Use examples when they help make things clearer.

Let me break down this “Zsh Git Prompt Optimization” thing for you. It’s basically a fancy way of saying that we can improve the speed and efficiency of our git prompt in Zsh by using a custom binary called `gitstatusd` instead of relying on slow and outdated methods like `git status`.

Here’s how it works: first, we clone this repository from GitHub (or use the official mirror if you’re in China) and then add a line to our Zsh configuration file that tells it where to find the custom binary. This is called “compiling” because we have to convert the source code into machine-readable instructions for our computer to follow.

Once we’ve done that, we can use this fancy new git prompt by sourcing a script called `gitstatus.prompt.zsh` (or using an alternative method if you prefer). This script communicates with `gitstatusd` over pipes and assembles the git status information into our Zsh prompt.

The best part is that this custom binary is 10x faster than any other alternative out there, which means we can have a snappy and responsive git prompt without sacrificing performance or speed. And if you’re using Powerlevel10k (which I highly recommend), you don’t even need to install `gitstatus` because it comes with Zsh bindings for integration.

However, let me provide some more context on how this custom binary works and why it is so much faster than traditional methods like `git status`. When we run `git status`, the command calls a function called `git_diff_index_to_workdir` in libgit2. This function scans through every file in our index (which contains information about all of the files that have been added, modified or deleted) and compares it to the corresponding file in our working directory. It then calculates whether any changes have occurred between these two versions and returns a list of differences.

This process can be very slow for large repositories with many files because `git_diff_index_to_workdir` has to call the `stat()` function (which retrieves information about a file) on every single file in our index, as well as read and write data from disk. In contrast, `gitstatusd` uses a more efficient approach by only scanning through files that have been modified or added since the last time we ran `git status`. This reduces the number of calls to `stat()` and other system functions, resulting in faster performance overall.

In addition, `gitstatusd` can be integrated into our Zsh prompt using a script called `gitstatus.prompt.zsh`, which communicates with the custom binary over pipes (a special type of communication channel that allows data to flow between two processes). This means that we don’t have to wait for the entire git status process to complete before seeing an updated prompt, resulting in a more responsive and interactive experience overall.

Overall, `gitstatusd` is a powerful tool for optimizing our Zsh Git Prompt by providing faster performance, better integration with other tools like Powerlevel10k, and improved usability through its custom binary and scripting capabilities.