HTTPRequest Accept Gzip limited the download speed

walterlcy713 · May 20, 2025, 6:17pm

Godot Version

4.3.stable

Question

I had a download file logic using HTTPRequest

and there is the HTTPRequest setting in inspector

When I download the same video file,
Accept Gzip: false, download time was round 0.9 seconds
Accept Gzip: true, download time was round 24 seconds

There are the logs that getting the downloaded bytes from HTTPRequest in every frame

When Accept Gzip is true, it will add [Accept-Encoding: gzip, deflate] into the header, it will start the decompression at the limited rate 4KB/s as discussed below*

Is it possible to expose the decompress rate in the project setting? Or does changing the decompress rate create other issues?

*Topic related with gzip compression:

github.com/godotengine/godot

FileAccess gzip & zstd modes get much worse compression ratios than corresponding cmd tools

opened 10:35PM - 03 Jun 23 UTC

paulmiller

discussion topic:core

### Godot version 4.0.2.stable ### System information Arch Linux ### Issue d…escription When you write data with ``` FileAccess.open_compressed( path, FileAccess.WRITE, FileAccess.COMPRESSION_GZIP) .store_buffer(data) ``` (or `COMPRESSION_ZSTD`), you get much worse compression ratios than if you compress the same data with `gzip` or `zstd` on the command line - sometimes 10-100x worse. I tested these files: `alice.txt` - Alice in Wonderland text `abc.txt` - the line `"abcdefghijklmnopqrstuvwxyz"`, 10,000 times `012.bin` - the bytes 0 through 255, 1,000 times `cells.bin` - an actual file from my game, in a custom binary format I compressed each file on the command line with `gzip -1` and `zstd -1` (minimum compression), and also in Godot with `COMPRESSION_GZIP` and `COMPRESSION_ZSTD`: |file|original|gzip|Godot gzip|zstd|Godot zstd| |-|-|-|-|-|-| |`alice.txt`|170 KiB|72 KiB|78 KiB|66 KiB|81 KiB| |`abc.txt`|264 KiB|1.6 KiB|5.1 KiB|74 B|3.2 KiB| |`012.bin`|250 KiB|2.2 KiB|20 KiB|295 B|17 KiB| |`cells.bin`|4.6 MiB|639 KiB|2.7 MiB|116 KiB|2.7 MiB| The discrepancy is even worse if I use the default or higher compression levels on `gzip` and `zstd`. I see Godot uses `Compression::zstd_level = 3` in `godot/core/io/compression.cpp`, so I'd expect Godot to do better than `zstd -1`, even with the extra [magic bytes](https://github.com/godotengine/godot/issues/28999). The discrepancy seems to be worse when the files are more repetitive (higher potential compression ratio), and when they're binary rather than plain text. ### Steps to reproduce Attached is a test project with the first 3 test files, their compressed versions, and the scripts which produced the compressed versions: `compress.sh` and `compress.gd`. (Use Ctrl+Shift+X in the script editor to run `compress.gd`.) ### Minimal reproduction project [compress-test.zip](https://github.com/godotengine/godot/files/11644387/compress-test.zip)

gertkeno · May 20, 2025, 8:09pm

The linked github topic is about compression, not decompression. When downloading you do not have control of how the file is being compressed and sent to Godot, decompression must adhere to the file’s settings.

Is this consistent on different servers? Strange that un-compressed sends big chunks all at once where compressed sends a steady, slow stream. Could just be an overworked/misconfigured file server

walterlcy713 · May 22, 2025, 6:00am

I explored the source codes about HTTPRequest.
Yes, there was no limit in compress and decompress. It assigned the Download Chunk Size for compress and decompress too.

But the weird part is when I use curl with [Accept-encoding: gzip] to request the same file, it was fast, there is logs