Teensy 4.1 server.streamFile not working

[David Asmuth]

• PlatformIO Core [5.2.5] · Home [3.4.1]
• • Platform: Teensy 4.15.0
• Builder: Windows 10 21H1
• EWS 2.1.2

Describe the bug

I try to send a html (actually a whole SPA) from an SD card over ethernet. But streaming files is not working.

Steps to Reproduce

• Get any SD card.
• Put a file on it
• Get your teensy 4.1 PlatformIO and install EthernetWebServer.
• Apply patches, insert SD Card
• Init the built-in SD card library SD.begin(BUILTIN_SDCARD); in setup()
• At any point in request handler function insert:

if (SD.exists(path_to_file.c_str()))
{
    File myFile = SD.open(path_to_file.c_str());
    uint32_t myFileSize = myFile .size();
    Serial.println("SIZE to send: " + String(myFileSize)); // Debug check size
   
    server.streamFile(myFile , getContentType(path_to_file));
    myFile.close();
    return;
 }

Expected behavior

The myFile is send to the client

Actual behavior

The debug check files size output shows correct size of file to send.
The browser fails with net::ERR_CONTENT_LENGTH_MISMATCH 200 (OK)
Reported: File is incomplete (Actually no file is written. I doubt that bytes are sent at all)

Debug and AT-command log (if applicable)

Connected! IP address: 192.168.1.109
[EWS] handleClient: New Client
[EWS] method:  GET
[EWS] url:  /js/61.28ba07b9.js
[EWS] search:
[EWS] headerName: Host
[EWS] headerValue: 192.168.1.109
[EWS] headerName: Connection
[EWS] headerValue: keep-alive
[EWS] headerName: Upgrade-Insecure-Requests
[EWS] headerValue: 1
[EWS] headerName: User-Agent
[EWS] headerValue: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.88 Safari/537.36
[EWS] headerName: Accept
[EWS] headerValue: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
[EWS] headerName: Accept-Encoding
[EWS] headerValue: gzip, deflate
[EWS] headerName: Accept-Language
[EWS] headerValue: de-DE,de;q=0.9,en-US;q=0.8,en;q=0.7
[EWS] args:
[EWS] args count:  0
[EWS] args:
[EWS] args count:  0
[EWS] Request: /js/61.28ba07b9.js
[EWS] Arguments:
[EWS] Final list of key/value pairs:
[EWS] _handleRequest: request handler not found
SIZE to send: 1834

[EWS] send1: len =  0
[EWS] content =
[EWS] _prepareHeader response = HTTP/1.1 200 OK

[EWS] _prepareHeader sendHeader Conn close
[EWS] handleClient: Don't keepCurrentClient

[Khoi Hoang]

FS is not supported for any board, but ESP32 and ESP8266 using native SPIFFS or LIttleFS.

This won't be worked on and supported in the near future.

[David Asmuth]

I would it find more intuitive if the readme.md would contain a hint that this library only supports sending http content in form of strings and not streams (except ESP controllers). Thank you for your work nonetheless.

EDIT: I found it noteworthy to attach a work around for sending files:

    File file = SD.open(curi);

    server.send(200, getContentType(uri), "");
    server.setContentLength(file.size());

    char cBuf[4096];
    uint32_t lenSend = 0;
    EthernetClient cl = server.client();
    while (file.available())
    {
        uint32_t len = file.read(cBuf, 4096);
        cl.writeFully(cBuf, len);
        lenSend += len;
    }

    file.close();