常见分析步骤
¥Common Profiling Steps
如果你在内存分配方面遇到 SWC 最小化问题并且你使用的是 Mac，则可以使用 ddt (opens in a new tab) 来分析内存使用情况。此外，许多步骤对于任何类型的分析都是通用的。
¥If you have a problem with SWC minifier about memory allocation and you are on mac, you can use ddt (opens in a new tab) to profile the memory usage.
Also, many steps are common to any kind of profiling.
步骤 1.准备输入
¥Step 1. Prepare the inputs
如果你想检查示例目录中的输入，你可以查看 https://github.com/kdy1/swc-minifier-inputs (opens in a new tab)。这些输入文件是从 github 上公开提供的真实 next.js 项目中提取的。详细信息请参见 debugging-nextjs-app。
¥If you want to check the example directory for inputs, you can take a look at https://github.com/kdy1/swc-minifier-inputs (opens in a new tab). These input files are extracted from real next.js projects publicly available on github. See debugging-nextjs-app for more details.
在此示例中，我们假设上面的链接已克隆到 ~/projects/minifier-inputs。（即 git clone https://github.com/kdy1/swc-minifier-inputs.git ~/projects/minifier-inputs）
¥In this example, we will assume that the link above is cloned to ~/projects/minifier-inputs.
(i.e. git clone https://github.com/kdy1/swc-minifier-inputs.git ~/projects/minifier-inputs)
将以下命令中的 ~/projects/minifier-inputs 替换为包含输入文件的目录。它可以是文件或包含输入文件的目录。所有 .js 文件都将被最小化，而不会将结果写入磁盘。
¥Replace ~/projects/minifier-inputs in the commands below with the directory containing your input files. It can be either a file or a directory containing the input files.
All .js files will be minified, without writing the result to the disk.
步骤 2.克隆存储库
¥Step 2. Clone the repository
git clone https://github.com/swc-project/swc.git
cd ./swc/crates/swc_ecma_minifier分析时间使用情况
¥Profiling Time Usage
步骤 3.运行分析器
¥Step 3. Run the profiler
你有两个选择。一种是使用跨平台的 samply，另一种是使用仅在 Mac 上可用的 XCode Instruments。
¥You have two options. One is to use samply, which is cross-platform, and the other is to use XCode Instruments, which is only available on mac.
使用 samply
¥Using samply
CARGO_PROFILE_RELEASE_DEBUG=1 RUST_LOG=off ddt profile samply cargo --release --features concurrent --example minify-all -- ~/projects/minifier-inputs to the directory containing your input files. It can be either a file or a directory containing the input files. All .js files will be minified (without writing the result to the disk)分析完成后，这将在你的浏览器中打开一个选项卡。
¥This will open a tab in your browser once the profiling is done.
使用 XCode 工具
¥Using XCode Instruments
CARGO_PROFILE_RELEASE_DEBUG=1 RUST_LOG=off ddt profile instruments cargo -t time --release --features concurrent --example minify-all -- ~/projects/minifier-inputs to the directory containing your input files. It can be either a file or a directory containing the input files. All .js files will be minified (without writing the result to the disk)分析完成后，这将打开 Instruments 应用。
¥This will open the Instruments app once the profiling is done.
分析内存使用情况
¥Profiling Memory Usage
步骤 3.运行分析器
¥Step 3. Run the profiler
运行分析器的命令如下：
¥The command to run the profiler is as follows:
CARGO_PROFILE_RELEASE_DEBUG=1 RUST_LOG=off ddt profile instruments cargo -t 'Memory' --release --features concurrent --example minify-all -- ~/projects/minifier-inputs to the directory containing your input files. It can be either a file or a directory containing the input files. All .js files will be minified (without writing the result to the disk)分析完成后，这将打开 Instruments 应用。
¥This will open the Instruments app once the profiling is done.