Can't decompress data which is compressed by rust code

[WindSoilder]

Here is simplest reproducing example:

import zstandard
zstandard.decompress(b'\x28\xb5\x2f\xfd\x00\x58\x11\x00\x00\x7b\x7d')

It raises an error: ZstdError: could not determine content size in frame header

More context

I'm trying to rewrite a client application in rust, it sends compressed data to server, then server decompresses it. Unfortunally the server failed to decompress data.

Here is how I do it in client side:

use std::io::Cursor;
use zstd;

fn main() {
    let body = zstd::encode_all(Cursor::new("{}".as_bytes()), 3).unwrap();
    for x in body.iter() {
        print!("\\x{x:x?}");
    }
}

And I copied the body and decompressed it in python, and it failed.

---

If I tried to compress data({} in my example) in python, and decompressed in rust, it successes. So I think it's the issue in python side.

In rust, I'm using zstd-rs for compressing/decompressing

[g2p]

See #150; you must pass a max_output_size to decompress in this case.

Docs

[aarshivv]

@WindSoilder , If the size of input is known, you can pass that to encoder, that way the content size will be added to the frame header and you will be able to decompress in python too without any issue (no need to pass max_output_size in this case.
Sample rust code:

    let input_bytes = serde_json::to_vec(&input)?;
    let mut output = Vec::new();
    let mut encoder = zstd::Encoder::new(&mut output, 0)?;
    encoder.set_pledged_src_size(Some(input_bytes.len() as u64))?;   // This adds the needed content size in frame header
    encoder.write_all(&input_bytes)?;
    encoder.finish()?;