Question

Seaside 书说:“在处理 http 请求时保存 [图像] 是您想要避免的风险”。

为什么是这样？它只是暂时减慢服务 http 请求的速度还是请求会丢失或会发生错误？

Answer 1

似乎这只是一个让事情变慢的问题。有this quite thorough thread在海边列表中，最相关的帖子是this case study电子商务网站:

Consequently, currently this is what happens:

1. image is saved from time to time (usually daily), and copied to a separate "backup" machine.
2. if anything bad happens, the last image is grabbed, and the orders and/or gift certificates that were issued since the last image save are simply re-entered.

And, #2 has been very rarely done-- maybe a two or three times a year, and then it turns out it is usually because I did something stupid.

此外，Smalltalk 的一大优点是运行快速实验非常容易。您可以下载 Seaside 并暂停其中一个示例的回调。例如:

WACounter>>renderContentOn: html
...
    html anchor
        callback: [ 
            self halt.
            self increase ];
        with: '++'.
...

在 Seaside 服务器上打开浏览器(默认为 8080 端口)

单击“计数器”转到示例应用程序

点击“++”链接

切换回海边。您将看到暂停的预调试窗口

保存图片

点击“继续”
您会看到计数器正确递增，保存没有明显的不良影响。