1. Storing "ctx" in a long-living object is wrong
2. Make the commit & tree cacheable (for the future performance
optimization)
3. Also fix some bad designs like `// FIXME: bad design, this field can
be nil if the commit is from "last commit cache"`
ref:
* #33893
The latest commit cache is currently used only for listing tree files.
However, a cold start may take longer than directly invoking the Git
command. This PR addresses the issue of slow response times when
accessing raw files, improving performance in such scenarios.
```log
gitea.log:105521:2024/12/23 08:22:18 ...eb/routing/logger.go:68:func1() [W] router: slow GET /xxxx/xxxxxx/raw/commit/xxxxxxxxxxxxxxxxxxxxxxxxxxx/.editorconfig for 172.18.0.5:53252, elapsed 3526.8ms @ repo/download.go:117(repo.SingleDownload)
```
Fixes#29101
Related #29298
Discard all read data to prevent misinterpreting existing data. Some
discard calls were missing in error cases.
---------
Co-authored-by: yp05327 <576951401@qq.com>
wxiaoguangandGitHub
silverwindandGitHub
TheFox0x7andGitHub
Lunny XiaoandGitHub
