https://ericrotenberg.wordpress.ncsu.edu/cbp2025/ 6th Championship Branch Prediction (CBP2025)
杰哥的{运维，编程，调板子}小笔记
导出飞书日历为 iCalendar 格式¶
背景¶
之前用了一段时间飞书日历，想要把日历里的事件导出来备份，但是发现飞书自己的导出功能太弱，因此参考 从飞书导出日历到 Fastmail - Xuanwo's Blog 进行了导出的尝试。
导出方法¶
上面提到的文章，是通过 CalDAV 的方式进行的日历同步。因此我第一步也是配置飞书的 CalDAV 服务：
1. 打开飞书客户端
2. 点击设置
3. 点击日历
4. 设置 CalDAV 同步
按照界面所示，配置 CalDAV 同步，就可以得到用于 CalDAV 的域名、用户名和密码了。如果只是要订阅，那么到这一步，就可以直接用 CalDAV 客户端来同步了。但我想进一步得到 iCalendar 格式的日历文件。
于是我参考了上述文章的评论区的做法：
也就是说，用 vdirsyncer 把日历同步到本地，再转换为 iCalendar 格式的日历文件。参考 vdirsyncer 文档，这件事情并不复杂：
1. 按照 vdirsyncer:
2. 编辑
3. 配置好以后，进行同步：
此时在
为了让一个
运行上述脚本：
source
导出飞书日历为 iCalendar 格式¶
背景¶
之前用了一段时间飞书日历，想要把日历里的事件导出来备份，但是发现飞书自己的导出功能太弱，因此参考 从飞书导出日历到 Fastmail - Xuanwo's Blog 进行了导出的尝试。
导出方法¶
上面提到的文章，是通过 CalDAV 的方式进行的日历同步。因此我第一步也是配置飞书的 CalDAV 服务：
1. 打开飞书客户端
2. 点击设置
3. 点击日历
4. 设置 CalDAV 同步
按照界面所示，配置 CalDAV 同步，就可以得到用于 CalDAV 的域名、用户名和密码了。如果只是要订阅，那么到这一步，就可以直接用 CalDAV 客户端来同步了。但我想进一步得到 iCalendar 格式的日历文件。
于是我参考了上述文章的评论区的做法：
@jason5ng32jason5ng32Oct 28, 2024分享一下我的方法：1. 在服务器上安装 vdirsyncer ，这个工具可以同步 CalDAV 的内容，在同步设置里，不需要先找到 UUID，可以直接用飞书提供的 URL。2. 写一个 Python 脚本，将 vdirsyncer 同步的内容合并成单一的 ics 文件。3. 将 ics 文件放到一个地址稍微复杂一点的 http 目录里，可以外部访问。4. 写一个 run.sh 脚本，通过 crontab 每 10 分钟执行一次 vdirsyncer 同步和日历文件合成。也就是说，用 vdirsyncer 把日历同步到本地，再转换为 iCalendar 格式的日历文件。参考 vdirsyncer 文档，这件事情并不复杂：
1. 按照 vdirsyncer:
pip3 install vdirsyncer2. 编辑
~/.vdirsyncer/config，填入在飞书处得到的用户密码:[general]status_path = "~/.vdirsyncer/status/"[pair my_contacts]a = "my_contacts_local"b = "my_contacts_remote"collections = ["from a", "from b"][storage my_contacts_local]type = "filesystem"path = "~/.contacts/"fileext = ".vcf"[storage my_contacts_remote]type = "caldav"url = "https://caldav.feishu.cn"username = "REDACTED"password = "REDACTED"3. 配置好以后，进行同步：
vdirsyncer discover && vdirsyncer sync此时在
~/.contacts 目录下，已经能看到很多个 vcf 文件了，每个 vcf 文件对应了日历中的一个事件。实际上，这些文件就已经是 iCalendar 格式了，只不过每个文件只有一个事件。为了让一个
.ics 文件包括日历的所有事件，写了一个脚本，实际上就是处理每个 vcf 文件，去掉每个文件开头结尾的 BEGIN:VCALENDAR 和 END:VCALENDAR，把中间的部分拼起来，最后再加上开头结尾：import sysall_lines = []all_lines += ["BEGIN:VCALENDAR"]for f in sys.argv[1:]: content = open(f).read().strip() lines = content.splitlines() all_lines += lines[1:-1]all_lines += ["END:VCALENDAR"]print("\n".join(all_lines))运行上述脚本：
python3 dump.py ~/.contacts/*/*.vcf > dump.ics，这样得到的 .ics 文件就可以直接导入到日历软件了。source
Arch Linux: Recent news updates
Glibc 2.41 corrupting Discord installation
We plan to move
This issue has been fixed in the Discord canary build. If you rely on audio connectivity, please use the canary build, login via browser or the flatpak version until the fix hits the stable Discord release.
There have been no reports that (written) chat connectivity is affected.
source
(author: Frederik Schwan)
Glibc 2.41 corrupting Discord installation
We plan to move
glibc and its friends to stable later today, Feb 3. After installing the update, the Discord client will show a red warning that the installation is corrupt.This issue has been fixed in the Discord canary build. If you rely on audio connectivity, please use the canary build, login via browser or the flatpak version until the fix hits the stable Discord release.
There have been no reports that (written) chat connectivity is affected.
source
(author: Frederik Schwan)
Chips and Cheese
A RISC-V Progress Check: Benchmarking P550 and C910
#ChipAndCheese
Telegraph | source
(author: Chester Lam)
A RISC-V Progress Check: Benchmarking P550 and C910
#ChipAndCheese
Telegraph | source
(author: Chester Lam)
Daniel Lemire's blog
Programmer time and the pitfalls of wasteful work
Programmer time is precious. This realization should shape our approach to software development, focusing our efforts on tasks that genuinely contribute to the improvement of our code and the software ecosystem.
What does matter?
1. 1. Hunting for bugs. I like to add tests, and then even more tests. The time spent building tests should proportionate to the time spent building the software. Fuzzing is also fantastically useful. I love using sanitizers.
2. Fixing bugs. Bugs disrupt user experience, compromise functionality, and can even introduce security vulnerabilities. Addressing bugs is critical to build trust in the software.
3. Documentation matters. Underdocumented code is mysterious and may trigger unnecessary surprises. Lack of documentation may also harm relationships with users.
4. Adding new features. Innovation and growth in software come from introducing new features. Features should be user visible: ‘internal’ features are often wasteful.
5. Improving Performance. Performance enhancement is all about making the software run faster, use fewer resources, or handle larger workloads more efficiently. This can significantly impact user satisfaction, particularly in applications where speed is paramount. Improving performance is not about identify bottlenecks… it is an ongoing journey. You need a good design and multiple rounds of optimizations. You can often continue to improve the performance for years and years.
However, there are areas where I believe our time is not well spent:
● Patching code to silence false positives from disabled-by-default static analyzers. The level 4 warnings under Visual Studio when compiling C++ code is a good example, but so are the obscure GCC and clang warnings. Static analyzers are tools that can scan code for potential issues without executing the program. However, when these tools are overly strict or misconfigured, they might report numerous false positives; issues that aren’t actually problems. Spending time patching code merely to quiet these false alarms is, in my view, wasteful. It diverts attention from more impactful work. This is not to say that static analysis is not beneficial; when used correctly, it can save considerable time and resources. But the effort required to address non-issues can quickly become counterproductive.
● Aimless refactoring is also often wasteful. Renaming classes, moving code around just so that it looks ‘nice’. I am not against the occasional cleaning round… but it is should not be time consuming. Refactoring for its own sake may become an excuse for not fixing bugs or for not improving the performance. It is easy work, but often not impactful.
While we strive for perfection in our code, we must also be strategic about where we invest our most precious resource: programmer time. Let us prioritize what truly matters in the grand scheme of software development.
source
Programmer time and the pitfalls of wasteful work
Programmer time is precious. This realization should shape our approach to software development, focusing our efforts on tasks that genuinely contribute to the improvement of our code and the software ecosystem.
What does matter?
1. 1. Hunting for bugs. I like to add tests, and then even more tests. The time spent building tests should proportionate to the time spent building the software. Fuzzing is also fantastically useful. I love using sanitizers.
2. Fixing bugs. Bugs disrupt user experience, compromise functionality, and can even introduce security vulnerabilities. Addressing bugs is critical to build trust in the software.
3. Documentation matters. Underdocumented code is mysterious and may trigger unnecessary surprises. Lack of documentation may also harm relationships with users.
4. Adding new features. Innovation and growth in software come from introducing new features. Features should be user visible: ‘internal’ features are often wasteful.
5. Improving Performance. Performance enhancement is all about making the software run faster, use fewer resources, or handle larger workloads more efficiently. This can significantly impact user satisfaction, particularly in applications where speed is paramount. Improving performance is not about identify bottlenecks… it is an ongoing journey. You need a good design and multiple rounds of optimizations. You can often continue to improve the performance for years and years.
However, there are areas where I believe our time is not well spent:
● Patching code to silence false positives from disabled-by-default static analyzers. The level 4 warnings under Visual Studio when compiling C++ code is a good example, but so are the obscure GCC and clang warnings. Static analyzers are tools that can scan code for potential issues without executing the program. However, when these tools are overly strict or misconfigured, they might report numerous false positives; issues that aren’t actually problems. Spending time patching code merely to quiet these false alarms is, in my view, wasteful. It diverts attention from more impactful work. This is not to say that static analysis is not beneficial; when used correctly, it can save considerable time and resources. But the effort required to address non-issues can quickly become counterproductive.
● Aimless refactoring is also often wasteful. Renaming classes, moving code around just so that it looks ‘nice’. I am not against the occasional cleaning round… but it is should not be time consuming. Refactoring for its own sake may become an excuse for not fixing bugs or for not improving the performance. It is easy work, but often not impactful.
While we strive for perfection in our code, we must also be strategic about where we invest our most precious resource: programmer time. Let us prioritize what truly matters in the grand scheme of software development.
source
频道主刚在玩这个，并获得第一题的红包，感觉好玩，哈哈
2025 乙巳蛇年的新年红包
https://hb.lohu.info
1. 这是每年春节 Soha 的传统节目，是一个解密寻宝游戏（a.k.a. CTF），利用你的知识（现学大概也是足够的）解决所有题目，获得红包口令，口令可进入支付宝领取红包。
2. 你应该需要电脑才能愉快玩耍，但手机可能也能解一部分。不涉及任何暴力解法（爆破等）。
3. 本次活动时间从北京时间 2025 年 1 月 28 日 20 时开始，持续 24 个小时。如果红包被提前领完不会补发。
4. 这个游戏由 Soha 制作，在游戏结束后将在我的博客放出题解，往年的内容也可以在博客上找到。更多提示请在活动页面查看。
5. 最后祝大家，新年快乐！
如有疑问可以私聊 @sohajin 提出。
https://hb.lohu.info
1. 这是每年春节 Soha 的传统节目，是一个解密寻宝游戏（a.k.a. CTF），利用你的知识（现学大概也是足够的）解决所有题目，获得红包口令，口令可进入支付宝领取红包。
2. 你应该需要电脑才能愉快玩耍，但手机可能也能解一部分。不涉及任何暴力解法（爆破等）。
3. 本次活动时间从北京时间 2025 年 1 月 28 日 20 时开始，持续 24 个小时。如果红包被提前领完不会补发。
4. 这个游戏由 Soha 制作，在游戏结束后将在我的博客放出题解，往年的内容也可以在博客上找到。更多提示请在活动页面查看。
5. 最后祝大家，新年快乐！
如有疑问可以私聊 @sohajin 提出。
Chips and Cheese
Inside SiFive’s P550 Microarchitecture
#ChipAndCheese
Telegraph | source
(author: George Cozma)
Inside SiFive’s P550 Microarchitecture
#ChipAndCheese
Telegraph | source
(author: George Cozma)
Daniel Lemire's blog
Regular expressions can blow up!
Regular expressions, often abbreviated as regex, are a powerful tool for pattern matching within text. For example, the expression
would match a positive number such as 1.1 or 12. If designed and tested with care, regular expressions may be used in mission-critical software. However, their power comes with a risk: it is possible to design small regular expressions that are very expensive to run on even small strings.
To make matters more complicated, there are several regular-expression engines, and they differ in their syntax and implementation. Let me consider the regular-expression engine used by the C++ language under Linux (libgc++).
Consider the following program. It uses the string “Everyone loves Lucy.” and d a regex pattern (.*+s}}@w. I am not exactly sure what this pattern is supposed to do, but it is accepted by the engine. The program then uses std::regex_search to look for matches of this pattern within the string, storing potential matches in a std::smatch object, and outputs whether a match was found or not.
Using GCC 12 and a recent Linux server, this program takes about 7 minutes to run.
In other words, a bad regular expression can crash your systems. It is not just theoretical, the Cloudflare corporation suffered a major outage in 2019 due to a bad regular expression.
Use regular expressions with care.
source
Regular expressions can blow up!
Regular expressions, often abbreviated as regex, are a powerful tool for pattern matching within text. For example, the expression
\d*\.?\d+would match a positive number such as 1.1 or 12. If designed and tested with care, regular expressions may be used in mission-critical software. However, their power comes with a risk: it is possible to design small regular expressions that are very expensive to run on even small strings.
To make matters more complicated, there are several regular-expression engines, and they differ in their syntax and implementation. Let me consider the regular-expression engine used by the C++ language under Linux (libgc++).
Consider the following program. It uses the string “Everyone loves Lucy.” and d a regex pattern (.*+s}}@w. I am not exactly sure what this pattern is supposed to do, but it is accepted by the engine. The program then uses std::regex_search to look for matches of this pattern within the string, storing potential matches in a std::smatch object, and outputs whether a match was found or not.
#include <iostream>
#include <regex>
int main() {
std::string text = "Everyone loves Lucy.";
std::regex pattern(R"(.*+s}}@w)");
// Perform regex search
std::smatch match;
bool found = std::regex_search(text, match, pattern);
std::cout << "Regex search result: "
<< (found ? "Match found" : "No match") << std::endl;
return 0;
}Using GCC 12 and a recent Linux server, this program takes about 7 minutes to run.
In other words, a bad regular expression can crash your systems. It is not just theoretical, the Cloudflare corporation suffered a major outage in 2019 due to a bad regular expression.
Use regular expressions with care.
source
Chips and Cheese
Disabling Zen 5’s Op Cache and Exploring its Clustered Decoder
#ChipAndCheese
Telegraph | source
(author: Chester Lam)
Disabling Zen 5’s Op Cache and Exploring its Clustered Decoder
#ChipAndCheese
Telegraph | source
(author: Chester Lam)
