Cannot set Accept-Encoding header on UnityWebRequest

Hi,

I'm attempting to use gzip requests/responses with UnityWebRequest using:

Code (CSharp):

1. currentRequest.SetRequestHeader("Accept-Encoding", "gzip");

which returns

Code (CSharp):

1. Message:Cannot set Request Header Accept-Encoding - name contains illegal characters or is not user-overridable Source:UnityEngine TargetSite: Void SetRequestHeader(System.String, System.String)

Are there any work arounds for this problem?

 

Your problem is that "Accept-Encoding" is a forbidden header name and cannot be set. I advice you to switch to another forum and ask about XMLHttpRequest to get and exact solution/workaround to this

 

Interesting! I've never come across forbidden header names before. Thanks for the help

 

Finally, Unity decided to allow it ..... Yeah!

https://unity3d.com/unity/beta?_ga=1.185755881.1547913725.1457563109

• Web: The Accept-Encoding header may now be set via scripting, but note that this is done at users' risk.

 

The documentation for SetRequestHeader now states the following:

"It is possible to set a custom value for the accept-encoding header but the resulting behavior is unreliable so it is strongly recommended to let it be automatically handled unless you can accept the risk of unexpected results."

Does anybody now what is behind these ominous words? I tried it, and it works fine, though I do have to decompress the contents myself.
What kind of unreliable, unexpected results could happen?

 

Something changed in Unity 2020 and now it spams warnings in logs every time Accept-Encoding is set... Could they be disabled somehow?

Very annoying with playfab for example https://community.playfab.com/quest...e-header-accept-encoding-is-managed-auto.html

 

Bump, let me gzip the content

 

They are completely spamming my console. It's not informational it's distracting. Show that message once per play not every time uwr is used...

These messages make everything worse as I may miss something really important.

 

Additionally that information is confusing.

What does it mean? Is it set automatically to I don't know... Something? Is it doing any decompression/compression automatically? (no it doesn't checked headers with fiddler) So what's the point?

Here's how informational these msgs are:


Thanks Unity for treating me like a child, now I have to disable warnings forever.

I consider switching to HttpClient. Even PlayFab support started to recommend Unity 2019 instead of 2020 bcs of it https://community.playfab.com/quest...arning-when-making-requests-on-unity-202.html.

 

Servers (and many cdn providers) won't return compressed content if there's no Accept-Encoding header. So what you said here is false. Obviously Windows supports compression but uwr doesn't do it.
Request with header manually set:


Automatic:

 

Yes I guess it's not "supported" but few lines of code does it:

Code (CSharp):

1.  
2.     string textResponse;
3.     if ( string.Equals( request.GetResponseHeader( "Content-Encoding" ), "gzip", StringComparison.InvariantCultureIgnoreCase ) )
4.     {
5.         using ( var decompress = new GZipStream( new MemoryStream( request.downloadHandler.data ), CompressionMode.Decompress ) )
6.         using ( var sr = new StreamReader( decompress ) )
7.         {
8.             textResponse = sr.ReadToEnd();
9.         }
10.     }
11.     else
12.         textResponse = request.downloadHandler.text;
13.  

How can this fail and give me unexpected results?

 

Eh... Then Unity code is wrong as it should remove Content-Encoding header.

But anyway...
1. Then show that warning only on those platforms...
2. My game runs on Windows only using many native calls anyway that are missing in il2cpp like Process.Start. Fun fact when using net Process.Start in editor everything is fine then it fails in the build.
3. When it would happen i'd just disable that code from a platform
4. Let us disable this warning
5. There are better ways like

Code (CSharp):

1. byte[] bytes = www.downloadHandler.data;
2. bool isGzip = bytes != null && bytes [0] == 31 && bytes [1] == 139;

but that's not the point.

 

Couldn't that message be moved to method summary? It's really annoying:

(sometimes when I get completely unrelated bug)

 

Did some tests to see how bad HttpClient is. Timings would be inconsistent but memory is something what can be tested:

HttpClient:
TotalAllocatedMemory 99,64 Megabyte
TotalReservedMemory 273,09 Megabyte

HttpClient with

"Accept-Encoding", "gzip"

:
TotalAllocatedMemory 100,64 Megabyte
TotalReservedMemory 274,09 Megabyte

UnityWebRequest:
TotalAllocatedMemory 116,39 Megabyte
TotalReservedMemory 289,65 Megabyte

UnityWebRequest with

"Accept-Encoding", "gzip"

:
TotalAllocatedMemory 104,44 Megabyte
TotalReservedMemory 278,09 Megabyte

Amazing results, UnityWebRequest even with "Accept-Encoding" and spamming warnings to console/logs it allocates less memory than pure UnityWebRequest due to much smaller response size. Interesting to see how response size doesn't matter for HttpClient (yes I did test if response size was gzipped, was 800kb down to 200kb).

Gzip tests include deserialization of the content, http client does:

Code (CSharp):

1. HttpClientHandler handler = new HttpClientHandler()
2. {
3.     AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate
4. };
5. client = new HttpClient( handler );

Uwr what I've sent before in this thread.

#Edit
One more test x100 requests:
HttpClient
TotalAllocatedMemory 100,70 Megabyte
TotalReservedMemory 274,09 Megabyte

UnityWebRequest
TotalAllocatedMemory 185,12 Megabyte
TotalReservedMemory 357,80 Megabyte

OK I'm definitely switching to HttpClient.

More in https://forum.unity.com/threads/unitywebrequest-allocates-way-more-memory-than-httpclient.964085/

 

I am not familiar with this header accept-encoding topic but I am using Playfab and am getting this header accept-encoding warning that is clogging up my console. I hope Unity and Playfab can resolve this.

 

Same problem here. Console full of playfab warning. Unity, can you simply add some way to just disable the warning? (config?)

 

Same, it is quite irritating.

 

I agree. This warning is annoying and we should be able to silence it.
My code handles the case where the content is already decompressed, and decompresses it when it isn't.

 

A way to suppress this warning is needed. Since it gets spammed to console it makes hard to spot any other warnings and worst thing is that Debug Logs delivered with crash logs are often full of the same warning so Debug Logs that might help with the crash/exception investigation can not be seen.

 

I tried

Code (CSharp):

1. Debug.unityLogger.logEnabled = false;
2. webRequest.SetRequestHeader("Accept-Encoding", "gzip");
3. Debug.unityLogger.logEnabled = true;

But still spamming warnings.
Seems like only way is to turn of all warnings

 

Is it documented anywhere which platforms do and do not support it?