【Hackintosh】SSDTs

Secondary System Description Table (SSDT)

So what are DSDTs and SSDTs? Well, these are tables present in your firmware that outline hardware devices like USB controllers, CPU threads, embedded controllers, system clocks and such. A DSDT(Differentiated System Description Table) can be seen as the body holding most of the info with smaller bits of info being passed by the SSDT(Secondary System Description Table).

You can think of the DSDT as the building blueprints with SSDTs being sticky notes outlining extra details to the project

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Posted by Wei on 2021-11-16, Last Modified on 2025-08-11

【Hackintosh】USB Mapping

Update!!

Use https://github.com/USBToolBox/tool instead to get the mapping

Refer to https://www.youtube.com/watch?v=WKJ3MeCXdVA

USB Map

Refer to https://dortania.github.io/OpenCore-Post-Install/usb/#macos-and-the-15-port-limit

So the process of USB mapping is defining your ports to macOS and telling it what kind they are, the reasons we want to do this are:

macOS is very bad at guessing what kind of ports you have
Some ports may run below their rated speed(3.1 ports running at 2.0)
Some ports may outright not work
Bluetooth not working
Certain services like Handoff may not work correctly
Sleep may break
Broken Hot-Plug
Even data corruption from XhciPortLimit

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Posted by Wei on 2021-11-16, Last Modified on 2025-08-11

【Git】Git Commit Best Practice

Summary

<type>(<scope>): <short summary>
  │       │             │
  │       │             └─⫸ Summary in present tense. Not capitalized. No period at the end.
  │       │
  │       └─⫸ Commit Scope: animations|bazel|benchpress|common|compiler|compiler-cli|core|
  │                          elements|forms|http|language-service|localize|platform-browser|
  │                          platform-browser-dynamic|platform-server|router|service-worker|
  │                          upgrade|zone.js|packaging|changelog|docs-infra|migrations|ngcc|ve
  │
  └─⫸ Commit Type: build|ci|docs|feat|fix|perf|refactor|test

The <type> and <summary> fields are mandatory, the (<scope>) field is optional.

Type

Must be one of the following:

build: Changes that affect the build system or external dependencies (example scopes: gulp, broccoli, npm)
ci: Changes to our CI configuration files and scripts (examples: CircleCi, SauceLabs)
docs: Documentation only changes
feat: A new feature
fix: A bug fix
perf: A code change that improves performance
refactor: A code change that neither fixes a bug nor adds a feature
test: Adding missing tests or correcting existing tests
style: (formatting, missing semi colons, etc; no production code change)
chore: (updating grunt tasks etc; no production code change)

Summary

Use the summary field to provide a succinct description of the change:

use the imperative, present tense: “change” not “changed” nor “changes”
don’t capitalize the first letter
no dot (.) at the end

Make small commits

Let’s say you have two bugs that you just fixed. Each bug fix should produce a separate commit. By doing that you are creating an organized log of commits, which makes it easy for other developers to read and maintain the code base. It is a good practice to push code more often and not end up with a messy repo. Make small commits more frequently and avoid committing large chunks of code. This makes it easy to glance through the commit history and find what you are looking for. It is recommended that the use of git add . and git add -A should be in moderation and instead the focus should be on making frequent commits.

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Posted by Wei on 2021-11-09, Last Modified on 2025-08-11

【Engineering】Buffer

Data Buffer

In computer science, a data buffer (or just buffer) is a region of a physical memory storage used to temporarily store data while it is being moved from one place to another. Typically, the data is stored in a buffer as it is retrieved from an input device (such as a microphone) or just before it is sent to an output device (such as speakers). However, a buffer may be used when moving data between processes within a computer.

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Posted by Wei on 2021-11-09, Last Modified on 2025-08-11

【Engineering】Domain-specific Language (DSL)

Domain-specific language

A domain-specific language (DSL) is a computer language specialized to a particular application domain. This is in contrast to a general-purpose language (GPL), which is broadly applicable across domains. There are a wide variety of DSLs, ranging from widely used languages for common domains, such as HTML for web pages, down to languages used by only one or a few pieces of software, such as MUSH soft code. DSLs can be further subdivided by the kind of language, and include domain-specific markup languages, domain-specific modeling languages (more generally, specification languages), and domain-specific programming languages. Special-purpose computer languages have always existed in the computer age, but the term “domain-specific language” has become more popular due to the rise of domain-specific modeling. Simpler DSLs, particularly ones used by a single application, are sometimes informally called mini-languages.

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Posted by Wei on 2021-11-09, Last Modified on 2025-08-11

【MySQL】Benchmark - SysBench

Install

macOS

On macOS, up-to-date sysbench packages are available from Homebrew:

# Add --with-postgresql if you need PostgreSQL support
brew install sysbench

Debian/Ubuntu

$ curl -s https://packagecloud.io/install/repositories/akopytov/sysbench/script.deb.sh | sudo bash; sudo apt -y install sysbench

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Posted by Wei on 2021-11-07, Last Modified on 2025-08-11

【MySQL】Benchmark

Measuring Performance (Benchmarking)

To measure performance, consider the following factors:

Whether you are measuring the speed of a single operation on a quiet system, or how a set of operations (a “workload”) works over a period of time. With simple tests, you usually test how changing one aspect (a configuration setting, the set of indexes on a table, the SQL clauses in a query) affects performance. Benchmarks are typically long-running and elaborate performance tests, where the results could dictate high-level choices such as hardware and storage configuration, or how soon to upgrade to a new MySQL version.

For benchmarking, sometimes you must simulate a heavy database workload to get an accurate picture.

Performance can vary depending on so many different factors that a difference of a few percentage points might not be a decisive victory. The results might shift the opposite way when you test in a different environment.

Certain MySQL features help or do not help performance depending on the workload. For completeness, always test performance with those features turned on and turned off. The most important feature to try with each workload is the adaptive hash index for InnoDB tables.

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Posted by Wei on 2021-11-07, Last Modified on 2025-08-11

【MySQL】InnoDB

Tables

Viewing InnoDB Table Properties

To view the properties of an InnoDB table, issue a SHOW TABLE STATUS statement:

mysql> SHOW TABLE STATUS FROM test LIKE 't%' \G;
*************************** 1. row ***************************
           Name: t1
         Engine: InnoDB
        Version: 10
     Row_format: Dynamic
           Rows: 0
 Avg_row_length: 0
    Data_length: 16384
Max_data_length: 0
   Index_length: 0
      Data_free: 0
 Auto_increment: NULL
    Create_time: 2021-02-18 12:18:28
    Update_time: NULL
     Check_time: NULL
      Collation: utf8mb4_0900_ai_ci
       Checksum: NULL
 Create_options: 
        Comment:

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Posted by Wei on 2021-11-07, Last Modified on 2025-08-11

【MySQL】Recovery

InnoDB Crash Recovery

To recover from an unexpected MySQL server exit, the only requirement is to restart the MySQL server. InnoDB automatically checks the logs and performs a roll-forward of the database to the present. InnoDB automatically rolls back uncommitted transactions that were present at the time of the crash. During recovery, mysqld displays output similar to this:

InnoDB: The log sequence number 664050266 in the system tablespace does not match
the log sequence number 685111586 in the ib_logfiles!
InnoDB: Database was not shutdown normally!
InnoDB: Starting crash recovery.
InnoDB: Using 'tablespaces.open.2' max LSN: 664075228
InnoDB: Doing recovery: scanned up to log sequence number 690354176
InnoDB: Doing recovery: scanned up to log sequence number 695597056
InnoDB: Doing recovery: scanned up to log sequence number 700839936
InnoDB: Doing recovery: scanned up to log sequence number 706082816
InnoDB: Doing recovery: scanned up to log sequence number 711325696
InnoDB: Doing recovery: scanned up to log sequence number 713458156
InnoDB: Applying a batch of 1467 redo log records ...
InnoDB: 10%
InnoDB: 20%
InnoDB: 30%
InnoDB: 40%
InnoDB: 50%
InnoDB: 60%
InnoDB: 70%
InnoDB: 80%
InnoDB: 90%
InnoDB: 100%
InnoDB: Apply batch completed!
InnoDB: 1 transaction(s) which must be rolled back or cleaned up in total 561887 row
operations to undo
InnoDB: Trx id counter is 4096
...
InnoDB: 8.0.1 started; log sequence number 713458156
InnoDB: Waiting for purge to start
InnoDB: Starting in background the rollback of uncommitted transactions
InnoDB: Rolling back trx with id 3596, 561887 rows to undo
...
./mysqld: ready for connections....

...

Posted by Wei on 2021-11-07, Last Modified on 2025-08-11

【Hugo】Support Latex Math Expressions

Create a file in your theme directory layouts/partials/mathjax_support.html as the following:

<script>
  MathJax = {
    tex: {
      inlineMath: [['$', '$'], ['\\(', '\\)']],
      displayMath: [['$$','$$'], ['\\[', '\\]']],
      processEscapes: true,
      processEnvironments: true
    },
    options: {
      skipHtmlTags: ['script', 'noscript', 'style', 'textarea', 'pre']
    }
  };

  window.addEventListener('load', (event) => {
      document.querySelectorAll("mjx-container").forEach(function(x){
        x.parentElement.classList += 'has-jax'})
    });

</script>
<script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
<script type="text/javascript" id="MathJax-script" async
  src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>

Next, open the file layouts/partials/header.html and add the following line just before the closing </head> tag:
```
{{ if .Params.mathjax }}{{ partial "mathjax_support.html" . }}{{ end }}
```

Then, add the following lines to your CSS file. You may need to tinker with the contents here depending on your theme, these are just the settings which worked for me.

code.has-jax {
    -webkit-font-smoothing: antialiased;
    background: inherit !important;
    border: none !important;
    font-size: 100%;
}

Finally, add mathjax: true to the YAML frontmatter of any pages containing math markup. Alternatively, you could omit the outer {{ if .Params.mathjax }} … {{ end }} conditional above to load the library automatically on all pages. However given that this library is quite heavy (it’s consistently the asset that Google PageSpeed Insights complains the most about) and that only <20% of my blog posts contain math at all, this is worth the extra effort for me.

...

Posted by Wei on 2021-11-06, Last Modified on 2025-08-11

USB Map

西维蜀黍

【Hackintosh】SSDTs

Secondary System Description Table (SSDT)

【Hackintosh】USB Mapping

Update!!

【Git】Git Commit Best Practice

Summary

Make small commits

【Engineering】Buffer

Data Buffer

【Engineering】Domain-specific Language (DSL)

Domain-specific language

【MySQL】Benchmark - SysBench

Install

macOS

Debian/Ubuntu

【MySQL】Benchmark

Measuring Performance (Benchmarking)

【MySQL】InnoDB

Tables

Viewing InnoDB Table Properties

【MySQL】Recovery

InnoDB Crash Recovery

【Hugo】Support Latex Math Expressions

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